NZ623841B2 - Neprilysin inhibitors - Google Patents
Neprilysin inhibitors Download PDFInfo
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- NZ623841B2 NZ623841B2 NZ623841A NZ62384112A NZ623841B2 NZ 623841 B2 NZ623841 B2 NZ 623841B2 NZ 623841 A NZ623841 A NZ 623841A NZ 62384112 A NZ62384112 A NZ 62384112A NZ 623841 B2 NZ623841 B2 NZ 623841B2
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- C07C233/56—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having carbon atoms of carboxamide groups bound to carbon atoms of carboxyl groups, e.g. oxamides
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Abstract
Disclosed herein are compounds having the formula: (I) where the substituents are as defined in the specification, or a pharmaceutically acceptable salt thereof. These compounds have neprilysin inhibition activity and are therefore intended for the treatment of conditions such as hypertension, heart failure or renal disease. Also disclosed are pharmaceutical compositions comprising such compounds; methods of using such compounds; and processes and intermediates for preparing such compounds. Examples of the compound of formula I include (2S,4S)-5-biphenyl-4-yl-2-hydroxymethyl-5-methyl-4-(oxalylamino)hexanoic acid and (2S,4R)-5-(5'-chloro-2'-fluorobiphenyl-4-yl)-2-hydroxymethyl-2-methyl-4-(oxalylamino)pentanoic acid. failure or renal disease. Also disclosed are pharmaceutical compositions comprising such compounds; methods of using such compounds; and processes and intermediates for preparing such compounds. Examples of the compound of formula I include (2S,4S)-5-biphenyl-4-yl-2-hydroxymethyl-5-methyl-4-(oxalylamino)hexanoic acid and (2S,4R)-5-(5'-chloro-2'-fluorobiphenyl-4-yl)-2-hydroxymethyl-2-methyl-4-(oxalylamino)pentanoic acid.
Description
NEPRILYSIN INHIBITORS
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to novel compounds having neprilysin-inhibition
activity. The invention also relates to pharmaceutical compositions comprising such
compounds and processes for preparing such compounds. Intermediates useful for
preparing the compounds and methods of using such compounds to treat diseases such as
hypertension, heart failure, pulmonary hypertension, and renal disease are also described.
STATE OF THE ART
Neprilysin (neutral endopeptidase, EC 3.4.24.11) (NEP), is an endothelial
membrane bound Zn metallopeptidase found in many organs and tissues, including the
brain, kidneys, lungs, gastrointestinal tract, heart, and the peripheral vasculature. NEP
degrades and inactivates a number of endogenous peptides, such as enkephalins,
circulating bradykinin, angiotensin peptides, and natriuretic peptides, the latter of which
have several effects including, for example, vasodilation and natriuresis/diuresis, as well as
inhibition of cardiac hypertrophy and ventricular fibrosis. Thus, NEP plays an important
role in blood pressure homeostasis and cardiovascular health.
NEP inhibitors, such as thiorphan, candoxatril, and candoxatrilat, have been studied
as potential therapeutics. Compounds that inhibit both NEP and angiotensin-I converting
enzyme (ACE) are also known, and include omapatrilat, gempatrilat, and sampatrilat.
Referred to as vasopeptidase inhibitors, this latter class of compounds is described in Robl
et al. (1999) Exp. Opin. Ther. Patents 9(12): 1665-1677.
Ksander et al. (1995) J. Med. Chem. 38:1689-1700 describes dicarboxylic acid
dipeptide NEP inhibitors of the formula:
N COOH
Compound R IC (nM)
21g -C(O)-CH -COOH 92
21a (R,S) -C(O)-(CH ) -COOH 5
21b (S,R) -C(O)-(CH ) -COOH 190
21c (R,R) -C(O)-(CH ) -COOH 700
21d (S,S) -C(O)-(CH ) -COOH 27
21e -C(O)-(CH ) -COOH 90
21f -C(O)-(CH ) -COOH 324
Compound 21a, which has a succinic acid substituent, is the most active compound, with
an IC of 5 nM. The authors observed that "the succininc acid in the P ' site appears to be
50 2
optimal since extension of the carboxylic acid chain by one (21e) and two (21f) methylene
units decreased activity 18- and 65-fold." The authors further noted that "decreasing the
chain length by one methylene (21g) also showed an 18-fold decrease in activity." (page
1692, 2 column).
In this specification where reference has been made to patent specifications, other
external documents, or other sources of information, this is generally for the purpose of
providing a context for discussing the features of the invention. Unless specifically stated
otherwise, reference to such external documents is not to be construed as an admission that
such documents, or such sources of information, in any jurisdiction, are prior art, or form
part of the common general knowledge in the art.
In the description in this specification reference may be made to subject matter that
is not within the scope of the claims of the current application. That subject matter should
be readily identifiable by a person skilled in the art and may assist in putting into practice
the invention as defined in the claims of this application.
SUMMARY OF THE INVENTION
The present invention provides novel compounds that have been found to possess
neprilysin (NEP) enzyme inhibition activity. Accordingly, compounds of the invention are
expected to be useful and advantageous as therapeutic agents for treating conditions such
as hypertension and heart failure.
One aspect of the invention relates to a compound of formula I:
(R )
(R )
where:
R is selected from H, -C alkyl, -C alkylene-C aryl, -C alkylene-
1-8 1-3 6-10 1-3
C heteroaryl, -C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-
1-9 3-7 2 2 1-3 3 1-6 1-6
11 12 13
NR R , -C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and ;
R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
11 12 15 15
-O-phenyl, -NR R , -CH(R )-NH , -CH(R )-NHC(O)O-C alkyl, and
2 1-6
11 12
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
11 12
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
13 11 12 14
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
-C alkyl or -C alkylene-C aryl; R is H, -CH , -CH(CH ) , phenyl, or benzyl;
1-6 0-6 6-10 3 3 2
2 21 21 3 21
R is -OR or -CH OR ; and R is H or -CH ; where R is H, -C(O)-C alkyl,
2 3 1-6
22 22 23 22
-C(O)-CH(R )-NH , -C(O)-CH(R )-NHC(O)O-C alkyl, or -P(O)(OR ) ; R is H,
2 1-6 2
-CH , -CH(CH ) , phenyl, or benzyl; R is H, -C alkyl, or phenyl; or
3 3 2 1-6
2 1 15 16 15 16 3
R is taken together with R to form –OCR R - or -CH O–CR R -, and R is
16
selected from H and -CH , where R and R are independently selected from H,
16
-C alkyl, and -O-C cycloalkyl, or R and R are taken together to form =O; or
1-6 3-7
R is taken together with R to form -CH -O-CH - or -CH -CH -; or
2 2 2 2
R and R are both -CH ;
Z is selected from -CH- and -N-;
R is selected from H, -C alkyl, -C alkylene-O-C alkyl, -C alkylene-C aryl,
1-8 1-3 1-8 1-3 6-10
-C alkylene-O-C aryl, -C alkylene-C heteroaryl, -C cycloalkyl, -[(CH ) O] CH ,
1-3 6-10 1-3 1-9 3-7 2 2 1-3 3
40 41 42 43
-C alkylene-OC(O)R , -C alkylene-NR R , -C alkylene-C(O)R ,
1-6 1-6 1-6
-C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
0-6 1-6 2 1-6
, , , and ;
R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
41 42 45 45
-O-phenyl, -NR R , -CH(R )-NH , -CH(R )-NHC(O)O-C alkyl, and
2 1-6
41 42
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
41 42
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
43 41 42 44
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
-C alkyl or -C alkylene-C aryl; R is H, -CH , -CH(CH ) , phenyl, or benzyl;
1-6 0-6 6-10 3 3 2
a is 0 or 1; R is selected from halo, –CH , –CF , and -CN;
b is 0 or an integer from 1 to 3; each R is independently selected from halo, -OH,
-CH , –OCH , -CN, and -CF ;
3 3 3
where each alkyl group in R and R is optionally substituted with 1 to 8 fluoro
atoms; and
where the methylene linker on the biphenyl is optionally substituted with one or
two -C alkyl groups or cyclopropyl;
or a pharmaceutically acceptable salt thereof.
Another aspect of the invention relates to pharmaceutical compositions comprising
a pharmaceutically acceptable carrier and a compound of the invention. Such
compositions may optionally contain other therapeutic agents. Accordingly, in yet another
aspect of the invention, a pharmaceutical composition comprises a compound of the
invention as the first therapeutic agent, one or more secondary therapeutic agent, and a
pharmaceutically acceptable carrier. Also described is a combination of active agents,
comprising a compound of the invention and a second therapeutic agent. The compound of
the invention can be formulated together or separately from the additional agent(s). When
formulated separately, a pharmaceutically acceptable carrier may be included with the
additional agent(s). Thus, also described is a combination of pharmaceutical compositions,
the combination comprising: a first pharmaceutical composition comprising a compound of
the invention and a first pharmaceutically acceptable carrier; and a second pharmaceutical
composition comprising a second therapeutic agent and a second pharmaceutically
acceptable carrier. Also described is a kit containing such pharmaceutical compositions,
for example where the first and second pharmaceutical compositions are separate
pharmaceutical compositions.
Compounds of the invention possess NEP enzyme inhibition activity, and are
therefore expected to be useful as therapeutic agents for treating patients suffering from a
disease or disorder that is treated by inhibiting the NEP enzyme or by increasing the levels
of its peptide substrates. Thus, described is a method of treating patients suffering from a
disease or disorder that is treated by inhibiting the NEP enzyme, comprising administering
to a patient a therapeutically effective amount of a compound of the invention. Also
described is a method of treating hypertension, heart failure, or renal disease, comprising
administering to a patient a therapeutically effective amount of a compound of the
invention. Also described is a method for inhibiting a NEP enzyme in a mammal
comprising administering to the mammal, a NEP enzyme-inhibiting amount of a compound
of the invention.
The invention also relates to a compound of the invention, for use in therapy.
The invention also relates to a compound of the invention, for use in treating
hypertension, heart failure, or renal disease.
Since compounds of the invention possess NEP inhibition activity, they are also
useful as research tools. Also described is a method of using a compound of the invention
as a research tool, the method comprising conducting a biological assay using a compound
of the invention. Compounds of the invention can also be used to evaluate new chemical
compounds. Also described is a method of evaluating a test compound in a biological
assay, comprising: (a) conducting a biological assay with a test compound to provide a first
assay value; (b) conducting the biological assay with a compound of the invention to
provide a second assay value; wherein step (a) is conducted either before, after or
concurrently with step (b); and (c) comparing the first assay value from step (a) with the
second assay value from step (b). Exemplary biological assays include a NEP enzyme
inhibition assay. Also described is a method of studying a biological system or sample
comprising a NEP enzyme, the method comprising: (a) contacting the biological system or
sample with a compound of the invention; and (b) determining the effects caused by the
compound on the biological system or sample.
Also described are processes and intermediates useful for preparing compounds of
the invention. Accordingly, another aspect of the invention relates to a process of
preparing compounds of formula I, comprising the step of coupling a compound of formula
1 with a compound of formula 2:
O Z P
2 3 O
(R )
(R )
to produce a compound of formula I; where P is selected from H and an amino-protecting
group selected from t-butoxycarbonyl, trityl, benzyloxycarbonyl, 9-
fluorenylmethoxycarbonyl, formyl, trimethylsilyl, and t-butyldimethylsilyl; and where the
process further comprises deprotecting the compound of formula 1 when P is an amino
protecting group; and where R -R , a, b, and Z are as defined for formula I. Also described
is a process of preparing a pharmaceutically acceptable salt of a compound of formula I,
comprising contacting a compound of formula I in free acid or base form with a
pharmaceutically acceptable base or acid. In other aspect, the invention relates to a
compound of formula I when prepared by any of a process of the invention. Intermediates
used in such processes are also described. For example, intermediates having formula 1 or
a salt thereof, as defined herein.
Yet another aspect of the invention relates to the use of a compound of formula I or
a pharmaceutically acceptable salt thereof, for the manufacture of a medicament, for
treating hypertension, heart failure, or renal disease. Also described is the use of a
compound of the invention for inhibiting a NEP enzyme in a mammal, and for use in
therapy generally. Also described is the use of a compound of the invention as a research
tool. Other aspects and embodiments of the invention are disclosed herein.
A particular group of compounds of formula I are those disclosed in U.S.
Provisional Application No. 61/554,625, filed on November 2, 2011. This group includes
compounds of formula I'; wherein:
(R )
(R )
(I')
where: R is selected from H, -C alkyl, -C alkylene-C aryl, -C alkylene-
1-8 1-3 6-10 1-3
C heteroaryl, -C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-
1-9 3-7 2 2 1-3 3 1-6 1-6
11 12 13
NR R , -C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and ;
R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
11 12
-O-phenyl, -NR R , -CH[CH(CH ) ]-NH , -CH[CH(CH ) ]-NHC(O)O-C alkyl, and
3 2 2 3 2 1-6
11 12
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
11 12
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
13 11 12 14
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
-C alkyl or -C alkylene-C aryl; R is selected from -OH, -CH OH, -OP(O)(OH) , and
1-6 0-6 6-10 2 2
3 2 1
-CH OP(O)(OH) ; and R is selected from H and -CH ; or R is taken together with R to
2 2 3
16 15 16 3 15
form –OCR R - or -CH O–CR R -, and R is selected from H and -CH , where R and
16 15 16
R are independently selected from H, -C alkyl, and -O-C cycloalkyl, or R and R
1-6 3-7
are taken together to form =O; or R is taken together with R to form -CH -O-CH - or
2 3 4
-CH -CH -; or R and R are both -CH ; Z is selected from -CH- and -N-; R is selected
2 2 3
from H, -C alkyl, -C alkylene-C aryl, -C alkylene-C heteroaryl, -C cycloalkyl,
1-8 1-3 6-10 1-3 1-9 3-7
40 41 42 43
-[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-NR R , -C alkylene-C(O)R ,
2 2 1-3 3 1-6 1-6 1-6
-C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
0-6 1-6 2 1-6
44 O
, , , and ;
R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
41 42
-O-phenyl, -NR R , -CH[CH(CH ) ]-NH , -CH[CH(CH ) ]-NHC(O)O-C alkyl, and
3 2 2 3 2 1-6
41 42
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
41 42
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
43 41 42 44
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
-C alkyl or -C alkylene-C aryl; a is 0 or 1; R is selected from halo, –CH , –CF , and
1-6 0-6 6-10 3 3
-CN; b is 0 or an integer from 1 to 3; each R is independently selected from halo, -OH,
-CH , –OCH , and -CF ; and where each alkyl group in R and R is optionally substituted
3 3 3
with 1 to 8 fluoro atoms; and; where the methylene linker on the biphenyl is optionally
substituted with one or two -C alkyl groups or cyclopropyl; or a pharmaceutically
acceptable salt thereof.
DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
When describing the compounds, compositions, methods and processes of the
invention, the following terms have the following meanings unless otherwise indicated.
Additionally, as used herein, the singular forms "a," "an," and "the" include the
corresponding plural forms unless the context of use clearly dictates otherwise. The terms
"comprising", "including," and "having" are intended to be inclusive and mean that there
may be additional elements other than the listed elements. All numbers expressing
quantities of ingredients, properties such as molecular weight, reaction conditions, and so
forth used herein are to be understood as being modified in all instances by the term
"about," unless otherwise indicated. Accordingly, the numbers set forth herein are
approximations that may vary depending upon the desired properties sought to be obtained
by the present invention. At least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each number should at least be construed
in light of the reported significant digits and by applying ordinary rounding techniques.
The term "alkyl" means a monovalent saturated hydrocarbon group which may be
linear or branched. Unless otherwise defined, such alkyl groups typically contain from 1 to
carbon atoms and include, for example, -C alkyl, -C alkyl, -C alkyl, -C alkyl,
1-4 1-5 2-5 1-6
-C alkyl, and -C alkyl. Representative alkyl groups include, by way of example,
1-8 1-10
methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, n-
heptyl, n-octyl, n-nonyl, n-decyl and the like.
When a specific number of carbon atoms is intended for a particular term used
herein, the number of carbon atoms is shown preceding the term as subscript. For
example, the term "-C alkyl" means an alkyl group having from 1 to 6 carbon atoms, and
the term "-C cycloalkyl" means a cycloalkyl group having from 3 to 7 carbon atoms,
respectively, where the carbon atoms are in any acceptable configuration.
The term "alkylene" means a divalent saturated hydrocarbon group that may be
linear or branched. Unless otherwise defined, such alkylene groups typically contain from
0 to 10 carbon atoms and include, for example, -C alkylene-, -C alkylene-,
0-1 0-6
-C alkylene-, and -C alkylene-. Representative alkylene groups include, by way of
1-3 1-6
example, methylene, ethane-1,2-diyl ("ethylene"), propane-1,2-diyl, propane-1,3-diyl,
butane-1,4-diyl, pentane-1,5-diyl and the like. It is understood that when the alkylene term
include zero carbons such as -C alkylene-, such terms are intended to include the absence
of carbon atoms, that is, the alkylene group is not present except for a covalent bond
attaching the groups separated by the alkylene term.
The term "aryl" means a monovalent aromatic hydrocarbon having a single ring
(i.e., phenyl) or one or more fused rings. Fused ring systems include those that are fully
unsaturated (e.g., naphthalene) as well as those that are partially unsaturated (e.g., 1,2,3,4-
tetrahydronaphthalene). Unless otherwise defined, such aryl groups typically contain from
6 to 10 carbon ring atoms and include, for example, -C aryl. Representative aryl groups
6-10
include, by way of example, phenyl and naphthaleneyl, naphthaleneyl, and the like.
The term "cycloalkyl" means a monovalent saturated carbocyclic hydrocarbon
group. Unless otherwise defined, such cycloalkyl groups typically contain from 3 to 10
carbon atoms and include, for example, -C cycloalkyl, -C cycloalkyl and
3-5 3-6
-C cycloalkyl. Representative cycloalkyl groups include, by way of example,
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.
The term "halo" means fluoro, chloro, bromo and iodo.
The term " heteroaryl " is intended to mean a monovalent unsaturated (aromatic)
heterocycle having a single ring or two fused rings. Monovalent unsaturated heterocycles
are also commonly referred to as "heteroaryl" groups. Unless otherwise defined, heteroaryl
groups typically contain from 5 to 10 total ring atoms, of which 1 to 9 are ring carbon
atoms, and 1 to 4 are ring heteroatoms, and include, for example, -C heteroaryl and
-C heteroaryl. Representative heteroaryl groups include, by way of example, pyrrole
(e.g., 3- pyrrolyl and 2H-pyrrolyl), imidazole (e.g., 2-imidazolyl), furan (e.g., 2-furyl
and 3-furyl), thiophene (e.g., 2-thienyl), triazole (e.g., 1,2,3-triazolyl and 1,2,4-triazolyl),
pyrazole (e.g., 1H-pyrazolyl), oxazole (e.g., 2-oxazolyl), isoxazole (e.g., 3-isoxazolyl),
thiazole (e.g., 2-thiazolyl and 4-thiazolyl), and isothiazole (e.g., 3-isothiazolyl), pyridine
(e.g., 2- pyridyl, 3-pyridyl, and 4-pyridyl), pyridylimidazole, pyridyltriazole, pyrazine,
pyridazine (e.g., 3-pyridazinyl), pyrimidine (e.g., 2- pyrimidinyl), tetrazole, triazine (e.g.,
1,3,5- triazinyl), indolyle (e.g., 1H-indolyl, 1H-indolyl and 1H-indolyl),
benzofuran (e.g., benzofuranyl), benzothiophene (e.g., benzo[b]thienyl and
benzo[b]thienyl), benzimidazole, benzoxazole, benzothiazole, benzotriazole, quinoline
(e.g., 2-quinolyl), isoquinoline, quinazoline, quinoxaline and the like.
The term "optionally substituted" means that group in question may be
unsubstituted or it may be substituted one or several times, such as 1 to 3 times, or 1 to 5
times, or 1 to 8 times. For example, an alkyl group that is "optionally substituted" with
fluoro atoms may be unsubstituted, or it may contain 1, 2, 3, 4, 5, 6, 7, or 8 fluoro atoms;.
Similarly, a group that is "optionally substituted" with one or two -C alkyl groups, may
be unsubstituted, or it may contain one or two -C alkyl groups.
As used herein, the phrase "having the formula" or "having the structure" is not
intended to be limiting and is used in the same way that the term "comprising" is
commonly used. For example, if one structure is depicted, it is understood that all
stereoisomer and tautomer forms are encompassed, unless stated otherwise.
The term "pharmaceutically acceptable" refers to a material that is not biologically
or otherwise unacceptable when used in the invention. For example, the term
"pharmaceutically acceptable carrier" refers to a material that can be incorporated into a
composition and administered to a patient without causing unacceptable biological effects
or interacting in an unacceptable manner with other components of the composition. Such
pharmaceutically acceptable materials typically have met the required standards of
toxicological and manufacturing testing, and include those materials identified as suitable
inactive ingredients by the U.S. Food and Drug administration.
The term "pharmaceutically acceptable salt" means a salt prepared from a base or
an acid which is acceptable for administration to a patient, such as a mammal (for example,
salts having acceptable mammalian safety for a given dosage regime). However, it is
understood that the salts covered by the invention are not required to be pharmaceutically
acceptable salts, such as salts of intermediate compounds that are not intended for
administration to a patient. Pharmaceutically acceptable salts can be derived from
pharmaceutically acceptable inorganic or organic bases and from pharmaceutically
acceptable inorganic or organic acids. In addition, when a compound of formula I contains
both a basic moiety, such as an amine, pyridine or imidazole, and an acidic moiety such as
a carboxylic acid or tetrazole, zwitterions may be formed and are included within the term
"salt" as used herein. Salts derived from pharmaceutically acceptable inorganic bases
include ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic,
manganous, potassium, sodium, and zinc salts, and the like. Salts derived from
pharmaceutically acceptable organic bases include salts of primary, secondary and tertiary
amines, including substituted amines, cyclic amines, naturally-occurring amines and the
like, such as arginine, betaine, caffeine, choline, N,N'-dibenzylethylenediamine,
diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine,
ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine,
histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine,
piperadine, polyamine resins, procaine, purines, theobromine, triethylamine,
trimethylamine, tripropylamine, tromethamine and the like. Salts derived from
pharmaceutically acceptable inorganic acids include salts of boric, carbonic, hydrohalic
(hydrobromic, hydrochloric, hydrofluoric or hydroiodic), nitric, phosphoric, sulfamic and
sulfuric acids. Salts derived from pharmaceutically acceptable organic acids include salts
of aliphatic hydroxyl acids (for example, citric, gluconic, glycolic, lactic, lactobionic,
malic, and tartaric acids), aliphatic monocarboxylic acids (for example, acetic, butyric,
formic, propionic and trifluoroacetic acids), amino acids (for example, aspartic and
glutamic acids), aromatic carboxylic acids (for example, benzoic, p-chlorobenzoic,
diphenylacetic, gentisic, hippuric, and triphenylacetic acids), aromatic hydroxyl acids (for
example, o-hydroxybenzoic, p-hydroxybenzoic, 1-hydroxynaphthalenecarboxylic and 3-
hydroxynaphthalenecarboxylic acids), ascorbic, dicarboxylic acids (for example,
fumaric, maleic, oxalic and succinic acids), glucoronic, mandelic, mucic, nicotinic, orotic,
pamoic, pantothenic, sulfonic acids (for example, benzenesulfonic, camphosulfonic,
edisylic, ethanesulfonic, isethionic, methanesulfonic, naphthalenesulfonic, naphthalene-
1,5-disulfonic, naphthalene-2,6-disulfonic and p-toluenesulfonic acids), xinafoic acid, and
the like.
As used herein, the term "prodrug" is generally intended to mean an inactive
precursor of a drug that is converted into its active form in the body under physiological
conditions, for example, by normal metabolic processes. Such compounds may not
possess pharmacological activity at NEP, but may be administered orally or parenterally
and thereafter metabolized in the body to form compounds that are pharmacologically
active at NEP. When orally administered, such compounds may also provide a better
fraction absorbed (i.e., better pK properties) for renal delivery, as compared to oral
administration of the active form. Exemplary prodrugs include esters such as
C alkylesters and aryl-C alkylesters. In one embodiment, the active compound has a
1-6 1-6
free carboxyl and the prodrug is an ester derivative thereof, i.e., the prodrug is an ester such
as -C(O)OCH CH . Such ester prodrugs are then converted by solvolysis or under
physiological conditions to be the free carboxyl compound. The term "prodrug" is also
intended to include a less active precursor of a drug that is converted into a more active
form in the body. For example, certain prodrugs may possess pharmacological activity at
NEP, but not necessarily at the desired level; such compounds are converted in the body
into a form having the desired level of activity. The term is also intended to include certain
protected derivatives of compounds of formula I that may be made prior to a final
deprotection stage. Thus, all protected derivatives and prodrugs of compounds formula I
are included within the scope of the invention.
The term "therapeutically effective amount" means an amount sufficient to effect
treatment when administered to a patient in need thereof, that is, the amount of drug
needed to obtain the desired therapeutic effect. For example, a therapeutically effective
amount for treating hypertension is an amount of compound needed to, for example,
reduce, suppress, eliminate, or prevent the symptoms of hypertension, or to treat the
underlying cause of hypertension. In one embodiment, a therapeutically effective amount
is that amount of drug needed to reduce blood pressure or the amount of drug needed to
maintain normal blood pressure. On the other hand, the term "effective amount" means an
amount sufficient to obtain a desired result, which may not necessarily be a therapeutic
result. For example, when studying a system comprising a NEP enzyme, an "effective
amount" may be the amount needed to inhibit the enzyme.
The term "treating" or "treatment" as used herein means the treating or treatment of
a disease or medical condition (such as hypertension) in a patient, such as a mammal
(particularly a human) that includes one or more of the following: (a) preventing the
disease or medical condition from occurring, i.e., preventing the reoccurrence of the
disease or medical condition or prophylactic treatment of a patient that is pre-disposed to
the disease or medical condition; (b) ameliorating the disease or medical condition, i.e.,
eliminating or causing regression of the disease or medical condition in a patient; (c)
suppressing the disease or medical condition, i.e., slowing or arresting the development of
the disease or medical condition in a patient; or (d) alleviating the symptoms of the disease
or medical condition in a patient. For example, the term "treating hypertension" would
include preventing hypertension from occurring, ameliorating hypertension, suppressing
hypertension, and alleviating the symptoms of hypertension (for example, lowering blood
pressure). The term "patient" is intended to include those mammals, such as humans, that
are in need of treatment or disease prevention or that are presently being treated for disease
prevention or treatment of a specific disease or medical condition, as well as test subjects
in which compounds of the invention are being evaluated or being used in an assay, for
example an animal model.
All other terms used herein are intended to have their ordinary meaning as
understood by those of ordinary skill in the art to which they pertain.
In one aspect, the invention relates to compounds of formula I:
(R )
(R )
or a pharmaceutically acceptable salt thereof.
As used herein, the term "compound of the invention" includes all compounds
encompassed by formula I such as the species embodied in formulas Ia and Ib, as well as
the compounds encompassed by formulas IIa-IIk, IIIa-IIIb, and IVa-IVd. In addition, the
compounds of the invention may also contain several basic or acidic groups (for example,
amino or carboxyl groups) and therefore, such compounds can exist as a free base, free
acid, or in various salt forms. All such salt forms are included within the scope of the
invention. Furthermore, the compounds of the invention may also exist as prodrugs.
Accordingly, those skilled in the art will recognize that reference to a compound herein, for
example, reference to a "compound of the invention" or a "compound of formula I"
includes a compound of formula I as well as pharmaceutically acceptable salts and
prodrugs of that compound unless otherwise indicated. Further, the term "or a
pharmaceutically acceptable salt and/or prodrug thereof" is intended to include all
permutations of salts and prodrugs, such as a pharmaceutically acceptable salt of a prodrug.
Furthermore, solvates of compounds of formula I are included within the scope of this
invention.
The compounds of formula I may contain one or more chiral centers and therefore,
these compounds may be prepared and used in various stereoisomeric forms. Accordingly,
the invention also relates to racemic mixtures, pure stereoisomers (e.g., enantiomers and
diastereoisomers), stereoisomer-enriched mixtures, and the like unless otherwise indicated.
When a chemical structure is depicted herein without any stereochemistry, it is understood
that all possible stereoisomers are encompassed by such structure. Thus, for example, the
terms "compound of formula I," "compounds of formula II," and so forth, are intended to
include all possible stereoisomers of the compound. Similarly, when a particular
stereoisomer is shown or named herein, it will be understood by those skilled in the art that
minor amounts of other stereoisomers may be present in the compositions of the invention
unless otherwise indicated, provided that the utility of the composition as a whole is not
eliminated by the presence of such other isomers. Individual stereoisomers may be
obtained by numerous methods that are well known in the art, including chiral
chromatography using a suitable chiral stationary phase or support, or by chemically
converting them into diastereoisomers, separating the diastereoisomers by conventional
means such as chromatography or recrystallization, then regenerating the original
stereoisomer.
Additionally, where applicable, all cis-trans or E/Z isomers (geometric isomers),
tautomeric forms and topoisomeric forms of the compounds of the invention are included
within the scope of the invention unless otherwise specified.
More specifically, compounds of formula I can contain at least two chiral centers
when the "Z" moiety is -CH-, and can contain at least one chiral center when the "Z"
moiety is -N-. These chiral centers are indicated by the symbols * and ** in the following
formulas Ia and Ib:
H 4 1
R R N
(R )
(R )
(R )
(R )
(Ia) and (Ib).
Note however, that there is no * chiral center when R is taken together with R to form -
CH -O-CH - or -CH -CH -, or R and R are both -CH .
2 2 2 2 3
In one stereoisomer of the compound of formula Ia, both carbon atoms identified by
the * and ** symbols have the (R) configuration. In this embodiment, compounds have the
(R,R) configuration at the * and ** carbon atoms or are enriched in a stereoisomeric form
having the (R,R) configuration at these carbon atoms. In another stereoisomer of the
compound of formula Ia, both carbon atoms identified by the * and ** symbols have the
(S) configuration. In this embodiment, compounds have the (S,S) configuration at the * and
** carbon atoms or are enriched in a stereoisomeric form having the (S,S) configuration at
these carbon atoms. In yet another stereoisomer of the compound of formula Ia, the carbon
atom identified by the symbol * has the (S) configuration and the carbon atom identified by
the symbol ** has the (R) configuration. In this embodiment, compounds have the (S,R)
configuration at the * and ** carbon atoms or are enriched in a stereoisomeric form having
the (S,R) configuration at these carbon atoms. In still another stereoisomer of the
compound of formula Ia, the carbon atom identified by the symbol * has the (R)
configuration and the carbon atom identified by the symbol ** has the (S) configuration.
In this embodiment, compounds have the (R,S) configuration at the * and ** carbon atoms
or are enriched in a stereoisomeric form having the (R,S) configuration at these carbon
atoms.
In one stereoisomer of the compound of formula Ib, the carbon atom identified by
the * symbol has the (R) configuration. In this embodiment, compounds have the (R)
configuration at the * carbon atom or are enriched in a stereoisomeric form having the (R)
configuration at this carbon atom. In another stereoisomer of the compound of formula Ib,
the carbon atom identified by the * symbol has the (S) configuration. In this embodiment,
compounds have the (S) configuration at the * carbon atom or are enriched in a
stereoisomeric form having the (S) configuration at this carbon atom.
These various embodiments can be shown as formula Ia-1:
(R )
(R )
(Ia-1),
formula Ia-2:
(R )
(R )
(Ia-2),
formula Ia-3:
(R )
(R )
(Ia-3),
formula Ia-4:
(R )
(R )
(Ia-4),
formula Ib-1:
(R )
(R )
(Ib-1),
and formula Ib-2:
(R )
(R )
(Ib-2).
Formula R R * **
Ia-1 -OR H (R) (R)
Ia-1 -OR -CH (R) (R)
Ia-1 -CH OR H (S) (S)
Ia-1 -CH OR -CH (S) (R)
R is taken together with R to form
Ia-1 H (R) (R)
16
-OCR R -
R is taken together with R to form
Ia-1 -CH (R) (R)
16 3
-OCR R -
R is taken together with R to form
Ia-1 H (S) (S)
16
-CH O–CR R -
R is taken together with R to form
Ia-1 -CH (R) (S)
16 3
-CH O–CR R -
Ia-2 -OR H (S) (S)
Ia-2 -OR -CH (S) (S)
Ia-2 -CH OR H (R) (R)
Ia-2 -CH OR -CH (R) (S)
R is taken together with R to form
Ia-2 H (S) (S)
16
-OCR R -
R is taken together with R to form
Ia-2 -CH (S) (S)
16 3
-OCR R -
R is taken together with R to form
Ia-2 H (R) (R)
16
-CH O–CR R -
R is taken together with R to form
Ia-2 -CH (S) (R)
16
-CH O–CR R -
Ia-3 -OR H (S) (R)
Ia-3 -OR -CH (S) (R)
Ia-3 -CH OR H (R) (S)
Ia-3 -CH OR -CH (R) (R)
R is taken together with R to form
Ia-3 H (R) (S)
16
-OCR R -
R is taken together with R to form
Ia-3 -CH (R) (S)
16 3
-OCR R -
R is taken together with R to form
Ia-3 H (S) (R)
16
-CH O–CR R -
R is taken together with R to form
Ia-3 -CH (R) (R)
16 3
-CH O–CR R -
Ia-4 -OR H (R) (S)
Ia-4 -OR -CH (R) (S)
Formula R R * **
Ia-4 -CH OR H (S) (R)
Ia-4 -CH OR -CH (S) (S)
R is taken together with R to form
Ia-4 H (S) (R)
16
-OCR R -
R is taken together with R to form
Ia-4 -CH (S) (R)
16 3
-OCR R -
R is taken together with R to form
Ia-4 H (R) (S)
16
-CH O–CR R -
R is taken together with R to form
Ia-4 -CH (S) (S)
16 3
-CH O–CR R -
Ib-1 -OR H (R) NA
Ib-1 -OR -CH (R) NA
Ib-1 -CH OR H (S) NA
Ib-1 -CH OR -CH (S) NA
R is taken together with R to form
Ib-1 H (R) NA
16
-OCR R -
R is taken together with R to form
Ib-1 -CH (R) NA
16 3
-OCR R -
R is taken together with R to form
Ib-1 H (S) NA
16
-CH O–CR R -
R is taken together with R to form
Ib-1 -CH (S) NA
16 3
-CH O–CR R -
Ib-2 -OR H (S) NA
Ib-2 -OR -CH (S) NA
Ib-2 -CH OR H (R) NA
Ib-2 -CH OR -CH (R) NA
R is taken together with R to form
Ib-2 H (S) NA
16
-OCR R -
R is taken together with R to form
Ib-2 -CH (S) NA
16 3
-OCR R -
R is taken together with R to form
Ib-2 H (R) NA
16
-CH O–CR R -
R is taken together with R to form
Ib-2 -CH (R) NA
16
-CH O–CR R -
In some embodiments, in order to optimize the therapeutic activity of the
compounds of the invention, e.g., to treat hypertension, it may be desirable that the carbon
atoms identified by the * and ** symbols have a particular configuration or are enriched in
a stereoisomeric form having such configuration. Thus, in certain aspects, this invention
relates to each individual enantiomer or to an enantiomer-enriched mixture of enantiomers
comprising predominately one enantiomer or the other enantiomer. In other embodiments,
the compounds of the invention are present as racemic mixtures of enantiomers.
The compounds of the invention, as well as those compounds used in their
synthesis, may also include isotopically-labeled compounds, that is, where one or more
atoms have been enriched with atoms having an atomic mass different from the atomic
mass predominately found in nature. Examples of isotopes that may be incorporated into
2 3 13 14
the compounds of formula I, for example, include, but are not limited to, H, H, C, C,
18 17 35 36 18
N, O, O, S, Cl, and F. Of particular interest are compounds of formula I enriched
in tritium or carbon-14 which can be used, for example, in tissue distribution studies;
compounds of formula I enriched in deuterium especially at a site of metabolism resulting,
for example, in compounds having greater metabolic stability; and compounds of formula I
11 18 15 13
enriched in a positron emitting isotope, such as C, F, O and N, which can be used,
for example, in Positron Emission Topography (PET) studies.
The nomenclature used herein to name the compounds of the invention is illustrated
in the Examples herein. This nomenclature has been derived using the commercially
available AutoNom software (MDL, San Leandro, California).
REPRESENTATIVE EMBODIMENTS
The following substituents and values are intended to provide representative
examples of various aspects and embodiments of the invention. These representative
values are intended to further define and illustrate such aspects and embodiments and are
not intended to exclude other embodiments or to limit the scope of the invention. In this
regard, the representation that a particular value or substituent is preferred is not intended
in any way to exclude other values or substituents from the invention unless specifically
indicated.
In one aspect, this invention relates to compounds of formula I:
(R )
(R )
The R moiety is selected from:
H;
-C alkyl, e.g., -CH , -CH CH , -(CH ) CH , -CH(CH ) , -C(CH ) ,
1-8 3 2 3 2 2 3 3 2 3 3
-CH CH(CH ) , -(CH ) CH , -(CH ) CH , -(CH ) CH(CH ) , -(CH ) CH , and
2 3 2 2 3 3 2 4 3 2 2 3 2 2 5 3
-(CH ) CH ;
2 6 3
-C alkylene-C aryl, e.g., benzyl;
1-3 6-10
-C alkylene-C heteroaryl, e.g., -CH -pyridinyl and -(CH ) -pyridinyl;
1-3 1-9 2 2 2
-C cycloalkyl, e.g., cyclopentyl;
-[(CH ) O] CH , e.g., -(CH ) OCH and -[(CH ) O] CH ;
2 2 1-3 3 2 2 3 2 2 2 3
-C alkylene-OC(O)R , e.g., -CH OC(O)CH , -CH OC(O)CH CH ,
1-6 2 3 2 2 3
-CH OC(O)(CH ) CH , -CH CH(CH )OC(O)CH CH , -CH OC(O)OCH ,
2 2 2 3 2 3 2 3 2 3
-CH OC(O)OCH CH , -CH(CH )OC(O)OCH CH , -CH(CH )OC(O)O-CH(CH ) ,
2 2 3 3 2 3 3 3 2
-CH CH(CH )OC(O)-cyclopentyl, -CH OC(O)O-cyclopropyl, -CH(CH )-OC(O)-O-
2 3 2 3
cyclohexyl, -CH OC(O)O-cyclopentyl, -CH CH(CH )OC(O)-phenyl, -CH OC(O)O-
2 2 3 2
phenyl, -CH OC(O)-CH[CH(CH ) ]-NH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)OCH ,
2 3 2 2 2 3 2 3
and -CH(CH )OC(O)-CH(NH )CH COOCH ;
3 2 2 3
11 12
-C alkylene-NR R , e.g., -(CH ) -N(CH ) ,
1-6 2 2 3 2
, and ;
-C alkylene-C(O)R , e.g., -CH C(O)OCH , -CH C(O)O-benzyl, -CH C(O)-
1-6 2 3 2 2
N(CH ) , and
-C alkylenemorpholine, e.g., -(CH ) -morpholine and -(CH ) -morpholine:
0-6 2 2 2 3
and ;
-C alkylene-SO -C alkyl, e.g., -(CH ) SO CH ;
1-6 2 1-6 2 2 2 3
; and
The R moiety is selected from:
-C alkyl, e.g., –CH and -CH CH ;
1-6 3 2 3
-O-C alkyl, e.g., -OCH , –O-CH CH , and –O-CH(CH ) ;
1-6 3 2 3 3 2
-C cycloalkyl, e.g., cyclopentyl);
-O-C cycloalkyl, e.g., -O-cyclopropyl, -O-cyclohexyl, and -O-cyclopentyl;
phenyl;
-O-phenyl;
11 12
-NR R ;
-CH(R )-NH , e.g., -CH[CH(CH ) ]-NH ;
2 3 2 2
-CH(R )-NHC(O)O-C alkyl, e.g., -CH[CH(CH ) ]-NHC(O)OCH ; and
1-6 3 2 3
-CH(NH )CH COOCH .
2 2 3
11 12
The R and R moieties are independently selected from H, -C alkyl (e.g., CH ), and
1-6 3
11 12
benzyl. Alternately, the R and R moieties can be taken together as -(CH ) -, -C(O)-
2 3-6
(CH ) -, or -(CH ) O(CH ) -, for example to form a group such as:
2 3 2 2 2 2
, , and .
13 11 12
The R moiety is selected from -O-C alkyl, e.g., -OCH , -O-benzyl, and -NR R , e.g.,
1-6 3
-N(CH ) , and
14 15
The R moiety is -C alkyl (e.g., -CH and -C(CH ) ) or -C alkylene-C aryl. The R
1-6 3 3 3 0-6 6-10
moiety is H, -CH , -CH(CH ) , phenyl, or benzyl.
3 3 2
In addition, each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms. For example, when R is -C alkyl, R can also be a group such as -CH CF ,
1-8 2 3
-CH(CH )CF -(CH ) CF , -CH CF CH , -CH CF CF , -CH(CF ) , -CH(CH F) ,
3 3, 2 2 3 2 2 3 2 2 3 3 2 2 2
-C(CF ) CH , and -CH(CH )CF CF .
3 2 3 3 2 3
1 10
In one embodiment, R is selected from H, -C alkyl, -C alkylene-OC(O)R , and
1-8 1-6
15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
1
R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms. In one specific embodiment, R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -(CH ) CH ,-CH CF , -(CH ) CF , -CH CF CH ,
2 3 2 2 3 3 2 6 3 2 3 2 2 3 2 2 3
-CH CF CF , -CH OC(O)CH , -CH OC(O)CH CH , -CH OC(O)(CH ) CH ,
2 2 3 2 3 2 2 3 2 2 2 3
-CH OC(O)OCH CH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)O-CH , and
2 2 3 2 3 2 3
,
where R is -CH . In other embodiments these compounds have formulas IIa-IId, IIi-IIk,
IIIa-IIIb, and IVa-IVd.
In one embodiment, R is H. In other embodiments these compounds have
formulas IIa-IId, IIi-IIk, IIIa-IIIb, and IVa-IVd.
In another embodiment, R is selected from -C alkyl, -C alkylene-C aryl,
1-8 1-3 6-10
-C alkylene-C heteroaryl, -C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R ,
1-3 1-9 3-7 2 2 1-3 3 1-6
11 12 13
-C alkylene-NR R , -C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-
1-6 1-6 0-6 1-6
SO -C alkyl,
2 1-6
, , , and .
In other embodiments these compounds have formulas IIa-IId, IIi-IIk, IIIa-IIIb, and IVa-
IVd. In one aspect of the invention, these compounds may find particular utility as
prodrugs or as intermediates in the synthetic procedures described herein. Specific
1 10
examples of such prodrug moieties include where R is -C alkylene-OC(O)R , such as
-CH(CH )OC(O)-O-cyclohexyl:
R = ,
making the compound a cilexetil ester; or R is -C alkylenemorpholine such as –(CH ) -
0-6 2 2
morpholine:
R = ,
making the compound a 2-morpholinoethyl or mofetil ester; or
R = ,
such as -CH methyl-[1,3]dioxolone:
R = ,
making the compound a medoxomil ester.
2 21 21 3
In one embodiment, R is -OR or -CH OR , and R is H or -CH . These
embodiments can be depicted as formulas IIa-IId:
H 4 H 4
R N R N
O Z O Z
21 O H O CH
O 21 O
(R ) (R )
(R ) (R )
(IIa) (IIb)
H 4 H 4
R N R N
Z O Z O
O H CH
(R ) (R )
(R ) (R )
(IIc) (IId)
21 22 22
The R moiety is H, -C(O)-C alkyl, -C(O)-CH(R )-NH , -C(O)-CH(R )-NHC(O)O-
1-6 2
23 21 22
C alkyl, or -P(O)(OR ) ; and in one particular embodiment, R moiety is H. The R
1-6 2
moiety is H, -CH , -CH(CH ) , phenyl, or benzyl. The R moiety is H, -C alkyl, or
3 3 2 1-6
phenyl.
