AU2007231810B2 - Retroviral protease inhibiting compounds - Google Patents

Description

S&F Ref: 421388D3 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address Abbott Laboratories, of 100 Abbott Park Road, Abbott of Applicant: Park, Illinois, 60064-6060, United States of America Actual Inventor(s): David A. Betebenner, Xiaoqi Chen, Stephen L Condon, Arthur J. Cooper, Daniel A. Dickman, Steven M. Hannick, Thomas R. Herrin, Dale J Kempf, Lawrence Kolaczkowski, Gondi N. Kumar, Jih-Hua Liu, Daniel W Norbeck, Patricia A. Oliver, Ketan M. Patel, Daniel J. Plata, Hing Leung Sham, Peter J. Stengel, Eric J. Stoner, Jieh-Heh J. Tien Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Retroviral protease inhibiting compounds The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(1010930 1) RETROVIRAL PROTEASE INHIBITING COMPOUNDS Technical Field The present invention relates to novel compounds and a composition and method for inhibiting retroviral proteases and in particular for inhibiting 5 human immunodeficiency virus (HIV) protease, a composition and method for inhibiting a retroviral infection and in particular an HIV infection, processes for making the compounds and synthetic intermediates employed in the processes. Background of the Invention Retroviruses are those viruses which utilize a ribonucleic acid (RNA) 10 intermediate and a RNA-dependent deoxyribonucleic acid (DNA) polymerase, reverse transcriptase, during their life cycle. Retroviruses include. but are not limited to, the RNA viruses of the Retroviridae family, and also the DNA viruses of the Hepadnavirus and Caulimovirus families. Retroviruses cause a variety of disease states in man, animals and plants. Some of the more important 1s retroviruses from a pathological standpoint include human immunodeficiency viruses (HIV-1 and HIV-2), which cause acquired immune deficiency syndrome (AIDS) in man, human T-cell lymphotrophic viruses 1, 11, IV and V, which cause human acute cell leukemia, and bovine and feline leukemia viruses which cause leukemia in domestic animals, Proteases are enzymes which cleave proteins at specific peptide bonds. Many biological functions are controlled or mediated by proteases and their complementary protease inhibitors. For example, the protease renin cleaves the peptide angiotensinogen to produce the peptide angiotensin 1. Angiolensin -2 I is further cleaved by the protease angiotensin converting enzyme (ACE) to form the hypotensive peptide angiotensin 1I. Inhibitors of renin and ACE are known to reduce high blood pressure in yly. An inhibitor of a retroviral protease will provide a therapeutic agent for diseases caused by the retrovirus. 5 The genomes of retroviruses encode a protease that is responsible for the proteolylic processing of one or more polyprotein precursors such as the pal and gag gene products. See Wellink, Arch. Virol. 22 1 (1988). Retroviral proteases most commonly process the g=g precursor into core proteins, and also process the Wd precursor into reverse transciptase and retroviral protease. io In addition, retroviral proteases are sequence specific. See Pearl, Nature 2 482 (1987). The correct processing of the precursor polyproteins by the retroviral protease is necessary for the assembly of infectious virions. It has been shown that in y=t mutagenesis that produces protease-defective virus leads to the is production of immature core forms which lack infectivity. See Crawford, J. Virol. 5. 899 (1985): Katoh, et al., Virology L45 280 (1985). Therefore, retroviral protease inhibition provides an attractive target for antiviral therapy. See Mitsuya, Nature ? 775 (1987). Current treatments for viral diseases usually involve administration of 20 compounds that inhibit viral DNA synthesis. Current treatments for AIDS involve administration of compounds such as 3'-azido-3'-deoxythymidine (AZT), 2',3' dideoxycytidine (DDC), 2',3'-dideoxyinosine (DDI), d4T and 3TC and compounds which treat the opportunistic infections caused by the immunosuppression resulting from HIV infection. None of the current AIDS 25 treatments have proven to be totally effective in treating and/or reversing the disease. In addition, many of the compounds currently used to treat AIDS cause adverse side effects including low platelet count, renal toxicity and bone marrow cytopenia. Recently the HIV protease inhibitors ritonavir, saquinavir and indinavir 30 have been approved in the U.S. for treatment of HIV infections. However, there is a continuing need for improved HIV protease inhibitors.

-3 Disclosure of the Invention In accordance with the present invention, there is a compound of the formula I: R~Rt R H4 Hij "NN

R

5 OH R 2 0 wherein R 1 and R 2 are independently selected from the group consisting of loweralkyl, cycloalkylalkyl and arylalkyl;

R

3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl;

R

4 is aryl or heterocyclic; 10 R 5 is x N Ay a) (CH 2 )n x N y (CH2)m -4 x C) " x d) (CH 2 )m z x e)y (CH2)m' x I) (CH 2 )m' x N N-R 5 g) 0 N N -R 6 h) OH or -5 0 NN - R6 i)HO wherein n is 1, 2 or 3, m is 1, 2 or 3, m'is 1 or 2, X is 0, S or NH, Y is -CH 2 -, -0 , -S- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y" is -CH 2 - or -N(R 6 ".)- wherein R 6 ., is hydrogen, loweralkyl, 5 cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 .)- wherein R 6 . is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, and Z is 0, S or NH; and Lj is 10 a) -0-, b) -S-, C) -N(R 7 )- wherein R 7 is hydrogen, loweralkyl, cycloalkyl or cycloalkylalkyl, d) -0-alkylenyl-, e) -S-alkylenyl f) -S(0)-alkylenyl-, g) -S(O)2-alkylenyl-, h) -N(R 7 )-alkylenyl- wherein R 7 is defined as above, i) -alkylenyl-O-, j) -alkylenyl-S-, 20 k) alkylenyl-N(R 7 )- wherein R 7 is defined as above. I) alkylenyl or m) alkenylenyl; or a pharmaceutically acceptable salt, ester or prodrug thereof.

-6 Preferred compounds are compounds of the formula I wherein R, and R2 are arylalkyl, R 3 is loweralkyl, R 4 is aryl, R 5 is x y a) (CH 2 )n x N y

(CH

2 )m x N Y c) (CH2' x N Y" d) (CH2)m' or x N

N-R

6 " e) -7 wherein X, Y, Y', Y", Z, R,., n, m and m' are defined as above and

L

1 is -0-alkylenyl. More preferred compounds are compounds of the formula I wherein Ri and R 2 are benzyl or R 1 is benzyl and R 2 is loweralkyl, R3 is loweralkyl, R 4 is s (a) phenyl which is substituted with two loweralkyl groups and which is optionally substituted with a third substituent selected from the group consisting of loweralkyl, hydroxy, amino and halo or (b) pyridyl or pyrimidinyl either of which is substituted with two loweralkyl groups and which is optionally substituted with a third substituent selected from the group consisting of to loweralkyl, hydroxy, amino and halo, R 5 is x a) (CH 2 )n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x N Ay

(CH

2 )m wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is 0, x N Y 15 c) (CH 2 )m' Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, -8 X I I d)

(CH

2 )m' wherein m' is 1, X is 0, Y" is -NH- and Y' is -NH- or x N KN - R 6 " e) wherein X is 0 and R 6 .. is hydrogen 5 and Li is --OCH 2 -. Even more preferred compounds are compounds of the formula I wherein R, and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl, R 4 is 10 2,6-dimethylphenyl which is optionally substituted with a third substituent selected from the group consisting of loweralkyl and halo, R 5 is x N ) y a) (CH2)nJ wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x (CH2)m b) Z -9 wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is 0, x N "kY c) (CH2)m wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x NY", Y, d) (CH 2 )m' 5 wherein m'is 1, X is 0, Y" is -NH- and Y' is -NH- or x N N - r>" e) N wherein X is 0 and R 6 is hydrogen and Li is -0-CH 2 .. Most preferred compounds are compounds of the formula I wherein

R

1 and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl, R 4 is 2.6-dimethylphenyl which is optionally substituted with a third substituent selected from the group consisting of loweralkyl and halo, R 5 is x N y a) (CH 2 )n wherein n is 1 or 2. X is 0 or S and Y is -CH 2 or -NH-, -10 x b)

(CH

2 )m, Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x NY" II /Y' C) (CH2)m' wherein m'is 1, X is 0, Y" is -NH- and Y' is -NH- or x N - R 6 " d) N wherein X is 0 and R 6 .. is hydrogen and Li is -0-CH 2

-

Most highly preferred compounds are compounds of the formula I 1o wherein R, and R 2 are benzyl or R, is benzyl and R 2 is isopropyl,

R

3 is loweralkyl, R 4 is 2,6-dimethylphenyl which is optionally substituted with a third substituent selected from the group consisting of loweralkyl and halo, R 5 is A (N y (CH 2 )nJ -11 wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH and

L

1 is -0-CH 2 -. Examples of highly and most highly preferred compounds of the formula I 5 are selected from the group consisting of: (2S, 3S, 5S)-2-(2,6-dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1 tetrahydro-pyrimid-2-onyl)-3-methyl butanoyl] amino-1,6-diphenylhexane; (2S.