In one embodiment, compounds of the invention have formula IIa, and in one
1 10
exemplary embodiment, R is selected from H, -C alkyl, -C alkylene-OC(O)R , and
1-8 1-6
15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
1
R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms; Z is selected from -CH- and -N-; R is selected from H, -C alkyl, -C alkylene-O-
1-8 1-3
C alkyl, -C alkylene-O-C aryl, -[(CH ) O] CH , and
1-8 1-3 6-10 2 2 1-3 3
44 4
where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms; a is 0 and b is 0; or a is 0, b is 1, and R is halo; or a is 0, b is 2, and one R is
6 5 5
halo and the other R is halo or -CH ; or a is 1, R is halo, and b is 0; or a is 1, R is halo, b
6 5 6
is 1, and R is halo; or a is 1, R is halo, b is 2, and each R is halo; and where the
methylene linker on the biphenyl is optionally substituted with two -CH groups; and in
another exemplary embodiment, R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -(CH ) CH ,-CH CF , -(CH ) CF , -CH CF CH ,
2 3 2 2 3 3 2 6 3 2 3 2 2 3 2 2 3
-CH CF CF , -CH OC(O)CH , -CH OC(O)CH CH , -CH OC(O)(CH ) CH ,
2 2 3 2 3 2 2 3 2 2 2 3
-CH OC(O)OCH CH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)O-CH , and
2 2 3 2 3 2 3
14 4
where R is -CH ; R is selected from H, -CH CH , -CH(CH ) , -CH CH(CH ) ,
3 2 3 3 2 2 3 2
-(CH ) CH , -C(CH ) , -(CH ) CF , -CH CF CH , -(CH ) -O-CH CH , -(CH ) -O-phenyl,
2 3 3 3 3 2 2 3 2 2 3 2 3 2 3 2 2
-(CH ) OCH , and
2 2 3
44 6
where R is -CH ; and a is 0 and b is 0; or a is 0, b is 1, and R is 2'-fluoro, 3'-fluoro, 3'-
chloro, or 4'-flouro; or a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-methyl, 5'-chloro or
5 6
2',5'-dichloro; or a is 1, R is 3-chloro, and b is 0; or a is 1, R is 3-chloro, b is 1, and R is
3'-chloro; or a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro.
In one embodiment, compounds of the invention have formula IIb, and in one
exemplary embodiment, H or -C alkyl; Z is -N-;R is H or -C alkyl; and a and b are 0;
1-8 1-8
and in another exemplary embodiment, R and R are H.
In one embodiment, compounds of the invention have formula IIc, and in one
exemplary embodiment, R is H or -C alkyl; Z is -CH-;R is H or -C alkyl; a is 0 or a is
1-8 1-8
1 and R is halo; b is 0 or b is 1 or 2 and R is halo; and where the methylene linker on the
biphenyl is optionally substituted with two -CH groups; and in another exemplary
1 4 5
embodiment, R is H, -CH CH , or -(CH ) CH ; R is H; a is 0 or a is 1 and R is 3-chloro;
2 3 2 3 3
b is 0 or b is 1 and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-flouro.
In one embodiment, compounds of the invention have formula IId, and in one
exemplary embodiment, R is H or -C alkyl; Z is -CH-; R is H or -C alkyl; a is 0; and b
1-8 1-8
is 0, or b is 1 and R is halo; and in another exemplary embodiment, R is H or -CH CH ;
R is H or -CH CH(CH ) ; and b is 0, or b is 1 and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or
2 3 2
4'-flouro.
2 1 15 16
In another embodiment, R is taken together with R to form –OCR R - or
16 3 15 16
-CH O–CR R -, and R is selected from H and -CH . The R and R moieties are
16
independently selected from H, -C alkyl, and -O-C cycloalkyl, or R and R are taken
1-6 3-7
together to form =O. These can be depicted as formulas IIe-IIh:
Z O Z O
H CH
15
R O O R O O
16 16
(R ) (R )
(R ) (R )
(IIe) (IIf)
H 4 H 4
O Z O Z
15
R H R CH
16 16
(R ) (R )
(R ) (R )
(IIg) (IIh)
In one aspect of the invention, these compounds may find particular utility as prodrugs or
as intermediates in the synthetic procedures described herein. Compounds where R is
-CH OP(O)(OH) may also find utility as prodrugs. In one embodiment of the compounds
4 6 15 16
of formulas IIe, IIf, IIg, and IIh, Z is -CH-, R is H, a is 0, b is 1, R is 3'Cl, and R and R
are H.
In another embodiment, R is taken together with R to form -CH -O-CH - or -CH -
2 2 2
CH -, which can be depicted as formulas IIi and IIj, respectively:
R N R N
O Z O Z
(R ) (R )
(R ) (R )
(IIi) (IIj)
In another embodiment, R and R are both -CH , which can be depicted as formula IIk:
H C CH
(R )
(R )
(IIk)
In one embodiment of the compounds of formulas IIi, IIj, and IIk, R is H, Z is -CH-, R is
-C alkyl (e.g., -CH CH(CH ) ), a is 0, b is 1, and R is 3'Cl.
1-8 2 3 2
The Z group is selected from -CH- and -N-. These embodiments can be depicted as
formulas IIIa and IIIb:
O O N
2 3 2 3
R R R R
(R ) (R )
(R ) (R )
(IIIa) (IIIb)
The R moiety is selected from:
-C alkyl, e.g., -CH , -CH CH , -(CH ) CH , -CH(CH ) , -C(CH ) ,
1-8 3 2 3 2 2 3 3 2 3 3
-CH CH(CH ) , -(CH ) CH , -(CH ) CH , -(CH ) CH(CH ) , -(CH ) CH , and
2 3 2 2 3 3 2 4 3 2 2 3 2 2 5 3
-(CH ) CH ;
2 6 3
-C alkylene-O-C alkyl e.g., -(CH ) -O-CH CH ;
1-3 1-8 2 3 2 3
-C alkylene-C aryl, e.g., benzyl;
1-3 6-10
-C alkylene-O-C aryl, e.g., -(CH ) -O-phenyl;
1-3 6-10 2 2
-C alkylene-C heteroaryl, e.g., -CH -pyridinyl and -(CH ) -pyridinyl;
1-3 1-9 2 2 2
-C cycloalkyl, e.g., cyclopentyl;
-[(CH ) O] CH , e.g., -(CH ) OCH and -[(CH ) O] CH ;
2 2 1-3 3 2 2 3 2 2 2 3
-C alkylene-OC(O)R , e.g., -CH OC(O)CH , -CH OC(O)CH CH ,
1-6 2 3 2 2 3
-CH OC(O)(CH ) CH , -CH CH(CH )OC(O)CH CH , -CH OC(O)OCH ,
2 2 2 3 2 3 2 3 2 3
-CH OC(O)OCH CH , -CH(CH )OC(O)OCH CH , -CH(CH )OC(O)O-CH(CH ) ,
2 2 3 3 2 3 3 3 2
-CH CH(CH )OC(O)-cyclopentyl, -CH OC(O)O-cyclopropyl, -CH(CH )-OC(O)-O-
2 3 2 3
cyclohexyl, -CH OC(O)O-cyclopentyl, -CH CH(CH )OC(O)-phenyl, -CH OC(O)O-
2 2 3 2
phenyl, -CH OC(O)-CH[CH(CH ) ]-NH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)OCH ,
2 3 2 2 2 3 2 3
and -CH(CH )OC(O)-CH(NH )CH COOCH ;
3 2 2 3
41 42
-C alkylene-NR R , e.g., -(CH ) -N(CH ) ,
1-6 2 2 3 2
, and ;
-C alkylene-C(O)R , e.g., -CH C(O)OCH , -CH C(O)O-benzyl, -CH C(O)-
1-6 2 3 2 2
N(CH ) , and
-C alkylenemorpholine, e.g., -(CH ) -morpholine and -(CH ) -morpholine:
0-6 2 2 2 3
and ;
-C alkylene-SO -C alkyl, e.g., -(CH ) SO CH ;
1-6 2 1-6 2 2 2 3
; and
.
The R moiety is selected from:
-C alkyl, e.g., –CH and -CH CH ;
1-6 3 2 3
-O-C alkyl, e.g., -OCH , –O-CH CH , and –O-CH(CH ) ;
1-6 3 2 3 3 2
-C cycloalkyl, e.g., cyclopentyl;
-O-C cycloalkyl, e.g., -O-cyclopropyl, -O-cyclohexyl, and -O-cyclopentyl;
phenyl;
-O-phenyl;
41 42
-NR R ;
-CH(R )-NH , e.g., -CH[CH(CH ) ]-NH ;
2 3 2 2
-CH(R )-NHC(O)O-C alkyl, e.g., -CH[CH(CH ) ]-NHC(O)OCH ; and
1-6 3 2 3
-CH(NH )CH COOCH .
2 2 3
41 42
The R and R moieties are independently selected from H, -C alkyl (e.g., CH ), and
1-6 3
41 42
benzyl. Alternately, the R and R moieties can be taken together as -(CH ) -, -C(O)-
2 3-6
(CH ) -, or -(CH ) O(CH ) -, for example to form a group such as:
2 3 2 2 2 2
, , and .
43 41 42
The R moiety is selected from -O-C alkyl, e.g., -OCH ,, -O-benzyl, and -NR R , e.g.,
1-6 3
-N(CH ) , and
44 45
The R moiety is -C alkyl (e.g., -CH and -C(CH ) ) or -C alkylene-C aryl. The R
1-6 3 3 3 0-6 6-10
moiety is H, -CH , -CH(CH ) , phenyl, or benzyl.
3 3 2
In addition, each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms. For example, when R is -C alkyl, R can also be a group such as -CH CF ,
1-8 2 3
-CH(CH )CF -(CH ) CF , -CH CF CH , -CH CF CF , -CH(CF ) , -CH(CH F) ,
3 3, 2 2 3 2 2 3 2 2 3 3 2 2 2
-C(CF ) CH , and -CH(CH )CF CF .
3 2 3 3 2 3
In one embodiment, R is selected from H, -C alkyl, -C alkylene-O-C alkyl,
1-8 1-3 1-8
-C alkylene-O-C aryl, -[(CH ) O] CH , and
1-3 6-10 2 2 1-3 3
,
44 4
where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms.. In one specific embodiment, R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -C(CH ) , -(CH ) CF , -CH CF CH , -(CH ) -O-CH CH ,
2 3 2 2 3 3 3 3 2 2 3 2 2 3 2 3 2 3
-(CH ) -O-phenyl, -(CH ) OCH , and
2 2 2 2 3
where R is -CH . In other embodiments these compounds have formulas IIa-IIk, IIIa-
IIIb, and IVa-IVd.
In one embodiment, R is H. In other embodiments these compounds have
formulas IIa-IIk, IIIa-IIIb, and IVa-IVd. In yet another embodiment, both R and R are H.
In other embodiments these compounds have formulas IIa-IIh, IIm-IIo, IIIa-IIIb, and IVa-
IVd.
In another embodiment, R is selected from -C alkyl, -C alkylene-O-C alkyl,
1-8 1-3 1-8
-C alkylene-C aryl, -C alkylene-O-C aryl, -C alkylene-C heteroaryl,
1-3 6-10 1-3 6-10 1-3 1-9
40 41 42
-C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-NR R ,
3-7 2 2 1-3 3 1-6 1-6
-C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and .
In other embodiments these compounds have formulas IIa-IIk, IIIa-IIIb, and IVa-IVd. In
one aspect of the invention, these compounds may find particular utility as prodrugs or as
intermediates in the synthetic procedures described herein. In one embodiment, both R
4 1 4
and R are such prodrug moieties. In another embodiment, one of R and R is a prodrug
moiety and the other is H. Specific examples of such prodrug moieties include where R is
-C alkylene-OC(O)R , such as –CH(CH )OC(O)-O-cyclohexyl:
1-6 3
R = ,
making the compound a cilexetil ester; or R is -C alkylenemorpholine such as –(CH ) -
0-6 2 2
morpholine:
R = ,
making the compound a 2-morpholinoethyl or mofetil ester; or
R = ,
such as -CH methyl-[1,3]dioxolone:
R = ,
making the compound a medoxomil ester.
The numbering for the R and R groups is as follows:
(R )
(R ) 2'
The integer "a" is 0 or 1. The R moiety, when present, is selected from halo, -CH ,
-CF , and -CN. In one embodiment, a is 0. In another embodiment, a is 1, and R is halo,
such as 3-chloro or 3-fluoro. In yet another embodiment a is 0, or a is 1 and R is halo. In
other embodiments these compounds have formulas IIa-IIk, IIIa-IIIb, and IVa-IVd.
The integer "b" is 0 or an integer from 1 to 3. The R moiety, when present, is
independently selected from halo, -OH, –CH , –OCH , -CN, and -CF . In one
3 3 3
embodiment, b is 0. In another embodiment, b is 1 and R is selected from Cl, F, -OH, –
CH , –OCH , -CN, and -CF , such 2'-chloro, 3'-chloro, 2'-fluoro, 3'-fluoro, 2'-hydroxy, 3'-
3 3 3
hydroxy, 3'-methyl, 2'-methoxy, 3'-cyano, or 3'-trifluoromethyl. In another embodiment, b
is 1 and R is halo, –CH , or –OCH , such 3'-chloro, 3'-methyl, or 2'-methoxy. In another
embodiment, b is 2 and R is 2'-fluoro-5'-chloro, 2',5'-dichloro, 2',5'-difluoro, 2'-methyl-5'-
chloro, 3'-fluoro-5'-chloro, 3'-hydroxy -5'-chloro, 3',5'-dichloro, 3',5'-difluoro, 2'-methoxy-
'-chloro, 2'-methoxy-5'-fluoro, 2'-hydroxy-5'-fluoro, 2'-fluoro-3'-chloro, 2'-hydroxy-5'-
chloro, or 2'-hydroxy-3'-chloro. In another embodiment, b is 3 and each R is
independently halo or –CH , such as 2'-methyl-3', 5'-dichloro or 2'-fluoro-3'-methyl-5'-
chloro. In one particular embodiment, b is 0, or b is 1 and R is halo, or b is 2 and each R
is independently selected from halo and -CH . In other embodiments these compounds
have formulas IIa-IIk, IIIa-IIIb, and IVa-IVd.
In other exemplary embodiments, a is 0 and b is 0; or a is 0, b is 1, and R is 2'-
fluoro, 3'-fluoro, 3'-chloro, or 4'-flouro; or a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-
methyl, 5'-chloro or 2',5'-dichloro; a is 1, R is 3-chloro, and b is 0; or a is 1, R is 3-chloro,
6 5 6
b is 1, and R is 3'-chloro; or a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro. In
other embodiments these compounds have formulas IIa-IIk, IIIa-IIIb, and IVa-IVd. Of
particular interest are compounds of the formulas:
O O O
O O O
H 4 H 4 H 4
1 1 1
R R R
R N R N R N
O Z O O Z O O Z O
2 3 2 3 2 3
R R R R R R
O O O
Cl Cl Cl
F Cl
, , and .
The methylene linker on the biphenyl is optionally substituted with one or two
-C alkyl groups or cyclopropyl. For example, in one embodiment, the methylene linker
on the biphenyl is unsubstituted; in another embodiment, the methylene linker on the
biphenyl is substituted with one -C alkyl group (e.g., -CH ); and in yet another
1-6 3
embodiment, the methylene linker on the biphenyl is substituted with two -C alkyl groups
(e.g., two -CH groups); in another embodiment, the methylene linker on the biphenyl is
substituted with a cyclopropyl group. These embodiments are depicted, respectively, as
formulas IVa-IVd:
O Z O Z
2 3 2 3
R R R R
(R ) (R )
(R ) (R )
(IVa), (IVb),
R N R N
Z O Z O
2 3 2 3
R R R R
(R ) (R )
(R ) (R )
(IVc), and (IVd)
In one embodiment of the compounds of formulas IVa, IVb, IVc, and IVd, R is H, R is
21 21 3 4
-OR andR is H, R is H, Z is -CH-, R is -C alkyl (e.g., -CH CH(CH ) ), a is 0, b is 1,
1-8 2 3 2
and R is 3'Cl.
1 10
In another embodiment, R is selected from H, -C alkyl, -C alkylene-OC(O)R ,
1-8 1-6
15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
1
R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms;
R is selected from H, -C alkyl, -C alkylene-O-C alkyl, -C alkylene-O-
1-8 1-3 1-8 1-3
C aryl, -[(CH ) O] CH , and
6-10 2 2 1-3 3
44 4
where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms;
a is 0 and b is 0; or a is 0, b is 1, and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-
flouro; or a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-methyl, 5'-chloro or 2',5'-
5 6
dichloro; or a is 1, R is 3-chloro, and b is 0; or a is 1, R is 3-chloro, b is 1, and R is 3'-
chloro; or a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro; and where the
methylene linker on the biphenyl is optionally substituted with two -CH groups. In one
2 21 21 3
particular embodiment of these compounds, R is -OR or -CH OR ; and R is H or -CH ;
where R is H.
In addition, particular compounds of formula I that are of interest include those set
forth in the Examples below, as well as pharmaceutically acceptable salts thereof.
GENERAL SYNTHETIC PROCEDURES
Compounds of the invention can be prepared from readily available starting
materials using the following general methods, the procedures set forth in the Examples, or
by using other methods, reagents, and starting materials that are known to those of ordinary
skill in the art. Although the following procedures may illustrate a particular embodiment
of the invention, it is understood that other embodiments of the invention can be similarly
prepared using the same or similar methods or by using other methods, reagents and
starting materials known to those of ordinary skill in the art. It will also be appreciated that
where typical or preferred process conditions (for example, reaction temperatures, times,
mole ratios of reactants, solvents, pressures, etc.) are given, other process conditions can
also be used unless otherwise stated. In some instances, reactions were conducted at room
temperature and no actual temperature measurement was taken. It is understood that room
temperature can be taken to mean a temperature within the range commonly associated
with the ambient temperature in a laboratory environment, and will typically be in the
range of about 18°C to about 30°C. In other instances, reactions were conducted at room
temperature and the temperature was actually measured and recorded. While optimum
reaction conditions will typically vary depending on various reaction parameters such as
the particular reactants, solvents and quantities used, those of ordinary skill in the art can
readily determine suitable reaction conditions using routine optimization procedures.
Additionally, as will be apparent to those skilled in the art, conventional protecting
groups may be necessary or desired to prevent certain functional groups from undergoing
undesired reactions. The choice of a suitable protecting group for a particular functional
group as well as suitable conditions and reagents for protection and deprotection of such
functional groups are well-known in the art. Protecting groups other than those illustrated
in the procedures described herein may be used, if desired. For example, numerous
protecting groups, and their introduction and removal, are described in T. W. Greene and
G. M. Wuts, Protecting Groups in Organic Synthesis, Fourth Edition, Wiley, New York,
2006, and references cited therein.
Carboxy-protecting groups are suitable for preventing undesired reactions at a
carboxy group, and examples include, but are not limited to, methyl, ethyl, t-butyl, benzyl
(Bn), p-methoxybenzyl (PMB), 9-fluorenylmethyl (Fm), trimethylsilyl (TMS), t-
butyldimethylsilyl (TBDMS), diphenylmethyl (benzhydryl, DPM) and the like. Amino-
protecting groups are suitable for preventing undesired reactions at an amino group, and
examples include, but are not limited to, t-butoxycarbonyl (BOC), trityl (Tr),
benzyloxycarbonyl (Cbz), 9-fluorenylmethoxycarbonyl (Fmoc), formyl, trimethylsilyl
(TMS), t-butyldimethylsilyl (TBDMS), and the like. Hydroxyl-protecting groups are
suitable for preventing undesired reactions at a hydroxyl group, and examples include, but
are not limited to C alkyls, silyl groups including triC alkylsilyl groups, such as
1-6 1-6
trimethylsilyl (TMS), triethylsilyl (TES), and t-butyldimethylsilyl (TBDMS); esters (acyl
groups) including C alkanoyl groups, such as formyl, acetyl, and pivaloyl, and aromatic
acyl groups such as benzoyl; arylmethyl groups such as benzyl (Bn), p-methoxybenzyl
(PMB), 9-fluorenylmethyl (Fm), and diphenylmethyl (benzhydryl, DPM); and the like.
Standard deprotection techniques and reagents are used to remove the protecting
groups, and may vary depending upon which group is used. For example, sodium or
lithium hydroxide is commonly used when the carboxy-protecting group is methyl, an acid
such as TFA or HCl is commonly used when the carboxy-protecting group is ethyl or t-
butyl, and H /Pd/C may be used when the carboxy-protecting group is benzyl. A BOC
amino-protecting group can be removed using an acidic reagent such as TFA in DCM or
HCl in 1,4-dioxane, while a Cbz amino-protecting group can be removed by employing
catalytic hydrogenation conditions such as H (1 atm) and 10% Pd/C in an alcoholic
solvent ("H /Pd/C"). H /Pd/C is commonly used when the hydroxyl-protecting group is
benzyl, while NaOH is commonly used when the hydroxyl-protecting group is an acyl
group.
Suitable bases for use in these schemes include, by way of illustration and not
limitation, potassium carbonate, calcium carbonate, sodium carbonate, triethylamine,
pyridine, 1,8-diazabicyclo-[5.4.0]undecene (DBU), N,N-diisopropylethylamine
(DIPEA), 4-methylmorpholine, sodium hydroxide, potassium hydroxide, potassium t-
butoxide, and metal hydrides.
Suitable inert diluents or solvents for use in these schemes include, by way of
illustration and not limitation, tetrahydrofuran (THF), acetonitrile (MeCN), N,N-
dimethylformamide (DMF), N,N-dimethylacetamide (DMA), dimethyl sulfoxide (DMSO),
toluene, dichloromethane (DCM), chloroform (CHCl ), carbon tetrachloride (CCl ), 1,4-
dioxane, methanol, ethanol, water, and the like.
Suitable carboxylic acid/amine coupling reagents include benzotriazol
yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP), benzotriazol
yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), N,N,N',N'-tetramethyl-
O-(7-azabenzotriazolyl)uronium hexafluorophosphate (HATU), (2-(6-chloro-1H-
benzotriazoleyl)-1,1,3,3-tetramethylaminium hexafluorophosphate) (HCTU), 1,3-
dicyclohexylcarbodiimide (DCC), N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide
(EDCI), carbonyldiimidazole (CDI), 1-hydroxybenzotriazole (HOBt), and the like.
Coupling reactions are conducted in an inert diluent in the presence of a base such as
DIPEA, and are performed under conventional amide bond-forming conditions.
All reactions are typically conducted at a temperature within the range of about
-78 C to 100°C, for example at room temperature. Reactions may be monitored by use of
thin layer chromatography (TLC), high performance liquid chromatography (HPLC),
and/or LCMS until completion. Reactions may be complete in minutes, or may take hours,
typically from 1-2 hours and up to 48 hours. Upon completion, the resulting mixture or
reaction product may be further treated in order to obtain the desired product. For
example, the resulting mixture or reaction product may be subjected to one or more of the
following procedures: concentrating or partitioning (for example, between EtOAc and
water or between 5% THF in EtOAc and 1M phosphoric acid); extraction (for example,
with EtOAc, CHCl , DCM, chloroform); washing (for example, with saturated aqueous
NaCl, saturated aqueous NaHCO , Na CO (5%), CHCl or 1M NaOH); drying (for
3 2 3 3
example, over MgSO , over Na SO , or in vacuo); filtering; crystallizing (for example,
4 2 4
from EtOAc and hexanes); being concentrated (for example, in vacuo); and/or purification
(e.g., silica gel chromatography, flash chromatography, preparative HPLC, reverse phase-
HPLC, or crystallization).
Compounds of formula I, as well as their salts, can be prepared as shown in Scheme
I:
Scheme I
Deprotection
O Z P
2 3 (optional)
Cl Coupling
(R )
Deprotection
(optional)
(R )
The process comprises the step of coupling compound 1 with compound 2, where R -R , Z,
a, and b are as defined for formula I, and P is selected from H and a suitable amino-
protecting group, examples of which include t-butoxycarbonyl, trityl, benzyloxycarbonyl,
9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl, and t-butyldimethylsilyl. When P is
an amino protecting group, the process further comprises deprotecting the compound of
formula 1, before or in situ with the coupling step.
In instances where R is a group such as -OCH or –OCH CH , the coupling step
3 2 3
may be followed by a deprotection step to provide a compound of formula I where R is a
group such as -OH. Thus, one method of preparing compounds of the invention involves
coupling compounds 1 and 2, with an optional deprotection step to form a compound of
formula I or a pharmaceutically acceptable salt thereof.
Methods of preparing compound 1 are described in the Examples. Compound 2 is
generally commercially available or can be prepared using procedures that are known in
the art.
Certain intermediates are described herein, for example, the compounds of formula
1, or a salt thereof:
O Z P
(R )
(R )
(1),
where P is H or a suitable amino-protecting group, examples of which include, t-
butoxycarbonyl, trityl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, formyl,
1 2 3 5 6
trimethylsilyl, and t-butyldimethylsilyl; and R , R , R , R , R , Z, a and b are as defined for
formula I.
Further details regarding specific reaction conditions and other procedures for
preparing representative compounds of the invention or intermediates thereof are described
in the Examples set forth below.
UTILITY
Compounds of the invention possess neprilysin (NEP) inhibition activity, that is,
the compounds are able to inhibit enzyme-catalytic activity. In another embodiment, the
compounds do not exhibit significant inhibitory activity of the angiotensin-converting
enzyme. One measure of the ability of a compound to inhibit NEP activity is the inhibition
constant (pK ). The pK value is the negative logarithm to base 10 of the dissociation
constant (K ), which is typically reported in molar units. Compounds of the invention of
particular interest are those having a pK at NEP greater than or equal to 6.0, particularly
those having a pK greater than or equal to 7.0, and even more particularly those having a
pK greater than or equal to 8.0. In one embodiment, compounds of interest have a pK in
the range of 6.0-6.9; in another embodiment, compounds of interest have a pK in the range
of 7.0-7.9; in yet another embodiment, compounds of interest have a pK in the range of
8.0-8.9; and in still another embodiment, compounds of interest have a pK in the range of
greater than or equal to 9.0. Such values can be determined by techniques that are well
known in the art, as well as in the assays described herein.
Another measure of the ability of a compound to inhibit NEP activity is the
apparent inhibition constant (IC ), which is the molar concentration of compound that
results in half-maximal inhibition of substrate conversion by the NEP enzyme. The pIC
value is the negative logarithm to base 10 of the IC . Compounds of the invention that are
of particular interest, include those that exhibit a pIC for NEP greater than or equal to
about 5.0. Compounds of interest also include those having a pIC for NEP ≥ about 6.0 or
a pIC for NEP ≥ about 7.0. In another embodiment, compounds of interest have a pIC
50 50
for NEP within the range of about 7.0-11.0; and in another embodiment, within the range
of about 8.0-11.0, such as within the range of about 8.0-10.0.
It is noted that in some cases, compounds of the invention may possess weak NEP
inhibition activity. In such cases, those of skill in the art will recognize that these
compounds still have utility as research tools.
Exemplary assays to determine properties of compounds of the invention, such as
the NEP inhibiting activity, are described in the Examples and include by way of
illustration and not limitation, assays that measure NEP inhibition (described in Assay 1).
Useful secondary assays include assays to measure ACE inhibition (also described in
Assay 1) and aminopeptidase P (APP) inhibition (described in Sulpizio et al. (2005) JPET
315:1306-1313). A pharmacodynamic assay to assess the in vivo inhibitory potencies for
ACE and NEP in anesthetized rats is described in Assay 2 (see also Seymour et al. (1985)
Hypertension 7(Suppl I):II-42 and Wigle et al. (1992) Can. J. Physiol. Pharmacol.
70:1525-1528), where ACE inhibition is measured as the percent inhibition of the
angiotensin I pressor response and NEP inhibition is measured as increased urinary cyclic
guanosine 3', 5'-monophosphate (cGMP) output.
There are many in vivo assays that can be used to ascertain further utilities of the
compounds of the invention. The conscious spontaneously hypertensive rat (SHR) model
is a renin dependent hypertension model, and is described in Assay 3. See also Intengan et
al. (1999) Circulation 100(22):2267-2275 and Badyal et al. (2003) Indian Journal of
Pharmacology 35:349-362. The conscious desoxycorticosterone acetate-salt (DOCA-salt)
rat model is a volume dependent hypertension model that is useful for measuring NEP
activity, and is described in Assay 4. See also Trapani et al. (1989) J. Cardiovasc.
Pharmacol. 14:419-424, Intengan et al. (1999) Hypertension 34(4):907-913, and Badyal et
al. (2003) supra). The DOCA-salt model is particularly useful for evaluating the ability of
a test compound to reduce blood pressure as well as to measure a test compound's ability to
prevent or delay a rise in blood pressure. The Dahl salt-sensive (DSS) hypertensive rat
model is a model of hypertension that is sensitive to dietary salt (NaCl), and is described in
Assay 5. See also Rapp (1982) Hypertension 4:753-763. The rat monocrotaline model of
pulmonary arterial hypertension described, for example, in Kato et al. (2008) J.
Cardiovasc. Pharmacol. 51(1):18-23, is a reliable predictor of clinical efficacy for the
treatment of pulmonary arterial hypertension. Heart failure animal models include the DSS
rat model for heart failure and the aorto-caval fistula model (AV shunt), the latter of which
is described, for example, in Norling et al. (1996) J. Amer. Soc. Nephrol. 7:1038-1044.
Other animal models, such as the hot plate, tail-flick and formalin tests, can be used to
measure the analgesic properties of compounds of the invention, as well as the spinal nerve
ligation (SNL) model of neuropathic pain. See, for example, Malmberg et al. (1999)
Current Protocols in Neuroscience 8.9.1-8.9.15.
Compounds of the invention are expected to inhibit the NEP enzyme in any of the
assays listed above, or assays of a similar nature. Thus, the aforementioned assays are
useful in determining the therapeutic utility of compounds of the invention, for example,
their utility as antihypertensive agents or antidiarrheal agents. Other properties and utilities
of compounds of the invention can be demonstrated using other in vitro and in vivo assays
well-known to those skilled in the art. Compounds of formula I may be active drugs as
well as prodrugs. Thus, when discussing the activity of compounds of the invention, it is
understood that any such prodrugs may not exhibit the expected activity in an assay, but
are expected to exhibit the desired activity once metabolized.
Compounds of the invention are expected to be useful for the treatment and/or
prevention of medical conditions responsive to NEP inhibition. Thus it is expected that
patients suffering from a disease or disorder that is treated by inhibiting the NEP enzyme
or by increasing the levels of its peptide substrates, can be treated by administering a
therapeutically effective amount of a compound of the invention. For example, by
inhibiting NEP, the compounds are expected to potentiate the biological effects of
endogenous peptides that are metabolized by NEP, such as the natriuretic peptides,
bombesin, bradykinins, calcitonin, endothelins, enkephalins, neurotensin, substance P and
vasoactive intestinal peptide. Thus, these compounds are expected to have other
physiological actions, for example, on the renal, central nervous, reproductive and
gastrointestinal systems.
In one embodiment described, patients suffering from a disease or disorder that is
treated by inhibiting the NEP enzyme, are treated by administering a compound of the
invention that is in its active form, i.e., a compound of formula I where R and R are H,
2 3 5 6
and R , R , R , R , a, b, and Z are as defined for formula I.
In another embodiment, patients are treated by administering a compound that is
1 4 2 3
metabolized in vitro to form a compound of formula I where R and R are H, and R , R ,
R , R , a, b, and Z are as defined for formula I.
In another embodiment, patients are treated by administering a compound of the
invention that is in its prodrug form at the R group, i.e., a compound of formula I where
R is selected from -C alkyl, -C alkylene-C aryl, -C alkylene-C heteroaryl,
1-8 1-3 6-10 1-3 1-9
11 12
-C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-NR R ,
3-7 2 2 1-3 3 1-6 1-6
-C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and .
In yet another embodiment, patients are treated by administering a compound of the
invention that is in its prodrug form at the R group, i.e., a compound of formula I where
R is selected from -C alkyl, -C alkylene-C aryl, -C alkylene-C heteroaryl,
1-8 1-3 6-10 1-3 1-9
40 41 42
-C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-NR R ,
3-7 2 2 1-3 3 1-6 1-6
-C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and
In still another embodiment, patients are treated by administering a compound of
the invention that is in its prodrug form at the R group and at the R group.
Cardiovascular Diseases
By potentiating the effects of vasoactive peptides like the natriuretic peptides and
bradykinin, compounds of the invention are expected to find utility in treating and/or
preventing medical conditions such as cardiovascular diseases. See, for example, Roques
et al. (1993) Pharmacol. Rev. 45:87-146 and Dempsey et al. (2009) Amer. J. of Pathology
174(3):782-796. Cardiovascular diseases of particular interest include hypertension and
heart failure. Hypertension includes, by way of illustration and not limitation: primary
hypertension, which is also referred to as essential hypertension or idiopathic hypertension;
secondary hypertension; hypertension with accompanying renal disease; severe
hypertension with or without accompanying renal disease; pulmonary hypertension,
including pulmonary arterial hypertension; and resistant hypertension. Heart failure
includes, by way of illustration and not limitation: congestive heart failure; acute heart
failure; chronic heart failure, for example with reduced left ventricular ejection fraction
(also referred to as systolic heart failure) or with preserved left ventricular ejection fraction
(also referred to as diastolic heart failure); and acute and chronic decompensated heart
failure, with or without accompanying renal disease. Thus, described is a method for
treating hypertension, particularly primary hypertension or pulmonary arterial
hypertension, comprising administering to a patient a therapeutically effective amount of a
compound of the invention.
For treatment of primary hypertension, the therapeutically effective amount is
typically the amount that is sufficient to lower the patient's blood pressure. This would
include both mild-to-moderate hypertension and severe hypertension. When used to treat
hypertension, the compound may be administered in combination with other therapeutic
agents such as aldosterone antagonists, aldosterone synthase inhibitors, angiotensin-
converting enzyme inhibitors and dual-acting angiotensin-converting enzyme/neprilysin
inhibitors, angiotensin-converting enzyme 2 (ACE2) activators and stimulators,
angiotensin-II vaccines, anti-diabetic agents, anti-lipid agents, anti-thrombotic agents, AT
receptor antagonists and dual-acting AT receptor antagonist/neprilysin inhibitors, β -
adrenergic receptor antagonists, dual-acting β-adrenergic receptor antagonist/α -receptor
antagonists, calcium channel blockers, diuretics, endothelin receptor antagonists,
endothelin converting enzyme inhibitors, neprilysin inhibitors, natriuretic peptides and
their analogs, natriuretic peptide clearance receptor antagonists, nitric oxide donors, non-
steroidal anti-inflammatory agents, phosphodiesterase inhibitors (specifically PDE-V
inhibitors), prostaglandin receptor agonists, renin inhibitors, soluble guanylate cyclase
stimulators and activators, and combinations thereof. In one particular embodiment of the
invention, a compound of the invention is combined with an AT receptor antagonist, a
calcium channel blocker, a diuretic, or a combination thereof, and used to treat primary
hypertension. In another particular embodiment described, a compound of the invention is
combined with an AT receptor antagonist, and used to treat hypertension with
accompanying renal disease. When used to treat resistant hypertension, the compound may
be administered in combination with other therapeutic agents such as aldosterone synthase
inhibitors.
For treatment of pulmonary arterial hypertension, the therapeutically effective
amount is typically the amount that is sufficient to lower the pulmonary vascular
resistance. Other goals of therapy are to improve a patient's exercise capacity. For
example, in a clinical setting, the therapeutically effective amount can be the amount that
improves a patient's ability to walk comfortably for a period of 6 minutes (covering a
distance of approximately 20-40 meters). When used to treat pulmonary arterial
hypertension the compound may be administered in combination with other therapeutic
agents such as α-adrenergic receptor antagonists, β -adrenergic receptor antagonists, β -
adrenergic receptor agonists, angiotensin-converting enzyme inhibitors, anticoagulants,
calcium channel blockers, diuretics, endothelin receptor antagonists, PDE-V inhibitors,
prostaglandin analogs, selective serotonin reuptake inhibitors, and combinations thereof.
In one particular embodiment described, a compound of the invention is combined with a
PDE-V inhibitor or a selective serotonin reuptake inhibitor and used to treat pulmonary
arterial hypertension.
Also described is a method for treating heart failure, in particular congestive heart
failure (including both systolic and diastolic congestive heart failure), comprising
administering to a patient a therapeutically effective amount of a compound of the
invention. Typically, the therapeutically effective amount is the amount that is sufficient to
lower blood pressure and/or improve renal functions. In a clinical setting, the
therapeutically effective amount can be the amount that is sufficient to improve cardiac
hemodynamics, like for instance reduction in wedge pressure, right atrial pressure, filling
pressure, and vascular resistance. In one embodiment, the compound is administered as an
intravenous dosage form. When used to treat heart failure, the compound may be
administered in combination with other therapeutic agents such as adenosine receptor
antagonists, advanced glycation end product breakers, aldosterone antagonists, AT
receptor antagonists, β -adrenergic receptor antagonists, dual-acting β-adrenergic receptor
antagonist/α -receptor antagonists, chymase inhibitors, digoxin, diuretics, endothelin
converting enzyme (ECE) inhibitors, endothelin receptor antagonists, natriuretic peptides
and their analogs, natriuretic peptide clearance receptor antagonists, nitric oxide donors,
prostaglandin analogs, PDE-V inhibitors, soluble guanylate cyclase activators and
stimulators, and vasopressin receptor antagonists. In one particular embodiment described,
a compound of the invention is combined with an aldosterone antagonist, a β -adrenergic
receptor antagonist, an AT receptor antagonist, or a diuretic, and used to treat congestive
heart failure.
Diarrhea
As NEP inhibitors, compounds of the invention are expected to inhibit the
degradation of endogenous enkephalins and thus such compounds may also find utility for
the treatment of diarrhea, including infectious and secretory/watery diarrhea. See, for
example, Baumer et al. (1992) Gut 33:753-758; Farthing (2006) Digestive Diseases 24:47-
58; and Marçais-Collado (1987) Eur. J. Pharmacol. 144(2):125-132. When used to treat
diarrhea, compounds of the invention may be combined with one or more additional
antidiarrheal agents.
Renal Diseases
By potentiating the effects of vasoactive peptides like the natriuretic peptides and
bradykinin, compounds of the invention are expected to enhance renal function (see Chen
et al. (1999) Circulation 100:2443-2448; Lipkin et al. (1997) Kidney Int. 52:792-801; and
Dussaule et al. (1993) Clin. Sci. 84:31-39) and find utility in treating and/or preventing
renal diseases. Renal diseases of particular interest include diabetic nephropathy, chronic
kidney disease, proteinuria, and particularly acute kidney injury or acute renal failure (see
Sharkovska et al. (2011) Clin. Lab. 57:507-515 and Newaz et al. (2010) Renal Failure
32:384-390). When used to treat renal disease, the compound may be administered in
combination with other therapeutic agents such as angiotensin-converting enzyme
inhibitors, AT receptor antagonists, and diuretics.
Preventative Therapy
By potentiating the effects of the natriuretic peptides, compounds of the invention
are also expected to be useful in preventative therapy, due to the antihypertrophic and
antifibrotic effects of the natriuretic peptides (see Potter et al. (2009) Handbook of
Experimental Pharmacology 191:341-366), for example in preventing the progression of
cardiac insufficiency after myocardial infarction, preventing arterial restenosis after
angioplasty, preventing thickening of blood vessel walls after vascular operations,
preventing atherosclerosis, and preventing diabetic angiopathy.
Glaucoma
By potentiating the effects of the natriuretic peptides, compounds of the invention
are expected to be useful to treat glaucoma. See, for example, Diestelhorst et al. (1989)
International Ophthalmology 12:99-101. When used to treat glaucoma, compounds of the
invention may be combined with one or more additional antiglaucoma agents.
Pain Relief
As NEP inhibitors, compounds of the invention are expected to inhibit the
degradation of endogenous enkephalins and thus such compounds may also find utility as
analgesics. See, for example, Roques et al. (1980) Nature 288:286-288 and Thanawala et
al. (2008) Current Drug Targets 9:887-894. When used to treat pain, the compounds of
the invention may be combined with one or more additional antinociceptive drugs such as
aminopeptidase N or dipeptidyl peptidase III inhibitors, non-steroidal anti-inflammatory
agents, monoamine reuptake inhibitors, muscle relaxants, NMDA receptor antagonists,
opioid receptor agonists, 5-HT serotonin receptor agonists, and tricyclic antidepressants.
Other Utilities
Due to their NEP inhibition properties, compounds of the invention are also
expected to be useful as antitussive agents, as well as find utility in the treatment of portal
hypertension associated with liver cirrhosis (see Sansoe et al. (2005) J. Hepatol. 43:791-
798), cancer (see Vesely (2005) J. Investigative Med. 53:360-365), depression (see Noble
et al. (2007) Exp. Opin. Ther. Targets 11:145-159), menstrual disorders, preterm labor,
pre-eclampsia, endometriosis, reproductive disorders (for example, male and female
infertility, polycystic ovarian syndrome, implantation failure), and male and female sexual
dysfunction, including male erectile dysfunction and female sexual arousal disorder. More
specifically, the compounds of the invention are expected to be useful in treating female
sexual dysfunction (see Pryde et al. (2006) J. Med. Chem. 49:4409-4424), which is often
defined as a female patient's difficulty or inability to find satisfaction in sexual expression.
This covers a variety of diverse female sexual disorders including, by way of illustration
and not limitation, hypoactive sexual desire disorder, sexual arousal disorder, orgasmic
disorder and sexual pain disorder. When used to treat such disorders, especially female
sexual dysfunction, compounds of the invention may be combined with one or more of the
following secondary agents: PDE-V inhibitors, dopamine agonists, estrogen receptor
agonists and/or antagonists, androgens, and estrogens. Due to their NEP inhibition
properties, compounds of the invention are also expected to have anti-inflammatory
properties, and are expected to have utility as such, particularly when used in combination
with statins.
Recent studies suggest that NEP plays a role in regulating nerve function in insulin-
deficient diabetes and diet induced obesity. Coppey et al. (2011) Neuropharmacology
60:259-266. Therefore, due to their NEP inhibition properties, compounds of the invention
are also expected to be useful in providing protection from nerve impairment caused by
diabetes or diet induced obesity.
The amount of the compound of the invention administered per dose or the total
amount administered per day may be predetermined or it may be determined on an
individual patient basis by taking into consideration numerous factors, including the nature
and severity of the patient's condition, the condition being treated, the age, weight, and
general health of the patient, the tolerance of the patient to the active agent, the route of
administration, pharmacological considerations such as the activity, efficacy,
pharmacokinetics and toxicology profiles of the compound and any secondary agents being
administered, and the like. Treatment of a patient suffering from a disease or medical
condition (such as hypertension) can begin with a predetermined dosage or a dosage
determined by the treating physician, and will continue for a period of time necessary to
prevent, ameliorate, suppress, or alleviate the symptoms of the disease or medical
condition. Patients undergoing such treatment will typically be monitored on a routine
basis to determine the effectiveness of therapy. For example, in treating hypertension,
blood pressure measurements may be used to determine the effectiveness of treatment.
Similar indicators for other diseases and conditions described herein, are well known and
are readily available to the treating physician. Continuous monitoring by the physician will
insure that the optimal amount of the compound of the invention will be administered at
any given time, as well as facilitating the determination of the duration of treatment. This
is of particular value when secondary agents are also being administered, as their selection,
dosage, and duration of therapy may also require adjustment. In this way, the treatment
regimen and dosing schedule can be adjusted over the course of therapy so that the lowest
amount of active agent that exhibits the desired effectiveness is administered and, further,
that administration is continued only so long as is necessary to successfully treat the
disease or medical condition.
Research Tools
Since compounds of the invention possess NEP enzyme inhibition activity, such
compounds are also useful as research tools for investigating or studying biological
systems or samples having a NEP enzyme, for example to study diseases where the NEP
enzyme or its peptide substrates plays a role. Any suitable biological system or sample
having a NEP enzyme may be employed in such studies which may be conducted either in
vitro or in vivo. Representative biological systems or samples suitable for such studies
include, but are not limited to, cells, cellular extracts, plasma membranes, tissue samples,
isolated organs, mammals (such as mice, rats, guinea pigs, rabbits, dogs, pigs, humans, and
so forth), and the like, with mammals being of particular interest. In one particular
embodiment described, NEP enzyme activity in a mammal is inhibited by administering a
NEP-inhibiting amount of a compound of the invention. Compounds of the invention can
also be used as research tools by conducting biological assays using such compounds.
When used as a research tool, a biological system or sample comprising a NEP
enzyme is typically contacted with a NEP enzyme-inhibiting amount of a compound of the
invention. After the biological system or sample is exposed to the compound, the effects
of inhibiting the NEP enzyme are determined using conventional procedures and
equipment, such as by measuring receptor binding in a binding assay or measuring ligand-
mediated changes in a functional assay. Exposure encompasses contacting cells or tissue
with the compound, administering the compound to a mammal, for example by i.p., p.o,
i.v., s.c., or inhaled administration, and so forth. This determining step can involve
measuring a response (a quantitative analysis) or can involve making an observation (a
qualitative analysis). Measuring a response involves, for example, determining the effects
of the compound on the biological system or sample using conventional procedures and
equipment, such as enzyme activity assays and measuring enzyme substrate or product
mediated changes in functional assays. The assay results can be used to determine the
activity level as well as the amount of compound necessary to achieve the desired result,
that is, a NEP enzyme-inhibiting amount. Typically, the determining step will involve
determining the effects of inhibiting the NEP enzyme.
Additionally, compounds of the invention can be used as research tools for
evaluating other chemical compounds, and thus are also useful in screening assays to
discover, for example, new compounds having NEP-inhibiting activity. In this manner, a
compound of the invention is used as a standard in an assay to allow comparison of the
results obtained with a test compound and with compounds of the invention to identify
those test compounds that have about equal or superior activity, if any. For example, pK
data for a test compound or a group of test compounds is compared to the pK data for a
compound of the invention to identify those test compounds that have the desired
properties, for example, test compounds having a pK value about equal or superior to a
compound of the invention, if any. This embodiment described includes, as separate
embodiments, both the generation of comparison data (using the appropriate assays) and
the analysis of test data to identify test compounds of interest. Thus, a test compound can
be evaluated in a biological assay, by a method comprising the steps of: (a) conducting a
biological assay with a test compound to provide a first assay value; (b) conducting the
biological assay with a compound of the invention to provide a second assay value;
wherein step (a) is conducted either before, after or concurrently with step (b); and (c)
comparing the first assay value from step (a) with the second assay value from step (b).
Exemplary biological assays include a NEP enzyme inhibition assay.
PHARMACEUTICAL COMPOSITIONS AND FORMULATIONS
Compounds of the invention are typically administered to a patient in the form of a
pharmaceutical composition or formulation. Such pharmaceutical compositions may be
administered to the patient by any acceptable route of administration including, but not
limited to, oral, rectal, vaginal, nasal, inhaled, topical (including transdermal), ocular, and
parenteral modes of administration. Further, the compounds of the invention may be
administered, for example orally, in multiple doses per day (for example, two, three, or
four times daily), in a single daily dose or a single weekly dose. It will be understood that
any form of the compounds of the invention, (that is, free base, free acid, pharmaceutically
acceptable salt, solvate, etc.) that is suitable for the particular mode of administration can
be used in the pharmaceutical compositions discussed herein.
Accordingly, in one embodiment, the invention relates to a pharmaceutical
composition comprising a pharmaceutically acceptable carrier and a compound of the
invention. The compositions may contain other therapeutic and/or formulating agents if
desired. When discussing compositions, the "compound of the invention" may also be
referred to herein as the "active agent, " to distinguish it from other components of the
formulation, such as the carrier. Thus, it is understood that the term "active agent" includes
compounds of formula I as well as pharmaceutically acceptable salts, solvates and
prodrugs of that compound.
The pharmaceutical compositions of the invention typically contain a
therapeutically effective amount of a compound of the invention. Those skilled in the art
will recognize, however, that a pharmaceutical composition may contain more than a
therapeutically effective amount, such as in bulk compositions, or less than a
therapeutically effective amount, that is, individual unit doses designed for multiple
administration to achieve a therapeutically effective amount. Typically, the composition
will contain from about 0.01-95 wt% of active agent, including, from about 0.01-30 wt%,
such as from about 0.01- 10 wt%, with the actual amount depending upon the formulation
itself, the route of administration, the frequency of dosing, and so forth. In one
embodiment, a composition suitable for an oral dosage form, for example, may contain
about 5-70 wt%, or from about 10-60 wt% of active agent.
Any conventional carrier or excipient may be used in the pharmaceutical
compositions of the invention. The choice of a particular carrier or excipient, or
combinations of carriers or excipients, will depend on the mode of administration being
used to treat a particular patient or type of medical condition or disease state. In this
regard, the preparation of a suitable composition for a particular mode of administration is
well within the scope of those skilled in the pharmaceutical arts. Additionally, carriers or
excipients used in such compositions are commercially available. By way of further
illustration, conventional formulation techniques are described in Remington: The Science
and Practice of Pharmacy, 20 Edition, Lippincott Williams & White, Baltimore,
Maryland (2000); and H. C. Ansel et al., Pharmaceutical Dosage Forms and Drug
Delivery Systems, 7 Edition, Lippincott Williams & White, Baltimore, Maryland (1999).
Representative examples of materials which can serve as pharmaceutically
acceptable carriers include, but are not limited to, the following: sugars, such as lactose,
glucose and sucrose; starches, such as corn starch and potato starch; cellulose, such as
microcrystalline cellulose, and its derivatives, such as sodium carboxymethyl cellulose,
ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients,
such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil,
safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols, such as propylene
glycol; polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol; esters, such as
ethyl oleate and ethyl laurate; agar; buffering agents, such as magnesium hydroxide and
aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution;
ethyl alcohol; phosphate buffer solutions; compressed propellant gases, such as
chlorofluorocarbons and hydrofluorocarbons; and other non-toxic compatible substances
employed in pharmaceutical compositions.
Pharmaceutical compositions are typically prepared by thoroughly and intimately
mixing or blending the active agent with a pharmaceutically acceptable carrier and one or
more optional ingredients. The resulting uniformly blended mixture may then be shaped or
loaded into tablets, capsules, pills, canisters, cartridges, dispensers and the like using
conventional procedures and equipment.
In one embodiment, the pharmaceutical compositions are suitable for oral
administration. Suitable compositions for oral administration may be in the form of
capsules, tablets, pills, lozenges, cachets, dragees, powders, granules; solutions or
suspensions in an aqueous or non-aqueous liquid; oil-in-water or water-in-oil liquid
emulsions; elixirs or syrups; and the like; each containing a predetermined amount of the
active agent.
When intended for oral administration in a solid dosage form (capsules, tablets,
pills and the like), the composition will typically comprise the active agent and one or more
pharmaceutically acceptable carriers, such as sodium citrate or dicalcium phosphate. Solid
dosage forms may also comprise: fillers or extenders, such as starches, microcrystalline
cellulose, lactose, sucrose, glucose, mannitol, and/or silicic acid; binders, such as
carboxymethylcellulose, alginates, gelatin, polyvinyl pyrrolidone, sucrose and/or acacia;
humectants, such as glycerol; disintegrating agents, such as agar-agar, calcium carbonate,
potato or tapioca starch, alginic acid, certain silicates, and/or sodium carbonate; solution
retarding agents, such as paraffin; absorption accelerators, such as quaternary ammonium
compounds; wetting agents, such as cetyl alcohol and/or glycerol monostearate;
absorbents, such as kaolin and/or bentonite clay; lubricants, such as talc, calcium stearate,
magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and/or mixtures
thereof; coloring agents; and buffering agents.
Release agents, wetting agents, coating agents, sweetening, flavoring and
perfuming agents, preservatives and antioxidants may also be present in the pharmaceutical
compositions. Exemplary coating agents for tablets, capsules, pills and like, include those
used for enteric coatings, such as cellulose acetate phthalate, polyvinyl acetate phthalate,
hydroxypropyl methylcellulose phthalate, methacrylic acid-methacrylic acid ester
copolymers, cellulose acetate trimellitate, carboxymethyl ethyl cellulose, hydroxypropyl
methyl cellulose acetate succinate, and the like. Examples of pharmaceutically acceptable
antioxidants include: water-soluble antioxidants, such as ascorbic acid, cysteine
hydrochloride, sodium bisulfate, sodium metabisulfate sodium sulfite and the like; oil-
soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole, butylated
hydroxytoluene, lecithin, propyl gallate, alpha-tocopherol, and the like; and metal-
chelating agents, such as citric acid, ethylenediamine tetraacetic acid, sorbitol, tartaric acid,
phosphoric acid, and the like.
Compositions may also be formulated to provide slow or controlled release of the
active agent using, by way of example, hydroxypropyl methyl cellulose in varying
proportions or other polymer matrices, liposomes and/or microspheres. In addition, the
pharmaceutical compositions of the invention may contain opacifying agents and may be
formulated so that they release the active agent only, or preferentially, in a certain portion
of the gastrointestinal tract, optionally, in a delayed manner. Examples of embedding
compositions which can be used include polymeric substances and waxes. The active
agent can also be in micro-encapsulated form, optionally with one or more of the above-
described excipients.
Suitable liquid dosage forms for oral administration include, by way of illustration,
pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups
and elixirs. Liquid dosage forms typically comprise the active agent and an inert diluent,
such as, for example, water or other solvents, solubilizing agents and emulsifiers, such as
ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl
benzoate, propylene glycol, 1,3-butylene glycol, oils (for example, cottonseed, groundnut,
corn, germ, olive, castor and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethylene
glycols and fatty acid esters of sorbitan, and mixtures thereof. Suspensions may contain
suspending agents such as, for example, ethoxylated isostearyl alcohols, polyoxyethylene
sorbitol and sorbitan esters, microcrystalline cellulose, aluminium metahydroxide,
bentonite, agar-agar and tragacanth, and mixtures thereof.
When intended for oral administration, the pharmaceutical compositions of the
invention may be packaged in a unit dosage form. The term "unit dosage form" refers to a
physically discrete unit suitable for dosing a patient, that is, each unit containing a
predetermined quantity of the active agent calculated to produce the desired therapeutic
effect either alone or in combination with one or more additional units. For example, such
unit dosage forms may be capsules, tablets, pills, and the like.
In another embodiment, the compositions of the invention are suitable for inhaled
administration, and will typically be in the form of an aerosol or a powder. Such
compositions are generally administered using well-known delivery devices, such as a
nebulizer, dry powder, or metered-dose inhaler. Nebulizer devices produce a stream of
high velocity air that causes the composition to spray as a mist that is carried into a
patient's respiratory tract. An exemplary nebulizer formulation comprises the active agent
dissolved in a carrier to form a solution, or micronized and combined with a carrier to form
a suspension of micronized particles of respirable size. Dry powder inhalers administer the
active agent as a free-flowing powder that is dispersed in a patient's air-stream during
inspiration. An exemplary dry powder formulation comprises the active agent dry-blended
with an excipient such as lactose, starch, mannitol, dextrose, polylactic acid, polylactide-
co-glycolide, and combinations thereof. Metered-dose inhalers discharge a measured
amount of the active agent using compressed propellant gas. An exemplary metered-dose
formulation comprises a solution or suspension of the active agent in a liquefied propellant,
such as a chlorofluorocarbon or hydrofluoroalkane. Optional components of such
formulations include co-solvents, such as ethanol or pentane, and surfactants, such as
sorbitan trioleate, oleic acid, lecithin, glycerin, and sodium lauryl sulfate. Such
compositions are typically prepared by adding chilled or pressurized hydrofluoroalkane to
a suitable container containing the active agent, ethanol (if present) and the surfactant (if
present). To prepare a suspension, the active agent is micronized and then combined with
the propellant. Alternatively, a suspension formulation can be prepared by spray drying a
coating of surfactant on micronized particles of the active agent. The formulation is then
loaded into an aerosol canister, which forms a portion of the inhaler.
Compounds of the invention can also be administered parenterally (for example, by
subcutaneous, intravenous, intramuscular, or intraperitoneal injection). For such
administration, the active agent is provided in a sterile solution, suspension, or emulsion.
Exemplary solvents for preparing such formulations include water, saline, low molecular
weight alcohols such as propylene glycol, polyethylene glycol, oils, gelatin, fatty acid
esters such as ethyl oleate, and the like. Parenteral formulations may also contain one or
more anti-oxidants, solubilizers, stabilizers, preservatives, wetting agents, emulsifiers, and
dispersing agents. Surfactants, additional stabilizing agents or pH-adjusting agents (acids,
bases or buffers) and anti-oxidants are particularly useful to provide stability to the
formulation, for example, to minimize or avoid hydrolysis of ester and amide linkages that
may be present in the compound. These formulations may be rendered sterile by use of a
sterile injectable medium, a sterilizing agent, filtration, irradiation, or heat. In one
particular embodiment, the parenteral formulation comprises an aqueous cyclodextrin
solution as the pharmaceutically acceptable carrier. Suitable cyclodextrins include cyclic
molecules containing six or more α-D-glucopyranose units linked at the 1,4 positions by a
linkages as in amylase, β-cyclodextrin or cycloheptaamylose. Exemplary cyclodextrins
include cyclodextrin derivatives such as hydroxypropyl and sulfobutyl ether cyclodextrins
such as hydroxypropyl-β-cyclodextrin and sulfobutyl ether β-cyclodextrin. Exemplary
buffers for such formulations include carboxylic acid-based buffers such as citrate, lactate
and maleate buffer solutions.
Compounds of the invention can also be administered transdermally using known
transdermal delivery systems and excipients. For example, the compound can be admixed
with permeation enhancers, such as propylene glycol, polyethylene glycol monolaurate,
azacycloalkanones and the like, and incorporated into a patch or similar delivery system.
Additional excipients including gelling agents, emulsifiers and buffers, may be used in
such transdermal compositions if desired.
Secondary Agents
The compounds of the invention may be useful as the sole treatment of a disease or
may be combined with one or more additional therapeutic agents in order to obtain the
desired therapeutic effect. Thus, in one embodiment, pharmaceutical compositions of the
invention contain other drugs that are co-administered with a compound of the invention.
For example, the composition may further comprise one or more drugs (also referred to as
"secondary agents(s)"). Such therapeutic agents are well known in the art, and include
adenosine receptor antagonists, α-adrenergic receptor antagonists, β -adrenergic receptor
antagonists, β -adrenergic receptor agonists, dual-acting β-adrenergic receptor
antagonist/α -receptor antagonists, advanced glycation end product breakers, aldosterone
antagonists, aldosterone synthase inhibitors, aminopeptidase N inhibitors, androgens,
angiotensin-converting enzyme inhibitors and dual-acting angiotensin-converting
enzyme/neprilysin inhibitors, angiotensin-converting enzyme 2 activators and stimulators,
angiotensin-II vaccines, anticoagulants, anti-diabetic agents, antidiarrheal agents, anti-
glaucoma agents, anti-lipid agents, antinociceptive agents, anti-thrombotic agents, AT
receptor antagonists and dual-acting AT receptor antagonist/neprilysin inhibitors and
multifunctional angiotensin receptor blockers, bradykinin receptor antagonists, calcium
channel blockers, chymase inhibitors, digoxin, diuretics, dopamine agonists, endothelin
converting enzyme inhibitors, endothelin receptor antagonists, HMG-CoA reductase
inhibitors, estrogens, estrogen receptor agonists and/or antagonists, monoamine reuptake
inhibitors, muscle relaxants, natriuretic peptides and their analogs, natriuretic peptide
clearance receptor antagonists, neprilysin inhibitors, nitric oxide donors, non-steroidal anti-
inflammatory agents, N-methyl d-aspartate receptor antagonists, opioid receptor agonists,
phosphodiesterase inhibitors, prostaglandin analogs, prostaglandin receptor agonists, renin
inhibitors, selective serotonin reuptake inhibitors, sodium channel blocker, soluble
guanylate cyclase stimulators and activators, tricyclic antidepressants, vasopressin receptor
antagonists, and combinations thereof. Specific examples of these agents are detailed
herein.
Accordingly, in yet another aspect of the invention, a pharmaceutical composition
comprises a compound of the invention, a second active agent, and a pharmaceutically
acceptable carrier. Third, fourth etc. active agents may also be included in the
composition. In combination therapy, the amount of compound of the invention that is
administered, as well as the amount of secondary agents, may be less than the amount
typically administered in monotherapy.
Compounds of the invention may be physically mixed with the second active agent
to form a composition containing both agents; or each agent may be present in separate and
distinct compositions which are administered to the patient simultaneously or at separate
times. For example, a compound of the invention can be combined with a second active
agent using conventional procedures and equipment to form a combination of active agents
comprising a compound of the invention and a second active agent. Additionally, the
active agents may be combined with a pharmaceutically acceptable carrier to form a
pharmaceutical composition comprising a compound of the invention, a second active
agent and a pharmaceutically acceptable carrier. In this embodiment, the components of
the composition are typically mixed or blended to create a physical mixture. The physical
mixture is then administered in a therapeutically effective amount using any of the routes
described herein.
Alternatively, the active agents may remain separate and distinct before
administration to the patient. In this embodiment, the agents are not physically mixed
together before administration but are administered simultaneously or at separate times as
separate compositions. Such compositions can be packaged separately or may be packaged
together in a kit. When administered at separate times, the secondary agent will typically
be administered less than 24 hours after administration of the compound of the invention,
ranging anywhere from concurrent with administration of the compound of the invention to
about 24 hours post-dose. This is also referred to as sequential administration. Thus, a
compound of the invention can be orally administered simultaneously or sequentially with
another active agent using two tablets, with one tablet for each active agent, where
sequential may mean being administered immediately after administration of the
compound of the invention or at some predetermined time later (for example, one hour
later or three hours later). It is also contemplated that the secondary agent may be
administered more than 24 hours after administration of the compound of the invention.
Alternatively, the combination may be administered by different routes of administration,
that is, one orally and the other by inhalation.
In one embodiment, the kit comprises a first dosage form comprising a compound
of the invention and at least one additional dosage form comprising one or more of the
secondary agents set forth herein, in quantities sufficient to carry out the methods of the
invention. The first dosage form and the second (or third, etc.) dosage form together
comprise a therapeutically effective amount of active agents for the treatment or prevention
of a disease or medical condition in a patient.
Secondary agent(s), when included, are present in a therapeutically effective
amount such that they are typically administered in an amount that produces a
therapeutically beneficial effect when co-administered with a compound of the invention.
The secondary agent can be in the form of a pharmaceutically acceptable salt, solvate,
optically pure stereoisomer, and so forth. The secondary agent may also be in the form of
a prodrug, for example, a compound having a carboxylic acid group that has been
esterified. Thus, secondary agents listed herein are intended to include all such forms, and
are commercially available or can be prepared using conventional procedures and reagents.
In one embodiment, compounds of the invention are administered in combination
with an adenosine receptor antagonist, representative examples of which include, but are
not limited to, naxifylline, rolofylline, SLV-320, theophylline, and tonapofylline.
In one embodiment, compounds of the invention are administered in combination
with an α-adrenergic receptor antagonist, representative examples of which include, but are
not limited to, doxazosin, prazosin, tamsulosin, and terazosin.
Compounds of the invention may also be administered in combination with a β -
adrenergic receptor antagonist ("β -blockers"). Representative β -blockers include, but are
not limited to, acebutolol, alprenolol, amosulalol, arotinolol, atenolol, befunolol, betaxolol,
bevantolol, bisoprolol, bopindolol, bucindolol, bucumolol, bufetolol, bufuralol, bunitrolol,
bupranolol, bubridine, butofilolol, carazolol, carteolol, carvedilol, celiprolol, cetamolol,
cloranolol, dilevalol, epanolol, esmolol, indenolol, labetolol, levobunolol, mepindolol,
metipranolol, metoprolol such as metoprolol succinate and metoprolol tartrate, moprolol,
nadolol, nadoxolol, nebivalol, nipradilol, oxprenolol, penbutolol, perbutolol, pindolol,
practolol, pronethalol, propranolol, sotalol, sufinalol, talindol, tertatolol, tilisolol, timolol,
toliprolol, xibenolol, and combinations thereof. In one particular embodiment, the β -
antagonist is selected from atenolol, bisoprolol, metoprolol, propranolol, sotalol, and
combinations thereof. Typically, the β -blocker will be administered in an amount
sufficient to provide from about 2-900 mg per dose.
In one embodiment, compounds of the invention are administered in combination
with a β -adrenergic receptor agonist, representative examples of which include, but are not
limited to, albuterol, bitolterol, fenoterol, formoterol, indacaterol, isoetharine, levalbuterol,
metaproterenol, pirbuterol, salbutamol, salmefamol, salmeterol, terbutaline, vilanterol, and
the like Typically, the β -adrenergic receptor agonist will be administered in an amount
sufficient to provide from about 0.05-500 μg per dose.
In one embodiment, compounds of the invention are administered in combination
with an advanced glycation end product (AGE) breaker, examples of which include, by
way of illustration and not limitation, alagebrium (or ALT-711), and TRC4149.
In another embodiment, compounds of the invention are administered in
combination with an aldosterone antagonist, representative examples of which include, but
are not limited to, eplerenone, spironolactone, and combinations thereof. Typically, the
aldosterone antagonist will be administered in an amount sufficient to provide from about
-300 mg per day.
In one embodiment, compounds of the invention are administered in combination
with an aminopeptidase N or dipeptidyl peptidase III inhibitor, examples of which include,
by way of illustration and not limitation, bestatin and PC18 (2-aminomethylsulfonyl
butane thiol, methionine thiol).
Compounds of the invention can also be administered in combination with an
angiotensin-converting enzyme (ACE) inhibitor. Representative ACE inhibitors include,
but are not limited to, accupril, alacepril, benazepril, benazeprilat, captopril, ceranapril,
cilazapril, delapril, enalapril, enalaprilat, fosinopril, fosinoprilat, imidapril, lisinopril,
moexipril, monopril, moveltipril, pentopril, perindopril, quinapril, quinaprilat, ramipril,
ramiprilat, saralasin acetate, spirapril, temocapril, trandolapril, zofenopril, and
combinations thereof. In a particular embodiment, the ACE inhibitor is selected from:
benazepril, captopril, enalapril, lisinopril, ramipril, and combinations thereof. Typically,
the ACE inhibitor will be administered in an amount sufficient to provide from about 1-150
mg per day.
In another embodiment, compounds of the invention are administered in
combination with a dual-acting angiotensin-converting enzyme/neprilysin (ACE/NEP)
inhibitor, examples of which include, but are not limited to: AVE-0848 ((4S,7S,12bR)
[3-methyl-2(S)-sulfanylbutyramido]oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]-
benzazepinecarboxylic acid); AVE-7688 (ilepatril) and its parent compound; BMS-
182657 (2-[2-oxo-3(S)-[3-phenyl-2(S)-sulfanylpropionamido]-2,3,4,5-tetrahydro-1H
benzazepinyl]acetic acid); CGS-35601 (N-[1-[4-methyl-2(S)-
sulfanylpentanamido]cyclopentylcarbonyl]-L-tryptophan); fasidotril; fasidotrilate;
enalaprilat; ER-32935 ((3R,6S,9aR)[3(S)-methyl-2(S)-sulfanylpentanamido]
oxoperhydrothiazolo[3,2-a]azepinecarboxylic acid); gempatrilat; MDL-101264
((4S,7S,12bR)[2(S)-(2-morpholinoacetylthio)phenylpropionamido]oxo-
1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepinecarboxylic acid); MDL-101287
([4S-[4α,7α(R*),12bβ]][2-(carboxymethyl)phenylpropionamido]oxo-
1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepinecarboxylic acid); omapatrilat;
RB-105 (N-[2(S)-(mercaptomethyl)-3(R)-phenylbutyl]-L-alanine); sampatrilat; SA-898
((2R,4R)-N-[2-(2-hydroxyphenyl)(3-mercaptopropionyl)thiazolidinylcarbonyl]-L-
phenylalanine); Sch-50690 (N-[1(S)-carboxy[N2-(methanesulfonyl)-L-
lysylamino]ethyl]-L-valyl-L-tyrosine); and combinations thereof, may also be included. In
one particular embodiment, the ACE/NEP inhibitor is selected from: AVE-7688,
enalaprilat, fasidotril, fasidotrilate, omapatrilat, sampatrilat, and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with an angiotensin-converting enzyme 2 (ACE2) activator or stimulator.
In one embodiment, compounds of the invention are administered in combination
with an angiotensin-II vaccine, examples of which include, but are not limited to
ATR12181 and CYT006-AngQb.
In one embodiment, compounds of the invention are administered in combination
with an anticoagulant, representative examples of which include, but are not limited to:
coumarins such as warfarin; heparin; and direct thrombin inhibitors such as argatroban,
bivalirudin, dabigatran, and lepirudin.
In yet another embodiment, compounds of the invention are administered in
combination with an anti-diabetic agent. Representative anti-diabetic agents include
injectable drugs as well as orally effective drugs, and combinations thereof. Examples of
injectable drugs include, but are not limited to, insulin and insulin derivatives. Examples
of orally effective drugs include, but are not limited to: biguanides such as metformin;
glucagon antagonists; α-glucosidase inhibitors such as acarbose and miglitol; dipeptidyl
peptidase IV inhibitors (DPP-IV inhibitors) such as alogliptin, denagliptin, linagliptin,
saxagliptin, sitagliptin, and vildagliptin; meglitinides such as repaglinide;
oxadiazolidinediones; sulfonylureas such as chlorpropamide, glimepiride, glipizide,
glyburide, and tolazamide; thiazolidinediones such as pioglitazone and rosiglitazone; and
combinations thereof.
In another embodiment, compounds of the invention are administered in
combination with antidiarrheal treatments. Representative treatment options include, but
are not limited to, oral rehydration solutions (ORS), loperamide, diphenoxylate, and
bismuth subsalicylate.
In yet another embodiment, a compound of the invention is administered in
combination with an anti-glaucoma agent. Representative anti-glaucoma agents include,
but are not limited to: α-adrenergic agonists such as brimonidine; β -adrenergic receptor
antagonists; topical β -blockers such as betaxolol, levobunolol, and timolol; carbonic
anhydrase inhibitors such as acetazolamide, brinzolamide, or dorzolamide; cholinergic
agonists such as cevimeline and DMXB-anabaseine; epinephrine compounds; miotics such
as pilocarpine; and prostaglandin analogs.
In yet another embodiment, compounds of the invention are administered in
combination with an anti-lipid agent. Representative anti-lipid agents include, but are not
limited to: cholesteryl ester transfer protein inhibitors (CETPs) such as anacetrapib,
dalcetrapib, and torcetrapib; statins such as atorvastatin, fluvastatin, lovastatin, pravastatin,
rosuvastatin and simvastatin; and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with an anti-thrombotic agent. Representative anti-thrombotic agents include, but are not
limited to: aspirin; anti-platelet agents such as clopidogrel, prasugrel, and ticlopidine;
heparin, and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with an AT receptor antagonist, also known as angiotensin II type 1 receptor blockers
(ARBs). Representative ARBs include, but are not limited to, abitesartan, azilsartan (e.g.,
azilsartan medoxomil), benzyllosartan, candesartan, candesartan cilexetil, elisartan,
embusartan, enoltasosartan, eprosartan, EXP3174, fonsartan, forasartan, glycyllosartan,
irbesartan, isoteoline, losartan, medoximil, milfasartan, olmesartan (e.g., olmesartan
medoxomil), opomisartan, pratosartan, ripisartan, saprisartan, saralasin, sarmesin, TAK-
591, tasosartan, telmisartan, valsartan, zolasartan, and combinations thereof. In a particular
embodiment, the ARB is selected from azilsartan medoxomil, candesartan cilexetil,
eprosartan, irbesartan, losartan, olmesartan medoxomil, saprisartan, tasosartan, telmisartan,
valsartan, and combinations thereof. Exemplary salts and/or prodrugs include candesartan
cilexetil, eprosartan mesylate, losartan potassium salt, and olmesartan medoxomil.
Typically, the ARB will be administered in an amount sufficient to provide from about 4-
600 mg per dose, with exemplary daily dosages ranging from 20-320 mg per day.
Compounds of the invention may also be administered in combination with a dual-
acting agent, such as an AT receptor antagonist/neprilysin inhibitor (ARB/NEP) inhibitor,
examples of which include, but are not limited to, compounds described in U.S.
Publication Nos. 2008/0269305 and 2009/0023228, both to Allegretti et al. filed on April
23, 2008, such as the compound, 4'-{2-ethoxyethyl[((S)mercapto
methylpentanoylamino)-methyl]imidazolylmethyl}-3'-fluorobiphenylcarboxylic acid.
Compounds of the invention may also be administered in combination with
multifunctional angiotensin receptor blockers as described in Kurtz & Klein (2009)
Hypertension Research 32:826-834.
In one embodiment, compounds of the invention are administered in combination
with a bradykinin receptor antagonist, for example, icatibant (HOE-140). It is expected
that this combination therapy may present the advantage of preventing angioedema or other
unwanted consequences of elevated bradykinin levels.
In one embodiment, compounds of the invention are administered in combination
with a calcium channel blocker. Representative calcium channel blockers include, but are
not limited to, amlodipine, anipamil, aranipine, barnidipine, bencyclane, benidipine,
bepridil, clentiazem, cilnidipine, cinnarizine, diltiazem, efonidipine, elgodipine, etafenone,
felodipine, fendiline, flunarizine, gallopamil, isradipine, lacidipine, lercanidipine,
lidoflazine, lomerizine, manidipine, mibefradil, nicardipine, nifedipine, niguldipine,
niludipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, nivaldipine, perhexiline,
prenylamine, ryosidine, semotiadil, terodiline, tiapamil, verapamil, and combinations
thereof. In a particular embodiment, the calcium channel blocker is selected from
amlodipine, bepridil, diltiazem, felodipine, isradipine, lacidipine, nicardipine, nifedipine,
niguldipine, niludipine, nimodipine, nisoldipine, ryosidine, verapamil, and combinations
thereof. Typically, the calcium channel blocker will be administered in an amount
sufficient to provide from about 2-500 mg per dose.
In one embodiment, compounds of the invention are administered in combination
with a chymase inhibitor, such as TPC-806 and 2-(5-formylaminooxophenyl-1,6-
dihydropyrimidineyl)-N-[{3,4-dioxophenyl(2-pyridyloxy)}heptyl]acetamide
(NK3201).
In one embodiment, compounds of the invention are administered in combination
with a diuretic. Representative diuretics include, but are not limited to: carbonic anhydrase
inhibitors such as acetazolamide and dichlorphenamide; loop diuretics, which include
sulfonamide derivatives such as acetazolamide, ambuside, azosemide, bumetanide,
butazolamide, chloraminophenamide, clofenamide, clopamide, clorexolone, disulfamide,
ethoxzolamide, furosemide, mefruside, methazolamide, piretanide, torsemide, tripamide,
and xipamide, as well as non-sulfonamide diuretics such as ethacrynic acid and other
phenoxyacetic acid compounds such as tienilic acid, indacrinone and quincarbate; osmotic
diuretics such as mannitol; potassium-sparing diuretics, which include aldosterone
antagonists such as spironolactone, and Na channel inhibitors such as amiloride and
triamterene; thiazide and thiazide-like diuretics such as althiazide, bendroflumethiazide,
benzylhydrochlorothiazide, benzthiazide, buthiazide, chlorthalidone, chlorothiazide,
cyclopenthiazide, cyclothiazide, epithiazide, ethiazide, fenquizone, flumethiazide,
hydrochlorothiazide, hydroflumethiazide, indapamide, methylclothiazide, meticrane,
metolazone, paraflutizide, polythiazide, quinethazone, teclothiazide, and
trichloromethiazide; and combinations thereof. In a particular embodiment, the diuretic is
selected from amiloride, bumetanide, chlorothiazide, chlorthalidone, dichlorphenamide,
ethacrynic acid, furosemide, hydrochlorothiazide, hydroflumethiazide, indapamide,
methylclothiazide, metolazone, torsemide, triamterene, and combinations thereof. The
diuretic will be administered in an amount sufficient to provide from about 5-50 mg per
day, more typically 6-25 mg per day, with common dosages being 6.25 mg, 12.5 mg or 25
mg per day.
Compounds of the invention may also be administered in combination with an
endothelin converting enzyme (ECE) inhibitor, examples of which include, but are not
limited to, phosphoramidon, CGS 26303, and combinations thereof.
In a particular embodiment, compounds of the invention are administered in
combination with an endothelin receptor antagonist. Representative endothelin receptor
antagonists include, but are not limited to: selective endothelin receptor antagonists that
affect endothelin A receptors, such as avosentan, ambrisentan, atrasentan, BQ-123,
clazosentan, darusentan, sitaxentan, and zibotentan; and dual endothelin receptor
antagonists that affect both endothelin A and B receptors, such as bosentan, macitentan,
tezosentan).
In yet another embodiment, a compound of the invention is administered in
combination with one or more HMG-CoA reductase inhibitors, which are also known as
statins. Representative statins include, but are not limited to, atorvastatin, fluvastatin,
lovastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin.
In one embodiment, compounds of the invention are administered in combination
with a monoamine reuptake inhibitor, examples of which include, by way of illustration
and not limitation, norepinephrine reuptake inhibitors such as atomoxetine, buproprion and
the buproprion metabolite hydroxybuproprion, maprotiline, reboxetine, and viloxazine;
selective serotonin reuptake inhibitors (SSRIs) such as citalopram and the citalopram
metabolite desmethylcitalopram, dapoxetine, escitalopram (e.g., escitalopram oxalate),
fluoxetine and the fluoxetine desmethyl metabolite norfluoxetine, fluvoxamine (e.g.,
fluvoxamine maleate), paroxetine, sertraline and the sertraline metabolite
demethylsertraline; dual serotonin-norepinephrine reuptake inhibitors (SNRIs) such as
bicifadine, duloxetine, milnacipran, nefazodone, and venlafaxine; and combinations
thereof.
In another embodiment, compounds of the invention are administered in
combination with a muscle relaxant, examples of which include, but are not limited to:
carisoprodol, chlorzoxazone, cyclobenzaprine, diflunisal, metaxalone, methocarbamol, and
combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with a natriuretic peptide or analog, examples of which include but are not limited to:
carperitide, CD-NP (Nile Therapeutics), CU-NP, nesiritide, PL-3994 (Palatin
Technologies, Inc.), ularitide, cenderitide, and compounds described in Ogawa et al (2004)
J. Biol. Chem. 279:28625-31. These compounds are also referred to as natriuretic peptide
receptor-A (NPR-A) agonists. In another embodiment, compounds of the invention are
administered in combination with a natriuretic peptide clearance receptor (NPR-C)
antagonist such as SC-46542, cANF (4-23), and AP-811 (Veale (2000) Bioorg Med Chem
Lett 10:1949-52). For example, AP-811 has shown synergy when combined with the NEP
inhibitor, thiorphan (Wegner (1995) Clin. Exper. Hypert. 17:861-876).
In another embodiment, compounds of the invention are administered in
combination with a neprilysin (NEP) inhibitor. Representative NEP inhibitors include, but
are not limited to: AHU-377; candoxatril; candoxatrilat; dexecadotril ((+)-N-[2(R)-
(acetylthiomethyl)phenylpropionyl]glycine benzyl ester); CGS-24128 (3-[3-(biphenyl-
4-yl)(phosphonomethylamino)propionamido]propionic acid); CGS-24592 ((S)[3-
(biphenylyl)(phosphonomethylamino)propionamido]propionic acid); CGS-25155 (N-
[9(R)-(acetylthiomethyl)oxoazacyclodecan-2(S)-ylcarbonyl]-4(R)-hydroxy-L-
proline benzyl ester); 3-(l-carbamoylcyclohexyl)propionic acid derivatives described in
to Hepworth et al. (Pfizer Inc.); JMV1 (2(R)-benzyl(N-
hydroxycarbamoyl)propionyl-L-isoleucyl-L-leucine); ecadotril; phosphoramidon;
retrothiorphan; RU-42827 (2-(mercaptomethyl)-N-(4-pyridinyl)benzenepropionamide);
RU-44004 (N-(4-morpholinyl)phenyl(sulfanylmethyl)propionamide); SCH-32615
((S)-N-[N-(1-carboxyphenylethyl)-L-phenylalanyl]-β-alanine) and its prodrug SCH-
34826 ((S)-N-[N-[1-[[(2,2-dimethyl-1,3-dioxolanyl)methoxy]carbonyl]phenylethyl]-
L-phenylalanyl]-β-alanine); sialorphin; SCH-42495 (N-[2(S)-(acetylsulfanylmethyl)(2-
methylphenyl)propionyl]-L-methionine ethyl ester); spinorphin; SQ-28132 (N-[2-
(mercaptomethyl)oxophenylpropyl]leucine); SQ-28603 (N-[2-(mercaptomethyl)
oxophenylpropyl]-β-alanine); SQ-29072 (7-[[2-(mercaptomethyl)oxo
phenylpropyl]amino]heptanoic acid); thiorphan and its prodrug racecadotril; UK-69578
(cis[[[1-[2-carboxy(2-methoxyethoxy)propyl]cyclopentyl]carbonyl]amino]
cyclohexanecarboxylic acid); UK-447,841 (2-{1-[3-(4-chlorophenyl)propylcarbamoyl]-
cyclopentylmethyl}methoxybutyric acid); UK-505,749 ((R)methyl{1-[3-(2-
methylbenzothiazolyl)propylcarbamoyl]cyclopentyl}propionic acid); 5-biphenylyl
(3-carboxypropionylamino)methylpentanoic acid and 5-biphenylyl(3-
carboxypropionylamino)methylpentanoic acid ethyl ester (); daglutril
[(3S,2'R){1-[2'-(ethoxycarbonyl)-4'-phenylbutyl]-cyclopentancarbonylamino}-
2,3,4,5-tetrahydrooxo-1Hbenzazepineacetic acid] described in
to Khder et al. (Novartis AG); and combinations thereof. In a particular
embodiment, the NEP inhibitor is selected from AHU-377, candoxatril, candoxatrilat,
CGS-24128, phosphoramidon, SCH-32615, SCH-34826, SQ-28603, thiorphan, and
combinations thereof. In a particular embodiment, the NEP inhibitor is a compound such
as daglutril or CGS-26303 ([N-[2-(biphenylyl)-1(S)-(1H-tetrazol
yl)ethyl]amino]methylphosphonic acid), which have activity both as inhibitors of the
endothelin converting enzyme (ECE) and of NEP. Other dual acting ECE/NEP
compounds can also be used. The NEP inhibitor will be administered in an amount
sufficient to provide from about 20-800 mg per day, with typical daily dosages ranging
from 50-700 mg per day, more commonly 100-600 or 100-300 mg per day.
In one embodiment, compounds of the invention are administered in combination
with a nitric oxide donor, examples of which include, but are not limited to nicorandil;
organic nitrates such as pentaerythritol tetranitrate; and sydnonimines such as linsidomine
and molsidomine.
In yet another embodiment, compounds of the invention are administered in
combination with a non-steroidal anti-inflammatory agent (NSAID). Representative
NSAIDs include, but are not limited to: acemetacin, acetyl salicylic acid, alclofenac,
alminoprofen, amfenac, amiprilose, aloxiprin, anirolac, apazone, azapropazone, benorilate,
benoxaprofen, bezpiperylon, broperamole, bucloxic acid, carprofen, clidanac, diclofenac,
diflunisal, diftalone, enolicam, etodolac, etoricoxib, fenbufen, fenclofenac, fenclozic acid,
fenoprofen, fentiazac, feprazone, flufenamic acid, flufenisal, fluprofen, flurbiprofen,
furofenac, ibufenac, ibuprofen, indomethacin, indoprofen, isoxepac, isoxicam, ketoprofen,
ketorolac, lofemizole, lornoxicam, meclofenamate, meclofenamic acid, mefenamic acid,
meloxicam, mesalamine, miroprofen, mofebutazone, nabumetone, naproxen, niflumic acid,
oxaprozin, oxpinac, oxyphenbutazone, phenylbutazone, piroxicam, pirprofen, pranoprofen,
salsalate, sudoxicam, sulfasalazine, sulindac, suprofen, tenoxicam, tiopinac, tiaprofenic
acid, tioxaprofen, tolfenamic acid, tolmetin, triflumidate, zidometacin, zomepirac, and
combinations thereof. In a particular embodiment, the NSAID is selected from etodolac,
flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, meloxicam, naproxen,
oxaprozin, piroxicam, and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with an N-methyl d-aspartate (NMDA) receptor antagonist, examples of which include, by
way of illustration and not limitation, amantadine, dextromethorphan, dextropropoxyphene,
ketamine, ketobemidone, memantine, methadone, and so forth.
In still another embodiment, compounds of the invention are administered in
combination with an opioid receptor agonist (also referred to as opioid analgesics).
Representative opioid receptor agonists include, but are not limited to: buprenorphine,
butorphanol, codeine, dihydrocodeine, fentanyl, hydrocodone, hydromorphone,
levallorphan, levorphanol, meperidine, methadone, morphine, nalbuphine, nalmefene,
nalorphine, naloxone, naltrexone, nalorphine, oxycodone, oxymorphone, pentazocine,
propoxyphene, tramadol, and combinations thereof. In certain embodiments, the opioid
receptor agonist is selected from codeine, dihydrocodeine, hydrocodone, hydromorphone,
morphine, oxycodone, oxymorphone, tramadol, and combinations thereof.
In a particular embodiment, compounds of the invention are administered in
combination with a phosphodiesterase (PDE) inhibitor, particularly a PDE-V inhibitor.
Representative PDE-V inhibitors include, but are not limited to, avanafil, lodenafil,
® ® ®
mirodenafil, sildenafil (Revatio ), tadalafil (Adcirca ), vardenafil (Levitra ), and udenafil.
In another embodiment, compounds of the invention are administered in
combination with a prostaglandin analog (also referred to as prostanoids or prostacyclin
analogs). Representative prostaglandin analogs include, but are not limited to, beraprost
sodium, bimatoprost, epoprostenol, iloprost, latanoprost, tafluprost, travoprost, and
treprostinil, with bimatoprost, latanoprost, and tafluprost being of particular interest.
In yet another embodiment, compounds of the invention are administered in
combination with a prostaglandin receptor agonist, examples of which include, but are not
limited to, bimatoprost, latanoprost, travoprost, and so forth.
Compounds of the invention may also be administered in combination with a renin
inhibitor, examples of which include, but are not limited to, aliskiren, enalkiren, remikiren,
and combinations thereof.
In another embodiment, compounds of the invention are administered in
combination with a selective serotonin reuptake inhibitor (SSRI). Representative SSRIs
include, but are not limited to: citalopram and the citalopram metabolite
desmethylcitalopram, dapoxetine, escitalopram (e.g., escitalopram oxalate), fluoxetine and
the fluoxetine desmethyl metabolite norfluoxetine, fluvoxamine (e.g., fluvoxamine
maleate), paroxetine, sertraline and the sertraline metabolite demethylsertraline, and
combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with a 5-HT serotonin receptor agonist, examples of which include, by way of
illustration and not limitation, triptans such as almotriptan, avitriptan, eletriptan,
frovatriptan, naratriptan rizatriptan, sumatriptan, and zolmitriptan.
In one embodiment, compounds of the invention are administered in combination
with a sodium channel blocker, examples of which include, by way of illustration and not
limitation, carbamazepine, fosphenytoin, lamotrigine, lidocaine, mexiletine, oxcarbazepine,
phenytoin, and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with a soluble guanylate cyclase stimulator or activator, examples of which include, but are
not limited to ataciguat, riociguat, and combinations thereof.
In one embodiment, compounds of the invention are administered in combination
with a tricyclic antidepressant (TCA), examples of which include, by way of illustration
and not limitation, amitriptyline, amitriptylinoxide, butriptyline, clomipramine,
demexiptiline, desipramine, dibenzepin, dimetacrine, dosulepin, doxepin, imipramine,
imipraminoxide, lofepramine, melitracen, metapramine, nitroxazepine, nortriptyline,
noxiptiline, pipofezine, propizepine, protriptyline, quinupramine, and combinations
thereof.
In one embodiment, compounds of the invention are administered in combination
with a vasopressin receptor antagonist, examples of which include, by way of illustration
and not limitation, conivaptan and tolvaptan.
Combined secondary therapeutic agents may also be helpful in further combination
therapy with compounds of the invention. For example, compounds of the invention can
be combined with a diuretic and an ARB, or a calcium channel blocker and an ARB, or a
diuretic and an ACE inhibitor, or a calcium channel blocker and a statin. Specific
examples include, a combination of the ACE inhibitor enalapril (in the maleate salt form)
and the diuretic hydrochlorothiazide, which is sold under the mark Vaseretic , or a
combination of the calcium channel blocker amlodipine (in the besylate salt form) and the
ARB olmesartan (in the medoxomil prodrug form), or a combination of a calcium channel
blocker and a statin, all may also be used with the compounds of the invention. Other
therapeutic agents such as α -adrenergic receptor agonists and vasopressin receptor
antagonists may also be helpful in combination therapy. Exemplary α -adrenergic receptor
agonists include clonidine, dexmedetomidine, and guanfacine.
The following formulations illustrate representative pharmaceutical compositions
of the invention.
Exemplary Hard Gelatin Capsules For Oral Administration
A compound of the invention (50 g), 440 g spray-dried lactose and 10 g magnesium
stearate are thoroughly blended. The resulting composition is then loaded into hard gelatin
capsules (500 mg of composition per capsule). Alternately, a compound of the invention
(20 mg) is thoroughly blended with starch (89 mg), microcrystalline cellulose (89 mg) and
magnesium stearate (2 mg). The mixture is then passed through a No. 45 mesh U.S. sieve
and loaded into a hard gelatin capsule (200 mg of composition per capsule).