3

S,

5

S)-

2 -(2,6-Dimethylphenoxyacetyl)amino-3-hydroxy-5-(2S-(1 imidazolidin-2-onyl)-3,3-dimethyl butanoyl)amino-1,6-diphenylhexane; 10 ( 2 S,3S, 5 S)-2-(2,6-dimethylphenoxyacetyl)amino-3-hydroxy-5-(2S-(1 imidazolidin-2-thionyl)-3-methyl butanoyl)amino-1,6-diphenylhexane;

(

2

S,

3 S,5S)-2-(2,4,6-trimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 imidazolidin-2-onyl)-3-methylbutanoyl) amino-1,6-diphenylhexane;

(

2 S,3S,5S)-2-(4-fluoro-2,6-dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 15 imidazolidin-2-onyl)-3-methyl- butanoyl) amino- 1,6-diphenylhexane; (2S,3S.5S)-2-(2,6-dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 pyrrolidin-2-onyl)-3-methyl-butanoyl) amino- 1,6-diphenylhexane;

(

2 S,3S,5S)-2-(2,6-dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 pyrrolidin-2,5-dionyl)-3-methyl-butanoyl) amino-1 6-diphenylhexane; 20 ( 2 S.3S.5S)-2-(trans-3-(2,6-dimethylphenyl) propenoyl) amino-3-hydroxy-5-(2S 1-tetrahydropyrimidin-2-onyl)-3-methyl-butanoyl) amino-1,6-diphenylhexane;

(

2 S,3S,5S)-2-(3-(2,6-dimethylphenyl) propanoyl) amino-3-hydroxy-5-(2S-(1 tetrahydropyrimidin-2-onyl)-3-methyl-butanoyl) amino- 1,6-diphenylhexane;

(

2 S.3S,5S)-2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 25 tetrahydro-pyrimid-2,4-dionyl)-3-methylbutanoyl)amino-1,6-diphenylhexane;

(

2

S.

3

S,

5

S)-

2 -(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(4-aza-1 tetrahydro-pyrimid-2-onyl)-3-methyl-butanoyl)amino- 1,6-diphenylhexane:

(

2 S.3S,5S)-2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 tetrahydro-pyrimid-2-onyl)-3-methylbutanoyl)amino -1 -phenyl-6-methylheptane; -12 (2S,3S,5S)-2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 tetrahydro-pyrimid-2,4-dionyl)-3-methylbutanoyl)amino-1 -phenyl-6 methylheptane; and (2S,3S,5S)-2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(4-aza-4,5 s dehydro-1-pyrimid-2-onyl)-3-methyl-butanoyl)amino-1,6-diphenylhexane; or a pharmaceutically acceptable salt, ester or prodrug thereof. The most highly preferred compound of the formula I is (2S, 3S, 5S)-2 (2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1 -tetrahydro-pyrimid-2 onyl)-3-methyl butanoyl) amino-1,6-diphenylhexane; 1o or a pharmaceutically acceptable salt, ester or prodrug thereof. In some circumstances it is preferred to be able to prepare (2S, 3S, 5S) 2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2 onyl)-3-methyl butanoyl] amino-1,6-diphenylhexane (or a pharmaceutically acceptable salt, ester or prodrug thereof) as an amorphous solid. Such an is amorphous solid can be prepared by dissolving (2S, 3S, 5S)-2-(2,6 Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2-onyl) 3-methyl butanoyl] amino-1,6-diphenylhexane in an organic solvent (for example, ethanol, isopropanol, acetone, acetonitrile and the like) and then adding the solution to water. Preferably, (2S, 3S, 5S)-2-(2,6 20 Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2-onyl) 3-methyl butanoyl] amino-1,6-diphenylhexane is dissolved in ethanol (from about 2 to about 4 mL/g) and the ethanolic solution is added with stirring to water (from about 10 about 100 mL/g) to provide amorphous (2S, 3S, 5S)-2 (2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2 25 onyl)-3-methyl butanoyl] amino-1,6-diphenylhexane. Another embodiment of the present invention comprises an HIV protease inhibiting compound comprising a substituent of the formula 1I:

R

3 - C R 5 Il -13 wherein R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; and R5 is x N "ky a) (CH 2 )nJ' x y

(CH

2 )m c) " Z x N Y d) (CH2)m' Z -14 x

N-

/Y e)

(CH

2 )m' x N Y" I I (CH2)m' x

N

N~ NR6 h) OH or 0 N N- R6 5 i) HO wherein n is 1, 2 or 3, m is 1, 2 or 3, m'is 1 or 2, X is 0, S or NH, Y is -CH 2 -, -0 -S- or -N(RS)- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, -15 aryl or arylalkyl, Y" is -CH 2 - or -N(R 6 ")- wherein R 6 " is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 ,)- wherein R, is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, and Z is 0, S or NH. 5 Preferred compounds are HIV protease inhibiting compounds comprising a substituent of the formula 11 wherein R 3 is loweralkyl and R 5 is x N ) y S (CH2)n x Y C)

(CH

2 ' Z x N Y Y' io d) (CH2)m' or -16 x N N - R 6 e) wherein X, Y, Y', Y", Z, RV,, n, m and m' are defined as above. More preferred compounds are HIV protease inhibiting compounds comprising a substituent of the formula 11 wherein R 3 is loweralkyl and R5 is x N y 5 a) (CH2)nJ wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x y (CH2)m wherein m is 1 or 2, X is O, Y is -CH 2 - and Z is 0, x N Y C) (CH2)m' Z 10 wherein m'is 1, X is 0, Z is 0 and Y is -NH-, -17 x Y," d) (CH 2 )m' wherein m'is 1, X is 0, Y" is -NH- and Y' is -NH- or x N - R 6 e) wherein X is 0 and R 6 . is hydrogen. s Even more preferred compounds are HIV protease inhibiting compounds comprising a substituent of the formula 11 wherein R 3 is isopropyl and R 5 is x N ' y a) (CH 2 )n wherein n is 1 or 2. X is 0 or S and Y is -CH 2 or -NH-, x N Ay (CH2)m b) Z 10 wherein m is 1 or 2. X is 0, Y is -CH 2 - and Z is 0, -18 x C) (CH 2 )m' Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x "Y' d)

(CH

2 )m' wherein mrs 1, X is 0, Y" is -NH- and Y' is -NH- or x NN - R 6 ". s e) wherein X is 0 and R 6 ., is hydrogen. Most preferred compounds are HIV protease inhibiting compounds comprising a substituent of the formula II wherein R 3 is isopropyl and R 5 is x Ny a) (CH 2 )n 10 wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x N Y b) (CH2)m Z -19 wherein m'is 1, X is 0, Z is 0 and Y is -NH-, X Y' c) (CH2)m' wherein m'is 1, X is 0, Y" is -NH- and Y' is -NH- or X N - RV d) N 5 wherein X is 0 and R 6 is hydrogen. Most highly preferred compounds are HIV protease inhibiting compounds comprising a substituent of the formula II wherein R 3 is isopropyl and R 5 is X Ny

(CH

2 )nJ wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-. 10 Examples of such HIV protease inhibiting compounds include: cis-N-tert-butyl-decahydro-2-[ 2(R)-hydroxy-4-phenyl-3(S)-(2S-(1 tetrahydropyrimid-2-onyl)-3-methylbutanoyl)aminobutylj-(4aS,8aS) isoquinoline-3(S)-carboxamide; cis-N-tert-butyl-decahydro-2-[ 2(R)-hydroxy-4-thiophenyl-3(S)-(2S-(1 15 tetrahydropyrimid-2-onyl)-3-methylbutanoyl)aminobutyl]-(4aSBaS) isoquinoline-3(S)-carboxamide; and 4-Amino-N-(( 2syn, 3S)-2-hydroxy-4-phenyl-3-(2S-( 1-tetrahydropyrimid-2 onyl)- 3 -methylbutanoylamino)-butyl)-N-isobutyl-benzenesulfonamide; and the like; 20 or pharmaceutically acceptable salts thereof -20 Such HIV protease inhibiting compounds comprising a substituent of the formula il can be prepared by coupling a suitable intermediate or precursor having an amino group (-NH 2 or -NHR' wherein R* is loweralkyl), a hydroxyl group (-OH) or a thiol group (-SH) to the compound of the formula III or a salt or 5 an activated ester derivative thereof:

R

3 HO-C R 5 II 0 wherein R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; and

R

5 is x N , y a) (CH 2 )n x N "ky 0 b) (CH2)m -21 x x d) (CH2)m x /Y f) (CH2)m x N