Alternately, a compound of the invention (30 g), a secondary agent (20 g), 440 g
spray-dried lactose and 10 g magnesium stearate are thoroughly blended, and processed as
described above.
Exemplary Gelatin Capsule Formulation For Oral Administration
A compound of the invention (100 mg) is thoroughly blended with polyoxyethylene
sorbitan monooleate (50 mg) and starch powder (250 mg). The mixture is then loaded into
a gelatin capsule (400 mg of composition per capsule). Alternately, a compound of the
invention (70 mg) and a secondary agent (30 mg) are thoroughly blended with
polyoxyethylene sorbitan monooleate (50 mg) and starch powder (250 mg), and the
resulting mixture loaded into a gelatin capsule (400 mg of composition per capsule).
Alternately, a compound of the invention (40 mg) is thoroughly blended with
microcrystalline cellulose (Avicel PH 103; 259.2 mg) and magnesium stearate (0.8 mg).
The mixture is then loaded into a gelatin capsule (Size #1, White, Opaque) (300 mg of
composition per capsule).
Exemplary Tablet Formulation For Oral Administration
A compound of the invention (10 mg), starch (45 mg) and microcrystalline
cellulose (35 mg) are passed through a No. 20 mesh U.S. sieve and mixed thoroughly. The
granules so produced are dried at 50-60 °C and passed through a No. 16 mesh U.S. sieve.
A solution of polyvinylpyrrolidone (4 mg as a 10 % solution in sterile water) is mixed with
sodium carboxymethyl starch (4.5 mg), magnesium stearate (0.5 mg), and talc (1 mg), and
this mixture is then passed through a No. 16 mesh U.S. sieve. The sodium carboxymethyl
starch, magnesium stearate and talc are then added to the granules. After mixing, the
mixture is compressed on a tablet machine to afford a tablet weighing 100 mg.
Alternately, a compound of the invention (250 mg) is thoroughly blended with
microcrystalline cellulose (400 mg), silicon dioxide fumed (10 mg), and stearic acid (5
mg). The mixture is then compressed to form tablets (665 mg of composition per tablet).
Alternately, a compound of the invention (400 mg) is thoroughly blended with
cornstarch (50 mg), croscarmellose sodium (25 mg), lactose (120 mg), and magnesium
stearate (5 mg). The mixture is then compressed to form a single-scored tablet (600 mg of
composition per tablet).
Alternately, a compound of the invention (100 mg) is thoroughly blended with
cornstarch (100 mg) with an aqueous solution of gelatin (20 mg). The mixture is dried and
ground to a fine powder. Microcrystalline cellulose (50 mg) and magnesium stearate
(5 mg) are then admixed with the gelatin formulation, granulated and the resulting mixture
compressed to form tablets (100 mg of the compound of the invention per tablet).
Exemplary Suspension Formulation For Oral Administration
The following ingredients are mixed to form a suspension containing 100 mg of the
compound of the invention per 10 mL of suspension:
Ingredients Amount
Compound of the invention 1.0 g
Fumaric acid 0.5 g
Sodium chloride 2.0 g
Methyl paraben 0.15 g
Propyl paraben 0.05 g
Granulated sugar 25.5 g
Sorbitol (70% solution) 12.85 g
Veegum K (magnesium aluminum silicate) 1.0 g
Flavoring 0.035 mL
Colorings 0.5 mg
Distilled water q.s. to 100 mL
Exemplary Liquid Formulation For Oral Administration
A suitable liquid formulation is one with a carboxylic acid-based buffer such as
citrate, lactate and maleate buffer solutions. For example, a compound of the invention
(which may be pre-mixed with DMSO) is blended with a 100 mM ammonium citrate
buffer and the pH adjusted to pH 5, or is blended with a 100 mM citric acid solution and
the pH adjusted to pH 2. Such solutions may also include a solubilizing excipient such as a
cyclodextrin, for example the solution may include 10 wt% hydroxypropyl-β-cyclodextrin.
Other suitable formulations include a 5% NaHCO solution, with or without
cyclodextrin.
Exemplary Injectable Formulation For Administration By Injection
A compound of the invention (0.2 g) is blended with 0.4 M sodium acetate buffer
solution (2.0 mL). The pH of the resulting solution is adjusted to pH 4 using 0.5 N
aqueous hydrochloric acid or 0.5 N aqueous sodium hydroxide, as necessary, and then
sufficient water for injection is added to provide a total volume of 20 mL. The mixture is
then filtered through a sterile filter (0.22 micron) to provide a sterile solution suitable for
administration by injection.
Exemplary Compositions For Administration By Inhalation
A compound of the invention (0.2 mg) is micronized and then blended with lactose
(25 mg). This blended mixture is then loaded into a gelatin inhalation cartridge. The
contents of the cartridge are administered using a dry powder inhaler, for example.
Alternately, a micronized compound of the invention (10 g) is dispersed in a
solution prepared by dissolving lecithin (0.2 g) in demineralized water (200 mL). The
resulting suspension is spray dried and then micronized to form a micronized composition
comprising particles having a mean diameter less than about 1.5 μm. The micronized
composition is then loaded into metered-dose inhaler cartridges containing pressurized
1,1,1,2-tetrafluoroethane in an amount sufficient to provide about 10 μg to about 500 μg of
the compound of the invention per dose when administered by the inhaler.
Alternately, a compound of the invention (25 mg) is dissolved in citrate buffered
(pH 5) isotonic saline (125 mL). The mixture is stirred and sonicated until the compound
is dissolved. The pH of the solution is checked and adjusted, if necessary, to pH 5 by
slowly adding aqueous 1 N NaOH. The solution is administered using a nebulizer device
that provides about 10 μg to about 500 μg of the compound of the invention per dose.
EXAMPLES
The following Preparations and Examples are provided to illustrate specific
embodiments of the invention. These specific embodiments, however, are not intended to
limit the scope of the invention in any way unless specifically indicated.
The following abbreviations have the following meanings unless otherwise
indicated and any other abbreviations used herein and not defined have their standard,
generally accepted meaning:
AcOH acetic acid
BOC t-butoxycarbonyl (-C(O)OC(CH ) )
(BOC) O di-t-butyl dicarbonate
Bn benzyl
DCC dicyclohexylcarbodiimide
DCM dichloromethane or methylene chloride
DIBAL diisobutylaluminum hydride
DIPEA N,N-diisopropylethylamine
DMAP 4-dimethylaminopyridine
DMF N,N-dimethylformamide
DMSO dimethyl sulfoxide
Dnp 2,4-dinitrophenyl
EDC 1-(3-dimethylaminopropyl)ethylcarbodiimide
Et N triethylamine
Et O diethyl ether
EtOAc ethyl acetate
EtOH ethanol
HEPES 4-(2-hydroxyethyl)piperazineethanesulfonic acid
HOBt 1-hydroxybenzotriazole
LiHMDS lithium hexamethyl disilazide
Mca (7-methoxycoumarinyl)acyl
MeCN acetonitrile
MeOH methanol
MTBE methyl t-butyl ether
NaHMDS sodium hexamethyldisilazide
Pd(dppf) Cl 1,1-bis(diphenylphosphino) ferrocene palladium
chloride
Pd(PPh ) tetrakis(triphenylphosphine)palladium(0)
PE petroleum ether
SilicaCat DPP-Pd silica based diphenylphosphine palladium (II) catalyst
SilicaCat Pd(0) silica based palladium (0) catalyst
TFA trifluoroacetic acid
THF tetrahydrofuran
Unless noted otherwise, all materials, such as reagents, starting materials and
solvents, were purchased from commercial suppliers (such as Sigma-Aldrich, Fluka
Riedel-de Haën, and the like) and were used without further purification.
Reactions were run under nitrogen atmosphere, unless noted otherwise. The
progress of reactions were monitored by thin layer chromatography (TLC), analytical high
performance liquid chromatography (anal. HPLC), and mass spectrometry, the details of
which are given in specific examples. Solvents used in analytical HPLC were as follows:
solvent A was 98% H O/2% MeCN /1.0 mL/L TFA; solvent B was 90% MeCN/10%
H O/1.0 mL/L TFA.
Reactions were worked up as described specifically in each preparation for
example; commonly reaction mixtures were purified by extraction and other purification
methods such as temperature-, and solvent-dependent crystallization, and precipitation. In
addition, reaction mixtures were routinely purified by preparative HPLC, typically using
Microsorb C18 and Microsorb BDS column packings and conventional eluents. Progress
of reactions was typically measured by liquid chromatography mass spectrometry (LCMS).
Characterization of isomers were done by Nuclear Overhauser effect spectroscopy (NOE).
Characterization of reaction products was routinely carried out by mass and H-NMR
spectrometry. For NMR measurement, samples were dissolved in deuterated solvent
(CD OD, CDCl , or DMSO-d ), and H-NMR spectra were acquired with a Varian Gemini
3 3 6
2000 instrument (400 MHz) under standard observation conditions. Mass spectrometric
identification of compounds was typically conducted using an electrospray ionization
method (ESMS) with an Applied Biosystems (Foster City, CA) model API 150 EX
instrument or an Agilent (Palo Alto, CA) model 1200 LC/MSD instrument.
Preparation 1
Acetoxy(diethoxyphosphoryl)acetic Acid Ethyl Ester
Ethyl 2-oxoacetate(50%) (74 g, 724.8 mmol) was added dropwise with stirring at
0°C to a solution of diethyl hydrogen phosphite (50 g, 362.1 mmol) in toluene (100 mL),
under nitrogen. Et N (110 g, 1.1 mol) was added dropwise with stirring at 0°C. The
resulting solution was stirred for 1 hour at room temperature. To the mixture was added
acetic anhydride (37 g, 362.4 mmol) dropwise with stirring at 0°C. The resulting solution
was stirred overnight at room temperature. The pH value of the solution was adjusted to 6
with 2N HCl. The resulting solution was extracted with DCM (3x150 mL) and the organic
layers were combined, dried over Na SO , and concentrated under vacuum. The residue
was loaded onto a silica gel column with EtOAc:hexanes (1:2~1:5) to yield the title
compound (52 g) as a light yellow liquid.
Preparation 2
(R)Aminobiphenylylhydroxypentanoic Acid Ethyl Ester
A solution of acetoxy(diethoxyphosphoryl)acetic acid ethyl ester (15.6 g, 55.3
mmol, 1.2 equiv) in THF (dried) (150 mL), under nitrogen, was cooled to -78°C. LiHMDS
(1M in THF) (55.3 mL) was added dropwise with stirring at -78°C. After stirring for 30
minutes at that temperature, a solution of crude ((R)biphenylyl
formylethyl)carbamic acid t-butyl ester (15.0 g, 1.0 eq.) in THF (dried) (30 mL) was added
dropwise over 15 minutes. Stirring was continued for 1.5 hours at -78°C before the
mixture was poured into a cold solution with water (200 mL) and EtOAc (200 mL). The
organic layer was repeatedly separated and the aqueous layer was re-extracted with EtOAc
(2x100 mL). The combined organic layers were dried over Na SO , filtered, and
evaporated, and the residue was purified by flash chromatography
(EtOAc/hexanes=0~1:10) to give Compound 1 (10.5 g) as a white solid.
O BOC
A stirred solution of Compound 1 (10.5 g, 23.2 mmol) in EtOH (anhydrous) (100
mL) was combined with palladium carbon (1.0 g), under nitrogen. The mixture was
purged four times with hydrogen and then hydrogen was bubbled over 2 hours at room
temperature. The palladium carbon was filtered out, and the filtrate was concentrated
under vacuum to yield crude Compound 2 (10.0 g) as a pale-yellow oil, which was used
without further purification.
Compound 2 (10.0 g, 22.0 mmol) in EtOH (anhydrous) (100 mL) was combined
with potassium carbonate (6.1 g, 44.1 mmol) and the resulting solution was stirred for 2
hours at room temperature. The solids were filtered out and the filtrate was concentrated
under vacuum. The residue was loaded onto a silica gel column (EtOAc/hexanes=0~1:5)
to yield Compound 3 (6.0 g) as a white solid.
ClH N
Compound 3 (6.0 g, 14.5 mmol) was dissolved in DCM (dried) (120 mL), and HCl
was bubbled into the mixture over 5~6 hours at room temperature. Solid precipitate was
observed. The mixture was concentrated to half volume then filtered. The solids were
collected and washed with cold EtOAc, and dried over reduced pressure to yield the title
compound (4.2 g) as an off-white solid HCl salt. LC-MS (ES, m/z): 314 [M-HCl+H] .
H NMR (300 MHz, DMSO): δ (ppm) =8.07 (s, 1.9H), 7.96 (s, 1.2H), 7.65-7.69
(m, 4.0H), 7.45-7.5 0(m, 2.0H), 7.33-7.39 (m, 3.0H), 6.05-6.07 (m, 0.63H), 5.88-5.90 (m,
0.88H), 4.32-4.38 (m, 0.80H), 4.18-4.31 (m, 0.51H), 4.05-4.11 (m, 2H), 3.50 (s, 1H), 2.75-
3.05 (m, 2.8H), 1.83-1.94 (m, 1H), 1.71-1.82 (m, 1H), 1.10-1.20 (m, 3.3H).
Preparation 3
(S)(4-Bromobenzyl)oxopyrrolidinecarboxylic Acid t-Butyl Ester
NH (R)
N BOC (R)
N BOC
Br Br
To a solution of (R)amino(4-bromophenyl)propionic acid (50 g, 0.2 mol) in
MeCN (700 mL) was added a solution of NaOH (16.4 g, 0.4 mol) in water (700 mL) at
-5 C. After stirring for 10 minutes, a solution of (BOC) O (44.7 g, 0.2 mol) in MeCN (100
mL) was added. The mixture was warmed to room temperature and stirred overnight.
After the evaporation of the MeCN, the residue was diluted with DCM (800 mL) and
acidified with 1 M HCl to pH 2 at -5 C. The aqueous was extracted with DCM (3x200
mL). The combined organic layers were washed with saturated aqueous NaCl (500 mL),
dried over Na SO and concentrated to yield Compound 1 (66.5 g) as a white solid. LC-
MS: 366 (M+Na), 709 (2M+Na).
To a solution of Compound 1 (66.5 g, 193 µmol), Meldrum’s acid (33.4 g, 232
mmol) and DMAP (37.7 g, 309 mmol) in anhydrous DCM (600 mL), was added dropwise
a solution of DCC (47.9 g, 232 mmol) in anhydrous DCM (200 mL) over 1 hour at -5 C
under nitrogen. The mixture was stirred at -5 C for 8 hours, then refrigerated overnight.
Crystals of dicyclohexylurea were observed. The mixture was filtered, washed with 5%
KHSO (5x200 mL) and saturated aqueous NaCl (200 mL), then dried over anhydrous
MgSO under refrigeration overnight. The solution was then evaporated to yield crude
Compound 2 (91 g) as a light yellow solid. LC-MS: 492(M+Na), 961(2M+Na).
N BOC
To a solution of crude Compound 2 (91 g, 193 mmol) in anhydrous DCM (1 L) was
added AcOH (127.5 g, 2.1 mol) at -5 C under nitrogen. The mixture was stirred at -5 C for
minutes, then NaBH (18.3 g, 483 mmol) was added in small portions over 1 hour.
After stirring for another 1 hour at -5 C, saturated aqueous NaCl (500 mL) was added. The
organic layer was washed with saturated aqueous NaCl (2x300 mL) and water (2x300 mL),
dried over MgSO , filtered, and concentrated to yield the crude product, which was further
purified by washing with Et O to yield Compound 3 (68 g) as a light yellow solid. LC-
MS: 478 (M+Na), 933 (2M+Na).
A solution of Compound 3 (68 g, 149 mmol) in anhydrous toluene (500 mL) was
refluxed under nitrogen for 3 hours. After evaporation of the solvent, the residue was
purified by chromatography (hexanes:EtOAc=10:1) to yield the title compound (38 g) as a
light yellow oil. LC-MS: 376 (M+Na), 729 (2M+Na).
Preparation 4
(2R,4R)Amino(4-bromophenyl)hydroxypentanoic Acid Ethyl Ester
(1) Br
To a solution of (S)(4-bromobenzyl)oxopyrrolidinecarboxylic acid t-butyl
ester (38 g, 107 mmol) in anhydrous DCM (250 mL) was added TFA (20 mL, 0.27 mol) at
-5 C under nitrogen. The mixture was warmed to room temperature and stirred overnight.
After evaporation of the solvent, the residue was diluted with EtOAc (300 mL) and washed
with saturated aqueous NaHCO (3x200 mL), water (200 mL), saturated aqueous NaCl
(250 mL), dried over Na SO and concentrated to yield crude Compound 1 (24 g) as a light
yellow solid. LC-MS: 254 [M+H].
To a solution of NaH (8.6 g, 250 mmol) in anhydrous THF (200 mL) was added
dropwise a solution of Compound 1 (24 g, 94 mmol) in anhydrous THF (200 mL) over 30
minutes at 0 C under nitrogen. The mixture was warmed to room temperature and stirred
for 2 hours. After cooling to 0 C, pivaloyl chloride (18 g, 150 mmol) was added dropwise
over 30 minutes. The mixture was warmed to room temperature and stirred overnight.
The reaction was quenched with saturated aqueous NH Cl (300 mL) and extracted with
EtOAc (3x200 mL). The combined organic layers were washed with saturated aqueous
NaCl (300 mL), dried over MgSO , filtered and concentrated to yield the crude product,
which was further purified by chromatography (hexanes:EtOAc=25:1) to yield Compound
2 (18 g) as a light yellow solid. LC-MS: 360 (M+Na).
(R) (R) (R)
NH NH
N HO O
(3) Br
Br Br
To a solution of Compound 2 (18 g, 53 mmol) in anhydrous THF (250 mL) was
added dropwise NaHMDS (47.7 mL, 96 mmol) over 30 minutes at -78 C under nitrogen.
After stirring at -78 C for 90 minutes, a solution of (+)-(8,8-dichlorocamphorylsulfonyl)-
oxaziridine (31.6 g, 106 mmol) was added dropwise over 30 minutes. After stirring at
-78 C for 2 hours, the reaction was quenched with saturated aqueous NH Cl (400 mL) and
extracted with EtOAc (3x300 mL). The combined organic layers were washed with
saturated aqueous NaCl (300 mL), dried over MgSO , filtered, and concentrated to give the
crude product which was further purified by chromatography (hexanes:EtOAc=15:1) to
yield Compound 3 (8.9 g) as a light yellow solid. LC-MS: 376 (M+Na).
A solution of Compound 3 (8.9 g, 25 mmol) in concentrated HCl (81 mL, 81
mmol) was heated at 100 C for 16 hours. The mixture was then concentrated to yield the
crude product which was further purified by washing with Et O to yield compound 4 (7 g)
as a light yellow solid HCl salt. LC-MS: 323 (M+ H).
A solution of compound 4 (7 g, 22 mmol) in EtOH (10 mL) was combined with 8M
HCl in EtOH (120 mL, 960 mmol) at room temperature. The mixture was heated at 50 C
for 16 hours, then concentrated. The crude product was further purified by washing with
Et O to yield the title compound (6 g) as a light yellow solid HCl salt. LC-MS: 352 (M+
Preparation 5
(3R,5R)(3'-Chlorobiphenylylmethyl)(2,2-dimethylpropionyl)-
3-hydroxypyrrolidinone
N (S)
To a solution of (S)(4-bromobenzyl)oxopyrrolidinecarboxylic acid t-butyl
ester (15 g, 43 mmol) in 1,4-dioxane (600 mL) was added 3-chlorophenylboronic acid (8 g,
51 mmol) and Pd(dppf) Cl (3.1 g, 4.2 mmol) at room temperature under nitrogen. After
stirring for 10 minutes, a solution of K CO (11.7 g, 85 mmol) in water (60 mL) was
added. The mixture was heated to 60 C and stirred overnight. After evaporation of the
solvent, water (200 mL) was added and extracted with EtOAc (3x200 mL). The combined
organic layers were washed with saturated aqueous NaCl (400 mL), dried over Na SO ,
and concentrated to yield the crude product which was further purified by column
chromatography (hexanes:EtOAc=6:1) to yield Compound 1 (15 g) as a light yellow solid.
LC-MS: 408 (M+Na).
To a solution of Compound 1 (15 g, 0.039 mol) in anhydrous DCM (250 mL) was
added TFA (20 mL, 270 mmol) at -5 C under nitrogen. The mixture was warmed to room
temperature and stirred overnight. After evaporation of the solvent, the residue was diluted
with EtOAc (300 mL), then washed with saturated aqueous NaHCO (3x200 mL), water
(200 mL), and saturated aqueous NaCl (250 mL), then dried over Na SO and concentrated
to yield crude Compound 2 (11 g) as a light yellow solid. LC-MS: 286 [M+H].
N (R)
(2) (4)
To a solution of NaH (2.3 g, 98 mmol) in anhydrous THF (200 mL) was added
dropwise a solution of Compound 2 (11 g, 39 mmol) in anhydrous THF (100 mL) over 30
minutes at 0 C under nitrogen. The mixture was warmed to room temperature and stirred
for 2 hours. After cooling to 0 C, pivaloyl chloride (6 g, 51 mmol) was added dropwise
over 30 minutes. The mixture was warmed to room temperature and stirred overnight.
The reaction was quenched with saturated aqueous NH Cl (200 mL) and extracted with
EtOAc (3x200 mL). The combined organic layers were washed with saturated aqueous
NaCl (300 mL), dried over MgSO , filtered, and concentrated to yield the crude product
which was further purified by chromatography (hexanes:EtOAc=25:1) to yield Compound
3 (10.5 g) as a light yellow solid. LC-MS: 391 (M+Na).
To a solution of Compound 3 (10.5 g, 29 mmol) in anhydrous THF (120 mL) was
added dropwise NaHMDS (29 mL, 58 mmol) over 30 minutes at -78 C under nitrogen.
After stirring at -78 C for 90 minutes, a solution of (+)-(8,8-dichlorocamphorylsulfonyl)-
oxaziridine (15.6 g, 52 mmol) was added dropwise over 30 minutes. After stirring at -78 C
for 2 hours, the reaction was quenched with saturated NH Cl (400 mL) and extracted with
EtOAc (3x300 mL). The combined organic layers were washed with saturated aqueous
NaCl (300 mL), dried over MgSO , filtered, and concentrated to give the crude product
which was further purified by chromatography (hexanes:EtOAc=15:1) to yield the title
compound (9.6 g) as a light yellow solid. LC-MS: 408 (M+Na).
Preparation 6
(2R,4R)Amino(3'-chlorobiphenylyl)hydroxypentanoic Acid Ethyl Ester
(1) Cl
A solution of (3R,5R)(3'-chlorobiphenylylmethyl)(2,2-dimethylpropionyl)-
3-hydroxypyrrolidinone (9.6 g, 25 mmol) in concentrated HCl (81 mL, 81 mmol) was
heated at 100 C for 16 hours. The mixture was then concentrated to give the crude product
which was further purified by washing with Et O to yield Compound 1 (5.7 g) as a light
yellow solid HCl salt. LC-MS: 320 (M+ H).
To a solution of Compound 1 (5.7 g, 18 mmol) in EtOH (10 mL) was added 8M
HCl in EtOH (120 mL, 960 mmol) at room temperature. The mixture was heated at 50 C
for 16 hours. After concentration, the crude product was further purified by washing with
Et O to yield the title compound (2.1 g) as a light yellow solid HCl salt. LC-MS: 348 (M+
Preparation 7
(2R,4R)Amino(3'-chlorobiphenylyl)hydroxypentanoic Acid
1 M aqueous HCl (2.0 mmol) was added to (2R,4R)amino(3'-chlorobiphenyl-
4-yl)hydroxypentanoic acid ethyl ester (150.0 mg, 431 µmol) and the mixture was
stirred at 100°C for 2 hours. The mixture was concentrated under vacuum for 3 hours and
the residue was purified by reverse phase to yield the title compound (117 mg) as a white
solid.
Preparation 8
Chloro-oxo-acetic Acid Isopropyl Ester
Isopropanol (158 µL, 2.1 mmol, 1.0 eq.) was added dropwise over 5 minutes to
oxalyl chloride (350 µL, 4.14 µmol, 2.0 eq.) at 0°C, and the resulting mixture was stirred at
room temperature for 2 hours. The excess oxalyl chloride was removed by rotary
evaporation (40°C, 50 mmHg) and used without further purification.
Preparation 9
Chloro-oxo-acetic Acid Isobutyl Ester
Isobutanol (191 µL, 2.1 mmol, 1.0 eq.) was added dropwise over 5 minutes to
oxalyl chloride (350 µL, 4.14 µmol, 2.0 eq.) at 0°C, and the resulting mixture was stirred at
room temperature for 2 hours. The excess oxalyl chloride was removed by rotary
evaporation (40°C, 40 mmHg) and used without further purification.
Preparation 10
t-Butyl Oxalyl Chloride
Oxalyl chloride (274 µL, 3.2 mmol) was added to a solution of t-butyl alcohol (289
µL, 3.0 mmol) in ether (2.0 mL, 19.0 mmol) and the mixture was stirred at room
temperature for 1 hour and then concentrated in vacuo to yield a clear colorless liquid. An
approximately 1M solution of t-butyl oxalyl chloride was prepared by dissolving the
resulting clear colorless liquid in DCM (~3.0 mL).
Preparation 11
Chloro-oxo-acetic Acid 2-Methoxyethyl Ester
A solution of 2-methoxyethanol (295 mg, 3.9 mmol) in DCM (total volume: 0.5
mL) was added to a solution of oxalyl chloride (0.5 mL, 5.8 mmol) in DCM (total volume
1.0 mL) at 0°C and the resulting mixture was stirred at room temperature for 30 minutes.
The mixture was concentrated in vacuo and the resulting residue was dissolved in DCM
(3.9 mL) to yield a 1.0M solution in DCM.
Preparation 12
Chloro-oxo-acetic Acid 3-Ethoxypropyl Ester
A solution of 3-ethoxypropanol (404 mg, 3.9 mmol) in DCM (total volume: 0.5
mL) was added to a solution of oxalyl chloride (0.5 mL, 5.8 mmol) in DCM (total volume
1.0 mL) at 0°C and the resulting mixture was stirred at room temperature for 30 minutes.
The mixture was concentrated in vacuo and the resulting residue was dissolved in DCM
(3.9 mL) to yield a 1.0M solution in DCM.
Preparation 13
Chloro-oxo-acetic Acid 2-Phenoxyethyl Ester
A solution of 2-phenoxyethanol (536 mg, 3.9 mmol) in DCM (total volume: 0.5
mL) was added to a solution of oxalyl chloride (0.5 mL, 5.8 mmol) in DCM (total volume
1.0 mL) at 0°C and the resulting mixture was stirred at room temperature for 30 minutes.
The mixture was concentrated in vacuo and the resulting residue was dissolved in DCM
(3.9 mL) to yield a 1.0M solution in DCM.
Preparation 14
(2R,4R)t-Butoxycarbonylamino(3'-chlorobiphenylyl)hydroxypentanoic Acid
N NH
HO BOC
Cl Cl
A solution of (3R,5R)(3'-chlorobiphenylylmethyl)(2,2-dimethylpropionyl)-
3-hydroxypyrrolidinone (4.5 g, 11.7 mmol) in concentrated HCl (30 mL) was stirred at
100ºC for 16 hours. The mixture was concentrated in vacuo to yield Compound 1 (4 g) as
a white solid HCl salt. LC-MS: 321 [M+H] .
To a solution of NaOH (1.8 g, 45.2 mmol) in water (100 mL), was added
Compound 1 (4 g, 11.3 mmol) in MeCN (100 mL) dropwise. The mixture was stirred for
minutes at 0ºC. Di-t-butyldicarbonate (7.17 g, 33.8 mmol) was added and the mixture
was stirred for 15 hours at room temperature. The resulting mixture was concentrated in
vacuo to remove MeCN, then diluted with DCM (300 mL), and the pH adjusted to pH=5-6
with 1N aqueous HCl. Then the organic layer was collected and the residue was extracted
with DCM (3x300 mL). The combined organic layers were concentrated and washed with
hexanes (150 mL) to yield the title compound (4 g) as a white solid. LC-MS: 442
[M+Na] .
Preparation 15
(2R,4R)Amino(3'-chlorobiphenylyl)hydroxypentanoic Acid 2,2,3,3,3-
pentafluoropropyl Ester
F O BOC
To a solution of (2R,4R)t-Butoxycarbonylamino(3'-chlorobiphenylyl)
hydroxypentanoic acid (0.9 g, 6 mmol) and 2,2,3,3,3-pentafluoropropanol (450 mg, 3
mmol) in DCM (30 mL) was added DCC (880 mg, 4.3 mmol) and DMAP (260 mg, 2.1
mmol). The resulting mixture was stirred for 15 hours at room temperature, then
concentrated in vacuo. The residue was dissolved in EtOAc (100 mL) and washed with
water (30 mL) and saturated aqueous NaCl (30 mL). The organic layer was collected and
concentrated and purified by column chromatography (hexanes/EtOAc=5:1) to yield
Compound 3 (0.4 g) as a white solid. LC-MS: 574 [M+Na] .
A solution of Compound 3 (0.4 g, 690 μmol ) in 1.4 M HCl in a 1,4-dixoane
solution (15 mL) was stirred overnight, and then concentrated in vacuo. The residue was
dispersed in EtOAc (10 mL), and the precipitate was collected by filtration to yield the title
compound as an off-white solid HCl salt (165 mg). LC-MS: 452 [M+H] . H NMR:
(DMSO-d ) 1.95-1.82 (m, 2H), 2.99-2.98 (m, 2H), 3.56 (br, 1H), 4.41-4.38 (m, 1H), 4.92-
4.82(m, 2H), 6.35(s, 1H), 7.71-7.38 (m, 8H), 8.09 (s, 3H).
Preparation 16
(2R,4R)Amino(3'-chlorobiphenylyl)hydroxypentanoic Acid 5-Methyl
oxo[1,3]dioxolylmethyl Ester
HO BOC
OH O
+ O OH
A suspension of (2R,4R)t-butoxycarbonylamino(3'-chlorobiphenylyl)
hydroxypentanoic acid (740 mg, 1.8 mmol), 4-(bromomethyl)methyl-1,3-dioxolone
(340 mg, 1.8 mmol), potassium iodide (58 mg, 350 μmol), and K CO (486 mg, 3.5 mmol)
in DMF (20 mL) was stirred for 4 hours at room temperature. The mixture was diluted
with EtOAc (150 mL) and washed with water (30 mL). The organic layer was collected
and concentrated and purified by column chromatography (hexanes/EtOAc=1:1) to yield a
white solid (490 mg). LC-MS: 554 [M+23] . A solution of this solid (476 mg, 890 μmol)
in 3 N HCl in 1,4-dioxane (20 mL) was stirred overnight, and then concentrated in vacuo.
The residue was dispersed in EtOAc (10 mL), and the precipitate was collected by
filtration to yield the title compound as an off-white solid (290 mg). LC-MS: 432 [M+H] .
H NMR: (DMSO-d ) 1.92-1.82 (m, 2H), 2.16 (s, 3H), 2.99 (br, 2H), 3.56 (br, 1H), 4.35-
4.32 (m, 1H), 5.017 (s, 2H), 6.17 (s, 1H), 7.39-7.36 (m, 4H), 7.71-7.68 (m, 4H), 8.05 (s,
3H).
Preparation 17
(2R,4R)Amino(3'-chlorobiphenylyl)hydroxypentanoic Acid Butyryloxymethyl
Ester
HO BOC O
A solution of (2R,4R)t-butoxycarbonylamino(3'-chlorobiphenylyl)
hydroxypentanoic acid (900 mg, 2.1 mmol), chloromethyl butyrate (350 mg, 2.6 mmol),
sodium iodide (481 mg, 3.21 mmol) and DIPEA (828 mg, 6.42 mmol) in DMF (20 mL)
was stirred for 16 hours at 30ºC. The mixture was diluted with EtOAc (150 mL) and
washed with water (50 mL) and saturated aqueous NaCl (50 mL). The organic layer was
collected and concentrated and purified by column chromatography (hexanes/EtOAc=5:1)
to yield a white solid (240 mg). LC-MS: 542 [M+Na] . A solution of this solid (240 mg,
460 μmol) in 1.4 M HCl in 1,4-dixoane (15 mL) was stirred overnight, and then
concentrated in vacuo. The residue was dispersed in EtOAc (10 mL), and the precipitated
was collected by filtration to yield the title compound as an off-white solid HCl salt (140
mg). LC-MS: 420 [M+H] . H NMR: (DMSO) 0.85 (t, J =7.5 Hz, 3H), 1.61-1.52 (m,
2H), 1.89-1.86 (m, 2H), 2.30(t, J =7.5 Hz, 2H), 2.98 (br, 2H), 3.56 (br, 1H), 4.33-4.30(m,
1H), 5.74-5.68 (m, 2H), 6.21 (s, 1H), 7.37-7.35 (m, 4H), 7.70-7.767 (m, 4H), 8.01 (brs,
3H).
Preparation 18
(2R,4R)Amino(2',5'-dichlorobiphenylyl)hydroxypentanoic Acid Ethyl Ester
N (S)
To a solution of (S)(4-bromobenzyl)oxopyrrolidinecarboxylic acid t-butyl
ester (33.5 g, 95 mmol) in 1,4-dioxane (1.2 L) was added 2,5-dichlorophenylboronic acid
(21.7 g, 114 mmol) and Pd(dppf) Cl (3.5 g, 4.7 mmol) at room temperature under
nitrogen. After stirring for 10 minutes, a solution of K CO (26.1 g, 189 mmol) in water
(120 mL) was added. The mixture was heated to 60 C and stirred overnight. After
evaporation of the solvent, water (400 mL) was added and extracted with EtOAc (3x400
mL). The combined organic layers were washed with saturated aqueous NaCl (500 mL),
dried over anhydrous Na SO , and concentrated to yield the crude product which was
further purified by column chromatography (hexanes:EtOAc=6:1) to yield Compound 1
(35.8 g) as a light yellow solid. LC-MS: 442 [M+Na].
To a solution of Compound 1 (35.8 g, 85 mmol) in anhydrous DCM (300 mL) was
added TFA (30 mL, 405 mmol) at -5 C under nitrogen. The mixture was warmed to room
temperature and stirred overnight. After evaporation of the solvent, the residue was diluted
with EtOAc (500 mL), then washed with saturated aqueous NaHCO (3x300 mL), water
(200 mL), and saturated aqueous NaCl (250 mL), then dried over Na SO and concentrated
to yield crude Compound 2 (26 g) as a light yellow solid. LC-MS: 320 [M+H].
N (R)
(2) (4)
Cl Cl
Cl Cl
To a solution of Compound 2 (26 g, 81 mmol) in anhydrous THF (500 mL) was
added dropwise n-BuLi in hexane (39 mL, 97 mmol) over 1 hour at -78 C under nitrogen.
After stirring at -78 C for 2 hours, the reaction was quenched by adding pivaloyl chloride
(12.7 g, 105 mmol) dropwise over 30 minutes. After stirring at -78 C for 2 hours, the
reaction was quenched with saturated aqueous NH Cl (200 mL) and extracted with EtOAc
(3x200 mL). The combined organic layers were washed with saturated aqueous NaCl (300
mL), dried over anhydrous MgSO , filtered and concentrated to yield the crude product
which was further purified by chromatography (hexanes:EtOAc=25:1) to yield Compound
3 (33 g) as a light yellow solid. LC-MS: 426 [M+Na].
To a solution of Compound 3 (10 g, 0.025 mol) in anhydrous THF (120 mL) was
added dropwise NaHMDS (18.6 mL, 37 mmol) over 30 minutes at -78 C under nitrogen.
After stirring at -78 C for 2 hours, a solution of (+)-(8,8-dichlorocamphorylsulfonyl)-
oxaziridine (11.1 g, 37 mmol) in THF (80 mL) was added dropwise over 30 minutes. After
stirring at -78 C for 2 hours, the reaction was quenched with saturated aqueous NH Cl (500
mL) and extracted with EtOAc (3x300 mL). The combined organic layers were washed
with saturated aqueous NaCl (300 mL), dried over MgSO , filtered and concentrated to
yield the crude product which was further purified by chromatography
(hexanes:EtOAc=15:1) to yield Compound 4 (4.2 g) as a light yellow oil. LC-MS: 442
[M+Na].
(R) NH 2
(5) Cl
A solution of Compound 4 (4.2 g, 10 mmol) in concentrated HCl (80 mL, 0.96 mol)
was heated at 100 C for 16 hours. The mixture was then concentrated to yield crude the
product which was further purified by washing with Et O to yield Compound 5 (3.8 g) as a
white solid. LC-MS: 354 [M+ H].
To a solution of Compound 5 (3.8 g, 10 mmol) in EtOH (5 mL) was added 4M HCl
in EtOH (100 mL, 0.4 mol) at room temperature. The mixture was heated at 50 C for 16
hours. After concentration, the crude product which was further purified by washing with
Et O to yield the title compound (3.3 g) as a white solid. LC-MS: 382 [M+ H].
Preparation 19
(3R,5R)Amino(4-bromochlorophenyl)ethoxyhexenol
O OH Br
Cl Br Cl Br Cl Br
(1) (2)
To a suspension of 4-bromochlorobenzaldehyde (50g, 22.8mmol) in MeOH
(500 mL) was added NaBH (17.3 g, 45.6 mmol) in portions at 0ºC. The mixture was
stirred for 30 minutes and then aqueous NH Cl was added to quench the reaction. The
mixture was concentrated in vacuo. The residue was extracted with EtOAc (2x200 mL)
and the combined organic layers were dried over anhydrous Na SO , and concentrated
under vacuum to yield Compound 1 (48g) as a white solid.
To a solution of Compound 1 (46.8 g, 21.1 mmol) in dry DCM (500 mL) was added
phosphorous tribromide (68.6 g, 25.3 mmol) dropwise at 0ºC under nitrogen. The mixture
was stirred for 2 hours and then washed with saturated aqueous NaHCO (2x200 mL) and
saturated aqueous NaCl (200 mL), dried over anhydrous Na SO , concentrated under
vacuum to yield Compound 2 (36 g) as a colorless oil.
NH O
COOH
COOH
O NH O
To a stirred solution of (R)-pyrrolidinecarboxylic acid (57.7 g, 0.5 mol) and
KOH (84 g, 1.5 mol) in isopropyl alcohol (330 mL) was added benzyl chloride (70 mL, 0.6
mol) dropwise at 0ºC over 3 hours. The mixture was then stirred overnight at the same
temperature. The resulting mixture was neutralized with concentrate HCl to pH=6,
followed by the addition of chloroform (200 mL). The mixture was stirred for 30 minutes,
then filtered and the precipitate was washed with chloroform (3x100 mL). The combined
chloroform solutions were dried over anhydrous Na SO , and concentrated under vacuum
to yield Compound 3 (52 g) as a white solid. LC-MS: 206 [M+H] .
To a solution of Compound 3 (10 g, 48.8 mmol) in dry DCM (50 mL) was added
SO Cl (7.3 g, 61 mmol) at -20ºC under nitrogen. The mixture was stirred at -20ºC for 3
hours followed by the addition of a solution of (2-aminophenyl)(phenyl)methanone (6 g,
.5 mmol) in dry DCM (25 mL) and the mixture was stirred overnight at room
temperature. A solution of Na CO (10.3 g) in water (40 mL) was added at 0 ºC. The
organic layer was separated and the aqueous layer was extracted with DCM (50 mL×3).
The combined organic layers were dried over anhydrous Na SO and concentrated under
vacuum. The residue was washed with MTBE (2x50 mL) to yield Compound 4 (8.5 g) as
a yellow solid. LC-MS: 385 [M+H] .
N NH
O Br
O N N
Cl Br
To a solution of Compound 4 (29.4 g, 76.5 mmol), glycine (28.7 g, 382.4 mmol)
and Ni(NO ) ·6H O (44.5 g, 152.9 mmol) in MeOH (280 mL) was added a solution of
3 2 2
KOH (30 g, 535.3 mmol) in MeOH (100 mL) at 45ºC under nitrogen. The mixture was
stirred at 60ºC for an hour. The resulting solution was neutralized with AcOH (31 mL) and
poured into ice water (380 mL). The resulting solid was filtered and dissolved in DCM
(450 mL), which was washed with saturated aqueous NaCl (150 mL), dried over anhydrous
Na SO and concentrated. The residue was washed with EtOAc (2x50 mL) to yield
compound 5 (38 g) as a red solid. LC-MS: 498 [M+H] .
Compound 5 (14.3 g, 28.7 mmol) and NaOH (3.4 g, 81.6 mmol) were added to a
flask which was purged with nitrogen twice. Anhydrous DMF (100 mL) was added and
the mixture was stirred for 5 minutes at 0ºC before a solution of compound 2 (8.6 g, 30.1
mmol) in DMF (20 mL) was added. The reaction mixture was stirred at room temperature
for 30 minutes until complete consumption of compound 4 (checked by TLC). The
resulting mixture was poured into a 5% AcOH aqueous solution (120 mL) which was then
extracted with DCM (3x150 mL) and the combined organic layers were washed with
saturated aqueous NaCl (150 mL), dried over anhydrous Na SO and concentrated under
vacuum. The residue was recrystallized with DCM/Et O (1:1) to yield Compound 6 (15.5
g) as a red solid. LC-MS: 702 [M+H] .
To a solution of Compound 6 (46 g, 65.6 mmol) in MeOH (300 mL) was added 3N
HCl (200 mL). The mixture was refluxed until the red color turned green. The resulting
solution was concentrated under vacuum and concentrated NH ·H O (100 mL) was added,
and followed by the extraction with DCM (2x200 mL). The aqueous phase was
concentrated under vacuum and subjected to the cation exchange resin (eluted with
NH ·H O/EtOH, 1:1) to yield Compound 7 (15 g) as a white solid. LC-MS: 280 [M+H] .
O BOC
O BOC O
HO O
(7) O
Cl Br
Cl Br
To a suspension of Compound 7 (15 g, 53.9 mmol) in MeCN (150 mL) was added a
solution of NaOH (4.3 g, 107.7 mmol) in water (150 mL) at 0 ºC, and followed by the
addition of (BOC) O (17.6 g, 80.8 mmol). The mixture was stirred overnight at room
temperature. The resulting solution was concentrated under vacuum, followed by the
extraction with DCM (2x150 mL). The aqueous phase was acidified with 1N HCl to pH=3
and extracted with EtOAc (3x150 mL). The combined organic layers were washed with
saturated aqueous NaCl (150 mL), dried over anhydrous Na SO and concentrated under
vacuum to yield Compound 8 (12.3 g, 60%) as a white solid. LC-MS: 402 [M+Na] .
To a suspension of Compound 8 (18.4 g, 48.5 mmol) and Meldrum’s acid (8.4 g,
58.2 mmol) in DCM (400 mL) was added DMAP (9.5 g, 77.6 mmol) at -5 ºC. After
stirring for 10 minutes, a solution of DCC (12 g, 58.2 mmol) in DCM (100 mL) was added
dropwise at -5 ºC. The mixture was stirred overnight at room temperature. The resulting
solution was cooled to 0ºC and filtered. The filtrate was washed with aqueous citric acid
(3x200 mL) and saturated aqueous NaCl (200 mL), dried over anhydrous Na SO , and
concentrated under vacuum. The residue was washed with Et O (2x50 mL) to yield
Compound 9 (22 g) as a light yellow solid.
O BOC
Cl Br
Cl Br
(12)
Cl Br (11)
(10)
To a solution of Compound 9 (22 g, 43.6 mmol) in DCM (400 mL) was added
AcOH (28.8 g, 479.4 mmol) at 0ºC. After stirring for 10 minutes, NaBH (4.1 g, 109
mmol) was added in portions. The mixture was stirred for an hour at 0ºC. The resulting
solution was washed with saturated aqueous NaHCO (2x200 mL) and saturated aqueous
NaCl (200 mL), dried over anhydrous Na SO and concentrated under vacuum. The
residue was washed with ether (2x100 mL) to yield Compound 10 (18.6 g) as an off-white
solid. LC-MS: 514 [M+Na] .
A solution of Compound 10 (18.6 g, 37.9 mmol) in toluene (350 mL) was heated
under reflux for 2 hours. Upon cooling, the mixture was evaporated to dryness to yield
Compound 11 (14 g) as a yellow syrup. LC-MS: 334 [M–tBu+H] .
To a solution of Compound 11 (14 g, 36.0 mmol) in DCM (250 mL) was added
TFA (20 mL). The mixture was stirred for 4 hours at 0ºC. The resulting solution was
concentrated under vacuum to remove TFA. The residue was dissolved in DCM (400 mL)
and washed with saturated aqueous NaHCO (2x200 mL), dried over anhydrous Na SO
3 2 4
and concentrated to yield Compound 12 (10 g) as a yellow solid. LC-MS: 290 [M+H] .
(12) N
Cl Br
Cl Br
(14)
(13)
To a solution of Compound 12 (10 g, 34.7 mmol) in dry THF (250 mL) was added
NaH (2.4 g, 69.3 mmol, 70%) at 0 ºC. The mixture was stirred for one hour at 0ºC under
nitrogen. Then pivaloyl chloride (5 g, 41.6 mmol) was added. After stirring for another 2
hours, saturated aqueous NaHCO (100 mL) was added to quench the reaction. The
resulting mixture was concentrated and extracted with EtOAc (3x100 mL) and the
combined organic layers were washed with saturated aqueous NaCl (100 mL), dried over
anhydrous Na SO and concentrated under vacuum. The residue was purified by silica gel
chromatography (hexanes/EtOAc, 5:1) to yield Compound 13 (11.8 g) as a white solid.
LC-MS: 374[M+H] .
To a solution of Compound 13 (11.8 g, 31.8 mmol) in dry THF (70 mL) was added
NaHMDS (24 mL, 47.7 mmol, 2.0 M in THF) dropwise at -78 ºC under nitrogen. After
stirring for 30 minutes, a solution of (+)-(8,8-dichlorocamphorylsulfonyl)oxaziridine (15.2
g, 50.8 mmol) in THF (70 mL) was added dropwise at -78 ºC. The mixture was stirred for
another hour at the same temperature before aqueous NH Cl (70 mL) was added to quench
the reaction. The resulting mixture was extracted with EtOAc (3x150 mL) and the
combined organic layers were washed with saturated aqueous NaCl (150 mL), dried over
anhydrous Na SO , concentrated under vacuum and purified by silica gel chromatography
(hexanes/EtOAc, 20:1~5:1) to yield the crude product (5 g), which was further purified by
preparative HPLC to yield Compound 14 (4 g) as a yellow solid. LC-MS: 390 [M+H] .
NH 2
(14)
Cl Br
Cl Br
(15)
A solution of Compound 14 (4 g, 10.3 mmol) in concentrated HCl (50 mL) was
heated under reflux overnight. The mixture was concentrated under vacuum and the
resulting solid was washed with Et O (2x50 mL) to yield Compound 15 (3.1 g) as a white
solid HCl salt. LC-MS: 324 [M+H] .
A solution of Compound 15 (3.1 g, 8.6 mmol) in HCl/EtOH (6.7M, 40 mL) was
stirred overnight at 50ºC. The resulting mixture was concentrated under vacuum and the
residue was washed with ether (2x50 mL) to yield the title compound (2.9 g) as an off-
white solid HCl salt. LC-MS: 352 [M+H] . H NMR: (CD OD) 1.268 (t, J = 6.9 Hz, 3H),
1.862-1.946 (m, 1H), 2.068-2.143 (m, 1H), 3.104-3.199 (m, 2H), 3.769-3.809 (m, 1H),
4.162-4.209 (m, 2H), 4.274-4.881 (m, 1H), 7.325 (dd, J = 8.1, 2.1 Hz, 1H), 7.522 (dd, J =
8.3, 3.0 Hz, 1H), 7.696 (d, J = 1.8 Hz, 1H).
Preparation 20
[(R)Biphenylylmethyl(2,2-dimethyl-4,6-dioxo-[1,3]dioxanyl)
oxoethyl]carbamic Acid t-Butyl Ester
To a solution of (R)biphenylylt-butoxycarbonylamino-propionic acid (50
g, 146 mmol), Meldrum’s acid (23.3 g, 161 mmol) and DMAP (27.8 g, 227 mmol) in
anhydrous DCM (500 mL) was added a solution of DCC (33.3 g, 161 mmol) in anhydrous
DCM (200 mL) over 1 hour at -5°C under nitrogen. The mixture was stirred at -5°C for 8
hours, then refrigerated overnight, during which tiny crystals of dicyclohexylurea
precipitated. After filtration, the mixture was washed with 5% KHSO (4x200 mL) and
saturated aqueous NaCl (1x200 mL), then dried under refrigeration with MgSO overnight.
The solution was evaporated to yield the title compound (68 g, light yellow solid), which
was used without further purification. LC-MS: 490 [M+Na], 957 [2M+Na].
Preparation 21
(2R,4S)biphenylylt-butoxycarbonylaminohydroxymethylpentanoic Acid Ethyl
Ester (compound 6) and (2S,4S)Biphenylylt-butoxycarbonylamino
hydroxymethylpentanoic Acid Ethyl Ester (compound 7)
To a solution of crude [(R)biphenylylmethyl(2,2-dimethyl-4,6-dioxo-
[1,3]dioxanyl)oxoethyl]carbamic acid t-butyl ester (68 g, 147 mmol) in anhydrous
DCM (1 L) was added AcOH (96.7 g, 1.6 mol) at -5°C under nitrogen. The mixture was
stirred at -5°C for 0.5 hour, then NaBH (13.9 g, 366 mmol) was added in small portions
over 1 hour. After stirring for another 1hour at -5°C, saturated aqueous NaCl (300 mL)
was added. The organic layer was washed with saturated aqueous NaCl (2x300 mL) and
water (2x300 mL), dried over MgSO , filtered, and evaporated to yield the crude product,
which was further purified by chromatography (hexanes:EtOAc=5:1) to yield Compound 1
(46 g, light yellow solid). LC-MS: 476 [M+Na], 929 [2M+Na].
BOC BOC
(S) (R)
A solution of Compound 1 (46 g, 101 mmol) in anhydrous toluene (300 mL) was
refluxed under nitrogen for 3 hours. After evaporation of the solvent, the residue was
purified by chromatography (hexanes:EtOAc=10:1) to yield Compound 2 (27 g, light
yellow solid). LC-MS: 374 [M+Na], 725 [2M+Na]. H NMR (300 MHz, CDCl3): δ7.64-
7.62 (m, 4H), 7.51-7.46 (m, 2H), 7.42-7.39 (m, 1H), 7.39-7.30 (m, 2H), 4.50-4.43 (m, 1H),
3.27-3.89 (m, 1H), 2.88-2.80 (m, 1H), 2.48-2.42 (m, 2H), 2.09-1.88 (m,2H), 1.66 (s,9H).
A mixture of Compound 2 (27 g, 77 mmol) and t-butoxy-N,N,N',N'-
tetramethylmethanediamine ( 40.3 g, 231 mmol) was heated to 80°C under nitrogen. After
stirring for 3 hours at 80°C, the mixture was diluted with EtOAc (300 mL), washed with
water (2x150 mL) and saturated aqueous NaCl (2x150 mL), dried over MgSO , filtered,
and evaporated to yield crude Compound 3 (29.7 g, light yellow oil). LC-MS: 425 [M+H],
835 [2M+H].
HO HO
To a solution of crude Compound 3 (29.7 g, 73 mmol) in THF (200 mL) was added
1 M HCl (81 mL) at 0°C under nitrogen. After stirring for 1 hour at room temperature, the
mixture was diluted with EtOAc (100 mL) and adjusted with saturated aqueous NaHCO to
pH 7. The aqueous layer was extracted with EtOAc (2x150 mL) and the combined organic
layers were washed with water (2x150 mL) and saturated aqueous NaCl (1x150 mL), dried
over MgSO , filtered, and evaporated to yield crude Compound 4 (29.4 g, yellow oil). LC-
MS: 402 [M+Na], 781 [2M+Na].
To a solution of Compound 4 (29.4 g, 77 mmol) in anhydrous THF (300 mL) was
added anhydrous EtOH (30 mL) and AcOH (92.5 g, 1.5 mol) at -5°C under nitrogen. The
mixture was stirred at -5°C for 0.5 hour, then NaBH CN (19.4 g, 308 mmol) was added in
small portions over 1 hour. After stirring for one additional hour at -5°C, the mixture was
adjusted with saturated aqueous NaHCO to pH 7. The aqueous layers were extracted with
EtOAc (2x200 mL) and the combined organic layers were washed with water (2x150 mL)
and saturated aqueous NaCl (1x150 mL), dried over MgSO , filtered, and concentrated to
yield the crude product, which was further purified by chromatography
(hexanes:EtOAc=5:1) to yield Compound 5 (11.2 g, light yellow solid). LC-MS: 404
[M+Na], 785 [2M+Na].
BOC BOC
(S) (S)
(R) (S)
HO HO
To a solution of Compound 5 (11.2 g, 29 mmol) in anhydrous EtOH (500 mL) was
added anhydrous K CO (8.0 g, 58 mmol) at 0°C under nitrogen. After stirring for 1 hour
at 0°C, the mixture was warmed to room temperature and stirred for 16 hours. After
filtration, the filtrate was concentrated and the residual was diluted with water (150 mL),
DCM (200 mL) and saturated aqueous NaCl (50 mL). After separation, the aqueous layer
was extracted with DCM (2x150 mL). The combined organic layers were washed with
saturated aqueous NaCl (2x200 mL), dried over MgSO , and concentrated to yield the
crude product which was further purified by column chromatography
(hexanes:EtOAc=5:1) to yield Compounds 6 and 7 (8.3 g, light yellow solid).
Compound 6: LC-MS: 450 [M+Na], 877 [2M+Na]. H NMR (300 MHz, CDCl3):
δ7.58-7.23 (m, 9H), 4.46-4.43 (d, 1H), 4.20-4.13 (m, 2H), 3.94 (s, 1H), 3.82-3.70 (m, 2H),
2.85-2.70 (m, 3H), 2.25-2.22 (d, 1H), 2.01-1.92 (m, 1H), 1.47 (s, 9H), 1.26-1.24 (m, 3H).
Compound 7: LC-MS: 450 [M+Na], 877 [2M+Na]. H NMR (300 MHz, CDCl3):
δ7.58-7.55 (m, 4H), 7.50-7.43 (m, 2H), 7.40-7.30 (m, 1H), 7.26-7.23 (m, 1H), 4.46 (m,
1H), 4.21-4.13 (m, 2H), 3.94 (m, 1H), 3.82-3.77 (m, 2H), 2.83-2.81 (d, 2H), 2.66-2.63 (m,
1H), 2.24 (m, 1H), 1.83-1.81 (m, 2H), 1.38 (s, 9H), 1.30-1.25 (m, 3H).
Preparation 22
(2S,4S)Biphenylylt-butoxycarbonylaminohydroxymethylpentanoic Acid (R =
H; P =BOC) and (2S,4S)Aminobiphenylylhydroxymethylpentanoic Acid Ethyl
Ester (R = -CH CH ; P removed)
(2S,4S)Biphenylylt-butoxycarbonylaminohydroxymethyl-pentanoic acid
ethyl ester (210 mg) was saponified with LiOH to yield the BOC-protected acid (R = H;
P =BOC) (120 mg). (2S,4S)Biphenylylt-butoxycarbonylaminohydroxymethyl-
pentanoic acid ethyl ester (~180 mg) was subjected to HCl deprotection to yield the amine
ester (R = -CH CH ; P removed) as an HCl salt (120 mg).
Preparation 23
(2S,4S)Amino(2'-fluorobiphenylyl)hydroxymethylpentanoic Acid Ethyl Ester
BOC BOC
(S) (R)
(1) (2)
To a solution of (S)(4-bromobenzyl)oxopyrrolidinecarboxylic acid t-butyl
ester (18.4 g, 52 mmol) in 1,4-dioxane (500 mL) was added 2-fluorophenylboronic acid
(8.7 g, 63mmol) and Pd(dppf) Cl (3.8 g, 5.2 mmol) at room temperature under nitrogen.
After stirring for 10 minutes, a solution of K CO (14.4 g, 104 mmol) in water (50 mL)
was added. The mixture was heated to 80 C and stirred at this temperature for 5 hours.
After evaporation of the solvent, water (300 mL) was added and the mixture was extracted
with EtOAc (3x200 mL). The combined organic layers were washed with saturated
aqueous NaCl (400 mL), dried over Na SO and concentrated to give the crude product
which was further purified by column chromatography (hexanes:EtOAc=8:1) to yield
Compound 1 (17.3 g) as a red oil. LC-MS: 392 [M+Na].
A mixture of Compound 1 (17.3 g, 46.7m mol) and t-butoxy-N,N,N',N'-
tetramethylmethanediamine (24.4 g, 140 mmol) was heated to 80 C under nitrogen. After
stirring for 3 hours at 80 C, the mixture was diluted with EtOAc (300 mL) and washed
with water (2x150 mL), saturated aqueous NaCl (150 mL), dried over MgSO , filtered, and
evaporated to yield crude Compound 2 (20.6 g) as a red oil. LC-MS: 425 [M+H], 849
(2M+H).
To a solution of crude Compound 2 (20.6 g, 48.6 mmol) in THF (300 mL), was
added 1 M HCl (58 mL, 58 mmol) at 0 C under nitrogen. After stirring for 1 hour at room
temperature, the mixture was diluted with EtOAc (100 mL) and adjusted with saturated
to a pH of 7. The aqueous layer was extracted with EtOAc (2x150 mL)
aqueous NaHCO
and the combined organic layers were washed with water (2x150 mL) and saturated
aqueous NaCl (150 mL), dried over MgSO , filtered, and evaporated to yield the crude
Compound 3 (18.9 g) as a red oil. LC-MS: 420 (M+Na), 817 (2M+Na).
To a solution of crude Compound 3 (18.9 g, 47.6 mmol) in anhydrous THF (400
mL) was added anhydrous EtOH (50 mL) and AcOH (57.2 g, 952 mmol) at -5 C under
nitrogen. The mixture was stirred at -5 C for 30 minutes, then NaBH CN (15 g, 238 mmol)
was added in small portions over 1 hour. After stirring for an additional 1 hour at -5°C, the
mixture was adjusted with saturated aqueous NaHCO to a pH of 7. The aqueous layer
was extracted with EtOAc (3x200 mL) and the combined organic layers were washed with
water (2x150 mL) and saturated aqueous NaCl (150 mL), dried over MgSO , filtered, and
concentrated to yield the crude product which was further purified by chromatography
(hexanes:EtOAc=6:1) to yield Compound 4 (7.1 g) as a light yellow solid. LC-MS: 422
(M+Na), 821 (2M+Na).
(S) N
O BOC
To a solution of Compound 4 (7.1 g, 17.7 mmol) in anhydrous EtOH (500 mL) was
added anhydrous K CO (9.8 g, 70.8 mmol) at 0 C under nitrogen. After stirring for 1 hour
at 0 C, the mixture was warmed to room temperature and stirred for 16 hours. After
filtration, the filtrate was concentrated and the residual was diluted with water (150 mL),
DCM (200 mL) and saturated aqueous NaCl (50 mL). After separation, the aqueous layer
was extracted with DCM (2x150 mL). The combined organic layers were washed with
saturated aqueous NaCl (2x200 mL), dried over MgSO , and concentrated to yield the
crude product which was further purified by column chromatography
(hexanes:EtOAc=5:1) to yield Compound 5 (2 g) as a light yellow solid. 2.1 g of the (R,S)
isomer was also obtained as a light yellow solid.
Compound 5 (400 mg, 0.9 mmol) was dissolved in MeCN (3 mL) and 4 M HCl in
dioxane (0.5 mL). The mixture was stirred at room temperature for 1 hour then
concentrated to yield the title compound as an HCl salt (340 mg), which was formed as an
oil and solidified overnight.
Preparation 24
[(R)Biphenylyl(2,2,5-trimethyl-4,6-dioxo-1,3-dioxinan-
-ylmethyl)ethyl]carbamic Acid t-Butyl Ester
O BOC
AcOH (8.6 mL) was added to a solution of crude [(R)biphenylylmethyl
(2,2-dimethyl-4,6-dioxo-[1,3]dioxanyl)oxo-ethyl]-carbamic acid t-butyl ester (6.4 g,
14 mmol) in anhydrous MeCN (90 mL) was added AcOH (8.6 mL) at -5°C under nitrogen.
The mixture was stirred at -5°C for 30minutes, then sodium borohydride (1.3 g, 34.5
mmol) was added in small portions over 2 hours. After stirring for another 1 hour at -5°C,
saturated aqueous NaCl and 1.7 M of NaCl in water (30 mL) was added. The layers were
separated and the organic layer was washed with saturated aqueous NaCl (2x30 mL) and
water (2x30 mL), dried under MgSO , filtered and evaporated. The resulting crude product
was further purified by chromatography (5:1 heptane:EtOAc) to yield [(S)biphenylyl-
1-(2,2-dimethyl-4,6-dioxo-[1,3]dioxanylmethyl)ethyl]carbamic acid t-butyl ester (1.1 g,
purity 98.4%) as a light yellow solid.
[(S)Biphenylyl(2,2-dimethyl-4,6-dioxo-[1,3]dioxanylmethyl)-
ethyl]carbamic acid t-butyl ester (5.0 g, 11 mmol) and K CO (1.8 g, 13.2 mmol) were
dissolved in DMF (33.9 mL) and cooled to 0°C with stirring under nitrogen. Methyl iodide
(892 µL) was added and the resulting mixture was stirred at 0°C for 1 hour. The mixture
was allowed to warm to room temperature. Saturated aqueous NaCl (35 mL) and EtOAc
(35 mL) were added, and the resulting mixture was stirred for 2 minutes. The layers were
separated and the organic layer was evaporated. The residue was triturated with EtOAc
(20 mL). The solid was filtered off and dried under vacuum. The filtrate was concentrated
and triturated again with EtOAc to yield the title compound (3.9 g).
Preparation 25
(2S,4R)Biphenylylt-butoxycarbonylaminohydroxymethylmethylpentanoic
Acid (P =BOC) and (2S,4R)Aminobiphenylylhydroxymethyl
methylpentanoic Acid (P removed)
HO P
Distilled Water (140 mL) was purged 30 minutes under nitrogen, then cannulated
into a vessel containing 0.1 M of samarium diiodide in THF (800 mL), exercising caution
not to allow any air to come into contact with solution. While maintaining an atmosphere
of nitrogen, a degassed solution of [(R)biphenylyl(2,2,5-trimethyl-4,6-dioxo-1,3-
dioxinanylmethyl)ethyl]carbamic acid t-butyl ester (3.7 g, 8.0 mmol) and THF (100 mL)
was added via canula. The resulting mixture was stirred for 15 minutes, then exposed to
air. Saturated aqueous NaCl (12 mL), 10% citric acid (6 mL), and EtOAc (30 mL) were
added. The mixture was stirred for 5 minutes, then both layers were extracted. The
organic layer was dried over Na SO and concentrated under vacuum. The crude product
was purified by chromatography (330g gold column, 50% EtOAc with 0.5% AcOH/ether
gradient) to yield the BOC-protected acid. (P =BOC) (1.4 g). The BOC-protected acid
was dissolved in MeCN (10 mL), followed by the addition of 4N HCl in dioxane (10 mL).
The solvent was evaporated and the product azeotroped with toluene (2x) to yield the acid.
(P removed) (1.0 g).
Preparation 26
(2S,4R)Aminobiphenylylhydroxymethylmethylpentanoic Acid Ethyl Ester
HO O
(2S,4R)Aminobiphenylylhydroxymethylmethylpentanoic acid (0.3 g,
957 µmol) was combined with EtOH (6 mL) and 4 M of HCl in 1,4-dioxane (718 µL), and
stirred overnight. The solvents were evaporated and the product was azeotroped with
toluene (2x) to yield the title compound (295 mg), which was used without further
purification.
Preparation 27
[(R)(3'-Fluorobiphenylylmethyl)(2,2,5-trimethyl-4,6-dioxo-[1,3]dioxanyl)-
ethyl]carbamic Acid t-Butyl Ester
O O H
NH N BOC
BOC (R)
HO HO
(R) (R)
Br Br
To a solution of (R)amino(4-bromophenyl)propionic acid (50 g, 0.2 mol) in
MeCN (700 mL) was added a solution of NaOH (16.4 g, 0.4 mol) in water (700 mL) at
-5°C. After stirring for 10 minutes, a solution of (BOC) O (44.7 g, 0.2 mol) in MeCN (100
mL) was added. The mixture was warmed to room temperature and stirred overnight.
After evaporation of the MeCN, the residue was diluted with DCM (800 mL) and acidified
with 1 M HCl to pH 2 at -5°C. The aqueous layer was extracted with DCM (3x200 mL).
The combined organic layers were washed with saturated aqueous NaCl (500 mL), dried
over anhydrous Na SO and concentrated to yield Compound 1 (64.2 g, white solid). LC-
MS: 366 [M+Na], 709 [2M+Na].
To a solution of Compound 1 (64.2 g, 187 mmol) in 1,4-dioxane (500 mL) was
added 3-fluorophenylboronic acid (31.3 g, 224 mmol) and Pd(dppf) Cl (13.7 g, 19 mmol)
at room temperature under nitrogen. After stirring for 10 min, a solution of K CO (51.7 g,
374 mmol) in water (250 mL) was added. The mixture was heated to 100°C and stirred
overnight. After evaporation of the solvent, water (200 mL) was added. The aqueous layer
was acidified with 1 M HCl to pH 2 and extracted with EtOAc (3x200 mL). The combined
organic layers were washed with saturated aqueous NaCl (400 mL), dried over anhydrous
Na SO , and concentrated to yield the crude product which was further purified by column
chromatography (hexanes:EtOAc=4:1) to yield Compound 2 (45 g, light yellow oil). LC-
MS: 382 [M+Na], 741 [2M+Na].
To a solution of Compound 2 (45 g, 125 mmol), Meldrum’s acid (23.5 g, 163
mmol), and DMAP (26.0 g, 213 mmol) in anhydrous DCM (500 mL) was added a solution
of DCC (33.3 g, 163 mmol) in anhydrous DCM (200 mL) over 1 hour at -5°C under
nitrogen. The mixture was stirred at -5°C for 8 hours, then refrigerated overnight, during
which tiny crystals of dicyclohexylurea precipitated. After filtration, the mixture was
washed with 5% KHSO (4x200 mL) and saturated aqueous NaCl (1x200 mL), then dried
under refrigeration with anhydrous MgSO overnight. The solution was evaporated to
yield the crude Compound 3 (57.7 g, light yellow oil). LC-MS: 508 [M+Na], 993
[2M+Na].
(S) N
O BOC
O BOC
To a solution of the crude Compound 3 (57.7 g, 119 mmol) in anhydrous DCM (1
L) was added AcOH (78.4 g, 1.3 mol) at -5°C under nitrogen. The mixture was stirred at
-5°C for 0.5 hour, then NaBH (11.3 g, 0.3 mol) was added in small portions over 1 hour.
After stirring for a another 1hour at -5°C, saturated aqueous NaCl (300 mL) was added.
The organic layer was washed with saturated aqueous NaCl (2x300 mL) and water (2x300
mL), dried over anhydrous MgSO , filtered and concentrated to yield the crude product,
which was further purified by chromatography (hexanes:EtOAc=6:1) to yield Compound 4
(28 g, light yellow oil). LC-MS: 494 [M+Na], 965 [2M+Na].
To a solution of Compound 4 (28 g, 60 mmol) in anhydrous DMF (250 mL) was
added K CO (9.9 g, 72 mmol) and CH I (25.6 g, 180 mmol) at 0°C under nitrogen. After
2 3 3
stirring for 1 hour at 0°C, the mixture was warmed to room temperature and stirred
overnight. The mixture was diluted with water (3 L) and extracted with EtOAc (3x300
mL). The combined organic layers were washed with saturated aqueous NaCl (500 mL),
dried over anhydrous Na SO , and concentrated to give the crude product which was
further purified by chromatography (hexanes:EtOAc=5:1) to yield the title compound
(11.7 g, light yellow solid). LC-MS: 508 [M+Na], 993 [2M+Na]. H NMR (300 MHz,
CD OD): δ7.52-7.49 (m, 2H), 7.41-7.39 (m, 2H), 7.32-7.27 (m, 3H), 7.07-7.01 (m, 1H),
6.21-6.18 (d, 1H), 3.79 (m, 1H), 2.78-2.61 (m, 2H), 2.35-2.20 (m, 2H), 1.76 (s, 6H), 1.59
(s, 3H), 2.21 (s, 1H), 1.28(s, 9H).
Preparation 28
(2S,4R)t-Butoxycarbonylamino(3'-fluorobiphenylyl)hydroxymethyl
methylpentanoic Acid (P =BOC) and (2S,4R)Amino(3'-fluorobiphenylyl)
hydroxymethylmethylpentanoic Acid (P removed)
Distilled Water (181 mL) was purged 1 hour under nitrogen, then cannulated into a
vessel containing 0.1 M of samarium diiodide in THF (800 mL). While maintaining an
atmosphere of nitrogen, a similarly degassed solution of [(R)(3'-fluorobiphenyl
ylmethyl)(2,2,5-trimethyl-4,6-dioxo-[1,3]dioxanyl)-ethyl]-carbamic acid t-butyl ester
(4.9 g, 10.0 mmol) and THF (20 mL) was added via canula. The resulting mixture was
stirred for 15 minutes, then exposed to air. The solvent was evaporated, and EtOAc (200
mL), saturated aqueous NaCl (50 mL) and 10% citric acid (20 mL) were added. The
mixture was stirred for 5 minutes, then both layers were extracted. The organic layer was
dried over Na SO and concentrated under vacuum. The crude product was purified by
chromatography (330g gold column, 1:1 ether:EtOAc with 0.5% AcOH) to yield the BOC-
protected acid. (P =BOC) (1.5 g). A portion of the BOC-protected acid was dissolved in
4M HCl in dioxane (6 mL) and MeCN (10 mL). The solvent was evaporated under
vacuum to yield the acid (P removed).
Preparation 29
3-(N-Biphenylylmethyl-N'-t-butoxycarbonylhydrazino)hydroxymethylpropionic
Acid Methyl Ester
4-(Bromomethyl)biphenyl (2.00 g, 8.09 mmol) and DIPEA (1.4 mL, 8.1 mmol)
were dissolved in DMF (40.0 mL), then t-butyl carbazate (2.1 g, 16.2 mmol) was added
and the mixture was stirred at room temperature overnight. Upon completion of the
reaction, the mixture was partially concentrated, and the residue was partitioned between
EtOAc and saturated aqueous NaHCO . The EtOAc layer was dried over Na SO and
3 2 4
concentrated. The crude product was purified by flash chromatography (0-60%
EtOAc/hexanes with 0.5% DIPEA) to yield Compound 1 (1.3 g.)
O N BOC
Compound 1 (460 mg, 1.5 mmol) was dissolved in isopropyl alcohol (10.0 mL),
then methyl 2-methylglycidate (180 µL, 1.7 mmol) was added and the mixture was heated
to 85°C overnight. Upon completion of the reaction, the mixture was partitioned between
EtOAc and saturated aqueous NaHCO . The EtOAc layer was then dried over Na SO and
3 2 4
concentrated to yield the title compound (0.5 g), which was used without further
purification.
Preparation 30
(R)[N-(4-Bromobenzyl)-N'-t-butoxycarbonylhydrazino]hydroxypropionic Acid
Methyl Ester
H N BOC
4-Bromobenzyl bromide (5.0 g, 20 mmol) and DIPEA (3.48 mL, 20.0 mmol) were
dissolved in DMF (20 mL). t-Butyl carbazate (7.9 g, 60.0 mmol) was added and the
mixture was stirred at room temperature until the reaction was complete. The mixture was
partially concentrated, then the residue was partitioned between EtOAc and saturated
aqueous NaHCO . The EtOAc layer was then dried over Na SO and concentrated. The
3 2 4
crude product was purified by flash chromatography to yield Compound 1 (3.8 g).
Compound 1 (1.9 g, 6.3 mmol) was dissolved in isopropyl alcohol (26.4 mL).
Methyl (2R)-glycidate (1.1 mL, 12.6 mmol) was added and the mixture was heated at 90°C
until the reaction was complete (~4 days). The mixture was cooled to room temperature
and concentrated to yield the title compound (2.5 g) as a white solid.
Preparation 31
(R)[N-(3'-Chlorobiphenylylmethyl)hydrazino]hydroxypropionic Acid Ethyl Ester
(R)[N-(4-Bromobenzyl)-N'-t-butoxycarbonylhydrazino]hydroxypropionic
acid methyl ester (600 mg, 1 mmol), 3-chlorophenylboronic acid (419 mg, 2.7 mmol), and
K CO (617 mg, 4.5 mmol) were combined in EtOH (5 mL) and water (1 mL), followed by
the addition of SilicaCat Pd(0) (0.09 mmol/g loading, 1160 mg, 104 µmol). The mixture
was heated in a microwave reactor at 120°C until the reaction was complete (~30 minutes).
The mixture was filtered and concentrated. The residue was dissolved into MeCN/AcOH
and purified by reverse phase chromatography (55 g column; gradient 30-95% MeCN in
water with 0.1%TFA). The clean fractions were collected, concentrated and then dissolved
in 4M HCl in dioxane (6 mL) and EtOH (6 mL). The mixture was stirred at room
temperature overnight, then concentrated to yield the title compound (250 mg), which was
used without further purification.
Preparation 32
(S)(1-Biphenylylmethylethyl)oxo-pyrrolidinecarboxylic Acid t-Butyl Ester
To a solution of 2-(4-bromophenyl)acetonitrile (130.0 g, 0.7 mol) and iodomethane
(103.9 mL, 1.7 mol) in THF (1.0 L) was added NaH (60% dispersion in mineral oil, 66.7 g,
1.7 mol) in small portions at 10°C. After completion of the addition, the mixture was
stirred at 10°C for another 2 hours. The mixture was poured into ice water (2.0 L) and
extracted with EtOAc (1.5 L). The organic layer was washed with saturated aqueous NaCl,
dried over anhydrous MgSO and concentrated to yield Compound 1 (175 g, containing
mineral oil) as a yellow oil, which was used directly without further purification. H NMR
(CDCl , 300 MHz) δ 7.52 (d, J = 9.0 Hz, 2H), 7.38 (d, J = 9.0 Hz, 2H), 1.72 (s, 6H).
To a solution of Compound 1 (175 g, containing mineral oil) in DCM (1.0 L) was
added DIBAL (1.0 M solution in DCM, 700 mL, 0.70 mol) dropwise at -78°C. The
reaction mixture was stirred at -78°C for 1.5 hours and then quenched carefully with 3.0 N
HCl (1.0 L). The resulting mixture was stirred at room temperature overnight and the
organic layer was washed with saturated aqueous NaCl, dried over anhydrous Na SO and
concentrated to yield Compound 2 (180 g) as a yellow oil, which was used directly without
further purification. H NMR (CDCl , 300 MHz) δ 9.48 (s, 1H), 7.53 (d, J = 11.0 Hz, 2H),
7.17 (d, J = 11.0 Hz, 2H), 1.46 (s, 6H).
COOMe
COOH
HN O
(2) NH
Br H
(3) (4)
To an aqueous solution of NaCN (32.7 g in 1.0 L of H O, 0.7 mol) were added
(NH ) CO (380 g, 4.0 mol) and Compound 2 (180 g). The reaction mixture was refluxed
4 2 3
overnight and then concentrated under reduced pressure at 75°C. Water (350 mL) was
added to the residue and the mixture was concentrated again. The residue was suspended
in petroleum ether (700 mL) and water (250 mL) and the resulting mixture was stirred at
room temperature for 15 minutes. The precipitate was collected by filtration and dried to
yield Compound 3 (150 g) as a white solid. H NMR (DMSO-d6, 300 MHz) δ 10.39 (s,
1H), 8.05 (s, 1H), 7.48 (d, J = 9.0 Hz, 2H), 7.28 (d, J = 9.0 Hz, 2H), 4.17 (s, 1H), 1.42 (s,
3H), 1.34 (s, 3H).
A suspension of Compound 3 (150 g, 0.51 mol) in 6.0 N NaOH (400 mL) and
ethane-1,2-diol (300 mL) was stirred at 120°C for 38 hours. The mixture was cooled to
room temperature and neutralized with an HCl solution. The precipitate was collected by
filtration and dried to yield Compound 4 (250 g, containing NaCl salt) as a white solid. H
NMR (DMSO-d6, 300 MHz) δ 7.35 (d, J = 9.0 Hz, 2H), 7.17 (d, J = 9.0 Hz, 2H), 3.22 (s,
1H), 1.16 (s, 3H), 1.15 (s, 3H).
To a suspension of Compound 4 (250 g, containing NaCl salt) in MeOH (1.0 L)
was added thionyl chloride (72.0 mL, 1.0 mol) dropwise at 5°C. The mixture was refluxed
overnight and the solvent was removed under reduced pressure. The residue was
partitioned between DCM (1.0 L) and saturated aqueous NaHCO (1.5 L). The organic
layer was washed with saturated aqueous NaCl, dried over anhydrous Na SO and
concentrated to yield the corresponding methyl ester (90.0 g). 2-Phenylacetyl chloride
(48.6 g, 0.32 mol) was added dropwise to a solution of the ester (90.0 g) and Et N (56.5
mL, 0.41 mol) in DCM (1.0 L) at 0°C and the mixture was stirred at 0°C for 30 minutes.
The mixture was washed with 1.0 N HCl (500 mL) and saturated aqueous NaCl,
respectively. The organic layer was dried over anhydrous Na SO and concentrated to
yield Compound 5 (120 g). H NMR (CDCl , 300 MHz) δ 7.32 (m, 5H), 7.18 (m, 2H),
6.95 (m, 2H), 5.68 (br s, 1H), 4.76 (d, J = 9.0 Hz, 1H), 3.57 (s, 3H), 3.53 (d, J = 5.0 Hz,
2H), 1.30 (s, 3H), 1.25 (s, 3H).
COOH
COOH
COOH
HN O
HN O
NHBoc
To a solution of Compound 5 (120 g, 0.30 mol) in MeOH (500 mL) was added 4.0
N NaOH (200 mL). The mixture was stirred at room temperature for 4 hours and then the
pH was adjusted to pH=1 with 3.0 N HCl. The resulting mixture was extracted with
EtOAc (2x300 mL). The combined extracts were washed with saturated aqueous NaCl,
dried over anhydrous Na SO , and concentrated under reduced pressure. The residue was
recrystallized from EtOAc/hexanes to yield Compound 6 (82.0 g). H NMR (DMSO-d6,
300 MHz) δ 7.41 (d, J = 6.0 Hz, 2H), 7.22 (m, 5H), 6.99 (d, J = 6.0 Hz, 2H), 4.65 (d, J =
9.0 Hz, 1H), 3.52 (d, J = 14.0 Hz, 1H), 3.36 (d, J = 14.0 Hz, 1H), 1.34 (s, 3H), 1.30 (s, 3H).
A suspension of Compound 6 (82.0 g, 0.21 mol) in distilled water (3.0 L) was
adjusted to pH=8.5 with 3.0 N LiOH and a clear solution was formed. Immobilized
Penicillinase (20.0 g) was added and the resulting mixture was stirred at 37°C for 60 hours.
The mixture was filtered and the filtrate was adjusted to pH=1 with 3.0 N HCl and
extracted with EtOAc. The combined extracts were washed with saturated aqueous NaCl,
dried over anhydrous Na SO and concentrated to yield Compound 7 (59.0 g, 80% ee,
containing 2-phenylacetic acid).
A suspension of Compound 7 (59.0 g, containing 2-phenylacetic acid) in 6.0 N HCl
(500 mL) was refluxed overnight. The mixture was washed with EtOAc (300 mL) and the
aqueous phase was concentrated under reduced pressure to yield the corresponding amino
acid as its hydrochloride salt. The salt was dissolved in water (300 mL) and the solution
was adjusted to pH=11. A solution of (BOC) O (33.0 g, 0.2 mol) in acetone (200 mL) was
added and the mixture was stirred at room temperature for 2 hours. The mixture was
washed with hexanes (200 mL) and the aqueous phase was adjusted to pH=2. The
resulting mixture was extracted with EtOAc (2x300 mL). The combined extracts were
washed with saturated aqueous NaCl, dried over anhydrous Na SO and concentrated to
yield Compound 8 (37.0 g) as a white solid. H NMR (CDCl , 300 MHz) δ 9.48 (br s, 1H),
7.46 (d, J = 7.0 Hz, 2H), 7.26 (d, J = 7.0 Hz, 2H), 5.02 (br s, 1H), 4.56 (d, J = 9.0 Hz, 1H),
1.39 (s, 9H).
COOH
NH O
(10)
A mixture of Compound 8 (37.0 g, 0.1 mol) in dioxane (200 mL) and 1.0 N K CO
(200 mL) was degassed for 30 minutes with nitrogen, followed by the addition of
phenylboronic acid (13.4 g, 0.1 mol) and Pd(PPh ) (1.6 g, 1.4 mmol). The mixture was
heated at 75°C for 8 hours and then cooled to room temperature. The mixture was washed
with EtOAc/hexanes (150 mL, 1:1) and the aqueous phase was adjusted to pH=2 and
extracted with EtOAc (2x300 mL). The combined extracts were washed with saturated
aqueous NaCl, dried over anhydrous Na SO and concentrated to yield Compound 9 (31.0
g, 84% yield) as a white solid.
A solution of Compound 9 (31.0 g, 84 mmol), Meldrum’s acid (13.3 g, 92 mmol)
and DMAP (15.4 g, 0.13 mol) in DCM (400 mL) was cooled to -5°C and a solution of
DCC (19.0 g, 92 mmol) in DCM (200 mL) was added over 1 hour. The mixture was
stirred at -5°C overnight. The precipitate was filtered off and the filtrate was washed with
1.0 N HCl (2x700 mL) and saturated aqueous NaCl, respectively. After the organic layer
containing Compound 10 was dried over anhydrous MgSO , it was used directly for the
next step without concentration.
(10)
(11)
A solution of Compound 10 in DCM (600 mL) was cooled to -5°C and AcOH (45.0
mL) was added. Then NaBH (7.0 g, 0.2 mol) was added in small portions over 30
minutes and the mixture was stirred at -5°C for 3 hours. Water (50.0 mL) was added
dropwise followed by addition of saturated aqueous NaCl (450 mL). The organic layer
was washed with water (2x300 mL) and saturated aqueous NaHCO (2x300 mL), dried
over anhydrous MgSO and concentrated to yield Compound 11 (32.0 g, 75% ee) as an off-
white solid. After recrystallization from EtOH, chirally pure Compound 11 (13.0 g) was
obtained. H NMR (CDCl , 300 MHz) δ 7.61 (m, 10H), 4.46 (br s, 1H), 4.26 (m, 1H), 3.72
(br s, 1H), 2.23 (m, 1H), 1.79 (s, 3H), 1.76 (s, 3H), 1.48 (s, 6H), 1.39 (s, 9H).
A solution of Compound 11 (13.0 g, 27.0 mmol) in toluene (100.0 mL) was
refluxed for 3 hours. After evaporation of the solvent, the residue was recrystallized from
hexanes/EtOAc (3:1) to yield the title compound (8.0 g) as a white solid.
Preparation 33
(2R,4S)Aminobiphenylylhydroxymethylhexanoic Acid Ethyl Ester
Ph Ph Piv
O (1) O
A mixture of (S)(1-biphenylylmethylethyl)oxo-pyrrolidinecarboxylic
acid t-butyl ester (14.0 g, 36.9 mmol, racemic) in a 3.0 N HCl-EtOAc solution (150 mL)
was stirred at room temperature for 3 hours. The solvent was removed under reduced
pressure to yield Compound 1 (10.0 g) as a white solid.
To a solution of Compound 1 (10.0 g, 35.8 mmol) in THF (80.0 mL) was added
BuLi (2.5 M in hexanes, 15.0 mL) dropwise at -78°C. After the mixture was stirred for 30
minutes pivaloyl chloride (4.8 mL, 39.4 mmol) was added dropwise. The mixture was
stirred at -78°C for 1 hour and then quenched with saturated aqueous NH Cl. The resulting
mixture was extracted with EtOAc and the combined extracts were washed with saturated
aqueous NaCl, dried over anhydrous MgSO and concentrated. The residue was purified
by flash column chromatography on silica gel to yield Compound 2 (9.0 g) as a white solid.
To a solution of Compound 2 (9.0 g, 24.7 mmol) in THF (50.0 mL) was added
sodium bis(trimethylsilyl)amide (2.0 M in THF, 18.5 mL, 37.0 mmol) dropwise at -78°C.
The mixture was stirred for 20 minutes and a solution of oxaziridine derivative (10.8 g,
37.0 mmol) in THF (30.0 mL) was added dropwise. The mixture was stirred at -78°C for
minutes and then quenched with saturated aqueous NH Cl. The resulting mixture was
extracted with EtOAc (1.0 L) and the extract was washed with 1.0 N HCl and saturated
aqueous NaCl, dried over anhydrous MgSO and evaporated to remove most of the solvent.
The precipitate was filtered off and the filtrate was concentrated. The residue was purified
by flash column chromatography on silica gel (DCM:hexanes= 1:1 to DCM) to yield
Compound 3 (4.3 g, racemic). This racemate was subjected to chiral AD-column
chromatography to afford chirally pure Compound 3 (1.4 g). H NMR (DMSO-d6, 300
MHz) δ 7.63 (m, 4H), 7.49 (m, 4H), 4.83 (d, 1H), 3.29 (m, 1H), 2.31 (m, 2H), 1.40 (s, 3H),
1.36 (s, 3H), 1.28 (s, 9H). LC-MS (ESI): m/z 380.1 [M+H]+.
A solution of Compound 3 (1.7 g, 160 mmol) in EtOH (15.0 mL) and 12.0 N HCl
(15.0 mL) was heated at 90~95°C for 20 hours. The solvent was removed and the residue
was treated with a 3.0 N HCl-EtOH solution (25.0 mL) under reflux for another 3 hours.
After removal of the solvent, the residue was purified by preparative HPLC to yield the
title compound (0.6 g) as a foamy solid HCl salt. H NMR (DMSO-d6, 300 MHz) δ 7.88
(br s, 3H), 7.68 (m, 4H), 7.49 (m, 4H), 7.35 (m, 1H), 6.11 (br s, 1H), 4.11 (br s, 1H), 4.05
(q, 2H), 3.61 (br s, 1H), 1.67 (m, 2H), 1.40 (s, 3H), 1.36 (s, 3H), 1.09 (t, 3H). LC-MS
(ESI): m/z 342.1 [M+H]+.
Preparation 34
(2S,4S)Aminobiphenylylhydroxymethylmethylhexanoic Acid Ethyl Ester
BOC Ph
A mixture of (S)(1-biphenylylmethylethyl)oxo-pyrrolidinecarboxylic
acid t-butyl ester (8.0 g, 21.2 mmol) and t-butoxy-N,N,N',N'- tetramethylmethanediamine
(10.0 g, 63.6 mmol) was heated at 80°C for 3 hours. The mixture was cooled to room
temperature and diluted with EtOAc (200 mL). The resulting solution was washed with
water (2x100 mL) and saturated aqueous NaCl, dried over anhydrous MgSO and
concentrated to yield Compound 1 (9.2 g, quantitative) as an oil. H NMR (CDCl , 300
MHz) δ 7.53 (m, 9H), 6.95 (s, 1H), 4.60 (br s, 1H), 2.90 (s, 1H), 2.62 (m, 2H), 1.61 (s, 9H),
1.39 (s, 3H), 1.34 (s, 3H).
To a solution of Compound 1 (9.2 g, 21.2 mmol) in THF (80.0 mL) was added 1.0
N HCl (25.0 mL) at 0°C. The mixture was stirred at room temperature for 2 hours and
then diluted with EtOAc (100 mL). The resulting mixture was neutralized with saturated
aqueous NaHCO and extracted with EtOAc (2x100 mL). The combined extracts were
washed with water (2x100 mL) and saturated aqueous NaCl, dried over anhydrous MgSO
and concentrated to yield Compound 2 (8.6 g, quantitative) as an oil. LC-MS (ESI): m/z
430.1 [M+Na]+.
COOEt
To a solution of Compound 2 (8.6 g, 21.2 mmol) in THF (150 mL) and EtOH (15.0
mL) was added AcOH (24.3 mL, 0.4 mol) at -5°C. After the mixture was stirred at -5°C
for 30 minutes, NaBH CN (5.3 g, 84.8 mmol) was added in small portions over 1 hour.
The mixture was stirred at -5°C for 1 hour and neutralized with saturated aqueous
NaHCO . The resulting mixture was extracted with EtOAc (2x100 mL). The combined
extracts were washed with water (2x100 mL) and saturated aqueous NaCl, dried over
anhydrous MgSO and concentrated to yield Compound 3 (8.67 g, quantitative) as a foamy
solid.