-

RV' 0 N J"N-R 6 h) OH or -22 0 N-R6 i) HO wherein n is 1, 2 or 3, m is 1, 2 or 3, m'is 1 or 2, X is O, S or NH, Y is -CH 2 -, -O -S- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y" is -CH 2 - or -N(R 6 .. )- wherein R 6 .. is hydrogen, loweralkyl, s cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 .)- wherein R 6 , is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, and Z is 0, S or NH. Preferred compounds are compounds of the formula III or an activated ester derivative thereof wherein R 3 is loweralkyl and R 5 is x N ) y i0 a) (CH2)nJ x N "kY

(CH

2 )m -23 x C) (CH 2 )m Z x "Y' d) (CH 2 )m' or x N N ,- RN- 6 e) wherein X, Y, Y', Y", Z, R 6 ,, n, m and m' are defined as above. 5 More preferred compounds are compounds of the formula III or an activated ester derivative thereof wherein R 3 is loweralkyl and R 5 is x N Ay a) (CH2)n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, -24 x Y (CH2)m wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is 0, x AY C) (CH 2 )m' wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x NY" d) (CH 2 )m' wherein m'is 1, X is 0, Y" is -NH- and Y' is -NH- or x N N - RV" e) wherein X is 0 and R 6 " is hydrogen. Even more preferred compounds are compounds of the formula III or an 10 activated ester derivative thereof wherein R 3 is isopropyl and R 5 is -25 x 'N ) y a) (CH2)n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x NY (CH2)m wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is 0, x NY 5 C) (CH2)m' Z wherein m' is 1, X is 0, Z is 0 and Y is -NH-, x N Y" /Y, d) (CH 2 )m' wherein m'is 1, X is 0, Y" is -NH- and Y is -NH- or x N N - RV" 10 e) wherein X is 0 and R... is hydrogen.

-26 Most preferred compounds are compounds of the formula IIl or an activated ester derivative thereof wherein R 3 is isopropyl and R 5 is N ky a) (CH 2 )n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x N Y 5 b) (CH2)m Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x NY" /Y' c) (CH 2 )m' wherein mis 1, X is 0, Y" is -NH- and Y' is -NH- or x N-- N - R 6 ' d) 10 wherein X is 0 and R 6 . is hydrogen. Most highly preferred compounds are compounds of the formula III or an activated ester derivative thereof wherein R 3 is isopropyl and R 5 is -27 X N y

(CH

2 )n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-. The compounds of the invention can comprise asymmetrically substituted carbon atoms. As a result, all stereoisomers of the compounds of the invention 5 are meant to be included in the invention, including racemic mixtures, mixtures of diastereomers, as well as single diastereomers of the compounds of the invention. The terms "S" and "R" configuration are as defined by the IUPAC 1974 Recommendations for Section E, Fundamental Stereochemistry, Pure Appl. 10 Chem. (1976) 45, 13 - 30. The term "N-protecting group" or "N-protected" as used herein refers to those groups intended to protect the N-terminus of an amino acid or peptide or to protect an amino group against undersirable reactions during synthetic procedures. Commonly used N-protecting groups are disclosed in Greene and 1s Wuts, "Protective Groups In Organic Synthesis," (John Wiley & Sons, New York (1991)), which is hereby incorporated by reference. N-protecting groups comprise acyl groups such as formyl, acetyl, propionyl, pivaloyl, t-butylacetyl, 2-chloroacetyl, 2-bromoacetyl, trifluoroacetyl, trichloroacetyl, phthalyl, o-nitrophenoxyacetyl, ax-chlorobutyryl, benzoyl, 4-chlorobenzoyl, 20 4-bromobenzoyl, 4-nitrobenzoyl, and the like; sulfonyl groups such as benzenesulfonyl, p-toluenesulfonyl and the like; carbamate forming groups such as benzyloxycarbonyl, p-chlorobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, 2-nitrobenzyloxycarbonyl, p-bromobenzyloxycarbonyl, 25 3.4-dimethoxybenzyloxycarbonyl, 3.5-dimethoxybenzyloxycarbonyl, 2.4-dimethoxybenzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, 2-nitro-4,5-dimethoxybenzyloxycarbonyl, 3,4,5-trimethoxybenzyloxycarbonyl, 1 -(p-biphenylyl)-1 -methylethoxycarbonyl, -28 a,a-dimethyl-3,5-dimethoxybenzyloxycarbonyl, benzhydryloxycarbonyl, t-butyloxycarbonyl, diisopropylmethoxycarbonyl, isopropyloxycarbonyl, ethoxycarbonyl, methoxycarbonyl, allyloxycarbonyl, 2,2,2,-trichloroethoxycarbonyl, phenoxycarbonyl, 4-nitrophenoxycarbonyl, 5 fluorenyl-9-methoxycarbonyl, cyclopentyloxycarbonyl, adamantyloxycarbonyl, cyclohexyloxycarbonyl, phenylthiocarbonyl and the like; alkyl groups such as benzyl, triphenylmethyl, benzyloxymethyl and the like; and silyl groups such as trimethylsilyl and the like. Preferred N-protecting groups are formyl, acetyl, benzoyl, pivaloyl, t-butylacetyl, phenylsulfonyl, benzyl, t-butyloxycarbonyl (Boc) 10 and benzyloxycarbonyl (Cbz). The term "activated ester derivative" as used herein refers to acid halides such as acid chlorides, and activated esters including, but not limited to, formic and acetic acid derived anhydrides, anhydrides derived from alkoxycarbonyl halides such as isobutyloxycarbonylchloride and the like, N-hydroxysuccinimide 15 derived esters, N-hydroxyphthalimide derived esters, N-hydroxybenzotriazole derived esters, N-hydroxy-5-norbornene-2,3-dicarboxamide derived esters, 2,4,5-trichlorophenol derived esters, thiophenol derived esters, propylphosphonic acid derived anhydrides and the like. The term "alkanoyl" as used herein refers to R 19 C(O)- wherein R 1 g is a 20 loweralkyl group. The term "alkenylenyl" as used herein refers to a divalent group derived from a straight or branched chain hydrocarbon containing from 2 to 10 carbon atoms and also containing at least one carbon-carbon double bond. Examples of alkenylene include -CH=CH-, -CH 2 CH=CH-, -C(CH 3 )=CH-, 25 -CH 2

CH=CHCH

2 -, and the like. The terms "alkoxy" and "thioalkoxy" as used herein refer to R 15 0- and R15S-, respectively, wherein R 15 is a loweralkyl group. The term "alkoxyalkoxy" as used herein refers to R 22 0-R 23 0- wherein

R

22 is loweralkyl as defined above and R 23 is an alkylenyl group. 30 Representative examples of alkoxyalkoxy groups include methoxymethoxy, ethoxymethoxy, t-butoxymethoxy and the like.

-29 The term "alkoxyalkyl" as used herein refers to an alkoxy group appended to a loweralkyl radical. The term "alkoxycarbonyl" as used herein refers to R 20 C(O)- wherein R 20 is an alkoxy group. 5 The term "alkylamino" as used herein refers to -NHR 16 wherein R 1 6 is a loweralkyl group. The term "alkylaminocarbonyl" as used herein refers to R 21 C(O)- wherein

R

21 is an alkylamino group. The term "alkylenyl" as used herein refers to a divalent group derived 10 from a straight or branched chain saturated hydrocarbon having from 1 to 10 carbon atoms by the removal of two hydrogen atoms, for example methylene

(-CH

2 -), 1,2-ethylene (-CH 2

CH

2 -), 1,1-ethylene =CH-CH 3 , 1,3-propylene

(-CH

2

CH

2

CH

2 -), 2,2-dimethylpropylene

(-CH

2

C(CH

3

)

2

CH

2 -), and the like. The term "aminocarbonyl" as used herein refers to -C(O)NH 2 . 1s The term "aryl" as used herein refers to a mono- or bicyclic carbocyclic ring system comprising 6 to 12 carbon atoms and having one or two aromatic rings including, but not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, indenyl and the like. Aryl groups can be unsubstituted or substituted with one, two or three substituents independently selected from loweralkyl, halo, 20 haloalkyl, haloalkoxy, alkoxy, alkoxycarbonyl, thioalkoxy, amino, alkylamino, dialkylamino, aminocarbonyl, mercapto, nitro, carboxaldehyde, carboxy and hydroxy. The term "arylalkyl" as used herein refers to an aryl group as previously defined, appended to a loweralkyl radical, for example, benzyl and the like. 25 The term "cycloalkyl" as used herein refers to an aliphatic ring system having 3 to 8 carbon atoms including, but not limited to, cyclopropyl, cyclopentyl, cyclohexyl, and the like. The term "cycloalkylalkyl" as used herein refers to a cycloalkyl group appended to a loweralkyl radical, including but not limited to cyclohexylmethyl. 30 The term "dialkylamino" as used herein refers to

-NR

16

R

1 7 wherein R 16 and R are independently selected from loweralkyl groups.

-30 The term "dialkylaminocarbonyl" as used herein refers to R22C(0) wherein R 22 is a dialkylamino group. The term "halo" or "halogen" as used herein refers to -Cl, -Br, -1 or -F. The term "haloalkoxy" as used herein refers to R 18 0- wherein R 18 is a 5 haloalkyl group. The term "haloalkyl" as used herein refers to a loweralkyl group in which one or more hydrogen atoms are replaced by halogen, for example, chloromethyl, chloroethyl, trifluoromethy and the like. The term "heterocyclic ring" or "heterocyclic" or "heterocycle" as used 10 herein refers to any 3- or 4-membered ring containing a heteroatom selected from oxygen, nitrogen and sulfur; or a 5-, 6- or 7-membered ring containing one, two or three heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur or a 5-membered ring containing 4 nitrogen atoms; and includes a 5-, 6- or 7-membered ring containing one, two or three nitrogen 1s atoms; one oxygen atom; one sulfur atom; one nitrogen and one sulfur atom; one nitrogen and one oxygen atom; two oxygen atoms in non-adjacent positions; one oxygen and one sulfur atom in non-adjacent positions; two sulfur atoms in non-adjacent positions; two sulfur atoms in adjacent positions and one nitrogen atom; two adjacent nitrogen atoms and one sulfur atom: two non 20 adjacent nitrogen atoms and one sulfur atom; two non-adjacent nitrogen atoms and one oxygen atom. The 5-membered ring has 0-2 double bonds and the 6 and 7-membered rings have 0-3 double bonds. The nitrogen heteroatoms can be optionally quaternized. The term "heterocyclic" also includes bicyclic groups in which any of the above heterocyclic rings is fused to a benzene ring or a 25 cyclohexane ring or another heterocyclic ring (for example, indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuryl, bistetrahydorfuranyl or benzothienyl and the like). Heterocyclics include: azetidinyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, piperidinyl, homopiperidinyl, pyrazinyl, piperazinyl, pyrimidinyl, 30 pyridazinyl, oxazolyl, oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzothiazolyl. benzoxazolyl, furyl, thienyl, tetrahydrofuranyl, tetrahydrothienyl, thiazolidinyl, isothiazolyl, triazolyl, tetrazolyl, -31 isoxazolyl, oxadiazolyl, thiadiazolyl, pyrrolyl, pyrimidyl and benzothienyl. is, Heterocyclics also include compounds of the formula z wherein X* is -CH 2 -, -NH- or -0-, Y' is -C(0)- or [-C(R") 2 -]v wherein R" is hydrogen or C 1

-C

4 -alkyl and v is 1, 2 or 3 and Z* is -0- or -NH-: such as 1,3 5 benzodioxolyl, 1,4-benzodioxanyl and the like. Heterocyclics can be unsubstituted or substituted with one, two, three or four substituents independently selected from the group consisting of hydroxy, halo, oxo (=0), alkylimino (R*N= wherein R* is a loweralkyl group), amino, alkylamino, dialkylamino, alkoxy, alkoxyalkoxy, haloalkyl, cycloalkyl, aryl, to arylalkyl, -COOH, -SO3H and loweralkyl. In addition, nitrogen containing heterocycles can be N-protected. The term "hydroxyakyl" as used herein refers to a loweralkyl radical to which is appended an hydroxy group. The term "loweralkyl" as used herein refers to a straight or branched 15 chain alkyl radical containing from 1 to 6 carbon atoms including, but not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n pentyl, 1-methylbutyl, 2,2-dimethylbutyl, 2-methylpentyl, 2,2-dimethylpropyl, n hexyl and the like. The term "thioalkoxyalkyl" as used herein refers to a thioalkoxy group 20 appended to a loweralkyl radical. The compound of the invention of formula I can be prepared as shown in Schemes I-IV. As outlined in Scheme I, intermediates 1 and 2 (wherein P 1 is an N-protecting group, for example, t-butyloxycarbonyl) can be coupled using standard peptide coupling reagents and methods, for example, reaction of 1 25 and 2 in the presence of 1-hydroxybenzotriazole and a diimide such as dicyclohexylcarbodiimide (DCC) or N-ethyl-N'-dimethylaminopropyl carbodiimide (EDAC) and the like to give 2. Alternatively, a salt or an activated ester derivative of intermediate 1 (for example, the acid chloride, prepared by reaction of the carboxylic acid with thionyl chloride) can be reacted with 30 intermediate 2.

-32 Compound a can be N-deprotected to give compound 4. N-deprotection of 3 wherein P, (especially wherein P 1 is t-butyloxycarbonyl) is an acid labile N-protecting group can lead to formation of impurities resulting from migration of the acyl group R 4

-L

1 -C(O)- from the amino group to the hydroxyl group. The s formation of this impurity can be minimized or eliminated by performing the deprotection using (1) trifluoroacetic acid in methylene chloride or (2) concentrated hydrochloric acid (from about 2 molar equivalents to about 6 molar equivalents, preferably, from about 2 molar equivalents to about 4 molar equivalents) in acetic acid at about room temperature. A preferred 10 N-deprotection method comprises reacting compound 3 (wherein P, is t-butyloxycarbonyl) with concentrated hydrochloric acid (from about 10 to about 20 molar equivalents) in acetonitrile (from about 2 to about 10 liters/kilogram of compound a) at a temperature of from about OC to about 50C. Compound 5 or an activated ester derivative thereof can then be coupled to compound 4 to give is the compound of the formula I (i.e., &). An alternative process is shown in Scheme IIA. Compound Z (wherein P2 is an N-protecting group, for example, benzyloxycarbonyl) can be coupled to compound 5, or a salt or an activated ester derivative thereof (for example, the acid chloride, prepared by reaction of the carboxylic acid with thionyl chloride), 20 to give a. Compound a can be N-deprotected to give q. Compound a can be coupled with compound 1 or an activated ester derivative thereof, to give the compound of the formula I (i.e., J). Scheme 11B shows a preferred alternative process wherein the N- protected amino alcohol 7g (P 3 is hydrogen and P 4 is an N-protecting group 25 or both P 3 and P 4 are N-protecting groups, preferably, P 3 and P 4 are benzyl) is reacted with from about 1 to about 1.3 molar equivalents of carboxylic acid 5 or a salt or an activated ester derivative thereof (for example, the acid chloride, prepared by reaction of the carboxylic acid with thionyl chloride in ethyl acetate or THF or oxalyl chloride in toluene/DMF and the like) in the presence of from 3o about 1.0 to about 4.0 molar equivalents (preferably, from about 2.5 to about 3.5 molar equivalents) of an organic amine base (for example, imidazole, 1-methylimidazole, 2-methylimidazole, 2-isopropylimidazole, 4-methylimidazole, 4-nitroimidazole, pyridine, N,N-dimethylaminopyridine, 1.2.4-triazole, pyrrole. 3-methylpyrrole, triethylamine or N-methylmorpholine -33 and the like) or from about 1 to about 20 molar equivalents of an inorganic base (for example, sodium carbonate or sodium bicarbonate and the like) in an inert solvent (for example, ethyl acetate, dimethylformamide, THF, acetonitrile, isopropyl acetate or toluene and the like) at a temperature of from about 00C to 5 about 500C to provide compound ga. Preferred organic amine bases include imidazole and 1,2,4-triazole. N-Debenzylation of Ia (for example, using hydrogen and a hydrogenation catalyst or Pd/C and a formic acid salt (for example, ammonium formate and the like) or Pd/C and formic acid and the like) provides a. 10 Compound 2 can be advantageously purified by crystallization with an organic carboxylic acid (for example, S-pyroglutamic acid, succinic acid or fumaric acid and the like). A preferred organic carboxylic acid is S-pyroglutamic acid. Compound 2 (or an organic carboxylic acid salt of compound Z) is reacted with from about 1.0 to about 1.3 molar equivalents of carboxylic acid 1 1s or a salt or an activated ester derivative thereof (for example, the acid chloride) in the presence of (1) from about 4 to about 8 molar equivalents (preferably, from about 5 to about 7 molar equivalents) of an inorganic base (for example, NaHCO 3 , Na 2