To a solution of Compound 3 (3.5 g, 8.6 mmol) in EtOH (30.0 mL) was added
K CO (2.4 g, 17.1 mmol) at 0°C. The mixture was stirred at 0°C for 1 hour and then
allowed to warm to room temperature and stirred overnight. The mixture was filtered and
the filtrate was concentrated. The residue was treated with water (20 mL) and the resulting
mixture was extracted with DCM (3x25 mL). The combined extracts were washed with
saturated aqueous NaCl, dried over anhydrous MgSO and concentrated. The residue was
purified by flash column chromatography on silica gel (hexanes:EtOAc= 6:1) to yield
Compound 4 (2.2 g) as a foamy solid . H NMR (CDCl , 300 MHz) δ 7.53 (m, 9H), 4.35
(br s, 1H), 4.15 (m, 2H), 3.95 (br s, 1H), 3.65 (m, 2H), 2.61 (br s, 1H), 1.79 (m, 1H), 1.45
(s, 9H), 1.35 (s, 3H), 1.29 (s, 3H), 1.25 (t, 3H). LC-MS (ESI): m/z 478.2 [M+Na]+.
A mixture of Compound 4 (2.2 g, 4.8 mmol) in a 2.0 N HCl-EtOH solution (30.0
mL) was stirred at room temperature for 3 hours. Removal of the solvent under reduced
pressure yielded the title compound (1.6 g) as a foamy solid HCl salt. H NMR (DMSO-
d6, 300 MHz) δ 8.08 (br s, 3H), 7.55 (m, 9H), 4.95 (br s, 1H), 3.95 (m, 2H), 3.48 (m, 2H),
2.75 (br s, 1H), 1.79 (m, 2H), 1.47 (s, 3H), 1.40 (s, 3H), 1.09 (t, 3H). LC-MS (ESI): m/z
356.1 [M+H]+.
Preparation 35
3-[N-(4-Bromobenzyl)hydrazino]hydroxypropionic Acid Ethyl Ester
N NH
O N BOC O N
OH OH
Br Br
A solution of (R)[N-(4-bromobenzyl)-N'-t-butoxycarbonylhydrazino]
hydroxypropionic acid methyl ester (25 g, 62 mmol) in EtOH/HCl (310 mL, 1.0 M, 0.3
mol) was stirred overnight. The mixture was concentrated and the reside was washed with
EtOAc (120 mL) and filtered to yield the title compound as a white solid HCl salt (15 g).
Preparation 36
Oxalic acid (R)[N-(4-bromobenzyl)-N'-ethoxyoxalylhydrazino]ethoxycarbonylethyl
Ester Ethyl Ester
Ethyl oxalyl chloride (70 μL, 630 μmol) was added dropwise to a solution of 3-[N-
(4-bromobenzyl)hydrazino]hydroxypropionic acid ethyl ester (200 mg, 630 μmol) and
Et N (220 μL, 1.6 mmol) in DCM (4.0 mL, 62.2 mmol) at 0°C. The resulting mixture was
stirred for 15 minutes at 0°C and for 15 minutes at room temperature. Water (3 mL) was
added, the layers were separated, and the aqueous layer was extracted with DCM (2x2
mL). The DCM layers were combined, dried over MgSO , and concentrated to yield the
title compound (275 mg).
Preparation 37
N'-(4-Bromobenzyl)hydrazinecarboxylic Acid t-Butyl Ester
H N BOC
To a stirred solution of t-butyl carbazate (50 g, 0.4 mol) in dry THF (400 mL) was
added dropwise a solution of 4-bromobenzaldehyde (70 g, 0.4 mol) in dry THF (200 mL).
The mixture was stirred at room temperature for 2 hours, and then concentrated in vacuo to
yield Compound 1 as a yellow solid (113.8 g). LC-MS: 243 [M-tBu+H] .
To a solution of Compound 1 (113.8 g, 0.4 mol) in dry THF (1 L) was added
NaCNBH (36 g, 0.6 mol) in portions at 0ºC. AcOH (180 mL) was added dropwise and
the resulting mixture was stirred at room temperature overnight. Water (2 L) and EtOAc
(1.5 L) were added and the aqueous phase was adjusted to pH = 7 with a saturated aqueous
Na CO solution. The organic layer was separated, washed with saturated aqueous NaCl
and water (200 mL), dried over anhydrous Na SO , and concentrated in vacuo. The
residue was treated with MeOH (2 L) and 1N NaOH (1.5 L), and then stirred at room
temperature for 2 hours. After the removal of the MeOH solvent, the precipitate was
collected by filtration to yield the title compound as a white solid (112 g). LC-MS: 245
[M-tBu+H] .
Preparation 38
(R)[N'-t-Butoxycarbonyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic Acid Methyl Ester
H HN BOC
HO OH
Cl (1)
To a solution of N'-(4-bromobenzyl)hydrazinecarboxylic acid t-butyl ester (60 g,
0.2 mol) in 1, 4-dioxane (1.5 mL) was added 5-chlorofluorophenylboronic acid (38 g,
0.2 mol) and Pd(dppf)Cl (7.3 g). The mixture was stirred at room temperature under
nitrogen for 10 minutes, and then, K CO (55.2 g, 0.4 mol) in water (240 mL) was added.
The resulting mixture was stirred at 60ºC for 3 hours, and then cooled to room temperature
and concentrated in vacuo. The residue was extracted with EtOAc (3×300 mL). The
combined organic layers were dried over anhydrous Na SO and concentrated in vacuo.
The product was purified by column chromatography (PE:EtOAc=10:1~5:1) to yield
Compound 1 as a pink solid (56 g). LC-MS: 701 [2M+H]
O BOC
O Cl
To a solution of Compound 1 (20 g, 57 mmol) in isopropyl alcohol (250 mL) was
added methyl (2R)-glycidate (8.7 g, 86 mmol) under nitrogen. The mixture was stirred at
85ºC for 3 days, then cooled to room temperature. The precipitated solid was collected by
filtration to yield the title compound as an off-white solid (18.5 g). LC-MS: 397 [M-
tBu+H] .
Preparation 39
(R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic Acid
Ethyl Ester
N NH
O N BOC O N
OH OH
Cl Cl
A solution of (R)[N'-t-butoxycarbonyl-N-(5'-chloro-2'-fluorobiphenyl
ylmethyl)hydrazino]hydroxypropionic acid methyl ester (20 g, 16 mmol) in HCl/EtOH
(1.1 M, 200 mL) was stirred overnight and then concentrated in vacuo. The residue was
dispersed in EtOAc (2 x 40 mL), and the precipitate was collected by filtration to give the
title compound as an off-white solid HCl salt (8.8 g). LC-MS: 367 [M+H] . H NMR (300
MHz, DMSO-d ) δ 1.05 (t, J=7.2 Hz, 3 H), 3.05-3.03 (q, J=7.2 Hz, 2 H), 4.06-3.95 (m, 4
H), 4.42 (br, 1 H), 6.46 (br, 1 H), 7.62-7.40 (m, 7 H), 9.42 (s, 3 H).
Preparation 40
(R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic acid 2-
oxophenylethyl Ester
NH N
O N O N BOC
OH OH
Br Br
3-[N-(4-Bromobenzyl)hydrazino]hydroxypropionic acid ethyl ester (3.1 g, 9.6
mmol) was combined with di-t-butyldicarbonate (4.2 g, 19.2 mmol) and DCM (92.4 mL,
1.4 mol). DIPEA (5.0 mL, 28.8 mmol) was added and the resulting mixture was stirred at
room temperature for 24 hours. The mixture was concentrated and the reside was
dissolved into DCM and purified by flash chromatography (10-95% EtOAc in hexanes).
The clean fractions were collected and concentrated to yield Compound 1 as a white
powder (4.0 g).
N BOC
Compound 1 (3.5 g, 8.4 mmol) was combined with 5-chlorofluorophenylboronic
acid (1.8 g, 10.1 mmol) and K CO (3.5 g, 25.2 mmol) in EtOH (29.4 mL, 503 mmol) and
water (7.6 mL, 419 mmol). The resulting mixture was placed under nitrogen and SilicaCat
DPP-Pd(0.28 mmol/g loading; 3.0 g, 839 μmol) was then added. The mixture was
microwaved at 120°C for 15 minutes. The mixture was then filtered and evaporated under
reduced pressure. The crude residue was purified using flash chromatography (10-90%
EtOAc in hexanes) to yield Compound 2 (2.0 g).
O OH
(2) +
Compound 2 (500 mg, 1 mmol) was combined with K CO (315 mg, 2.3 mmol) in
DMF (5.3 mL, 68.4 mmol). 2-Bromoacetophenone (249 mg, 1.3 mmol) was then added
and the resulting mixture was stirred at room temperature for 15 minutes. The mixture was
then purified using flash chromatography (50-100% EtOAc in Hexanes). This purified
material (605 mg) was then dissolved in MeCN (3.6 mL, 68.4 mmol). A solution of 4 M
HCl in 1,4-dioxane (1.4 mL, 5.7 mmol) was then added, and the resulting mixture was
stirred for 1 hour to yield the title compound (245 mg).
Preparation 41
(R)[N'-t-Butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic Acid
O BOC
HO N
HO N NH
t-Butyl oxalyl chloride was prepared by adding oxalyl chloride (102 μL, 1.2 mmol)
to a solution of t-butyl alcohol (35 μL, 361 μmol) in ether (632 μL, 6.0 mmol). The
resulting mixture was stirred at room temperature for 15 minutes and then concentrated in
vacuo to yield a clear colorless liquid.
(R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic
acid 2-oxophenylethyl ester (55.0 mg, 120 μmol) was dissolved in DCM (463 μL, 7.2
mmol). The t-butyl oxalyl chloride was added, and the resulting mixture was stirred at
room temperature for 30 minutes, and then concentrated in vacuo. The resulting residue
was dissolved in AcOH (411 μL, 7.2 mmol). Zinc (394 mg, 6.0 mmol) was added to the
mixture, which was then stirred at room temperature for 10 minutes. The mixture was
filtrated and purified (Interchim reverse phase column) to yield the title compound (25.0
mg).
Preparation 42
(R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic Acid 5-
methyloxo-[1,3]dioxolylmethyl Ester
HO N BOC
O N BOC
LiOH hydrate (3g, 73mmol) in water (60 mL) was added to (R)[N'-t-
butoxycarbonyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic
acid methyl ester (16.5 g, 36.5 mmol) in MeOH (300 mL). The mixture was stirred at
room temperature for 2 hours, and the MeOH was evaporated in vacuo. The mixture was
adjusted to pH=5 with 1 M aqueous HCl, and the residue was extracted with EtOAc
(2x300 mL). The combined organic layers were dried over anhydrous Na SO , and
concentrated in vacuo to yield Compound 1 as a white solid (18 g). LC-MS: 383 [M-
tBu+H].
N BOC
O Cl
To a solution of Compound 1 (1.5 g, 3.42 mmol), K CO (0.95g, 6.84 mmol) and
potassium iodide (20mg) in DMF (40 mL) was added 4-(bromomethyl)methyl-1,3-
dioxolone (0.8 g, 4.1 mmol) in DMF (15 mL). The resulting mixture was stirred for 4
hours at room temperature. Saturated aqueous NaCl (30 mL) was added and the mixture
was extracted with EtOAc (2x50 mL). The combined organic layers were dried over
anhydrous Na SO and concentrated in vacuo. The residue was purified by column
chromatography (hexanes/EtOAc=1:1) to yield Compound 2 as a yellow solid (930 mg).
LC-MS: 495 [M-tBu+H] .
O O N
Compound 2 (400 mg, 0.73mmol) was dissolved in MeCN (20 mL), and cooled to
0ºC. N-trimethylsilylimidazole (290 mg, 1.46mmol) was added dropwise and the resulting
mixture was stirred for 2 hours. MeOH (50 mL) was added to quench the reaction. The
mixture was washed with saturated aqueous NaCl (2x50 mL) and extracted with DCM
(2x80 mL). The combined organic layers were dried over anhydrous Na SO and
concentrated in vacuo. The product was collected to yield the title compound as a yellow
solid (200 mg). LC-MS: 451 [M+H] .
Preparation 43
(R)[N'-t-Butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)-hydrazino]
hydroxypropionic Acid
HO N NH
F Cl
To a mixture of (R)[N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic acid 2-oxophenylethyl ester (2.0 g, 4.4 mmol) in DCM (10 mL) was
added dropwise t-butyl 2-chlorooxoacetate (1.5 g, 8.8 mmol) at 0°C under nitrogen.
DIPEA (1.15 g, 8.8 mmol) was then added dropwise, and the resulting mixture was stirred
for 5 minutes at 0°C. The solvent was removed by evaporation and the residue was
purified by column chromatography (PE:EtOAc=2:1) to yield Compound 1 as a yellow
liquid (2.0 g). LC-MS: 585[M+H] .
A mixture of Compound 1(2.0 g, 3.4 mmol) and Zn (15.5 g, 240 mmol) in AcOH
(15 mL) was stirred for 1 hour at room temperature, then filtered. Water (30 mL) was
added to the filtrate, and the mixture was extracted with EtOAc (3x40 mL). The combined
organic layers were washed with saturated aqueous NaCl (2x50 mL), dried over anhydrous
Na SO , and concentrated in vacuo. The residue was purified by column chromatography
(DCM/MeOH=10:1) to yield the title compound as a yellow liquid (1.4 g). LC-MS: 467
[M+H] .
EXAMPLE 1
(R)Biphenylylhydroxy(oxalylamino)pentanoic Acid
O O OH
NH NH
O HO
(R)Aminobiphenylylhydroxypentanoic acid ethyl ester (HCl salt; 47
mg, 0.2 mmol) and ethyl oxalyl chloride (18.4 µL, 1.1 eq) were combined with DIPEA
(52.2 µL, 0.3 mmol) in DMF (0.3 mL)/DCM (0.3 mL). The mixture was stirred at room
temperature until the reaction was complete. The solvent was removed and the residue was
dissolved in EtOH (750 µL) and 1 M aqueous NaOH (750 µL), and stirred at room
temperature overnight. The solvent was removed and the residue was purified by
preparative HPLC to yield the title compound (28.2 mg, purity 100%). MS m/z [M+H]
calc'd for C H NO , 358.12; found 358.0.
19 19 6
EXAMPLE 2
A. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
O OH
A solution of ethyl oxalyl chloride (70.7 µL, 0.6 mmol) in DIPEA (165 µL, 0.9
mmol) was added to a solution of (2R,4R)amino(4-bromophenyl)
hydroxypentanoic acid ethyl ester (100 mg, 0.3 mmol) and DCM (0.7 mL), and the
resulting mixture was stirred at room temperature for 10 minutes, followed by evaporation
of the solvent under reduced pressure. 3-Chlorophenylboronic acid, pinacol ester (112 mg,
468 µmol), K CO (97 mg, 702 µmol), EtOH (2 mL), and water (0.6 mL) were added,
followed by the addition of SilicaCat Pd(0) (0.09 mmol/g loading, 260 mg, 23.4 µmol).
The mixture was heated at 120°C for 20 minutes. The reaction mixture was concentrated
and 10 M of aqueous NaOH (316 µL) and THF (4.0 mL) with 1 drop of MeOH was added.
The resulting mixture was stirred at room temperature for 1 hour. The residue was
dissolved in AcOH and purified by preparative HPLC to yield the title compound (9 mg,
purity 95%). MS m/z [M+H] calc'd for C H ClNO , 392.08; found 392.4.
19 18 6
B. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid Ethyl
Ester
O OH
Oxalyl chloride (54.5 µL, 0.6 mmol) was added to a solution of t-butyl alcohol
(56.0 µL) in ether (1.0 mL) and the mixture was stirred for 1 hour at room temperature.
The mixture was concentrated under vacuum and a solution of (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid ethyl ester (67.9 mg, 0.2 mmol) and DIPEA
(102 µL, 0.6 mmol,) in DCM (1.0 mL) was added to the resulting clear colorless liquid
residue. The resulting mixture was stirred at room temperature for 2 hours and
concentrated under vacuum to yield a clear yellow liquid. A 1:1 TFA/DCM (1.6 mL) was
added to the crude liquid and the reaction mixture was stirred at room temperature for 2
hours and concentrated under vacuum to yield a clear yellow liquid. The crude liquid was
purified by reverse phase preparative HPLC (40-90% MeCN/H O) to yield the title
compound (25.0 mg, purity 95%) as a white solid. MS m/z [M+H] calc'd for
C H ClNO , 420.11; found 420.1.
21 22 6
C. (2R,4R)(3'-Chlorobiphenylyl)(ethoxyoxalylamino)hydroxypentanoic Acid
Ethyl Ester
O O O
NH NH
OH OH
A solution of ethyl oxalyl chloride (24.6 µL, 0.2 mmol) in DCM (0.4 mL) was
added to a solution of (2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic
acid ethyl ester (69.6 mg, 0.2 mmol) and Et N (69.7 µL, 0.5 mmol) in DCM (1.0 mL) at
0°C over a period of 10 minutes. The resulting mixture was stirred at 0°C for 30 minutes,
and then for 15 minutes at room temperature. Water (2 mL) was added, the layers were
separated, and the aqueous layer was extracted with DCM (2x2 mL). The DCM layers
were combined, dried over Na SO , and concentrated to yield a clear yellow liquid. The
crude liquid was purified by flash chromatography (4g column, 16 mL/min, using 35%
EtOAc/hexanes (2 min), 35-50% (1 min), 50% (4 min), 50-70% (1 min) and 70%
EtOAc/hexanes (3 min)) to yield the title compound (63.9 mg, purity 90%) as a clear
colorless liquid which solidified upon standing to a white solid. MS m/z [M+H] calc'd for
C H ClNO , 448.14; found 448.2.
23 26 6
D. (2R,4R)(Butoxyoxalylamino)(3'-chlorobiphenylyl)hydroxypentanoic Acid
Butyl Ester
p-Toluenesulfonic acid monohydrate (849 µg, 4 µmol) was added to a solution of
(2R,4R)(3'-chlorobiphenylyl)(ethoxyoxalylamino)hydroxypentanoic acid ethyl
ester (20.0 mg, 45 µmol) in 1-butanol (0.5 mL). The reaction mixture was stirred at 80°C
for 14 hours, at 90°C for 4 hours, and then was allowed to cool to room temperature.
Saturated aqueous NaHCO (2 mL) was added, and the aqueous layer was extracted with
DCM (3x2 mL). The DCM layers were combined, dried over Na SO , and concentrated
under vacuum to yield a clear colorless liquid. The crude liquid was purified by flash
chromatography (4 g column, 40% EtOAc/hexanes) to yield the title compound (18.1 mg,
purity 99%) as a clear colorless liquid. MS m/z [M+H] calc'd for C H ClNO , 504.21;
27 34 6
found 504.2.
E. (2R,4R)(3'-Chlorobiphenylyl)hydroxy[(5-methyloxo-[1,3]dioxol
ylmethoxyoxalyl)amino]pentanoic Acid 5-methyloxo-[1,3]dioxolylmethyl Ester
Cl Cl
Oxalyl chloride (22.4 µL, 264 µmol) was added to a solution of 4-hydroxymethyl-
-methyl-[1,3]dioxolone (29.1 mg, 224 µmol) in ether (1.5 mL) and the mixture was
stirred at room temperature for 2 hours. The ether was removed under vacuum and the
residue was dissolved in DMF (1.5 mL). The resulting solution was added to a solution of
(2R,4R)amino(3'-chloro-biphenylyl)hydroxy-pentanoic acid (65.0 mg, 203
µmol) and NaHCO (51.2 mg) at 0°C. The resulting mixture was stirred at room
temperature for 3 hours, then concentrated under vacuum. The residue was then purified
by reverse phase preparative HPLC (30%-90% MeCN/H O) to yield compound 1 (19.1
mg) as a white solid.
O Cl
1-Hydroxybenzotriazole (7.7 mg, 56.8 µmol) and N-(3-dimethylaminopropyl)-N'-
ethylcarbodiimide hydrochloride (10.9 mg, 56.8 µmol) were added to a solution of
compound 1 (19.1 mg, 37.9 µmol) in DCM (1.0 mL) and the mixture was stirred at room
temperature for 10 minutes. 4-Hydroxymethylmethyl-[1,3]dioxolone (14.8 mg, 114
µmol) and 4-methylmorpholine (7.7 mg, 75.8 µmol) were added and the resulting mixture
was stirred at room temperature for 6 hours. Water was added and the mixture was
extracted with DCM (3x1.5 mL). The DCM layers were combined, dried over Na SO ,
and concentrated to yield a yellow liquid. The crude liquid was purified by reverse phase
preparative HPLC to yield the title compound as a white solid (5.1 mg). MS m/z [M+H]
calc'd for C H ClNO , 616.11; found 616.1.
29 26 12
F. (2R,4R)(3'-Chlorobiphenylyl)(ethoxyoxalylamino)hydroxypentanoic Acid
Cl Cl
Ethyl oxalyl chloride (46.1 µL, 0.4 mmol) was added to a solution of (2R,4R)
amino(3'-chloro-biphenylyl)hydroxy-pentanoic acid (120 mg, 0.4 mmol) and Et N
(157 µL, 1.1 mmol) in DMF (2.0 mL, 25.8 mmol) at 0°C, and the resulting mixture was
stirred at room temperature for 20 minutes. Additional ethyl oxalyl chloride (30 µL) was
added and the mixture was stirred an additional 10 minutes. Water (2 mL) was added and
the mixture was extracted with DCM (3x2 mL). The extracts were combined, dried over
Na SO and concentrated to yield a yellow liquid. The crude liquid was purified by (C-18
column chromatography, 20 g; 40-90% MeCN in water with 0.05% TFA) to yield the title
compound (28.5 mg) as a white solid. MS m/z [M+H] calc'd for C H ClNO , 420.11;
21 22 6
found 420.2.
G. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(isopropoxyoxalylamino)pentanoic
Acid
Chloro-oxo-acetic acid isopropyl ester (62.1 mg, 413 µmol; ~ 53 µL) was added
dropwise to a solution of (2R,4R)amino(3'-chloro-biphenylyl)hydroxy-
pentanoic acid (100 mg, 313 µmol) and Et N (157 µL, 1.1 mmol) in DMF (2.0 mL, 25.8
mmol) at 0°C, and the resulting mixture was stirred at room temperature for 10 minutes.
Additional ethyl oxalyl chloride (50 µL) was added and the mixture was stirred an
additional 10 minutes. Saturated aqueous NaHCO (5 mL) was added and the mixture was
stirred at room temperature for 1 hour. The mixture was extracted with DCM (3x3 mL),
the extracts were combined, dried over Na SO , and concentrated to yield a yellow liquid.
The crude liquid was purified (pre HPLC C-18 column chromatography, small column,
using 40-95% MeCN in water with 0.05% TFA) to yield the title compound (53.0 mg) as a
white solid. MS m/z [M+H] calc'd for C H ClNO , 434.13; found 434.1.
22 24 6
H. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(isobutoxyoxalylamino)pentanoic
Acid
O O O
OH OH
1.0 M of aqueous HCL (2.5 mL, 2.5 mmol) was added to (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid ethyl ester (100 mg, 287 µmol) and the
resulting mixture was stirred at 100°C for 1 hour. The mixture was concentrated to yield
(2R,4R)amino(3'-chlorobiphenylyl)hydroxy-pentanoic acid.
Chloro-oxo-acetic acid isobutyl ester (99.4 mg, 604 µmol) was added dropwise to a
solution of (2R,4R)amino(3'-chlorobiphenylyl)hydroxy-pentanoic acid and
Et N (160 µL, 1.2 mmol) in DMF (2.0 mL, 25.8 mmol) at 0°C, and stirred room
temperature for 10 minutes. Saturated aqueous NaHCO (5 mL) was added and the
mixture was stirred at room temperature for 2 hours. The mixture was extracted with DCM
(3x5 mL), the DCM extracts were combined, washed with saturated aqueous NaCl, dried
over Na SO , and concentrated to yield a white solid residue. The crude solid was purified
be preparative HPLC C18 column chromatography (small column; 40-90% MeCN in water
with 0.05% TFA) to yield the title compound (40.0 mg) as a white solid. MS m/z [M+H]
calc'd for C H ClNO , 448.14; found 448.1.
23 26 6
I. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Isobutyl Ester
O OH
4.0 M HCl in 1,4-dioxane (216 µL, 862 µmol) was added to a suspension of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (75.0 mg,
216 µmol) in isobutyl alcohol (0.5 mL, 5.4 mmol), and the resulting mixture was stirred at
60°C for 2 hours. The mixture was then concentrated in vacuo to yield a white solid. The
white solid was dissolved in DCM and DIPEA (113 µL, 647 µmol) was then added to the
mixture followed by ~0.22 mL of a 1M t-butyl oxalyl chloride solution in DCM (0.2
mmol) dropwise. The resulting mixture was stirred at room temperature for 30 minutes
and then concentrated in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.3 mL, 7.7
mmol) solution was added to the yellow liquid and the resulting mixture was stirred at
room temperature for 30 minutes and then concentrated in vacuo to yield a clear yellow
liquid. The crude liquid was purified (preparative scale HPLC C18 column
chromatography, 40-90% MeCN in water with 0.05% TFA) to yield the title compound
(70.5 mg, purity 99%) as a white solid. MS m/z [M+H] calc'd for C H ClNO , 448.14;
23 26 6
found 448.1.
J. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Isopropyl Ester
O OH
4.0 M HCl in 1,4-dioxane (216 µL, 862 µmol) was added to a suspension of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (75.0 mg,
216 µmol) in isopropyl alcohol (0.5 mL, 6.5 mmol) and the resulting mixture was stirred at
60°C overnight. The mixture was then concentrated in vacuo to yield a white solid. The
white solid was dissolved in DCM and DIPEA (113 µL, 647 µmol) was then added to the
mixture followed by ~0.22 mL of a 1M t-butyl oxalyl chloride solution in DCM (0.2
mmol) dropwise. The resulting mixture was stirred at room temperature for 30 minutes
and then concentrated in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.3 mL, 7.7
mmol) solution was added to the yellow liquid and the resulting mixture was stirred at
room temperature for 30 minutes and then concentrated in vacuo to yield a clear yellow
liquid. The crude liquid was purified (preparative scale HPLC C18 column
chromatography, 40-90% MeCN in water with 0.05% TFA) to yield the title compound
(62.8 mg, purity 98%) as a white solid. MS m/z [M+H] calc'd for C H ClNO , 434.13;
22 24 6
found 434.1.
K. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Heptyl Ester
O OH
NH NH
OH OH
4.0 M HCl in 1,4-dioxane (216 µL, 862 µmol) was added to a suspension of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (75.0 mg,
216 µmol) in 1-heptanol (250 µL, 1.8 mmol) and the resulting mixture was stirred at 60°C
for 2 hours. The mixture was then concentrated in vacuo to yield a white solid, which was
purified (Interchim reverse phase chromatography column; 30-90% MeCN in water
gradient with 0.5% TFA). The purified white solid was dissolved in DCM and DIPEA
(113 µL, 647 µmol) was then added to the mixture followed by ~0.22 mL of a 1M t-butyl
oxalyl chloride solution in DCM (0.2 mmol) dropwise. The resulting mixture was stirred
at room temperature for 30 minutes and then concentrated in vacuo to yield a yellow liquid.
A TFA/DCM (1:1, 1.3 mL, 7.7 mmol) solution was added to the yellow liquid and the
resulting mixture was stirred at room temperature for 30 minutes and then concentrated in
vacuo to yield a clear yellow liquid. The crude liquid was purified (preparative scale
HPLC C18 column chromatography, 40-90% MeCN in water with 0.05% TFA) to yield
the title compound (43.3 mg, purity 99%) as a white solid. MS m/z [M+H] calc'd for
C H ClNO , 490.19; found 490.2.
26 32 6
L. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid 3,3,3-
Trifluoropropyl Ester
O OH
NH NH
OH OH
4.0 M HCl in 1,4-dioxane (287 μL, 1.2 mmol) was added to a suspension of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (50.0 mg,
144 μmol) in 3,3,3-trifluoropropanol (492 mg, 4.3 mmol) and the resulting mixture was
stirred at 80°C for 12 hours. The mixture was then concentrated in vacuo to yield a white
solid, which was dissolved in DCM (1.0 mL) and ~0.2 mL of a 1M t-butyl oxalyl chloride
solution in DCM (0.2 mmol). DIPEA (75.1 μL, 431 μmol) was then added dropwise and
the resulting mixture was stirred at room temperature for 30 minutes and then concentrated
in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.3 mL, 7.7 mmol) solution was
added to the yellow liquid and the resulting mixture was stirred at room temperature for 30
minutes and then concentrated in vacuo to yield a clear yellow liquid. The crude liquid
was purified (preparative scale HPLC C18 column chromatography, 40-90% MeCN in
water with 0.05% TFA) to yield the title compound (44.9 mg, purity 99%) as white solid.
MS m/z [M+H] calc'd for C H ClF NO , 488.10; found 488.1.
22 21 3 6
M. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid 2,2,2-
Trifluoroethyl Ester
O O OH
OH OH
4.0 M HCl in 1,4-dioxane (287 μL, 1.2 mmol) was added to a suspension of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (50.0 mg,
144 μmol) in 2,2,2-trifluoroethanol (0.5 mL, 6.9 mmol) and the resulting mixture was
stirred at 110°C for 12 hours. The mixture was then concentrated in vacuo to yield a white
solid, which was dissolved in DCM (1.0 mL) and ~0.2 mL of a 1M t-butyl oxalyl chloride
solution in DCM (0.2 mmol). DIPEA (75.1 μL, 431 μmol) was then added dropwise and
the resulting mixture was stirred at room temperature for 30 minutes and then concentrated
in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.3 mL, 7.7 mmol) solution was
added to the yellow liquid and the resulting mixture was stirred at room temperature for 30
minutes and then concentrated in vacuo to yield a clear yellow liquid. The crude liquid
was purified (preparative scale HPLC C18 column chromatography, 40-90% MeCN in
water with 0.05% TFA) to yield the title compound (22.5 mg, purity 98%) as a white solid.
MS m/z [M+H] calc'd for C H ClF NO , 474.09; found 474.1.
21 19 3 6
N. (2R,4R)(3'-Chlorobiphenylyl)hydroxy[(3,3,3-trifluoropropoxyoxalyl)-
amino]pentanoic Acid
Bn NH
OH OH
Cl Cl
Benzyl alcohol (13.0 mL, 126 mmol) was added to (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid ethyl ester (1.9 g, 5.3 mmol) followed by
4.0 M HCl in 1,4-dioxane (5.3 mL, 21.3 mmol), and the mixture was stirred at 60°C for 1
hour. The mixture was purified (Interchim reverse phase chromatography column; 30-90%
MeCN in water with 0.05% TFA) to yield (2R,4R)amino(3'-chlorobiphenylyl)
hydroxy-pentanoic acid benzyl ester (2.2 g) as a white solid. (evaporated in vacuo with
water (4 x 300 mL) to remove excess benzyl alcohol).
O O F
Bn NH
2 HO
3,3,3-trifluoropropyl oxalyl chloride was prepared by adding oxalyl chloride (51.6
μL, 610 μmol) to a solution of 3,3,3-trifluoropropanol (62.6 mg, 549 μmol) in ether (500
μL, 4.8 mmol). The resulting mixture was stirred at room temperature for 1 hour and then
concentrated in vacuo yield a clear colorless liquid. A ~1M solution of the oxalyl chloride
was prepared by dissolving the resulting liquid in ~0.61 mL DCM.
A 3,3,3-trifluoropropyl oxalyl chloride solution (~140 μL) was added to a solution
of (2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid benzyl ester (50.0
mg, 122 μmol) in DCM (1.0 mL) at 0 °C, and the mixture was stirred at 0°C for 15
minutes. Saturated aqueous NaHCO (1 mL) was added and the mixture was stirred at
room temperature for 1 hour. The layers were separated and the aqueous layer was
extracted with DCM (2x2 mL). The DCM layers were combined, dried over Na SO , and
concentrated to yield a clear yellow liquid. 10% Pd/C, 50% wet (0.45 mmol/g loading;
13.6 mg, 6.1 μmol) was added to a solution of the yellow liquid in DCM and THF (1.0
mL), and the mixture was stirred under hydrogen for 30 minutes. The mixture was filtered
and the filtrate was concentrated to yield a clear yellow liquid. The crude liquid was
purified by preparative HPLC (40-90% MeCN in water with 0.05% TFA) to yield the title
compound (16.5mg, purity 99%) as a white solid. MS m/z [M+H] calc'd for
C H ClF NO , 488.10; found 4880.
22 21 3 6
O. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
2,2,3,3,3-Pentafluoropropyl Ester
O OH
NH NH O
OH OH
Cl Cl
A ~1M solution of t-butyl oxalyl chloride (~0.2 mL) was added to a solution of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid 2,2,3,3,3-
pentafluoropropyl ester (50.0 mg, 111 μmol) in DCM (1.0 mL) at 0°C followed by the
dropwise addition over 10 minutes of DIPEA (21.2 μL, 122 μmol). The mixture was
stirred at 0°C for 15 minutes. Saturated aqueous NaHCO (5 mL) was added and the
mixture was extracted with DCM (3x5 mL). The DCM extracts were combined, dried over
Na SO , and concentrated to yield a clear colorless liquid. The crude liquid was purified
by flash chromatography (50 % EtOAc/hexanes to yield a clear colorless liquid. 1:1
TFA/DCM (1.0 mL) was added to a solution of the colorless liquid and stirred at room
temperature for 30 minutes. The mixture was concentrated in vacuo to yield a clear yellow
liquid. The crude liquid was purified preparative HPLC (40%-90% MeCN in water with
0.05% TFA) to yield the title compound (21.6 mg, purity 98%) as a white solid. MS m/z
[M+H] calc'd for C H ClF NO , 524.08; found 524.0.
22 19 5 6
P. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid 5-
Methyloxo-[1,3]dioxolylmethyl Ester
O OH
A ~1M solution of t-butyl oxalyl chloride (160 μL) was added to a solution of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid 5-methyl
oxo[1,3]dioxolylmethyl ester (50.0 mg, 116 μmol) in DCM (1.00 mL, 15.6 mmol) at
0°C followed by the dropwise addition over 10 minutes of N,N-diisopropylamine (17.8 μL,
127 μmol). The resulting mixture was stirred at 0°C for 15 minutes, then concentrated in
vacuo. 1:1 TFA/DCM (1.0 mL, 6.2 mmol) was added to the residue and the resulting
mixture was stirred at room temperature for 30 minutes. The mixture was concentrated in
vacuo to yield a clear yellow liquid. The crude liquid was purified (preparative scale C18
column chromatography, small column, using 30-90% MeCN in water with 0.05% TFA) to
yield the title compound as a white solid (9.6 mg). MS m/z [M+H] calc'd for
C H ClNO , 504.10; found 504.0.
24 22 9
Q. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Butyryloxymethyl Ester
O O OH
A ~1M solution of t-butyl oxalyl chloride (160 μL) was added to a solution of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid butyryloxymethyl
ester (48.6 mg, 116 μmol) in DCM (1.00 mL, 15.6 mmol) at 0°C followed by the dropwise
addition over 10 minutes of N,N-diisopropylamine (17.8 μL, 127 μmol). The resulting
mixture was stirred at 0°C for 15 minutes, then concentrated in vacuo. 1:1 TFA/DCM (1.0
mL, 6.2 mmol) was added to the residue and the resulting mixture was stirred at room
temperature for 30 minutes. The mixture was concentrated in vacuo to yield a clear yellow
liquid. The crude liquid was purified (preparative scale C18 column chromatography,
small column, using 30-90% MeCN in water with 0.05% TFA) to yield the title compound
as a white solid (10.2 mg). MS m/z [M+H] calc'd for C H ClNO , 492.13; found 492.0.
24 26 8
R. (2R,4R)(3'-Chloro-biphenylyl)hydroxy(oxalylamino)pentanoic Acid
Acetoxymethyl Ester
HO O O
O O O
HO O HO O HO O
O O O
O O OH
Cl Cl Cl
To a solution of (2R,4R)(t-butoxyoxalylamino)(3'-chlorobiphenylyl)
hydroxypentanoic acid (200 mg, 450 μmol) and bromomethyl acetate (97 mg, 0.9 mmol) in
DMF (2 mL) was added 2, 6-lutidine (144 mg, 1.3 mmol) and NaI (67 mg, 450 μmol).
After stirring at room temperature for 24 hours, the mixture was diluted with water (20
mL) and extracted with EtOAc (2x20 mL). The combined organic layers were washed
with saturated aqueous NaCl (2x70 mL), dried over anhydrous Na SO , filtered, and
concentrated to give the crude product which was further purified by preparative TLC
(PE:EtOAc =2:1) to yield Compound 1 (100 mg) as a yellow solid. LC-MS: 542[M+Na] .
To a solution of Compound 1 (100 mg, 0.2 mmol) in DCM (5 mL) was added TFA
(2 mL) at 0°C. The mixture was stirred at room temperature for 2 hours, the solvent was
removed, and the residue was further purified by preparative TLC (DCM:MeOH = 8:1) to
yield the title compound as a white solid (10 mg). LC-MS: 464[M+H] . H NMR (400
MHz, MeOD) δ 7.61 (s, 1H), 7.55 (d, J=8.0 Hz, 3H), 7.42 (t, J=7.8 Hz, 1H), 7.34 (d, J=8.1
Hz, 3H), 5.78 (s, 2H), 4.40 (s, 1H), 4.31 (t, J=5.9 Hz, 1H), 2.94 (ddd, J=22.0, 13.8, 7.2 Hz,
2H), 2.09 (m, 5H).
S. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Ethoxycarbonyloxymethyl Ester
HO O O O
HO O O
HO HO
O OH
Cl Cl
To a solution of (2R,4R)(t-butoxyoxalylamino)(3'-chlorobiphenylyl)
hydroxypentanoic acid (100 mg, 220 μmol) and chloromethyl ethyl carbonate (61 mg, 440
μmol) in DMF (3 mL) was added 2, 6-lutidine (72 mg, 660 μmol) and NaI (33 mg, 220
μmol). After stirring at room temperature for 24 hours, the mixture was diluted with water
(20 mL) and extracted with EtOAc (2x20 mL). The combined organic layers were washed
with saturated aqueous NaCl (2x70 mL), dried over anhydrous Na SO , filtered, and
concentrated to give the crude product which was further purified by preparative TLC
(PE:EtOAc =2:1) to yield Compound 1 (40 mg) as a yellow solid. LC-MS: 572[M+Na] .
To a solution of Compound 1 (40 mg, 70 μmol) in DCM (3 mL) was added TFA (1
mL) at 0°C. The mixture was stirred at room temperature for 2 hours, the solvent was
removed, and the residue was further purified by preparative TLC (DCM:MeOH = 8:1) to
yield the title compound as a white solid (18 mg). LC-MS: 494[M+H] . H NMR (400
MHz, MeOD) δ 7.55 (m, 4H), 7.38 (m, 4H), 5.80 (d, J=18.6 Hz, 2H), 4.34 (s, 2H), 4.21
(dd, J=14.3, 7.1 Hz, 2H), 2.95 (m, 2H), 2.07 (d, J=28.0 Hz, 2H), 1.29 (dd, J=12.6, 5.5 Hz,
3H). MS m/z [M+H] calc'd for C H ClNO , 494.11; found 494.
23 24 9
T. (2R,4R)(3'-Chlorobiphenylyl)hydroxy[(2-methoxyethoxyoxalyl)amino]-
pentanoic Acid
Bzl NH
2 NH
DIPEA (64 μL, 366 μmol) was added to a solution of (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid benzyl ester (50.0 mg, 122 μmol) in DCM
(3 mL) followed by the dropwise addition of a 1.0M chloro-oxo-acetic acid 2-
methoxyethyl ester (22 mg, 134 μmol) solution in DCM. The resulting mixture was stirred
at room temperature for 30 minutes, then concentrated to yield a clear yellow liquid. The
crude liquid was purified (Interchim C18 chromatography column, 20g, 340-90% MeCN in
water with 0.05% TFA). THF (3 mL) was added to the purified material, followed by the
addition of palladium carbon (10wt% on carbon, wet 50g, 12.9 mg, 12 μmol) and the
mixture was stirred under hydrogen for 30 minutes. The mixture was filtered and
concentrated in vacuo, and the residue dissolved in AcOH (0.5 mL) and purified by
preparative HPLC to yield the title compound (9.8 mg). MS m/z [M+H] calc'd for
C H ClNO , 450.12; found 450.2.
22 24 7
U. (2R,4R)(3'-Chlorobiphenylyl)hydroxy[(2-phenoxyethoxyoxalyl)amino]-
pentanoic Acid
Bzl NH
Cl Cl
DIPEA (64 μL, 366 μmol) was added to a solution of (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid benzyl ester (50.0 mg, 122 μmol) in DCM
(3 mL) followed by the dropwise addition of a 1.0M chloro-oxo-acetic acid 2-
phenoxyethyl ester (31 mg, 134 μmol) solution in DCM. The resulting mixture was stirred
at room temperature for 30 minutes, then concentrated to yield a clear yellow liquid. The
crude liquid was purified (Interchim C18 chromatography column, 20g, 340-90% MeCN in
water with 0.05% TFA). THF (3 mL) was added to the purified material, followed by the
addition of palladium carbon (10wt% on carbon, wet 50g, 12.9 mg, 12 μmol) and the
mixture was stirred under hydrogen for 30 minutes. The mixture was filtered and
concentrated in vacuo, and the residue dissolved in AcOH (0.5 mL) and purified by
preparative HPLC to yield the title compound (3.5 mg). MS m/z [M+H] calc'd for
C H ClNO , 512.14; found 512.2.
27 26 7
V. (2R,4R)(3'-Chlorobiphenylyl)[(3-ethoxypropoxyoxalyl)amino]hydroxy-
pentanoic Acid
O O O
Bzl NH
O HO
OH Cl
DIPEA (64 μL, 366 μmol) was added to a solution of (2R,4R)amino(3'-
chlorobiphenylyl)hydroxypentanoic acid benzyl ester (50.0 mg, 122 μmol) in DCM
(3 mL) followed by the dropwise addition of a 1.0M chloro-oxo-acetic acid 3-ethoxypropyl
ester (26 g, 134 μmol) solution in DCM. The resulting mixture was stirred at room
temperature for 30 minutes, then concentrated to yield a clear yellow liquid. The crude
liquid was purified (Interchim C18 chromatography column, 20g, 340-90% MeCN in water
with 0.05% TFA). THF (3 mL) was added to the purified material, followed by the
addition of palladium carbon (10wt% on carbon, wet 50g, 12.9 mg, 12 μmol) and the
mixture was stirred under hydrogen for 30 minutes. The mixture was filtered and
concentrated in vacuo, and the residue dissolved in AcOH (0.5 mL) and purified by
preparative HPLC to yield the title compound (10.5 mg). MS m/z [M+H] calc'd for
C H ClNO , 478.16; found 478.2.
24 28 7
W. (2R,4R)(3'-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid (S)
Methoxycarbonylaminomethylbutyryloxymethyl Ester
Following the methods described herein, the title compound was also prepared
(12.6 mg). MS m/z [M+H] calc'd for C H ClN O , 579.17; found 579.2
27 31 2 10
EXAMPLE 3
A. (2R,4R)(2',5'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
O OH
O NH
O OH
Br Cl
A solution of ethyl oxalyl chloride (42.4 µL, 0.4 mmol) in DCM (0.4 mL, 6 mmol)
was added to a solution of (2R,4R)amino(4-bromophenyl)hydroxypentanoic acid
ethyl ester (80 mg, 0.2 mmol) and Et N (0.1 mL, 0.8 mmol) in DCM (1 mL), and the
resulting mixture was stirred at room temperature for 30 minutes, then evaporated under
reduced pressure. The product was then combined with 2,5-dichlorophenylboronic acid
(72.4 mg, 0.4 mmol), K CO (104.9 mg, 759 µmol), EtOH (0.9 mL), and water (0.2 mL).
The mixture was placed under nitrogen and SilicaCat DPP-Pd (0.28 mmol/g loading, 90.4
mg, 25.3µmol) was added. The mixture was microwaved at 120°C for 20 minutes, then
filtered. 1 M Aqueous LiOH (2.5 mL, 2.5 mmol) was added to yield the title compound
(11.9 mg, purity 100%). MS m/z [M+H] calc'd for C H Cl NO , 426.04; found 426.0.