CO

3 , KHCO 3 , K 2

CO

3 , NaOH or KOH and the like) in an inert solvent (for example, 1:1 ethyl acetate/water or isopropyl acetate/water or 20 toluene/water or THF/water and the like) at about room temperature or (2) from about 1.0 to about 4.0 molar equivalents (preferably, from about 2.5 to about 3.5 molar equivalents) of an organic amine base (for example, imidazole, 1-methylimidazole, 2-methylimidazole, 2-isopropylimidazole, 4-methylimidazole, 4-nitroimidazole, pyridine, N,N-dimethylaminopyridine, 25 1,2,4-triazole, pyrrole, 3-methylpyrrole, triethylamine or N-methylmorpholine and the like) in an inert solvent (for example, ethyl acetate, isopropyl acetate, THF, toluene, acetonitrile, dimethylformamide and the like) at a temperature of from about 00C to about 500C to provide compound g. In a preferred embodiment of the invention (shown in Scheme l1l), 30 intermediate compound a has the formula of compound 1 (R 3 is as defined for the compound of formula I and is preferably isopropyl). Compound .1Q can be prepared in variety ways as shown in Scheme Ill. In one method, amino acid 1 (either as the free carboxylic acid or as the carboxylic acid ester (i.e., loweralkyl -34 ester)) is converted to carbamate 12 (R" is phenyl, loweralkyl-substituted phenyl, halo-substituted phenyl, nitro-substituted phenyl, trifluoromethylphenyl and the like) by reaction with the appropriate chloroformate ester and the like. Reaction of carbamate 22 with from about 1.0 to about 1.5 molar equivalents of s amine 13 or an acid addition salt thereof (Q is a leaving group, for example, Cl, Br or I, or a sulfonate such as methanesulfonate, triflate, p-toluenesulfonate, benzenesulfonate and the like) in an inert solvent (for example, THF, methyl t-butyl ether, dimethoxyethane, THF/water, dimethoxyethane/water, toluene or heptane and the like) in the presence of a base (for example, LiOH, io NaOH, Li 2 CO3, Na 2

CO

3 , lithium phenoxide or sodium phenoxide and the like) in the amount of from about 2.5 to about 3.5 molar equivalents provides urea 14. Urea 14 can be isolated and reacted further or can be converted in situ to cyclic urea 10 by reaction in an inert solvent (for example, THF, dimethoxyethane, methyl t-butyl ether, toluene or heptane and the like) with a base (for example, is potassium t-butoxide, sodium hydride, potassium hydride or dimethylaminopyridine and the like) in the amount of from about 2.0 to about 5.0 molar equivalents. If the amino acid ester of 11 was the starting material, the ester is then hydrolyzed to provide the carboxylic acid 10. Alternatively, amino acid 11 (either as the free carboxylic acid or as the 20 carboxylic acid ester) is converted to urea 14 by reaction with from about 1 .0 to about 1.5 molar equivalents of isocyanate IL (Q is a leaving group, for example, Cl. Br or I, or a sulfonate such as methanesulfonate, triflate, p-toluenesulfonate. benzenesulfonate and the like) in an inert solvent (for example, THF, dimethoxyethane, methyl t-butyl ether, toluene or heptane and the like) in the 25 presence of a base. In yet another alternative, amino acid 11 (either as the free carboxylic acid or as the carboxylic acid ester) is converted to diamine 16 by reaction with from about 1.0 to about 1.5 molar equivalents of amine 1_3 or an N-protected 30 derivative thereof (Q is a leaving group, for example, Cl, Br or I, or a sulfonate such as methanesulfonate, triflate, p-toluenesulfonate, benzenesulfonate and the like) in an inert solvent (for example, THF, dimethoxyethane, methyl t-butyl ether, toluene or heptane and the like) in the presence of a base (for example, NaH or potassium t-butoxide and the like) in the amount of from about 1.0 to -35 about 4.0 molar equivalents. N-deprotection is required if the N-protected derivative of j3 was used. Reaction of diamine . with a carbonyl equivalent 17 (for example, phosgene, carbonyldiimidazole and the like wherein Q' and Q" are leaving groups such as Cl, Br, I, -0-loweralkyl, -0-aryl or imidazolyl and the 5 like) in an inert solvent (for example, THF, dimethoxyethane, methyl t-butyl ether, toluene or heptane and the like) in the presence of a base (for example, NaH or potassium t-butoxide and the like and the like) in the amount of from about 2.0 to about 4.0 molar equivalents provides cyclic urea IQ. If the amino acid ester of 11 was the starting material, the ester is then hydrolyzed to provide 10 the carboxylic acid 0. In yet another alternative shown in Scheme IV, compound 11 (either as the free carboxylic acid or as the carboxylic acid ester (i.e., loweralkyl ester)) is reacted with acrylonitrile according to J. Am. Chem. Soc. 72 2599 (1950) to give aminonitrile 18. Alternatively, acrylonitrile can be replaced with 15 3-chloropropionitrile to provide 1 8. N-protection of aminonitrile 18 as the carbamate (R 30 is loweralkyl or phenyl or haloalkyl (for example, 2-chloroethyl, 2-bromoethyl and the like) and the like) using standard conditions (for example, reaction of the amine with the appropriate chloroformate ester (CIC(O)OR 30 wherein R 30 is loweralkyl, phenyl, haloalkyl and the like) neat or in an inert 20 solvent (for example, water, THF and the like) in the presence of an inorganic base (for example, NaOH, KOH, K 2 C0 3 and the like) or an organic base (for example, an alkylamine or dialkylamine and the like) and the like) provides compound 19. Hydrogenation of 19 in the presence of a catalyst (for example, Ni-Al alloy (basic) or Raney nickel (neutral or basic) or PtO 2 (acidic) and the 25 like) in an inert solvent (for example, water or methanol or ethanol or THF and the like) provides cyclic urea j2. In a preferred process, compound 19 is hydrogenated in the presence of a Ni-Al alloy catalyst in an inert solvent (for example, water or methanol or ethanol or THF and the like) in the presence of a base (for example, KOH or NaOH or LiOH or an organic amine base and the 30 like) in the amount of from about 1.1 to about 5 molar equivalents to provide cyclic urea 10. If the amino acid ester of 11 was the starting material, the ester is then hydrolyzed to provide the carboxylic acid 10.

-36 Alternatively, hydrogenation of compound 18 (as described above for compound 12) provides diamine .J§ which can be converted to compound 10 as previously described. If the amino acid ester of 11 was the starting material, the ester is then hydrolyzed to provide the carboxylic acid.

-37 Scheme I O

R

1 R4 L1 )"OH H 2 N NHP1 OH

R

2 2 O R1 R4 LKNNHP 1 H OH R 2 $3 O R1

R

4 , L1UKN

NH

2 OH

R

2 4

R

3 10 HO 5 O R

R

3 I! H

R

4 , L1 N N H OH R 2 0 6 -38 Scheme IIA R1 P2H N N H 2 HR

P

2 HN HO Rs O OH R2 O 80 7 R1 R3 H N

P

2 HN Rs OH R 2 0 8 R4 3 H N

H

2 N s OH R 2 0 9 0 Rl R 3 H R4- i'I N-t N R 5 H OH R 2 0 6 -39 Scheme IB R1

R

3

P

3 -N NH2 HO

P

4 OH R 2 O P3=P 4 =benzyl R1 R3 H N s

P

3 -N

R

5

P

4 OH R 2 0 R1 R 3 H N

H

2 N RS OH R 2 0 OH 10 ~ ~~R4,LiJ"O 1 R1

R

3 H R 4 N R4L1 N R5 H R OH R 2 0 6 -40

H

2 N y C0 2 H R"O-(O)C-HN y C0 2 H

R

3 R 3 11 12 5 H H N C0 2 H 0 R 14 13 0 0' 17O HN N C0 2 H

NH

2 HN C0 2 H 0 I 3 3 0 R3 16 R

-

-41 Scheme IV

H

2 N CO 2 H - CN NC NH CO 2 H R3

R

3 0 NO OR30 s N N CO 2 H

R

3

NH

2 HN CO 2 H HN N CO 2 H 0

R

3 10 I0 -42 Key intermediates for the preparation of the compounds of the invention include compounds of the formula III as described above and compounds of the formula IV:

R

1 R3 H

P

3 -N R5

P

4 OH R 2 0 or a salt thereof, wherein P 3 and P 4 are independently selected from hydrogen or an N-protecting group;

R

1 and R 2 are independently selected from the group consisting of loweralkyl, to cycloalkylalkyl and arylalkyl; R3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; and

R

5 is x N K y a) (CH2)n x N Y

(CH

2 )m -43 V NY c) Z x NAY d) (CH2)' , x e) (CH2)m' x N Y" K/Y 1) (CH2)m x N- R6 s g) N 0 N N- R 6 h) OH or -44 0 N - R6 j) HO wherein n is 1, 2 or 3, m is 1, 2 or 3, m'is 1 or 2, X is 0, S or NH, Y is -CH 2 -, -O , -S- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y" is -CH 2 - or -N(R 6 .,)- wherein R 6 ." is hydrogen, loweralkyl, s cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 .)- wherein R 6 , is hydrogen, loweralkyl, cycloalkyl, cycloalkylaikyl, aryl or arylalkyl, and Z is 0, S or NH. Preferred compounds are compounds of the formula IV wherein P 3 and

P

4 are hydrogen or benzyl, R, and R 2 are arylalkyl, R 3 is loweralkyl and R 5 is x ---- N N y 10 a)

(CH

2 )nJ x N AY (CH2)m -45 x c) (CH2)m' x d) (CH2)m' or x N N - RV. e) wherein X, Y, Y', Y", Z, R 6 ", n, m and m' are defined as above. 5 More preferred compounds are compounds of the formula IV wherein R 1 and R 2 are benzyl or R, is benzyl and R 2 is loweralkyl, R 3 is loweralkyl and R5 is x Ny a) (CH2)n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, -46 x 'N AY (CH2)m wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is 0, x c) (CH2)m, Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x N Y" /Y' s d) (CH 2 )m' wherein m' is 1, X is 0, Y" is -NH- and Y' is -NH- or x N 'K N - R6" e) wherein X is 0 and R 6 , is hydrogen. Even more preferred compounds are compounds of the formula IV 10 wherein R, and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl and R 5 is -47 x Nk y a (CH 2 )n wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x N 'kY

(CH

2 )m wherein m is 1 or 2, X is 0, Y is -CH 2 - and Z is O, x N Y C) (CHz)m Z wherein m'is 1, X is 0, Z is 0 and Y is -NH-, x N Y" II Y' d) (CH 2 )m' wherein m' is 1, X is 0, Y" is -NH- and Y is -NH- or x N N - R 6 " e) -N 10 wherein X is 0 and R.., is hydrogen.

-48 Most preferred compounds are compounds of the formula IV wherein R and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl and R 5 is x Nk y a) (CH 2 )nJ wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-, x N KY s b) (CH2)m' wherein m'is 1, X is 0, Z is O and Y is -NH-, x N Y" II Y' C) (CH2)m' wherein m'is 1. X is 0, Y" is -NH- and Y' is -NH- or x N N - R 6 1O d) wherein X is 0 and R 6 .. is hydrogen. Most highly preferred compounds are compounds of the formula IV wherein R, and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl and R 5 is -49 X N y

(CH

2 )nJ wherein n is 1 or 2, X is 0 or S and Y is -CH 2 or -NH-. Preferred salts of the compound of formula IV are organic carboxylic acid salts, especially the (S)-pyroglutamic acid salt. 5 The following examples will serve to further illustrate the preparation of the novel compounds of the invention. Example 1 (2S, 3S, 5S)-2-(2.6-dimethylphenoxvacetvl) amino-3-hydroxv-5-42S-(1 imidazolidin-2-onvl)-3-methyl-butanoylI amino-1 .6-diphenylhexane. 0 A. NN-Dibenzyl-(L)-phenylalanine Benzyl Ester. A solution containing L-phenylalanine (161 kg, 975 moles), potassium carbonate (445 kg, 3220 moles), water (675 L), ethanol (340 L), and benzyl chloride (415 kg, 3275 moles) was heated to 90±15*C for 10-24 hours. The reaction mixture was cooled to 600C and the lower aqueous layer was ' removed. Heptane (850 L) and water (385 L) were added to the organics, stirred, and the layers separated, The organics were then washed once with a water/methanol mixture (150 L/150 L). The organics were then stripped to give the desired product as an oil,which was carried on in the next step without purification. 20 IR (neat) 3090, 3050, 3030, 1730, 1495, 1450, 1160 cm- 1 , 1 H NMR (300 MHz, CDCl3) 5 7.5-7.0 (m, 20H), 5.3 (d, 1 H, J = 13.5 Hz), 5.2 (d, 1 H, J = 13.5 Hz), 4.0 (d, 2H, J = 15 Hz), 3.8 (t, 2H, J = 8.4 Hz), 3.6 (d, 2H, J = 15 Hz), 3.2 (dd, 1H, J = 8.4, 14.4 Hz), 13 C NMR (300 MHz, CDCl 3 ) 6 172.0, 139.2, 138.0, 135.98.2, 128.1, 128.1, 126.9, 126.2, 66.0, 62.3, 54.3, 35.6. 25 [:10 -79' (c = 0.9, DMF).

-50 B. (4S)-4-(N.N-Dibenzvlamino)-3-oxo-5-ohenyl-oentanonitrile. A solution containing the product of Example 1A (i.e., benzyl ester) (approx. 0.45 moles) in 520 mL tetrahydrofuran and 420 mL acetonitrile was cooled to -400C under nitrogen. A second solution containing sodium amide s (48.7g, 1.25 moles) in 850 mL tetrahydrofuran was cooled to -400C. To the sodium amide solution was slowly added 75 mL acetonitrile and the resulting solution was stirred at -400C for more than 15 minutes. The sodium amide/acetonitrile solution was then slowly added to the benzyl ester solution at -400C. The combined solution was stirred at -400C for one hour and then io quenched with 1150 mL of a 25% (w/v) citric acid solution. The resulting slurry was warmed to ambient temperature and the organics separated. The organics were then washed with 350 mL of a 25% (w/v) sodium chloride solution, then diluted with 900 mL heptane. The organics were then washed three times with 900 mL of a 5% (w/v) sodium chloride solution, two times with 900 mL of a 10% 15 methanolic water solution, one time with 900 mL of a 15% methanolic water solution, and then one time with 900 mL of a 20% methanolic water solution. The organics were stripped and the resulting material dissolved into 700 mL of hot ethanol. Upon cooling to room temperature, the desired product precipitated. Filtration gave the desired product in 59% yield from the L 20 phenylalanine. IR (CHCI3) 3090, 3050, 3030, 2250, 1735, 1600, 1490, 1450, 1370, 1300, 1215 cm- 1 , 1 H NMR (CDCl3) 6 7.3 (m, 15H), 3.9 (d, 1H, J = 19.5 Hz), 3.8 (d, 2H, J = 13.5 Hz), 3.6 (d, 2H, J = 13.5 Hz), 3.5 (dd, 1 H, J = 4.0, 10.5 Hz), 3.2 (dd, 1H, J = 10.5, 13.5 Hz), 3.0 (dd, 1H, J = 4.0, 13.5 Hz), 3.0 (d, 1H, J = 19.5 Hz), 13 C NMR (300MHz, CDCl3) 5 197.0, 138.4, 138.0, 129.5, 129.0, 25 128.8, 128.6, 127.8, 126.4, 68.6, 54.8, 30.0, 28.4. [ajD -95' (c = 0.5, DMF). C. (5S)-2-Amino-5-(N .N-dibenzvlamino)-4-oxo-1.6-diphenvlhex-2-ene. To a -50C solution of the nitrile product of Example 1B (90 Kg, 244 moles) in tetrahydrofuran (288 L), was added benzylmagnesium chloride (378 Kg, 2M in THF, 708 moles). The solution was warmed to ambient temperature 3o and stirred until analysis showed no starting material. The solution was then recooled to 5 0 C and slowly transferred to a solution of 15% citric acid (465 kg). Additional tetrahydrofuran (85 L) was used to rinse out the original container and the rinse was added to the citric acid quench container. The organics were -51 separated and washed with 10% sodium chloride (235 kg) and stripped to a solid. The product was stripped again from ethanol (289 L) and then dissolved in 800C ethanol (581 L)). After cooling to room temperature and stirring for 12 hours, the resulting product was filtered and dried in a vacuum oven at 300C to 5 give approx. 95 kg of the desired product. mp 101-102"C, IR (CDC13) 3630, 3500, 3110, 3060, 3030, 2230, 1620, 1595, 1520, 1495, 1450 cm- 1 , 1H NMR (300 MHZ, CDC3) d 9.8 (br s, 1 H), 7.2 (m, 20H), 5.1 (s, 1 H), 4.9 (br s, 1 H), 3.8 d, 2H, J = 14.7 Hz), 3.6 (d, 2H, J = 14.7Hz), 3.5 (m, 3H), 3.2 (dd, 1 H, J = 7.5, 14.4 Hz), 3.0 (dd, 1 H, J = 6.6, 14.4 Hz), 13 C NMR (CDC13) d 198.0, 162.8, 140.2, 10 140.1, 136.0, 129.5, 129.3, 128.9, 128.7, 128.1, 128.0, 127.3, 126.7, 125.6, 96.9, 66.5, 54.3, 42.3, 32.4. [aiD -147* (c = 0.5, DMF). D, (2S. 3S. 5S)-5-Amino-2-(N.N-dibenzylamino)-3-hvdroxy-1 .6-diphenyl hexane i) A suspension of sodium borohydride (6.6 kg, 175 moles) in 15 tetrahydrofuran (157 L) was cooled to less than -10t5*C. Methanesulfonic acid (41.6 kg, 433 moles) was slowly added and the temperature kept below 00C during the addition. Once the addition was complete, a solution of water (6 L, 333 moles), the product of Example 1C (20 kg, 43 moles) and tetrahydrofuran (61 L) was slowly added while maintaining the temperature below 00C during 20 the addition. The mixture was stirred for not less than 1 9h at 0±50C. ii) To a separate flask was added sodium borohydride (6.6 kg, 175 moles) and tetrahydrofuran (157 L). After cooling to -5±50C, trifluoroacetic acid (24.8 kg, 218 moles) was added while maintaining the temperature below 15 0 C. The solution was stirred 30 min at 15±5 0 C and was then added to the reaction mixture resulting from step i, keeping the temperature at less than 25 20*C. This was stirred at 20150C until reaction was complete. The solution was then cooled to 10±5'C and quenched with 3N NaOH (195 kg). After agitating with tert-butyl methyl ether (162 L), the organic layer was separated and washed one time with 0.5N NaOH (200 kg), one time with 20% w/v aqueous 30 ammonium chloride (195 kg), and two times with 25% aqueous sodium chloride (160 kg). The organics were stripped to give the desired product as an oil which was used directly in the next step.