19 17 2 6
B. (2R,4R)(2',5'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Isobutyl Ester
O OH
2 NH
4.0 M HCl in 1,4-dioxane (196 µL, 785 µmol) was added to a suspension of
(2R,4R)amino(2',5'-dichlorobiphenylyl)hydroxy-pentanoic acid ethyl ester
(75.0 mg, 196 µmol) in isobutyl alcohol (0.5 mL, 5.4 mmol), and the resulting mixture was
stirred at 60°C for 2 hours. The mixture was then concentrated in vacuo to yield a white
solid. The white solid was dissolved in DCM (1 mL) and DIPEA (102 µL, 588 µmol) was
then added to the mixture followed by ~0.2 mL of a 1M t-butyl oxalyl chloride solution in
DCM (0.2 mmol) dropwise. The resulting mixture was stirred at room temperature for 30
minutes and then concentrated in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.1
mL, 7.0 mmol) solution was added to the yellow liquid and the resulting mixture was
stirred at room temperature for 30 minutes and then concentrated in vacuo to yield a clear
yellow liquid. The crude liquid was purified (preparative scale HPLC C18 column
chromatography, 40-90% MeCN in water with 0.05% TFA) to yield the title compound (80
mg, purity 99%) as a white solid. MS m/z [M+H] calc'd for C H Cl NO , 482.11; found
23 25 2 6
482.1.
C. (2R,4R)(2',5'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
Isopropyl Ester
Cl Cl
4.0 M HCl in 1,4-dioxane (196 µL, 785 µmol) was added to a suspension of
(2R,4R)amino(2',5'-dichlorobiphenylyl)hydroxy-pentanoic acid ethyl ester
(75.0 mg, 196 µmol) in isopropyl alcohol (0.5 mL, 6.5 mmol), and the resulting mixture
was stirred at 60°C overnight. The mixture was then concentrated in vacuo to yield a white
solid. The white solid was dissolved in DCM (1 mL) and DIPEA (102 µL, 588 µmol) was
then added to the mixture followed by ~0.2 mL of a 1M t-butyl oxalyl chloride solution in
DCM (0.2 mmol) dropwise. The resulting mixture was stirred at room temperature for 30
minutes and then concentrated in vacuo to yield a yellow liquid. A TFA/DCM (1:1, 1.1
mL, 7.0 mmol) solution was added to the yellow liquid and the resulting mixture was
stirred at room temperature for 30 minutes and then concentrated in vacuo to yield a clear
yellow liquid. The crude liquid was purified (preparative scale HPLC C18 column
chromatography, 40-90% MeCN in water with 0.05% TFA) to yield the title compound
(60.6 mg, purity 98%) as a white solid. MS m/z [M+H] calc'd for C H Cl NO , 468.09;
22 23 2 6
found 468.1.
D. (2R,4R)(2',5'-Dichlorobiphenylyl)hydroxy(isobutoxyoxalylamino)-
pentanoic Acid
Cl Cl
Cl Cl
1.0 M Aqueous HCl (3.5 mL, 3.5 mmol) was added to (2R,4R)amino(2',5'-
dichlorobiphenylyl)hydroxy-pentanoic acid ethyl ester (155 mg, 405 µmol) and the
mixture was stirred at 100°C for 1 hour then concentrated. The product was combined
with Et N (226 µL, 1.6 mmol) in DMF (2.5 mL, 32.3 mmol). Chloro-oxo-acetic acid
isobutyl ester (140 mg, 851 µmol) was added dropwise at 0°C and the resulting mixture
was stirred at room temperature for 10 minutes. Saturated aqueous NaHCO (5 mL) was
added and the mixture was stirred at room temperature for 2 hours. The mixture was
extracted with DCM (3x5 mL), the extracts were combined, washed with a saturated
aqueous NaCl solution, dried over Na SO and concentrated to yield a white solid residue.
The crude solid was purified via preparative HPLC (C18 column; 40-90% MeCN in water
with 0.05% TFA) to yield the title compound (98.0 mg, purity 99%) as a white solid. MS
m/z [M+H] calc'd for C H Cl NO , 482.11; found 482.1.
23 25 2 6
EXAMPLE 4
(2R,4R)(3-Chlorobiphenylyl)hydroxy(oxalylamino)pentanoic Acid
HO OH
NH HO
A solution of ethyl oxalyl chloride (41 µL, 0.4 mmol) in DCM (0.5 mL) was added
to a solution of (3R,5R)amino(4-bromochloro-phenyl)ethoxy-hexenol (96
mg, 0.3 mmol) and Et N (0.1192 mL, 0.8556 mmol) in DCM (1.4 mL), and stirred for 20
minutes at room temperature. The mixture was evaporated under reduced pressure and
combined with phenylboronic acid (52.2 mg, 0.4 mmol), K CO (100 mg, 0.9 mmol),
water (0.2 mL), and EtOH (1 mL). The resulting mixture was placed under nitrogen, and
SilicaCat DPP-Pd (0.28 mmol/g loading; 100 mg, 0.03 mmol) was added. The mixture
was heated at 120°C for 20 minutes until the reaction was complete. The mixture was
filtered and a solution of 1 M aqueous LiOH (3 mL, 3 mmol) was added. The product was
then purified (Interchim reverse phase chromatography column) to yield the title
compound (12.6 mg). MS m/z [M+H] calc'd for C H ClNO , 392.08; found 392.2.
19 18 6
EXAMPLE 5
Following the procedures described in the examples herein, and substituting the
appropriate starting materials and reagents, the following compounds were prepared:
(R )
(R )
MS m/z: [M+H]
1 5 6
Ex. R a R b R Formula
calcd found
2'-CH ,
1 H 0 - 2 C H ClNO 406.10 406.0
20 6
'-Cl
-CH- 2'-CH ,
2 0 - 2 C H ClNO 448.14 448.0
23 26 6
(CH ) 5'-Cl
MS m/z: [M+H]
1 5 6
Ex. R a R b R Formula
calcd found
2'-CH ,
3 -CH CH 0 - 2 C H ClNO 434.13 434.4
2 3 22 24 6
'-Cl
-CH -CH- 2'-CH ,
4 0 - 2 C H ClNO 462.16 462.0
24 28 6
(CH ) 5'-Cl
2'-F, 5'-
H 0 - 2 C H ClFNO 410.07 410.0
19 17 6
2'-F, 5'CH CH 0 - 2 C H ClFNO 438.10 438.0
2 3 21 21 6
-CH CH- 2'-F, 5'-
7 0 - 2 C H ClFNO 466.14 466.0
23 25 6
(CH ) Cl
-CH- 2'-F, 5'-
8 0 - 2 C H ClFNO 452.12 452.0
22 23 6
(CH ) Cl
9 H 1 3-Cl 1 3'-Cl C H Cl NO 426.04 426.0
19 17 2 6
-CH CH 1 3-Cl 1 3'-Cl C H Cl NO 454.07 454.0
2 3 21 21 2 6
-CH CH-
11 1 3-Cl 1 3'-Cl C H Cl NO 482.11 482.0
23 25 2 6
(CH )
-CH-
12 1 3-Cl 1 3'-Cl C H Cl NO 468.09 468.1
22 23 2 6
(CH )
2'-F, 5'- C H Cl FN
18 15 2 2
13 H 1 3-Cl 2 445.03 445.0
Cl O
1. (2R,4R)(5'-Chloro-2'-methylbiphenylyl)hydroxy(oxalylamino)-
pentanoic acid
2. (2R,4R)(5'-Chloro-2'-methylbiphenylyl)hydroxy(oxalylamino)-
pentanoic acid isopropyl ester
3. (2R,4R)(5'-Chloro-2'-methylbiphenylyl)hydroxy(oxalylamino)pentanoic
acid ethyl ester
4. (2R,4R)(5'-Chloro-2'-methylbiphenylyl)hydroxy(oxalylamino)pentanoic
acid isobutyl ester
5. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(oxalylamino)pentanoic
acid
6. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(oxalylamino)pentanoic
acid ethyl ester
7. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(oxalylamino)pentanoic
acid isobutyl ester
8. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(oxalylamino)pentanoic
acid isopropyl ester
9. (2R,4R)(3,3'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic acid
. (2R,4R)(3,3'-Dichlorobiphenylyl)hydroxy(isobutoxyoxalylamino)-
pentanoic acid
11. (2R,4R)(3,3'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic acid
isobutyl ester
12. (2R,4R)(3,3'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic acid
isopropyl ester
13. (R)[N-(3,5'-Dichloro-2'-fluorobiphenylylmethyl)-N'-oxalyl-hydrazino]
hydroxypropionic acid
(R )
(R )
MS m/z: [M+H]
4 5 6
Ex. R a R b R Formula
calcd found
2'-F, 5'CH CH 0 - 2 C H ClFNO 438.10 438.2
2 3 21 21 6
-CH- 2'-F, 5'-
0 - 2 C H ClFNO 452.12 452.2
22 23 6
(CH ) Cl
-CH CH- 2'-F, 5'-
16 0 - 2 C H ClFNO 466.14 466.4
23 25 6
(CH ) Cl
-CH CH-
17 1 3-Cl 1 3'-Cl C H Cl NO 482.11 482.1
23 25 2 6
(CH )
14. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)(ethoxyoxalylamino)hydroxy-
pentanoic acid
. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(isopropoxyoxalyl-
amino)-pentanoic acid
16. (2R,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxy(isobutoxyoxalylamino)-
pentanoic acid
17. (2R,4R)(3,3'-Dichlorobiphenylyl)hydroxy(oxalylamino)pentanoic acid
ethyl ester
EXAMPLE 6
A. (2S,4S)Biphenylylhydroxymethyl(oxalylamino)pentanoic Acid
O O OH
Ethyl oxalyl chloride (27 µL, 0.2 mmol, 1.1 eq) was added to a solution of (2S,4S)-
4-aminobiphenylylhydroxymethyl-pentanoic acid ethyl ester (HCl salt; 80 mg,
0.22 mmol) in DMF (0.5 mL)/DCM (0.5 mL), and stirred at room temperature for 20
minutes. The solvent was removed and the residue was dissolved in LiOH (monohydrate;
92.2 mg, 2.2 mmol), water (1.0 mL) and EtOH (2.0 mL), and stirred at room temperature
for 30 minutes. The reaction was quenched with AcOH and the solvent was removed. The
residue was dissolved into AcOH/MeCN and purified by preparative HPLC. The clean
fractions were combined and lyophilized to yield the title compound (37 mg, purity 95%).
MS m/z [M+H] calc'd for C H NO , 372.14; found 372.2.
21 6
B. (2S,4S)Biphenylylhydroxymethyl(oxalylamino)pentanoic Acid Ethyl
Ester
O OH
Oxalyl chloride (232 µL, 2.8 mmol) and t-butyl alcohol (228 µL) were combined in
ether (6.7 mL) under nitrogen at 0°C. The resulting mixture was stirred for 30 minutes at
room temperature. The solvent was evaporated under vacuum to form chloro-oxo-acetic
acid t-butyl ester, which was then dissolved in DCM (10 mL) and combined with (2S,4S)-
4-aminobiphenylylhydroxymethyl-pentanoic acid ethyl ester (HCl salt; 667 mg,
1.8 mmol), which had been dissolved in DCM with Et N (2.6 mL) at 0°C. The resulting
mixture was stirred for 5 minutes at room temperature. The crude product was
concentrated, dissolved in DCM and purified by flash chromatography (20-80%
EtOAc/hexanes). The solvent was removed and the residue was dissolved in DCM (5 mL)
and TFA (1 mL), and stirred for 1 hour. The product was dried under vacuum and purified
by preparative HPLC to yield the title compound (135 mg, purity 95%). MS m/z [M+H]
calc'd for C H NO , 400.17; found 400.2.
22 25 6
EXAMPLE 7
A. (2S,4S)(2'-Fluorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic Acid
Butyl Ester
O O OH
NH NH
Oxalyl chloride (44.1 µL. 0.5 mmol) and t-butyl alcohol (46.5 µL) were combined
in ether (1 mL) and was stirred for 30 minutes at room temperature. The solvent was
evaporated under vacuum to form chloro-oxo-acetic acid t-butyl ester, which was then
dissolved in DCM (2 mL). (2S,4S)amino(2'-fluorobiphenylyl)
hydroxymethylpentanoic acid ethyl ester (HCl salt; 120 mg, 0.3 mmol) was combined with
1-butanol (3 mL) and 4 M of HCl in 1,4-dioxane (3 mL) and stirred at 60°C for 2 hours.
The solvent were evaporated and azeotroped with toluene (2x). and the product was
dissolved in Et N (155 µL) and DCM, then combined with the chloro-oxo-acetic acid t-
butyl ester. The resulting mixture was stirred for 20 minutes at room temperature. The
solvent was evaporated and the residue was redissolved in 1:1 TFA:DCM, and stirred for
minutes at 40°C. AcOH was added and the product was purified by preparative HPLC
to yield the title compound (30 mg, purity 95%). MS m/z [M+H] calc'd for C H FNO ,
24 28 6
446.19; found 446.4.
B. (2S,4S)(2'-Fluorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic Acid
O OH
Ethyl oxalyl chloride (13.8 µL, 0.1 mmol) and DIPEA (39.2 µL, 0.2 mmol) were
combined with (2S,4S)amino(2'-fluorobiphenylyl)hydroxymethylpentanoic acid
ethyl ester (HCl salt; 43 mg, 0.1 mmol) dissolved in DCM (0.9 mL). The mixture was
stirred at room temperature for 10 minutes, then concentrated under vacuum. 1 M aqueous
LiOH (0.9 mL) and EtOH (0.9 mL) was added and the resulting mixture was stirred at
room temperature for 1 hour. The reaction mixture was quenched with AcOH and the
solvent was evaporated. The residue was dissolved in AcOH/MeCN and purified by
preparative HPLC. The clean fractions were combined and lyophilized to yield the title
compound (32.7 mg, purity 95%). MS m/z [M+H] calc'd for C H FNO , 390.13; found
20 6
390.2.
EXAMPLE 8
Following the procedures described in the examples herein, and substituting the
appropriate starting materials and reagents, the following compound were prepared:
O OH
R NH
MS m/z: [M+H]
Ex. R R Formula
calcd found
1 -CH CH F C H FNO 418.16 418.4
2 3 22 24 6
2 H F C H FNO 390.13 390.4
20 6
3 H Cl C H ClNO 406.10 406.4
20 6
1. (2S,4S)(3'-Fluorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid ethyl ester
2. (2S,4S)(3'-Fluorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid
3. (2S,4S)(3'-Chlorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid
O OH
R NH
MS m/z: [M+H]
Ex. R R Formula
calcd found
4 H F C H FNO 390.13 390.2
20 6
4. (2S,4S)(4'-Fluorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid
O OH
R NH
MS m/z: [M+H]
Ex. R R Formula
calcd found
H Cl C H ClNO 406.10 406.0
20 6
6 H Cl C H ClNO 406.10 406.0
20 6
. (2S,4S)(3-Chlorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid
6. (2R,4S)(3-Chlorobiphenylyl)hydroxymethyl(oxalylamino)pentanoic
acid
EXAMPLE 9
A. (2S,4R)Biphenylylhydroxymethylmethyl(oxalylamino)pentanoic Acid
O OH
2 HO
Ethyl oxalyl chloride (13.1 µL, 0.1 mmol) was combined with (2S,4R)amino
biphenylylhydroxymethylmethylpentanoic acid ethyl ester (40 mg, 0.1 mmol)
dissolved in DCM (0.3 mL) and a small amount of DMF. The mixture was stirred at room
temperature for 20 minutes, then concentrated under vacuum. 1 M aqueous NaOH (117
µL) and THF (1.5 mL) was added and the resulting mixture was stirred at room
temperature for 30 minutes. The residue was dissolved in AcOH and purified by
preparative HPLC to yield the title compound (8 mg, purity 95%). MS m/z [M+H] calc'd
for C H NO , 386.15; found 386.0.
21 23 6
B. (2S,4R)Biphenylylhydroxymethylmethyl(oxalylamino)pentanoic Acid
Ethyl Ester
O OH
Oxalyl chloride (12.4 µL. 0.1 mmol) and t-butyl alcohol (13.1 µL) were combined
in ether (0.3 mL) under nitrogen at 0°C. The resulting mixture was stirred for 30 minutes
at room temperature. The solvent was evaporated under vacuum to form chloro-oxo-acetic
acid t-butyl ester, which was then dissolved in DCM (0.7 mL) and combined with (2S,4R)-
4-aminobiphenylylhydroxymethylmethylpentanoic acid ethyl ester (33.4 mg,
98 µmol). Et N (43.6 µL, ) at 0°C was added and the resulting mixture was stirred for 30
minutes at room temperature. The solvent were evaporated and the residue was dissolved
in 1:1 TFA:DCM and stirred for 1 hour. AcOH was added and the product was purified by
preparative HPLC to yield the title compound (7 mg, purity 95%). MS m/z [M+H] calc'd
for C H NO , 414.18; found 414.4.
23 27 6
EXAMPLE 10
(2S,4R)(3'-Fluorobiphenylyl)hydroxymethylmethyl(oxalylamino)pentanoic
Acid
O O OH
Ethyl oxalyl chloride (9.1 µL, 0.1 mmol) was combined with (2S,4R)amino
(3'-fluorobiphenylyl)hydroxymethylmethylpentanoic acid (27 mg, 0.1 mmol)
dissolved in DCM (0.2 mL) and a small amount of DMF. The mixture was stirred at room
temperature for 20 minutes. The solvent was evaporated amd 10 M aqueous NaOH (81.5
µL), and THF (1.0 mL) was added and the resulting mixture was stirred at room
temperature for 30 minutes. The residue was dissolved in AcOH and purified by
preparative HPLC to yield the title compound (6 mg, purity 95%). MS m/z [M+H] calc'd
for C H FNO , 404.14; found 404.4.
21 22 6
EXAMPLE 11
Following the procedures described in the examples herein, and substituting the
appropriate starting materials and reagents, the following compounds were prepared:
O OH
(R )
MS m/z: [M+H]
Ex. b R Formula
calcd found
1 1 2'-F C H FNO 404.14 404.4
21 22 6
2 2 2'-F, 5'-Cl C H ClFNO 438.10 438.2
21 21 6
1. (2S,4R)(2'-Fluorobiphenylyl)hydroxymethylmethyl
(oxalylamino)pentanoic acid
2. (2S,4R)(5'-Chloro-2'-fluorobiphenylyl)hydroxymethylmethyl(oxalyl-
amino)pentanoic acid
O OH
MS m/z: [M+H]
Ex. R Formula
calcd found
3 F C H FNO 404.14 404.4
21 22 6
3. (2S,4R)(4'-Fluorobiphenylyl)hydroxymethylmethyl
(oxalylamino)pentanoic acid
MS m/z: [M+H]
Ex. R Formula
calcd found
4 Cl C H ClNO 476.18 476.2
30 6
4. (2S,4R)(3'-Chlorobiphenylyl)hydroxymethyl(isobutoxyoxalyl-amino)
methylpentanoic acid
EXAMPLE 12
3-(N-Biphenylylmethyl-N'-oxalylhydrazino)hydroxymethylpropionic Acid
HO N OH
O N BOC
3-(N-Biphenylylmethyl-N'-t-butoxycarbonylhydrazino)hydroxy
methylpropionic acid methyl ester (0.1 g, 241 µmol) was dissolved in DCM (1.0 mL), then
TFA (1.0 mL) was added and the mixture was stirred at room temperature for 1 hour. The
mixture was concentrated and the residue was dissolved in DMF (2.00 mL). DIPEA (126
µL, 724 µmol) was added followed by ethyl oxalyl chloride (29.6 µL, 265 µmol) and the
resulting mixture was stirred at room temperature until the reaction was complete (~3
hours). The mixture was concentrated and the residue was dissolved in THF (1.5 mL),
then lithium hydroxide monohydrate (101 mg, 2.4 mmol) in water (1.50 mL) was added
and the mixture was stirred at room temperature for 30 minutes. The reaction was
quenched with AcOH and the solution was concentrated. The crude product was purified
by preparative HPLC (10-70% MeCN/H O) to yield the title compound (10.9 mg, purity
95%). MS m/z [M+H] calc'd for C H N O , 373.13; found 373.2.
19 20 2 6
EXAMPLE 13
(R)[N-(3'-Chlorobiphenylylmethyl)-N'-oxalylhydrazino]hydroxypropionic Acid
(R)[N-(3'-Chlorobiphenylylmethyl)hydrazino]hydroxy-propionic acid
ethyl ester (70 mg, 0.2 mmol) was dissolved in DCM (1.5 mL), followed by the addition of
ethyl oxalyl chloride (24.7 µL, 221 µmol) and DIPEA (69.9 µL, 401 µmol). The mixture
was stirred at room temperature until the reaction was complete (~10 minutes). The
mixture was the concentrated under vacuum. 1 M aqueous lithium hydroxide (1.6 mL, 1.6
mmol) and EtOH (1.5 mL) was added and the mixture was stirred at room temperature
until the reaction was complete (~2 hours). The reaction was quenched with AcOH and the
solvent was evaporated. The residue was dissolved in AcOH/MeCN and purified by
preparative HPLC. The clean fractions were combined and lyophilized to yield the title
compound (8.3 mg, purity 95%). MS m/z [M+H] calc'd for C H ClN O , 393.08; found
18 17 2 6
393.2.
EXAMPLE 14
A. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalylhydrazino]
hydroxypropionic Acid
O OH
HO OH
HO N
Oxalic acid (R)[N-(4-bromobenzyl)-N'-ethoxyoxalylhydrazino]
ethoxycarbonylethyl ester ethyl ester (675 mg, 1.3 mmol) was combined with 5-chloro
fluorophenylboronic acid (273 mg, 1.6 mmol) and K CO (541 mg, 3.9 mmol) in EtOH
(4.6 mL, 78.3 mmol) and water (1.2 mL, 65.2 mmol). The resulting mixture was placed
under nitrogen atmosphere and SilicaCat DPP-Pd (0.28 mmol/g loading; 466 mg, 130
μmol) was then added. The mixture was microwaved at 120°C for 10 minutes, then
filtered and evaporated under reduced pressure. The residue was purified by preparative
HPLC to yield the title compound (40 mg). MS m/z [M+H] calc'd for C H ClFN O ,
18 16 2 6
411.07; found 411.0.
B. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalylhydrazino]
hydroxypropionic Acid Ethyl Ester
2 O N
A ~1M solution of t-butyl oxalyl chloride in DCM (136 μL) was added to a stirred
solution of (R)[N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic acid ethyl ester (HCl salt; 55.0 mg, 136 μmol) in DCM (1.3 mL, 20
mmol) at 0°C. After stirring at room temperature for 2 hours, DIPEA (11.9 μL, 68 μmol)
in a DCM solution (80 μL) was added dropwise. After one minute, additional DIPEA (10
μL) in DCM (80 μL) was added, and the mixture was stirred at room temperature
overnight. The mixture was concentrated and the resulting residue was purified by purified
by flash chromatography (4g silica gel, 0-100% EtOAc/hexanes). The desired fractions
were combined and concentrated to yield a colorless oil (60mg). A portion of this oil (20
mg) was treated with a 1:1 mixture of DCM:TFA (0.2 mL) at room temperature for 20
minutes. The mixture was concentrated, the residue was dissolved in 50% water/AcOH
(1.5 mL), filtered, and purified by reverse phase preparative to yield the title compound (10
mg) as a TFA salt. MS m/z [M+H] calc'd for C H ClFN O , 439.10; found 439.4.
20 2 6
C. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-isobutoxyoxalylhydrazino]
hydroxypropionic Acid
HO N
O OH
Chloro-oxo-acetic acid isobutyl ester was prepared by adding oxalyl chloride (21
μL, 252 μmol) to a solution of isobutanol (21 μL, 226 μmol) in ether (206 μL, 2.0 mmol).
The mixture was stirred at room temperature for 15 min and then evaporated.
The chloro-oxo-acetic acid isobutyl ester was then added to a solution of (R)[N-
(5'-Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic acid 2-oxo
phenylethyl ester (23.0 mg, 50 μmol) in DCM (413 μL, 6.4 mmol) at 0°C. The resulting
mixture was stirred at 0°C for 15 minutes. Saturated aqueous NaHCO was then added and
the layers were separated. The aqueous layer was extracted with DCM. The DCM layers
were combined, dried over MgSO and concentrated to yield a clear yellow liquid. Zinc
(164 mg, 2.5 mmol) was added to a solution of this yellow liquid in AcOH (172 μL, 3.0
mmol) and the mixture was stirred at room temperature for 10 minutes. The mixture was
filtrated using AcOH and water, the solvents were evaporated in vacuo, and the residue
was purified by preparative HPLC to yield the title compound (9.0 mg). MS m/z [M+H]
calc'd for C H ClFN O , 467.13; found 467.1
22 24 2 6
D. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-(2,2-difluoropropoxyoxalyl)-
hydrazino]hydroxypropionic Acid
2 HO N
O N F
2,2-Difluoropropyl oxalyl chloride was prepared by adding oxalyl chloride (21 μL,
252 μmol) to a solution of 2,2-difluoropropanol (21.8 mg, 226 μmol) in ether (206 μL, 2.0
mmol). The mixture was stirred at room temperature for 15 minutes and then evaporated.
The 2,2-difluoropropyl oxalyl chloride was then added to a solution of (R)[N-(5'-
Chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic acid 2-oxo
phenylethyl ester (23.0 mg, 50 μmol) in DCM (413 μL, 6.4 mmol) at 0°C. The resulting
mixture was stirred at 0°C for 15 minutes. Saturated aqueous NaHCO was then added and
the layers were separated. The aqueous layer was extracted with DCM. The DCM layers
were combined, dried over MgSO , and concentrated to yield a clear yellow liquid. Zinc
(164 mg, 2.5 mmol) was added to a solution of this yellow liquid in AcOH (172 μL, 3.0
mmol) and the mixture was stirred at room temperature for 10 minutes. The mixture was
filtrated using AcOH and water, the solvents were evaporated in vacuo, and the residue
was purified by preparative HPLC to yield the title compound (1.1 mg). MS m/z [M+H]
calc'd for C H ClF N O , 489.10; found 489.0.
21 20 3 2 6
E. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalyl-hydrazino]
hydroxypropionic acid 5-Methyloxo-[1,3]dioxolylmethyl Ester
O HO
N NH N N
Cl F Cl
To a solution of (R)[N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic acid 5-methyloxo-[1,3]dioxolylmethyl ester (350 mg, 780 μmol) in
anhydrous DCM (15 mL) was added t-butyl oxalyl chloride (193 mg, 1.2 mmol) and
DIPEA (302 mg, 2.3 mmol) at 0ºC. The resulting mixture was stirred at room temperature
for 5 hours. The mixture was then washed with saturated aqueous NaCl (2x30 mL) and
extracted with DCM (3x50 mL). The combined organic layers were dried over anhydrous
Na SO , and concentrated in vacuo to yield a white solid (300 mg). LC-MS: 523 [M-
tBu+H] .
This solid (100 mg, 170 μmol) was dissolved in TFA (5 mL) and DCM (15 mL).
The resulting mixture was stirred overnight. The mixture was evaporated in vacuo, and the
residue was purified by preparative HPLC to yield the g title compound as a white solid
(20 mg. LC-MS: 523.1 [M+H] . H-NMR: (DMSO-d ): δ 2.14 (s, 3H), 3.17-3.16 (m, 2
H), 4.11-4.08 (m, 2 H), 4.26 (br, 1 H), 4.98 (br, 2 H), 5.50 (br, 1 H), 7.58-7.36 (m, 7 H),
9.94 (s, 1 H), 13.8 (br, 1 H).
F. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-ethoxyoxalylhydrazino]
hydroxypropionic Acid
O O O
O NH
Cl HO N
O OH
O OH
Ethyl oxalyl chloride (12.4 μL, 111 μmol) was added to a solution of (R)[N-(5'-
chloro-2'-fluorobiphenylylmethyl)hydrazino]hydroxypropionic acid 2-oxo
phenylethyl ester (23.0 mg, 50 μmol) in DCM (413 μL, 6.4 mmol) at 0°C and the resulting
mixture was stirred at 0°C for 15 minutes. Saturated aqueous NaHCO (1 mL) was then
added and the layers were separated. The aqueous layer was extracted with DCM (2x2
mL). The DCM layers were combined, dried over MgSO , and concentrated. Zinc (164
mg, 2.5 mmol) was added to a solution of this residue in AcOH (172 μL, 3.0 mmol) and
the resulting mixture was stirred at room temperature for 10 minutes. The mixture was
filtrated and the residue was purified by preparative HPLC to yield the title compound (10
mg). MS m/z [M+H] calc'd for C H ClFN O , 439.10; found 439.1.
20 2 6
G. (R)[N-(5'-Chloro-2'-fluoro-iphenylylmethyl)-N'-oxalylhydrazino]
hydroxypropionic Acid 2,2-Difluoropropyl Ester
O BOC
O OH
HO N
OH F
(R)[N'-t-Butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]2-
hydroxy-propionic acid (15.0 mg, 32 μmol) was combined with HOBt (26.0 mg, 193 μmol)
and EDC (34 μL, 0.2 mmol) in DCM (0.2 mL, 4 mmol). The solution was stirred for 10
minutes and 2,2-difluoropropanol (24.7 mg, 257 μmol) was added. The reaction was
stirred at room temperature and monitored for completion. After 2 hours, the mixture was
concentrated by rotary evaporation and the solvent was removed in vacuo. The resulting
residue was dissolved in DCM (124 μL, 1.9 mmol). TFA (124 μL, 1.6 mmol) was added,
and the resulting mixture was stirred for 2 hours. The solvent was removed in vacuo and
the residue was purified by preparative HPLC to yield the title compound (2.2 mg). MS
m/z [M+H] calc'd for C H ClF N O , 489.10; found 489.1.
21 20 3 2 6
H. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalylhydrazino]
hydroxypropionic Acid Isobutyl Ester
2 HO N
To a mixture of (R)[N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic acid ethyl ester (HCl salt; 500.0 mg, 1.3 mmol) in DCM (6.0 mL, 94
mmol) at room temperature was added di-t-butyldicarbonate (342 μL, 1.5 mmol) and
DIPEA (216 μL, 1.3 mmol). After stirring at room temperature overnight, the mixture was
concentrated and the residue was purified by flash chromatography (12g silica gel, 0-50%
EtOAc/hexanes). The desired fractions were combined and concentrated to give a light
yellowish oil. This oily residue was dissolved in MeOH (6.0 mL, 150 mmol) and water
(1.0 mL, 56 mmol), then treated with LiOH monohydrate (104 mg, 2.5 mmol) at room
temperature for 30 minutes. The mixture was concentrated and the residue was diluted
with water (2.0 mL) and EtOAc (10.0 mL), then acidified with 1N aqueous HCl until
pH~2.0 with vigorous stirring. The organic layer was washed with saturated aqueous NaCl
(2x2.0 mL), dried over Na SO , filtered, and concentrated to give Compound 1 as a white
solid (528.6 mg).
Compound 1 (65.0 mg, 148 μmol) was dissolved in isobutyl alcohol (684 μL, 7.4
mmol). A solution of 4.0 M HCl in 1,4-dioxane (1.2 mL, 4.9 mmol) was added and the
resulting mixture was stirred at room temperature for 2 hours, then at 60°C for an other
couple of hours, until the reaction was complete. The solvent was removed in vacuo to
yield Compound 2, which was used without further purification.
O OH
t-Butyl oxalyl chloride was prepared by adding oxalyl chloride (63 μL, 741 μmol)
to a solution of t-butyl alcohol (43 μL, 444 μmol) in ether (778 μL, 7.4 mmol). The
mixture was stirred at room temperature for 15 minutes, then concentrated in vacuo.
Compound 2 (58.5 mg, 148 μmol) was dissolved in DCM (570 μL, 8.9 mmol) and t-butyl
oxalyl chloride was added. The resulting mixture was stirred at room temperature for 30
minutes and then concentrated in vacuo. The residue was dissolved in a 1:1 DCM:TFA
solution and stirred at room temperature for 1 hour. The solvent was removed in vacuo
and the residue was purified by preparative HPLC to yield the title compound (8.5 mg).
MS m/z [M+H] calc'd for C H ClFN O , 467.13; found 467.0.
22 24 2 6
I. (R)[N'-t-Butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic Acid Ethyl Ester
HO N NH N N
F Cl
To a solution of (R)[N-(5'-chloro-2'-fluorobiphenylylmethyl)hydrazino]
hydroxypropionic acid ethyl ester (200 mg, 0.5 mmol) in DCM (2.0 mL) was added
dropwise a solution of t-butyl oxalyl chloride (165 mg, 1.0 mmol) at 0°C under nitrogen.
The resulting mixture was stirred for 5 minutes and then DIPEA (130 mg, 1.0 mmol). was
added dropwise. The solvent was removed by evaporation, and the residue was purified by
column chromatography (petroleum ether/EtOAc=4:1) to yield the title compound as a
yellow liquid (144 mg). LC-MS: 495 [M+H] . H NMR (CDCl , 400 MHz): δ 1.30 (t, J=
7.1 Hz, 3H), 1.56 (s, 9H), 3.37-3.24 (m, 2H), 4.27- 4.16 (m, 4H), 4.38-4.30 (m, 1H), 7.14-
7.09 (m, 1H), 7.30-7.28 (m, 1H), 7.48-7.41 (m, 3H), 7.56-7.50 (m, 2H), 8.05 (s, 1H).
J. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalylhydrazino]hydroxy-
propionic Acid Ethoxycarbonyloxymethyl Ester
HO N N
A mixture of (R)[N'-t-butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenyl
ylmethyl)hydrazino]hydroxypropionic acid (270 mg, 580 μmol), chloromethyl ethyl
carbonate (160 mg, 1.16 mmol), NaI (174 mg, 1.2 mmol) and 2,6-dimethylpyridine (620
mg, 5.8 mmol) in DMF (10 mL) was stirred at room temperature overnight. The mixture
was poured into water (30 mL) and the mixture was then extracted with EtOAc (3x30 mL).
The combined organic layers were washed with saturated aqueous NaCl (2x30 mL), dried
over anhydrous Na SO , and concentrated in vacuo. The crude Compound 1 (300 mg) was
used without purification. LC-MS: 569 [M+H] .
TFA (1.0 mL) was added dropwise at room temperature to a solution of Compound
1 (300 mg, 530 μmol) in DCM (5 mL). The resulting mixture was stirred for 2 hours at
room temperature, and the solvent was then removed. The residue was purified by column
chromatography (DCM/MeOH, 10:1) to yield the title compound as a yellow liquid (10
mg). LC-MS: 512.9 [M+H] . H NMR (400 MHz, MeOD) δ 1.28 (t, J=7.3 Hz, 3H), 3.24-
3.28 (m, 2H), 4.18-4.20 (m, 4H), 4.41 (br, 1H), 5.80 (dd, J=11.6, 5.8 Hz, 2H), 7.22 (d,
J=10.1 Hz, 1H), 7.34-7.40 (m, 1H), 7.48-7.51 (m, 5H).
K. Butyric Acid (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-
oxalylhydrazino]hydroxypropionyloxymethyl Ester
N N O
F Cl
A mixture of (R)[N'-t-butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenyl
ylmethyl)hydrazino]hydroxypropionic acid (300 mg, 430 μmol), chloromethyl butyrate
(175 mg, 1.3 mmol), NaI (192 mg, 1.3 mmol) and 2,6-dimethylpyridine (680 mg, 6.4
mmol) in DMF (10 mL) was stirred at room temperature overnight. The mixture was
poured into water (30 mL) and the mixture was then extracted with EtOAc (3x20 mL).
The organic layer was separated, washed with saturated aqueous NaCl (30 mL), dried over
anhydrous Na SO , and concentrated in vacuo. The crude Compound 1 (300 mg) was used
without purification. LC-MS: 567[M+H] .
TFA (1.0 mL) was added dropwise at room temperature to a solution of Compound
1 (300 mg, 464 μmol) in DCM (5 mL). The resulting mixture was stirred for 2 hours at
room temperature, and the solvent was then removed. The residue was purified by column
chromatography (DCM/MeOH, 10:1) to yield the title compound as a yellow oil (21 mg).
LC-MS: 511.1[M+H] . H NMR (400 MHz, MeOD) δ 0.94 (t, J=7.4 Hz, 3H), 1.62 (dd,
J=14.8, 7.4 Hz, 2H), 2.33 (t, J=7.3 Hz, 2H), 3.28 (d, J=6.1 Hz, 2H), 4.14 (q, J=13.2 Hz,
2H), 4.38 (dd, J=6.0, 4.2 Hz, 1H), 5.80 (br, 2H), 7.16-7.26 (m, 1H), 7.33-7.40 (m, 1H),
7.47-7.52 (m, 5H).
L. (R)[N-(5'-Chloro-2'-fluorobiphenylylmethyl)-N'-oxalylhydrazino]
hydroxypropionic Acid Acetoxymethyl Ester
N N O
F Cl
A mixture of (R)[N'-t-butoxyoxalyl-N-(5'-chloro-2'-fluorobiphenyl
ylmethyl)hydrazino]hydroxypropionic acid (300 mg, 640 μmol), bromomethyl acetate
(196 mg, 1.3 mmol), NaI (192 mg, 1.3 mmol) and 2,6-dimethylpyridine (680 mg, 6.4
mmol) in DMF (10 mL) was stirred at room temperature overnight. The mixture was
poured into water (30 mL) and the mixture was then extracted with EtOAc (3x20 mL).
The organic layer was separated, washed with saturated aqueous NaCl (30 mL), dried over
anhydrous Na SO , and concentrated in vacuo. The crude Compound 1 (300 mg) was used
without purification. LC-MS: 539 [M+H] .
TFA (1.0 mL) was added dropwise at room temperature to a solution of Compound
1 (300 mg, 550 μmol) in DCM (5 mL). The resulting mixture was stirred for 2 hours at
room temperature, and the solvent was then removed. The residue was purified by column
chromatography (DCM/MeOH, 10:1) to yield the title compound as a yellow oil (15 mg).
LC-MS: 482.9 [M+H] . H NMR (400 MHz, MeOD) δ 2.07 (s, 3H), 3.25-3.28 (m, 2H),
4.14 (q, J=13.2 Hz, 2H), 4.38 (t, J=5.9Hz, 1H), 5.88-5.71 (m, 2H), 7.25-7.17 (m, 1H),
7.41-7.31 (m, 1H), 7.70-7.46 (m, 5H).
EXAMPLE 15
(2R,4S)Biphenylylhydroxymethyl(oxalylamino)hexanoic Acid
(2R,4S)Aminobiphenylylhydroxymethylhexanoic acid ethyl ester (70
mg, 0.2 mmol) was dissolved in DCM (5 mL) and stirred for 2 minutes, followed by the
addition of ethyl oxalyl chloride (23 µL, 0.2 mmol) and DIPEA (79 mg, 0.6 mmol). The
mixture was stirred at room temperature for 1 hour, then evaporated under reduced
pressure. The mixture was the concentrated under vacuum. The residue was dissolved in
EtOH, and sufficient equivalents of 10N NaOH were added to make the solution basic.
The reaction was monitored over 1 hour until final deprotection was complete. The
solution was acidified with an equal volume of AcOH and evaporated under reduced
pressure. The product was then purified using reverse phase chromatography (gradient of
-70% MeCN to yield the title compound (37 mg, purity 95%). MS m/z [M+H] calc'd
for C H NO , 386.15; found 386.4.
21 23 6
EXAMPLE 16
(2S,4S)Biphenylylhydroxymethylmethyl(oxalylamino)hexanoic Acid
(2S,4S)Aminobiphenylylhydroxymethylmethylhexanoic acid ethyl
ester (HCl salt; 40 mg, 0.1 mmol) was dissolved in DCM and DMF (1 mL), followed by
the addition of ethyl oxalyl chloride (17 µL, 0.2 mmol) and DIPEA (53.3 µL, 0.3 mmol).
The mixture was stirred at room temperature until the reaction was complete (~5 minutes).
The reaction was quenched with water. The product extracted with EtOAc and the
resulting organic layer was concentrated. 1 M aqueous lithium hydroxide (1.0 mL, 1.0
mmol) and EtOH (2.0 mL) was added and the mixture was stirred at room temperature
until the reaction was complete (~2 hours). The reaction was quenched with AcOH and the
product was purified by preparative HPLC. The clean fractions were combined and
lyophilized to yield the title compound (19 mg, purity 95%). MS m/z [M+H] calc'd for
C H NO , 400.17; found 400.2.
22 25 6
Additional compounds of the invention can be prepared using the following starting
materials:
(R)Aminobiphenylylhydroxymethyl-pentanoic Acid Ethyl Ester
H (S)
O BOC
O BOC
HO BOC
To a solution of (R)biphenylylt-butoxycarbonylamino-propionic acid (50
g, 0.1 mol), Meldrum’s acid (23.3 g, 0.2 mol) and DMAP (27.8 g, 0.2 mol) in anhydrous
DCM (500 mL) was added a solution of DCC (33.3 g, 0.2 mol) in anhydrous DCM (200
mL) over 1 hour at -5°C under nitrogen. The mixture was stirred at -5°C for 8 hours, then
refrigerated overnight, during which tiny crystals of dicyclohexylurea precipitated. After
filtration, the mixture was washed with 5% KHSO (4x200 mL), saturated aqueous NaCl
(200 mL) and dried under refrigeration with MgSO overnight. The resulting solution was
evaporated to yield crude Compound 1 as a light yellow solid (68 g). LC-MS: 490
[M+Na], 957 [2M+Na].
To a solution of crude Compound 1 (68 g, 0.1 mol) in anhydrous DCM (1 L) was
added AcOH (96.8 g, 1.6 mol) at -5°C under nitrogen. The mixture was stirred at -5°C for
0.5 hour, then NaBH (13.9 g, 0.4 mol) was added in small portions over 1 hour. After
stirring at -5°C for another 1 hour, saturated aqueous NaCl (300 mL) was added. The
organic layer was washed with saturated aqueous NaCl (2x300 mL) and water (2x300 mL),
dried over MgSO , filtered, and concentrated to give the crude product which was further
purified by chromatography (hexanes:EtOAc=5:1) to yield Compound 2 as a light yellow
solid (46 g). LC-MS: 476 [M+Na], 929 [2M+Na].
(R) H (R)
O BOC BOC
(3) (4)
To a solution of Compound 2 (46 g, 0.1 mol) in tertiary butyl alcohol (100 mL) was
added dimethylmethyleneimmonium iodide (46.3 g, 0.3 mol) at room temperature under
nitrogen. The mixture was heated to 65°C and stirred at this temperature for 16 hours.
After filtration, the filtrate was concentrated to give the crude product which was further
purified by chromatography (hexanes:EtOAc=20:1~10:1) to yield Compound 3 as a light
yellow solid) (18 g). LC-MS: 460 [M+Na], 897 [2M+Na].
To a solution of Compound 3 (18 g, 44 mmol) in acetone (430 mL) and water (22
mL) was added Sudan Red as indicator. Ozone atmosphere was introduced into the
mixture at 0°C until the red color of Sudan Red disappeared. Dimethyl sulfide (45 mL)
was added and the mixture was stirred at room temperature overnight. The mixture was
then concentrated and the residual was purified by chromatography
(hexanes:EtOAc=15:1~7:1) to yield Compound 4 as a light yellow solid (9.5 g). LC-MS:
434 [M+H], 845 [2M+H].
O BOC
HO HO
To a solution of Compound 4 (9.5 g, 23 mmol) in anhydrous THF (120 mL) was
added a solution of methylmagnesium bromide in THF (9.2 mL, 28 mmol) at -70°C under
nitrogen. The mixture was stirred at -60°C for 3 hours and the reaction was then quenched
with saturated aqueous NH Cl (50 mL). The organic layer was separated and dried over
MgSO . The mixture was then concentrated and the residual was purified by
chromatography (hexanes:EtOAc=10:1~5:1) to yield Compound 5 as an oil (7.9 g). LC-
MS: 450 [M+H], 877 [2M+H].
To a solution of Compound 5 (7.9 g, 18.4 mmol) in anhydrous DCM (300 mL) was
pumped HCl atmosphere at 0°C for 6 hours. The mixture was then concentrated and the
residue was washed with anhydrous Et O to yield the title compound as a white solid HCl
salt (5.8 g). LC-MS: 364 [M+H], 727 [2M+H]. H NMR (300 MHz, DMSO): δ8.00-7.97
(d, 4H), 7.67-7.62 (m, 6H), 7.47-7.28 (m, 8H), 6.32 (s, 1H), 6.09 (s, 1H), 4.13-4.06 (m,
2H), 3.95-3.78 (m, 2H), 3.60 (s, 1H), 3.22-3.08 (m, 3H), 2.95-2.65 (m, 2H), 1.99-1.79 (m,
4H), 1.30-0.87 (m, 9H).