-52 IR (CHCI3) 3510, 3400, 3110, 3060, 3030, 1630, 1 H NMR (300 MHz, CDCl3) 6 7.2 (m, 20H), 4.1 (d, 2H, J = 13.5 Hz), 3.65 (m, 1H), 3.5 (d, 2H, J = 13.5 Hz), 3.1 (m, 2H), 2.8 (m, 1H), 2.65 (m, 3H), 1.55 (m, 1H), 1.30 (m, 1H), 13 C NMR (300 MHz, CDCl3) 6 140.8, 140.1, 138.2, 129.4, 129.4, 128.6, 128.4, 128.3, s 128.2, 126.8, 126.3, 125.7, 72.0, 63.6, 54.9, 53.3, 46.2, 40.1, 30.2. E. (2S.3S.5S)-2-(N.N-Dibenzylamino)-3-hydroxv-5-(t-butyloxvcarbonvlamino) 1.6-diphenylhexane. To a solution of the [2S,3S,5S]-2-N,N-dibenzylamino-3-hydroxy-5-amino V,6-diphenylhexane (approx. 105 kg, 226 moles) in MTBE (1096 L), was added 10 BOC Anhydride (65 kg, 373 moles) and 10% potassium carbonate (550 kg). This mixture was stirred until reaction was complete (approx. 1 hour). The bottom layer was removed and the organics were washed with water (665 L). The solution was then stripped to give the desired product as an oil. 300 MHz 1 H NMR (CDCl3) 5 1.40 (s,9H), 1.58 (s, 2H), 2.45-2.85 (m, 4H), 3.05 (m, 1H), is 3.38 (d, 2H), 3.6 (m, 1H), 3.79 (m, 1H), 3.87 (d, 2H), 4.35 (s, 1H), 4.85 (s, broad, 1lH), 7.0-7.38 (m, 20 H). F-1. (2S.3S.5S)-2-Amino-3-hydroxy-5-(t-butyloxycarbonylamino)-1.6 diphenvlhexane. To a stirred solution of [2S,3S,5S]-2-N,N-dibenzylamino-3-hydroxy-5-t 20 butyloxycarbonylamino-1,6-diphenylhexane (12 g, 21.3 mmol) in methanol (350 mL) was charged ammonium formate (8.05 g, 128 mmol, 6.0 eq) and 10% palladium on carbon (2.4 g). The solution was stirred under nitrogen at 60 0C for three hours and then at 75 0C for 12 hours. An additional amount of ammonium formate (6 g) and 10% palladium on carbon (1.5 g) was added as 25 well as 1 mL of glacial acetic acid. The reaction was driven to completion within 2 hours at a reflux temperature. The reaction mixture was then cooled to room temperature and then filtered through a bed of celite. The filter cake was washed with methanol (75 mL) and the combined filtrates were concentrated under reduced pressure. The residue was taken up in 1 N NaOH (300 mL) and 30 extracted into methylene chloride (2 X 200 mL). The combined organic layers were washed with brine (250 mL) and dried over sodium sulfate. Concentration -53 of the solution under reduced pressure provided the desired product as a light colored oil which slowly crystallized upon standing (5 g). Further purification of the product could be accomplished by flash chromatography (silica gel, 5% methanol in methylene chloride). 300 MHz 1 H NMR (CDCI3) 6 1.42 (s, 9H), s 1.58 (m, 1H), 1.70 (m, 1H), 2.20 (s, broad, 2H), 2.52 (m, 1H), 2.76-2.95 (m, 4H), 3.50 (m, 1H), 3.95 (m, 1H), 4.80 (d, broad, 1H), 7.15-7.30 (m, 1OH). F-2. t2S.3S.5S1-2-Amino-3-hydroxv-5-t-butvloxvcarbonvlamino-1.6 diphenylhexane succinate salt To a solution of [2S,3S,5S]-2-N,N-dibenzylamino-3-hydroxy-5-t io butyloxycarbonylamino-1,6-diphenylhexane(approx. 127 kg, 225 moles) in methanol (437 L), was added a methanolic (285 L) slurry of 5% palladium on carbon (24 kg). To this was added a solution of ammonium formate (84 kg, 1332 moles) in methanol (361 L). The solution was heated to 75 0 C for 6-12 hours and then cooled to room temperature. Solids were filtered from the i5 reaction mixture using a filter coated with filteraid (Celite) and the methanol was stripped from the reaction mixture using heat and vacuum (up to 700C). The residue was dissolved in isopropyl acetate (4400 kg) with heat (400C) and then washed with a 10% sodium carbonate solution (725 kg), and finally with water (665 L). Both of the washes were performed at 40 0 C to keep the product in 20 solution. The solvent was removed under vacuum with heat (up to 700C). Isopropyl alcohol (475 L) was then added and stripped off to remove residual solvents. Isopropanol (1200 L) was added to the residue and stirred until homogeneous. To this solution was added a solution of succinic acid (15-40 kg) in isopropanol (1200 L). The solution jacket was heated to 700C to dissolve 25 all of the solids and then allowed to slowly cool to room temperature and stir for 6 hours. The solution was then filtered to give the desired product as a white solid (55-80 kg). .mp 145-146 *C. 1 H NMR: (Me 2 SO-d 6 , 300 MHz) 5 0.97 (d, 3H, IPA), 1.20 (s, 9H), 1.57 (t, 2H), 2.20 (s, 2H, succinic acid), 2.55 (m, 2H), 2.66 (m, 2H), 2.98 (m, 30 1 H), 3.42 (m, 1 H), 3.70 (m, 1 H), 3.72 (m, 1 H, IPA), 6.60 (d, 1 H, aide NH), 7.0 7.3 (m, 10H).