(R)Aminobiphenylyl-2,2-dimethyl-pentanoic Acid Ethyl Ester
O BOC
A solution of [(S)biphenylylmethyl(2,2-dimethyl-4,6-dioxo-[1,3]dioxan
yl)-ethyl]-carbamic acid t-butyl ester (46 g, 0.1 mol) in anhydrous toluene (300 mL) was
refluxed for 3 hours under nitrogen. After evaporation of the solvent, the residue was
purified by chromatography (hexanes:EtOAc=10:1) to yield Compound 1 as a light yellow
solid (27 g). LC-MS: 374 [M+Na], 725 [2M+Na].
To a solution of Compound 1 (6.2 g, 17.6 mmol) in anhydrous THF (100 mL) was
added a solution of LiHMDS in THF (39 mL, 39 mmol) at -78°C under nitrogen. The
mixture was stirred at -78°C for 2 hours, and then methyl iodide (7.5 g, 53 mmol) was
added. After stirring for 0.5 hour at -78°C, the mixture was warmed to room temperature
and stirred at room temperature for 3 hours. After the mixture cooled to -10°C, the
reaction was quenched with saturated aqueous NH Cl (100 mL) and extracted with EtOAc
(100 mL×4). The combined organic layers were washed with saturated aqueous NaCl (300
mL), dried over MgSO , filtered, and concentrated to yield the crude product which was
further purified by chromatography (hexanes:EtOAc=10:1) to yield Compound 2 as a light
yellow solid (5.7 g). LC-MS: 402 [M+Na], 781 [2M+Na].
HO BOC
To a solution of Compound 2 (5.7 g, 15 mmol) in acetone (120 mL) was added 1 M
NaOH (60 mL, 60 mmol) at -5°C under nitrogen. The mixture was warmed to room
temperature and stirred at room temperature for 20 hours. The mixture was concentrated
and the residual was diluted with water (250 mL) and washed with EtOAc (150 mL). The
pH of the aqueous layer was adjusted to 2 with 6 M HCl at 0°C, and the solid was filtrated
and dried in vacuo to yield the crude Compound 3 as a white solid (5 g). LC-MS: 420
[M+Na], 817 [2M+Na].
To a solution of crude Compound 3 (5 g, 12.7 mmol) in anhydrous EtOH (300 mL)
was added SOCl (13.4 mL, 190 mmol) at -30°C under nitrogen. The mixture was warmed
to room temperature and stirred for 20 hours at room temperature. The mixture was
concentrated, and the residual was washed with anhydrous Et O to yield the title compound
as a white solid HCl salt (3.7 g). LC-MS: 326 [M+H], 651 [2M+H]. H NMR (300 MHz,
DMSO): δ7.86 (s, 3H), 7.67-7.64 (m, 4H), 7.49-7.33 (m, 5H), 4.09-3.97 (m, 2H), 3.42 (m,
1H), 2.90-2.80 (m, 2H), 1.88-1.84 (m, 2H), 1.17-1.12 (m, 9H).
1-((R)Aminobiphenyl- 4-yl-propyl)-cyclopropanecarboxylic Acid
HO BOC
O BOC
Into a flask containing BOC-D-4,4'-biphenylalanine (11.3 g, 33.1 mmol, 1.0 eq.), 4-
dimethylaminopyridine (6.5 g, 53.0 mmol, 1.6 eq.), 2,2-dimethyl-1,3-dioxane-4,6-dione
(5.3 g, 36.4 mmol, 1.1 eq.) in DCM (100 mL) was added 1 M of DCC in DCM (38.1 mL)
at 0°C over 30 minutes. The mixture was maintained at 0°C for 6 hours and the resulting
precipitate was filtered off. The filtrate was washed with aqueous 10% KHSO (2x50 mL)
then dried. The solution was acidified with AcOH (20 mL) at 0 °C and sodium
borohydride (3.1 g, 82.7 mmol, 2.5 eq.) was added over 30 minutes in 3 portions. The
mixture was maintained at 0°C for 3 hours, washed with water and dried, then concentrated
under vacuum. The crude material was purified by chromatography (0-40%
EtOAc/hexanes gradient). Eschenmoser's salt (15.9 g, 86.0 mmol) in t-butyl alcohol
(70 mL) was added and the resulting mixture was stirred at 65°C overnight. The mixture
was concentrated and Et O (10 mL)was added. The organic solution was then washed with
saturated aqueous NaHCO (10 mL) and 10% KHSO (10 mL). The organic solution was
dried over Na SO and concentrated. The crude product was purified by chromatography
(0-40% EtOAc/hexanes gradient) to yield Compound 1 (3.3 g).
O BOC
Trimethylsufoxonium iodide (2.0 g, 9.2 mmol, 1.0 eq.) in dimethyl sulfoxide
(50 mL) was combined with NaH (366 mg, 9.2 mmol, 1.1 eq.) amd stirred for 15 minutes
at room temperature. To this was added Compound 1 (3.6 g, 8.3 mmol, 1.0 eq) dissolved
dimethyl sulfoxide (50 mL). The resulting mixture was stirred at room temperature
overnight. The solution was mixed with saturated aqueous NaCl (50 mL) and extracted
with EtOAc (3x10 mL), and the organic layer was washed with saturated aqueous NaCl
(2x50 mL) and dried over anhydrous Na SO . After evaporation of the solvent, the crude
reaction was purified by chromatography (0-40% EtOAc/hexanes gradient) to yield
Compound 2, 1-((R)biphenylylt-butoxycarbonylaminopropyl)-
cyclopropanecarboxylic acid t-butyl ester. TFA (200 µL) and DCM (500 µL) were added
and the resulting mixture was stirred for 30 minutes. The solvent was evaporated under
vacuum and azeotroped with toluene (2x) to obtain the title compound.
ASSAY 1
In vitro Assays for the Quantitation of Inhibitor Potencies
at Human and Rat NEP, and Human ACE
The inhibitory activities of compounds at human and rat neprilysin (EC 3.4.24.11;
NEP) and human angiotensin converting enzyme (ACE) were determined using in vitro
assays as described below.
Extraction of NEP Activity from Rat Kidneys
Rat NEP was prepared from the kidneys of adult Sprague Dawley rats. Whole
kidneys were washed in cold phosphate buffered saline (PBS) and brought up in ice-cold
lysis buffer (1% Triton X-114, 150 mM NaCl, 50 mM tris(hydroxymethyl) aminomethane
(Tris) pH 7.5; Bordier (1981) J. Biol. Chem. 256: 1604-1607) in a ratio of 5 mL of buffer
for every gram of kidney. Samples were homogenized on ice using a polytron hand held
tissue grinder. Homogenates were centrifuged at 1000 x g in a swinging bucket rotor for 5
minutes at 3°C. The pellet was resuspended in 20 mL of ice cold lysis buffer and
incubated on ice for 30 minutes. Samples (15-20 mL) were then layered onto 25 mL of
ice-cold cushion buffer (6% w/v sucrose, 50 mM pH 7.5 Tris, 150 mM NaCl, 0.06%,
Triton X-114), heated to 37°C for 3-5 minutes and centrifuged at 1000 x g in a swinging
bucket rotor at room temperature for 3 minutes. The two upper layers were aspirated off,
leaving a viscous oily precipitate containing the enriched membrane fraction. Glycerol
was added to a concentration of 50% and samples were stored at -20°C. Protein
concentrations were quantitated using a BCA detection system with bovine serum albumin
(BSA) as a standard.
Enzyme Inhibition Assays
Recombinant human NEP and recombinant human ACE were obtained
commercially (R&D Systems, Minneapolis, MN, catalog numbers 1182-ZN and 929-ZN,
respectively). The fluorogenic peptide substrate Mca-D-Arg-Arg-Leu-Dap-(Dnp)-OH
(Medeiros et al. (1997) Braz. J. Med. Biol. Res. 30:1157-62; Anaspec, San Jose, CA) and
Abz-Phe-Arg-Lys(Dnp)-Pro-OH (Araujo et al. (2000) Biochemistry 39:8519-8525;
Bachem, Torrance, CA) were used in the NEP and ACE assays respectively.
The assays were performed in 384-well white opaque plates at 37°C using the
fluorogenic peptide substrates at a concentration of 10 μM in Assay Buffer (NEP: 50 mM
HEPES, pH 7.5, 100 mM NaCl, 0.01% polyethylene glycol sorbitan monolaurate (Tween-
), 10 μM ZnSO ; ACE: 50 mM HEPES, pH 7.5, 100 mM NaCl, 0.01% Tween-20, 1 μM
ZnSO ). The respective enzymes were used at concentrations that resulted in quantitative
proteolysis of 1 μM of substrate after 20 minutes at 37°C.
Test compounds were assayed over the range of concentrations from 10 μM to
pM. Test compounds were added to the enzymes and incubated for 30 minute at 37°C
prior to initiating the reaction by the addition of substrate. Reactions were terminated after
minutes of incubation at 37°C by the addition of glacial acetic acid to a final
concentration of 3.6% (v/v).
Plates were read on a fluorometer with excitation and emission wavelengths set to
320 nm and 405 nm, respectively. Inhibition constants were obtained by nonlinear
regression of the data using the equation (GraphPad Software, Inc., San Diego, CA):
v = v / [1 + (I / K′)]
where v is the reaction rate, v is the uninhibited reaction rate, I is the inhibitor
concentration and K′ is the apparent inhibition constant.
Compounds of the invention were tested in this assay and found to have pK values
at human NEP as follows. In general, either the prodrug compounds did not inhibit the
enzyme in this in vitro assay, or the prodrugs were not tested (n.d.) since activity would not
be expected.
Ex. pK Ex. pK
1 7.0-7.9 5-13 ≥9
2A ≥9 5-14 ≥9
2B n.d. 5-15 ≥9
2C n.d. 5-16 n.d.
2D n.d. 5-17 ≥9
2E n.d. 6A ≥9
2F ≥9 6B n.d.
2G 8.0-8.9 7A n.d.
2H ≥9 7B ≥9
2I 8.0-8.9 8-1 n.d.
2J 7.0-7.9 8-2 ≥9
2K n.d. 8-3 ≥9
2L n.d. 8-4 8.0-8.9
2M n.d. 8-5 8.0-8.9
2N ≥9 8-6 7.0-7.9
2O n.d. 9A 8.0-8.9
2P n.d. 9B n.d.
2Q n.d. 10 8.0-8.9
2R n.d. 11-1 8.0-8.9
2S n.d. 11-2 ≥9
2T ≥9 11-3 7.0-7.9
2U ≥9 11-4 8.0-8.9
2V ≥9 12 7.0-7.9
3A ≥9 13 8.0-8.9
3B n.d. 14A ≥9
3C n.d. 14B n.d.
3D ≥9 14C 8.0-8.9
4 8.0-8.9 14D n.d.
-1 ≥9 14E n.d.
-2 n.d. 14F 8.0-8.9
Ex. pK Ex. pK
-3 n.d. 14G n.d.
-4 n.d. 14H n.d.
-5 ≥9 14I n.d.
-6 n.d. 14J n.d.
-7 n.d. 14K n.d.
-8 n.d. 14L n.d.
-9 ≥9 15 7.0-7.9
-10 n.d. 16 8.0-8.9
-11 n.d.
-12 n.d.
n.d. = not determined
ASSAY 2
Pharmacodynamic (PD) assay for ACE and NEP Activity in Anesthetized Rats
Male, Sprague Dawley, normotensive rats are anesthetized with 120 mg/kg (i.p.) of
inactin. Once anesthetized, the jugular vein, carotid artery (PE 50 tubing) and bladder
(flared PE 50 tubing) catheters are cannulated and a tracheotomy is performed (Teflon
Needle, size 14 gauge) to faciliate spontaneous respiration. The animals are then allowed a
60 minute stablization period and kept continuously infused with 5 mL/kg/h of saline
(0.9%) throughout, to keep them hydrated and ensure urine production. Body temperature
is maintained throughout the experiment by use of a heating pad. At the end of the 60
minute stabilization period, the animals are dosed intravenously (i.v.) with two doses of
AngI (1.0 μg/kg, for ACE inhibitor activity) at 15 minutes apart. At 15 minutes post-
second dose of AngI, the animals are treated with vehicle or test compound. Five minutes
later, the animals are additionally treated with a bolus i.v. injection of atrial natriuretic
peptide (ANP; 30 μg/kg). Urine collection (into pre-weighted eppendorf tubes) is started
immediately after the ANP treatment and continued for 60 minutes. At 30 and 60 minutes
into urine collection, the animals are re-challenged with AngI. Blood pressure
measurements are done using the Notocord system (Kalamazoo, MI). Urine samples are
frozen at -20 °C until used for the cGMP assay. Urine cGMP concentrations are
determined by Enzyme Immuno Assay using a commercial kit (Assay Designs, Ann Arbor,
Michigan, Cat. No. 901-013). Urine volume is determined gravimetrically. Urinary cGMP
output is calculated as the product of urine output and urine cGMP concentration. ACE
inhibition is assessed by quantifying the % inhibition of pressor response to AngI. NEP
inhibition is assessed by quantifying the potentiation of ANP-induced elevation in urinary
cGMP output.
ASSAY 3
In Vivo Evaluation of Antihypertensive Effects
in the Conscious SHR Model of Hypertension
Spontaneously hypertensive rats (SHR, 14-20 weeks of age) are allowed a
minimum of 48 hours acclimation upon arrival at the testing site with free access to food
and water. For blood pressure recording, these animals are surgically implanted with
small rodent radiotransmitters (telemetry unit; DSI Models TA11PA-C40 or C50-PXT,
Data Science Inc., USA). The tip of the catheter connected to the transmitter is inserted
into the descending aorta above the iliac bifurcation and secured in place with tissue
adhesive. The transmitter is kept intraperitoneally and secured to the abdominal wall
while closing of the abdominal incision with a non-absorbable suture. The outer skin is
closed with suture and staples. The animals are allowed to recover with appropriate post
operative care. On the day of the experiment, the animals in their cages are placed on top
of the telemetry receiver units to acclimate to the testing environment and baseline
recording. After at least of 2 hours baseline measurement is taken, the animals are then
dosed with vehicle or test compound and followed out to 24 hours post-dose blood
pressure measurement. Data is recorded continuously for the duration of the study using
Notocord software (Kalamazoo, MI) and stored as electronic digital signals. Parameters
measured are blood pressure (systolic, diastolic and mean arterial pressure) and heart rate.
ASSAY 4
In Vivo Evaluation of Antihypertensive Effects
in the Conscious DOCA-Salt Rat Model of Hypertension
CD rats (male, adult, 200-300 grams, Charles River Laboratory, USA) are allowed
a minimum of 48 hours acclimation upon arrival at the testing site before they are placed
on a high salt diet. One week after the start of the high salt diet (8% in food or 1% NaCl
in drinking water), a deoxycorticosterone acetate (DOCA) pellet (100 mg, 90 days release
time, Innovative Research of America, Sarasota, FL ) is implanted subcutaneously and
unilateral nephrectomy is performed. At this time, the animals are also surgically
implanted with small rodent radiotransmitters for blood pressure measurement (see Assay
3 for details). The animals are allowed to recover with appropriate post operative care.
Study design, data recording, and parameters measured is similar to that described for
Assay 3.
ASSAY 5
In Vivo Evaluation of Antihypertensive Effects
in the Conscious Dahl/SS Rat Model of Hypertension
Male, Dahl salt sensitive rats (Dahl/SS, 6-7 weeks of age from Charles River
Laboratory, USA) are allowed at least 48 hours of acclimation upon arrival at the testing
site before they were placed on a 8% NaCl high salt diet (TD.92012, Harlan, USA) then
surgically implanted with small rodent radiotransmitters for blood pressure measurement
(see Assay 3 for details). The animals are allowed to recover with appropriate post
operative care. At approximately 4 to 5 weeks from the start of high salt diet, these
animals are expected to become hypertensive. Once the hypertension level is confirmed,
these animals are used for the study while continued with the high salt diet to maintain
their hypertension level. Study design, data recording, and parameters measured is similar
to that described in Assay 3.
COMPARATIVE EXAMPLE 1
HOOC N HOOC N
CH CH
(2R,4S)Biphenylylmethyl(oxalyl-amino)-pentanoic Acid (Comparative
Compound A; R = -C(O)-COOH)
(2R,4S)Aminobiphenylylmethyl-pentanoic acid ethyl ester (HCl salt;
527 mg, 0.2 mmol) and ethyl oxalyl chloride (18.4 µL, 1.1 eq) were combined with
DIPEA (52.2 µL, 0.3 mmol) in DMF (0.3 mL)/DCM (0.3 mL). The mixture was stirred at
room temperature until the reaction was complete. The solvent was removed and the
residue was dissolved in EtOH (750 µL) and 1 M aqueous NaOH (750 µL), and stirred at
room temperature overnight. The solvent was removed and the residue was purified by
preparative HPLC to yield Comparative Compound A (11.2 mg, 100% purity). MS m/z
[M+H] calc'd for C H NO , 356.14; found 356.2.
21 5
(2R,4S)Biphenylyl(3-carboxy-propionylamino)methyl-pentanoic Acid
(Comparative Compound B; R = -C(O)-(CH ) -COOH)
(2R,4S)Biphenylyl(3-carboxy-propionylamino)methyl-pentanoic acid
ethyl ester (Na salt; 400 mg, 923 µmol) was mixed with EtOH (7 mL, 0.1 mol) then THF
(6 mL, 0.1 mol). 1 M Aqueous NaOH (2.8 mL, 2.8 mmol) was then added and the
resulting mixture was stirred at room temperature for 4 hours and was then concentrated.
The product was purified by preparative HPLC (10-60% MeCN:water w/0.5% TFA) to
yield Comparative Compound B (150 mg, 97% purity). MS m/z [M+H] calc'd for
C H NO , 384.17; found 384.6.
22 25 5
Comparative Compounds A and B were tested as described in Assay 1 and found
to have pK values at human NEP as follows:
Compound R pK
Comparative Compound A -C(O)-COOH 8.2
Comparative Compound B -C(O)-(CH ) -COOH 8.2
The data shows that Comparative Compounds A and B have the same pK values for the
inhibition of NEP.
COMPARATIVE EXAMPLE 2
HOOC N
(R)Biphenylyl(2-carboxyacetylamino)hydroxypentanoic Acid (Comparative
Compound C; R = -C(O)-CH -COOH)
(R)Aminobiphenylylhydroxypentanoic acid ethyl ester (HCl salt; 60.3
mg, 0.2 mmol) and methyl malonyl chloride (21 µL, 0.2 mmol) were combined with
DIPEA (84 µL, 0.5 mmol) in DMF (5 mL). The mixture was stirred at room temperature
until the reaction was complete (1 hour). The solvent was removed and the residue was
dissolved in MeOH (3 mL) and 10N NaOH (250 µL), and stirred at 60°C until the reaction
was complete (1 hour). Glacial acetic acid (250 µL) was added and the product was
evaporated under reduced pressure and purified by preparative HPLC to yield
Comparative Compound C (6.3 mg, 98% purity). MS m/z [M+H] calc'd for C H NO ,
21 6
372.14; found 372.2.
(R)Biphenylyl(3-carboxypropionylamino)hydroxypentanoic Acid
(Comparative Compound D; R = -C(O)-(CH ) -COOH)
(R)Aminobiphenylylhydroxypentanoic acid ethyl ester (HCl salt; 60.3
mg, 0.2 mmol) and 3-(carbomethoxy)propionyl chloride (24 µL, 0.2 mmol) were
combined with DIPEA (84 µL, 0.5 mmol) in DMF (5 mL). The mixture was stirred at
room temperature until the reaction was complete (1 hour). The solvent was removed and
the residue was dissolved in MeOH (3 mL) and 10N NaOH (250 µL), and stirred at 60°C
until the reaction was complete (1 hour). Glacial acetic acid (250 µL) was added and the
product was evaporated under reduced pressure and purified by preparative HPLC to yield
Comparative Compound D (8.0 mg, 100% purity). MS m/z [M+H] calc'd for C H NO ,
21 23 6
386.15; found 386.2.
(R)Biphenylyl(4-carboxybutyrylamino)hydroxypentanoic Acid (Comparative
Compound E; R = -C(O)-(CH ) -COOH)
(R)Aminobiphenylylhydroxypentanoic acid ethyl ester (HCl salt; 60.3
mg, 0.2 mmol) and methyl 5-chlorooxovalerate (31.7 mg, 0.2 mmol) were combined
with DIPEA (84 µL, 0.5 mmol) in DMF (5 mL). The mixture was stirred at room
temperature until the reaction was complete (1 hour). The solvent was removed and the
residue was dissolved in MeOH (3 mL) and 10N NaOH (250 µL), and stirred at 60°C until
the reaction was complete (1 hour). Glacial acetic acid (250 µL) was added and the
product was evaporated under reduced pressure and purified by preparative HPLC to yield
Comparative Compound E (8.7 mg, 100% purity). MS m/z [M+H] calc'd for C H NO ,
22 25 6
400.17; found 400.2.
The compound of Example 1 and Comparative Compounds C, D, and E were
tested as described in Assay 1 and found to have pK values at human NEP as follows:
Compound R pK
Example 1 -C(O)-COOH 7.9
Comparative Compound C -C(O)-CH -COOH 6.7
Comparative Compound D -C(O)-(CH ) -COOH 7.4
Comparative Compound E -C(O)-(CH ) -COOH 7.3
The data shows that the compound of Example 1 had higher potency at NEP than
Comparative Compounds C, D, and E.
COMPARATIVE EXAMPLE 3
HOOC N
(2S,4S)Biphenylyl(2-carboxy-acetylamino)hydroxymethylpentanoic Acid
(Comparative Compound F; R = -C(O)-CH -COOH)
(2S,4S)Aminobiphenylylhydroxymethyl-pentanoic acid (HCl salt; (5
mg, 10 µmol) was dissolved in 1 M aqueous NaOH (119 µL, 119 µmol) and slowly added
to a solution of methyl malonyl chloride (1.9 µL, 18 µmol) and MeCN (0.5 mL, 10 mmol).
The resulting solution was stirred at room temperature until the reaction was complete
(overnight) and the product was purified by preparative HPLC to yield Comparative
Compound F (1.0 mg, 95% purity). MS m/z [M+H] calc'd for C H NO , 386.15; found
21 23 6
386.1.
(2S,4S)Biphenylyl(3-carboxy-propionylamino)hydroxymethylpentanoic Acid
(Comparative Compound G; R = -C(O)-(CH ) -COOH)
(2S,4S)Aminobiphenylylhydroxymethyl-pentanoic acid (HCl salt; (5
mg, 10 µmol) was dissolved in 1 M aqueous NaOH (119 µL, 119 µmol) and slowly added
to a solution of 3-(carbomethoxy)propionyl chloride (2.2 µL, 18 µmol) and MeCN (0.5
mL, 10 mmol). The resulting solution was stirred at room temperature until the reaction
was complete (overnight) and the product was purified by preparative HPLC to yield
Comparative Compound G (3.4 mg, 95% purity). MS m/z [M+H] calc'd for C H NO ,
22 25 6
400.17; found 400.3.
(2S,4S)Biphenylyl(4-carboxy-butyrylamino)hydroxymethylpentanoic Acid
(Comparative Compound H; R = -C(O)-(CH ) -COOH)
(2S,4S)Aminobiphenylylhydroxymethyl-pentanoic acid (HCl salt; (5
mg, 10 µmol) was dissolved in 1 M aqueous NaOH (119 µL, 119 µmol) and slowly added
to a solution of methyl 5-chlorooxovalerate (2.5 µL, 18 µmol) and MeCN (0.5 mL, 10
mmol). The resulting solution was stirred at room temperature until the reaction was
complete (overnight) and the product was purified by preparative HPLC to yield
Comparative Compound H (3.0 mg, 95% purity). MS m/z [M+H] calc'd for C H NO ,
23 27 6
414.18; found 414.7.
The compound of Example 5A and Comparative Compounds F, G, and H were
tested as described in Assay 1 and found to have pK values at human NEP as follows:
Compound R pK
Example 5A -C(O)-COOH 9.2
Comparative Compound F -C(O)-CH -COOH 8.2
Comparative Compound G -C(O)-(CH ) -COOH 9
Comparative Compound H -C(O)-(CH ) -COOH 8.6
The data shows that the compound of Example 5A had higher potency at NEP than
Comparative Compounds F, G, and H.
COMPARATIVE EXAMPLE 4
HOOC
(2R,4R)(2-Carboxy-acetylamino)(3'-chloro-biphenylyl)hydroxy-pentanoic
Acid (Comparative Compound I; R = -C(O)-CH -COOH)
Methyl malonyl chloride (18.5 µL, 172 µmol) was added to a solution of (2R,4R)-
4-amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (50.0 mg, 144
µmol) and DIPEA (75.1 µL, 431 µmol) in DCM (1.5 mL, 23.4 mmol) and the resulting
mixture was stirred at room temperature for 30 minutes. The mixture was then
concentrated to yield a yellow liquid. 1 M Aqueous LiOH (719 µL, 719 µmol) was added
dropwise to the oil, and the mixture was stirred at 60°C for 1 hour. The mixture was
concentrated in vacuo and the resulting residue was dissolved in AcOH (1.0 mL) purified
by preparative HPLC to yield Comparative Compound I (2.0 mg, 100% purity). MS m/z
[M+H] calc'd for C H ClNO , 406.10; found 406.1.
20 6
(2R,4R)(3-Carboxy-propionylamino)(3'-chloro-biphenylyl)hydroxy-pentanoic
Acid (Comparative Compound J; R = -C(O)-(CH ) -COOH)
3-(Carbomethoxy)propionyl chloride (21.2 µL, 172 µmol) was added to a solution
of (2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (50.0
mg, 144 µmol) and DIPEA (75.1 µL, 431 µmol) in DCM (1.5 mL, 23.4 mmol) and the
resulting mixture was stirred at room temperature for 30 minutes. The mixture was then
concentrated to yield a yellow liquid. 1 M Aqueous LiOH (719 µL, 719 µmol) was added
dropwise to the oil, and the mixture was stirred at 60°C for 1 hour. The mixture was
concentrated in vacuo and the resulting residue was dissolved in AcOH (1.0 mL) purified
by preparative HPLC to yield Comparative Compound J (31.1 mg, 100% purity). MS m/z
[M+H] calc'd for C H ClNO , 420.11; found 420.2.
21 22 6
(2R,4R)(4-Carboxy-butyrylamino)(3'-chloro-biphenylyl)hydroxy-pentanoic
Acid (Comparative Compound K; R = -C(O)-(CH ) -COOH)
Methyl 5-chlorooxovalerate (23.8 µL, 172 µmol) was added to a solution of
(2R,4R)amino(3'-chlorobiphenylyl)hydroxypentanoic acid ethyl ester (50.0
mg, 144 µmol) and DIPEA (75.1 µL, 431 µmol) in DCM (1.5 mL, 23.4 mmol) and the
resulting mixture was stirred at room temperature for 30 minutes. The mixture was then
concentrated to yield a yellow liquid. 1 M Aqueous LiOH (719 µL, 719 µmol) was added
dropwise to the oil, and the mixture was stirred at 60°C for 1 hour. The mixture was
concentrated in vacuo and the resulting residue was dissolved in AcOH (1.0 mL) purified
by preparative HPLC to yield Comparative Compound K (29.2 mg, 100% purity). MS
m/z [M+H] calc'd for C H ClNO , 434.13; found 434.2.
22 24 6
The compound of Example 2A and Comparative Compounds I, J, and K were
tested as described in Assay 1 and found to have pK values at human NEP as follows:
Compound R pK
Example 2A -C(O)-COOH 9.7
Comparative Compound I -C(O)-CH -COOH 8.4
Comparative Compound J -C(O)-(CH ) -COOH 9.5
Comparative Compound K -C(O)-(CH ) -COOH 9.3
The data shows that the compound of Example 2A had higher potency at NEP than
Comparative Compounds I, J, and K.
While the present invention has been described with reference to specific aspects or
embodiments thereof, it will be understood by those of ordinary skilled in the art that
various changes can be made or equivalents can be substituted without departing from the
true spirit and scope of the invention. Additionally, to the extent permitted by applicable
patent statutes and regulations, all publications, patents and patent applications cited herein
are hereby incorporated by reference in their entirety to the same extent as if each
document had been individually incorporated by reference herein.
Claims (5)
1. A compound of formula I:
(R )
(R )
where:
5 R is selected from H, -C alkyl, -C alkylene-C aryl, -C alkylene-
1-8 1-3 6-10 1-3
C heteroaryl, -C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R , -C alkylene-
1-9 3-7 2 2 1-3 3 1-6 1-6
11 12 13
NR R , -C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
1-6 0-6 1-6 2 1-6
, , , and ;
R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
11 12 15 15
10 -O-phenyl, -NR R , -CH(R )-NH , -CH(R )-NHC(O)O-C alkyl, and
2 1-6
11 12
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
11 12
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
13 11 12 14
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
-C alkyl or -C alkylene-C aryl; R is H, -CH , -CH(CH ) , phenyl, or benzyl;
1-6 0-6 6-10 3 3 2
2 21 21 3 21
15 R is -OR or -CH OR ; and R is H or -CH ; where R is H, -C(O)-C alkyl,
2 3 1-6
22 22 23 22
-C(O)-CH(R )-NH , -C(O)-CH(R )-NHC(O)O-C alkyl, or -P(O)(OR ) ; R is H,
2 1-6 2
-CH , -CH(CH ) , phenyl, or benzyl; R is H, -C alkyl, or phenyl; or
3 3 2 1-6
2 1 15 16 15 16 3
R is taken together with R to form –OCR R - or -CH O–CR R -, and R is
15 16
selected from H and -CH , where R and R are independently selected from H,
15 16
20 -C alkyl, and -O-C cycloalkyl, or R and R are taken together to form =O; or
1-6 3-7
R is taken together with R to form -CH -O-CH - or -CH -CH -; or
2 2 2 2
R and R are both -CH ;
Z is selected from -CH- and -N-;
R is selected from H, -C alkyl, -C alkylene-O-C alkyl, -C alkylene-C aryl,
1-8 1-3 1-8 1-3 6-10
-C alkylene-O-C aryl, -C alkylene-C heteroaryl, -C cycloalkyl, -[(CH ) O] CH ,
1-3 6-10 1-3 1-9 3-7 2 2 1-3 3
40 41 42 43
-C alkylene-OC(O)R , -C alkylene-NR R , -C alkylene-C(O)R ,
1-6 1-6 1-6
-C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
0-6 1-6 2 1-6
44 O
, , , and ;
5 R is selected from -C alkyl, -O-C alkyl, -C cycloalkyl, -O-C cycloalkyl, phenyl,
1-6 1-6 3-7 3-7
41 42 45 45
-O-phenyl, -NR R , -CH(R )-NH , -CH(R )-NHC(O)O-C alkyl, and
2 1-6
41 42
-CH(NH )CH COOCH ; and R and R are independently selected from H, -C alkyl,
2 2 3 1-6
41 42
and benzyl; or R and R are taken together as -(CH ) -, -C(O)-(CH ) -, or
2 3-6 2 3
43 41 42 44
-(CH ) O(CH ) -; R is selected from -O-C alkyl, -O-benzyl, and -NR R ; and R is
2 2 2 2 1-6
10 -C alkyl or -C alkylene-C aryl; R is H, -CH , -CH(CH ) , phenyl, or benzyl;
1-6 0-6 6-10 3 3 2
a is 0 or 1; R is selected from halo, –CH , –CF , and -CN;
b is 0 or an integer from 1 to 3; each R is independently selected from halo, -OH,
-CH , –OCH , -CN, and -CF ;
3 3 3
where each alkyl group in R and R is optionally substituted with 1 to 8 fluoro
15 atoms; and
where the methylene linker on the biphenyl is optionally substituted with one or
two -C alkyl groups or cyclopropyl;
or a pharmaceutically acceptable salt thereof.
2. The compound of Claim 1, where R is H.
20
3. The compound of Claim 1, where R is selected from -C alkyl,
-C alkylene-C aryl, -C alkylene-C heteroaryl, -C cycloalkyl, -[(CH ) O] CH ,
1-3 6-10 1-3 1-9 3-7 2 2 1-3 3
10 11 12 13
-C alkylene-OC(O)R , -C alkylene-NR R , -C alkylene-C(O)R ,
1-6 1-6 1-6
-C alkylenemorpholinyl, -C alkylene-SO -C alkyl,
0-6 1-6 2 1-6
, , , and ;
1 2 15 16 15 16
25 or R is taken together with R to form –OCR R - or -CH O–CR R -.
4. The compound of Claim 1, where R is selected from H, -C alkyl, -C alkylene-
1-8 1-6
OC(O)R , and
10 15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
15 1
R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
5 atoms.
5. The compound of Claim 4, where R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -(CH ) CH ,-CH CF , -(CH ) CF , -CH CF CH ,
2 3 2 2 3 3 2 6 3 2 3 2 2 3 2 2 3
-CH CF CF , -CH OC(O)CH , -CH OC(O)CH CH , -CH OC(O)(CH ) CH ,
2 2 3 2 3 2 2 3 2 2 2 3
-CH OC(O)OCH CH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)O-CH , and
2 2 3 2 3 2 3
10 ,
where R is -CH .
2 21 3
6. The compound as claimed in any one of Claims 1 to 5, where R is -OR , R is H,
and R is H.
2 21 3
7. The compound as claimed in any one of Claims 1 to 5, where R is -OR , R is
15 -CH , and R is H.
2 21 3
8. The compound as claimed in any one of Claims 1 to 5, where R is -CH OR , R is
H, and R is H.
2 21 3
9. The compound as claimed in any one of Claims 1 to 5, where R is -CH OR , R is
-CH , and R is H.
20 10. The compound as claimed in any one of Claims 1 to 9, where R is H.
11. The compound as claimed in any one of Claims 1 to 9, where R is selected from
-C alkyl, -C alkylene-O-C alkyl, -C alkylene-C aryl, -C alkylene-O-C aryl,
1-8 1-3 1-8 1-3 6-10 1-3 6-10
-C alkylene-C heteroaryl, -C cycloalkyl, -[(CH ) O] CH , -C alkylene-OC(O)R ,
1-3 1-9 3-7 2 2 1-3 3 1-6
41 42 43
-C alkylene-NR R , -C alkylene-C(O)R , -C alkylenemorpholinyl, -C alkylene-
1-6 1-6 0-6 1-6
25 SO -C alkyl,
2 1-6
44 O
, , , and .
12. The compound as claimed in any one of Claims 1 to 9, where R is selected from H,
-C alkyl, -C alkylene-O-C alkyl, -C alkylene-O-C aryl, -[(CH ) O] CH , and
1-8 1-3 1-8 1-3 6-10 2 2 1-3 3
44 4
5 where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms.
13. The compound of Claim 12, where R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -C(CH ) , -(CH ) CF , -CH CF CH , -(CH ) -O-CH CH ,
2 3 2 2 3 3 3 3 2 2 3 2 2 3 2 3 2 3
-(CH ) -O-phenyl, -(CH ) OCH , and
2 2 2 2 3
10 ,
where R is -CH .
14. The compound as claimed in any one of Claims 1 to 13, where a is 0, or a is 1 and
R is halo.
15. The compound as claimed in any one of Claims 1 to 14, where b is 0, or b is 1 and
15 R is halo, or b is 2 and each R is independently selected from halo and -CH .
16. The compound of Claim 1, where:
a is 0 and b is 0; or
a is 0, b is 1, and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-flouro; or
a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-methyl, 5'-chloro or 2',5'-dichloro;
20 or
a is 1, R is 3-chloro, and b is 0; or
a is 1, R is 3-chloro, b is 1, and R is 3'-chloro; or
a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro.
17. The compound of Claim 6, where R is selected from H, -C alkyl, -C alkylene-
1-8 1-6
OC(O)R , and
10 15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
15 1
R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
5 atoms;
Z is selected from -CH- and -N-;
R is selected from H, -C alkyl, -C alkylene-O-C alkyl, -C alkylene-O-
1-8 1-3 1-8 1-3
C aryl, -[(CH ) O] CH , and
6-10 2 2 1-3 3
44 4
10 where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms;
a is 0 and b is 0; or a is 0, b is 1, and R is halo; or a is 0, b is 2, and one R is halo
6 5 5
and the other R is halo or -CH ; or a is 1, R is halo, and b is 0; or a is 1, R is halo, b is 1,
6 5 6
and R is halo; or a is 1, R is halo, b is 2, and each R is halo; and
15 where the methylene linker on the biphenyl is optionally substituted with two -CH
groups.
18. The compound of Claim 17, where R is selected from H, -CH CH , -CH(CH ) ,
2 3 3 2
-CH CH(CH ) , -(CH ) CH , -(CH ) CH ,-CH CF , -(CH ) CF , -CH CF CH ,
2 3 2 2 3 3 2 6 3 2 3 2 2 3 2 2 3
-CH CF CF , -CH OC(O)CH , -CH OC(O)CH CH , -CH OC(O)(CH ) CH ,
2 2 3 2 3 2 2 3 2 2 2 3
20 -CH OC(O)OCH CH , -CH OC(O)-CH[CH(CH ) ]-NHC(O)O-CH , and
2 2 3 2 3 2 3
where R is -CH ;
R is selected from H, -CH CH , -CH(CH ) , -CH CH(CH ) , -(CH ) CH ,
2 3 3 2 2 3 2 2 3 3
-C(CH ) , -(CH ) CF , -CH CF CH , -(CH ) -O-CH CH , -(CH ) -O-phenyl,
3 3 2 2 3 2 2 3 2 3 2 3 2 2
-(CH ) OCH , and
2 2 3
where R is -CH ; and
a is 0 and b is 0; or a is 0, b is 1, and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-
5 flouro; or a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-methyl, 5'-chloro or 2',5'-
5 5 6
dichloro; or a is 1, R is 3-chloro, and b is 0; or a is 1, R is 3-chloro, b is 1, and R is 3'-
chloro; or a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro.
19. The compound of Claim 7, where R is H or -C alkyl; Z is -N-; R is H or
-C alkyl; and a and b are 0.
10 20 The compound of Claim 19, where R and R are H.
21. The compound of Claim 8, where R is H or -C alkyl; Z is -CH-; R is H or
-C alkyl; a is 0 or a is 1 and R is halo; b is 0 or b is 1 or 2 and R is halo; and where the
methylene linker on the biphenyl is optionally substituted with two -CH groups.
22. The compound of Claim 21, where R is H, -CH CH , or -(CH ) CH ; R is H; a is
2 3 2 3 3
15 0 or a is 1 and R is 3-chloro; b is 0 or b is 1 and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-
flouro.
23. The compound of Claim 9, where R is H or -C alkyl; Z is -CH-; R is H or
-C alkyl; a is 0; and b is 0, or b is 1 and R is halo.
24. The compound of Claim 23, where R is H or -CH CH ; R is H or -CH CH(CH ) ;
2 3 2 3 2
20 and b is 0, or b is 1 and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-flouro.
25. The compound of Claim 1, where R is selected from H, -C alkyl, -C alkylene-
1-8 1-6
OC(O)R , and
10 15 14
where R is -C alkyl, -O-C alkyl, or -CH[R ]-NHC(O)O-C alkyl; R is -C alkyl;
1-6 1-6 1-6 1-6
15 1
25 R is -CH(CH ) ; and each alkyl group in R is optionally substituted with 1 to 8 fluoro
atoms;
R is selected from H, -C alkyl, -C alkylene-O-C alkyl, -C alkylene-O-
1-8 1-3 1-8 1-3
C aryl, -[(CH ) O] CH , and
6-10 2 2 1-3 3
44 4
where R is -C alkyl; and each alkyl group in R is optionally substituted with 1 to 8
fluoro atoms;
5 a is 0 and b is 0; or a is 0, b is 1, and R is 2'-fluoro, 3'-fluoro, 3'-chloro, or 4'-
flouro; or a is 0, b is 2, and R is 2'-fluoro, 5'-chloro or 2'-methyl, 5'-chloro or 2',5'-
5 5 6
dichloro; or a is 1, R is 3-chloro, and b is 0; or a is 1, R is 3-chloro, b is 1, and R is 3'-
chloro; or a is 1, R is 3-chloro, b is 2, and R is 2'-fluoro, 5'-chloro; and
where the methylene linker on the biphenyl is optionally substituted with two -CH
10 groups.
2 21 21 3
26. The compound of Claim 25, where R is -OR or -CH OR ; and R is H or -CH ;
where R is H.
27. The compound of Claim 9, where Z is -CH-.
28. The compound of Claim 9, where a is 0, b is 2, and R is 2'-fluoro, 5'-chloro.
15 29. (2S,4R)(5'-chloro-2'-fluorobiphenylyl)hydroxymethylmethyl(oxalyl-
amino)pentanoic acid or a pharmaceutically acceptable salt thereof.
30. A process for preparing a compound as claimed in any one of Claims 1 to 29,
comprising the step of coupling a compound of formula 1 with a compound of formula 2:
(R )
(1) (2)
(R )
20 to produce a compound of formula I; where R -R , a, and b are as defined in Claim 1, and
P is selected from H and an amino-protecting group selected from t-butoxycarbonyl, trityl,
benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl, and t-
butyldimethylsilyl; and where the process further comprises deprotecting the compound of
formula 1 when P is an amino protecting group.
25 31. A pharmaceutical composition comprising a compound as claimed in any one of
Claims 1 to 29 and a pharmaceutically acceptable carrier.
32. The pharmaceutical composition of Claim 31, further comprising a therapeutic
agent selected from adenosine receptor antagonists, α-adrenergic receptor antagonists, β -
adrenergic receptor antagonists, β -adrenergic receptor agonists, dual-acting β-adrenergic
5 receptor antagonist/α -receptor antagonists, advanced glycation end product breakers,
aldosterone antagonists, aldosterone synthase inhibitors, aminopeptidase N inhibitors,
androgens, angiotensin-converting enzyme inhibitors and dual-acting angiotensin-
converting enzyme/neprilysin inhibitors, angiotensin-converting enzyme 2 activators and
stimulators, angiotensin-II vaccines, anticoagulants, anti-diabetic agents, antidiarrheal
10 agents, anti-glaucoma agents, anti-lipid agents, antinociceptive agents, anti-thrombotic
agents, AT receptor antagonists and dual-acting AT receptor antagonist/neprilysin
inhibitors and multifunctional angiotensin receptor blockers, bradykinin receptor
antagonists, calcium channel blockers, chymase inhibitors, digoxin, diuretics, dopamine
agonists, endothelin converting enzyme inhibitors, endothelin receptor antagonists, HMG-
15 CoA reductase inhibitors, estrogens, estrogen receptor agonists and/or antagonists,
monoamine reuptake inhibitors, muscle relaxants, natriuretic peptides and their analogs,
natriuretic peptide clearance receptor antagonists, neprilysin inhibitors, nitric oxide donors,
non-steroidal anti-inflammatory agents, N-methyl d-aspartate receptor antagonists, opioid
receptor agonists, phosphodiesterase inhibitors, prostaglandin analogs, prostaglandin
20 receptor agonists, renin inhibitors, selective serotonin reuptake inhibitors, sodium channel
blocker, soluble guanylate cyclase stimulators and activators, tricyclic antidepressants,
vasopressin receptor antagonists, and combinations thereof.
33. The pharmaceutical composition of Claim 32, wherein the therapeutic agent is an
AT receptor antagonist.
25 34. A compound as claimed in any one of Claims 1 to 29, for use in therapy.
35. A compound as claimed in Claim 34, for use in treating hypertension, heart failure,
or renal disease.
36. The use of a compound as claimed in any one of Claims 1 to 29, for the
manufacture of a medicament for treating hypertension, heart failure, or renal disease.
30 37. A compound of formula (I) as claimed in any one of Claims 1 to 29, when prepared
by the process of Claim 30.
38. A compound of formula (I) as claimed in any one of Claims 1 to 29, 34, 35 and 37,
substantially as herein described with reference to any example thereof.
39. A process as claimed in Claim 30, substantially as herein described with reference
to any example thereof.
40. A pharmaceutical composition as claimed in any one of Claims 31 to 33,
substantially as herein described with reference to any example thereof.
5 41. The use as claimed in Claim 36, substantially as herein described with reference to
any example thereof.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201161554625P | 2011-11-02 | 2011-11-02 | |
US61/554,625 | 2011-11-02 | ||
PCT/US2012/063036 WO2013067163A1 (en) | 2011-11-02 | 2012-11-01 | Neprilysin inhibitors |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ623841A NZ623841A (en) | 2015-05-29 |
NZ623841B2 true NZ623841B2 (en) | 2015-09-01 |
Family
ID=
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