-54 1 H NMR: (CD 3 0D, 300 MHz) 8 1.11 (d, 3H, J=7 Hz, IPA), 1.29 (s, 9H), 1.70 (m, 2H), 2.47 (s, 2H, succinic acid), 2.65 (m, 2H), 2.85 (m, 2H), 3.22 (m,1 H), 3.64 (m, 1H), 3.84 (m, 1 H), 7.05-7.35 (m, 10H). G. Ethyl 2.6-dimethylohenoxy acetate, 5 To a solution of 2,6-dimethylphenol (8.0 g, 66 mmole) in dioxane (600 ml) was added ethyl bromoacetate (18.2 ml, 164 mmole) and cesium carbonate (58 g, 176 mmole). The reaction mixture was heated at reflux for 18 h, cooled to room temperature, filtered and concentrated in vacuo. Purification by silica gel column chromatography (5% to 20% ether in hexane) provided the desired 10 compound (80%). 300 MHz 1 H NMR (CDC13) 8 1.35 (t, J = 7.5 Hz, 3H), 2.30 (s, 6H), 4.31 (q, J = 7.5 Hz, 2H), 4.40 (s, 2H), 7.0 (m, 3H). H. 2.6-Dimethylohenoxy acetic acid. To a solution of the compound from Example 1G (5.15 g, 24.7 mole) in methanol (170 ml) and water (56 ml) was added 5.3 g of lithium hydroxide at is OC, the solution was stirred for 1.5 h at RT and concentrated in vacuo. The residue was acidified with 0.5M HCI and extracted with ethyl acetate (300 ml). The organic layer was dried and concentrated to give a white solid (4.05 g, 91%). 300 MHz 1 H NMR (CDCI3) 8 2.30 (s, 6H), 4.48 (s, 2H), 7.0 (m, 3H). 1. (2S. 3S. 5S) -2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(t 20 butyloxycarbonylamino)-1 .6-diphenylhexane. Coupling of the amine from Example 1 F with the acid from Example 1 H using standard EDAC coupling procedure provided the desired compound (78%). 300 MHz 1 H NMR (CDC13) 8 1.40 (s, 9H), 1.65 (m, 3H), 2.18 (s, 6H), 2.78 (m, 2H), 2.98 (d, J = 9 Hz, 2H), 3.75 (m, 1H), 3.90 (m, 1H), 4.15 (m, 1H), 25 4.20 (s, 2H), 4.60 (m, 1H), 7.0 (m, 3H), 7.25 (m, 1OH). Mass spectrum: (M = H)+ = 547. J. 2-N-(Benzvloxvcarbonyl) amino-acetaldehyde. To a solution of 1.45 ml of DMSO in 20 ml of CH2Cl2 at -78)C was added dropwise 1.34 ml of oxalyl chloride. After 15 minutes at -78*C, a solution of -55 N-Cbz-aminoethanol in 40 ml of CH2Cl2 was added. After 15 minutes at -78 0 C and 2 minutes at 0"C, the solution was cooled to -78"C and triethylamine (6.14 ml) was added dropwise. The solution was stirred at -78'C for 30 minutes and poured into 50 ml of cold 10% aq. citric acid and extracted with ether (150 ml). 5 The combined organic layer was washed with brine and dried with anhydrous Na2SO4; filtered and concentrated in vacuo. Purification of the crude product -by silica gel column chromatography (10% EtOAc/CH2Cl2) provided the desired compound (42%). 300 MHz 1 H NMR (CDCl 3 ) 8 4.17 (d, J = 6 Hz, 2H), 5.15 (s, 2H), 5.40 (br s, 1H), 7.36 (m, 5H), 9.66 (s, 1H). Mass spectrum: 1o (M+NH4)+ = 211. K. N-(Benzyloxycarbonylamino)-ethyl valine methyl ester. To a solution of the aldehyde from Example 1J (0.829 g, 4.29 mmole) in 17 ml of methanol was added valine methyl ester hydrochloride (0.72 g, 4.29 mmole), sodium acetate (0.7 g, 8.58 molee, and sodium cyanoborohydride 1s (0.54 g, 8.58 mmole. The mixture was stirred at RT overnight and the solvent was evaporated in vacuo. The residue was taken up in ethyl acetate (100 ml) and washed with satd. NaHCO3 (10 ml) and the aq. layer was extracted with ethyl acetate (2 x 50 ml). The combined organic layer was washed with brine and dried with anhy. sodium sulfate, filtered and concentrated in vacuo. The 20 residue was purified by silica gel column chromatography (20% EtOAc/CH2CI 2 ) to provide the desired compound (60%). 300 MHz 1 H NMR (CDC13) 8 0.91 (d, J = 3 Hz, 3H), 0.94 (d, J = 3 Hz, 3H), 1.90 (m, 1 H), 2.55 (m, 1 H), 2.80 (m, 1 H). 2.98 (d, J = 6 Hz, 1H), 3.20 (m, 1H), 3.30 (m, 1H), 3.71 (s, 3H), 5.10 (s, 2H), 5.27 (br s, 1H), 7;.37 (m, 5H). Mass spectrum: (M+H)+ = 309. 25 L. 2S-(1-midazolidin-2-onvl)-3-methyl butanoic acid methyl ester. The Cbz-protecting of the compound in Example 1 K was removed by hydrogenolysis and the crude product was treated with one equivalent of 1,1.

carbonyldiimidazole in CH2Cl 2 to provide the desired compound (64%), 300 MHz 1 H NMR (CDCl3) 6 0.95 (d, J = 7.5 Hz, 3H), 0.98 (d, J = 7.5 Hz, 3H), 2.15 30 (m, 1H), 3.47 (m, 3H), 3.71 (s, 3H), 3.73 (m, 1H), 4.23 (d, J = 10.5 Hz, 1H), 4.81 (br s, 1H), Mass spectrum: (M+H)+ = 201.

-56 M. 2S-(1-lmidazolidin-2-onvl)-3-methyl butanoic acid. To a solution of the compound from Example 1 L (151 mg, 0.75 mmole) in 2.5 ml of water and 5 ml of dioxane was added at 00C lithium hydroxide monohydrate (2.0 eq.). The solution was stirred at 00C for 1.5 h and RT for 1 h. 5 Acidification with 1 N HCI, extraction with EtOAc (100 ml + 2 x 50 ml), dried with sodium sulfate and evaporation of the filtered solution in vacuo provided the desired compound (88%). 300 MHz 1 H NMR (DMSO-d6) 8 0.85 (d, J = 12 Hz, 3H), 0.92 (d, J = 12 Hz, 3H), 2.05 (m, 1 H), 3.25 (m, 2H), 3.30 (m, 1 H), 3.50 (m, 1H), 3.90 (d, J = 15 Hz, 1 H), 6.40 (br s, 1H), 12.60 (br s, 1H). Mass spectrum: io (M+H)+ = 187. N. (2S. 33, 55) -2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-amino-1.6 diphenvlhexane. To 4.5 g of the compound from Example 11 was added 40 ml each of

CH

2 Cl 2 and trifluoroacetic acid. The solution was left at RT for 1 h. 15 Concentration of the solution in vacuo provided the desired compound (100%). 300 MHz 1 H NMR (CDC13) 5 1.48 (m, 1H), 1.62 (m, 1H), 2.05 (m, 1H), 2.24 (s, 6H), 2.50 (m, 1 H), 2.80 (m, 1 H), 3.0-3.10 (m, 4H), 3.90 (d, J = 10 Hz, 1 H), 4.17 (m, 1 H), 4.26 (ABq, J = 13.5 Hz, 2H), 7.0 (m, 3H), 7.10 (m, 2H), 7.30 (m, 7H), 7.41 (d, J = 10 Hz, 1 H). Mass spectrum: (M+H)+ = 447. 0. (2S, 3S. 5S)-2-(2.6-Dimethylphenoxvacetyl) amino-3-hydroxy-5-[2S-(1 20 imidazolidin-2-onyl)-3-methyl-butanoyll amino-1.6-diphenylhexane. Coupling of the amino compound from Example 1 N with the acid from Example 1M using standard coupling procedure [1-(3-dimethylaminopropyl)-3 ethylcarbodiimide in DMF] provided the desired compound. (80%). 300 MHz 1 H NMR (CDCl3) S 0.83 (d, J = 6 Hz, 3H), 0.86 (d, J = 6 Hz, 3H), 1.75 (m, 2H), 25 2.16 (m, 1H), 2.18 (s, 6H), 2.76 (m, 2H), 2.97 (d, J = 7.5 Hz, 2H), 3.14 (m, 2H), 3.30 (m, 2H), 3.70 (d, J = 1- Hz, 1H), 3.75 (m, 1H), 4.20 (m, 4H), 4.50 (br s, 1H), 6.70 (d, J = 7.5 Hz, 1H), 7.0 (m, 3H), 7.25 (m, 1OH). Mass Spectrum: (M+H)+ = 615.

-57 Examle 2 (2S, 3S, 5S)-2-(2.6-Dimethylphenoxvacetyl) amino-3-hydroxv-5-[2S-(1 tetrahydro-ovrimid-2-onyl)-3-methyl butanovll amino-1.6-dighenvlhexane A. 2S-(1-Tetrahydro-yrimid-2-onyl)-3-methyl butanoic acid. 5 Using the procedures described in Examples 1J to 1M, but replacing the N-Cbz-aminoethanol in Example 1J with N-Cbz-3-aminopropanol provided the desired compound. 300 MHz IH NMR (DMSO-d6) 8 0.82 (d, J = 7 Hz, 3H), 0.93 (d, J - 7 Hz, 3H), 1.77 (m, 2H), 2.10 (m, 1H), 3.10-3.23 (m, 4H), 4.42 (d, J = 10.5 Hz, 1 H), 6.37 (br s, 1 H). Mass spectrum: (M+H)+ = 201. 10 B. (2S. 3S. 5S)-2-(2.6-Dimethylphenoxyaceyl) amino-3-hydroxy-5-[2S-(1 tetrahydro-pyrimid-2-onyl)-3-methyl butanovl amino-1.6-diphenylhexane. Coupling of the amino compound from Example 1 N with the acid from Example 2A using standard procedure (EDAC in DMF) provided the desired compound (70%). 300 MHz 1 H NMR (CDCl3) 5 0.80 (d, J = 4.5 Hz, 3H), 0.83 (d, 15 J = 4.5 Hz, 3H), 1.50 (m, 1H), 1.65-1.72 (m, 6H), 2.20 (s, 6H), 2.68 (m, 1H), 2.82 (m, 2H), 3.0 (d, J =7.5 Hz, 1 H), 3.05 (m, 4H), 3.77 (m, 1 H), 4.07 (d, J = 4.5 Hz, 1 H), 4.20 (m, 4H), 4.50 (br s, 1 H), 6.78 (br d, 1H), 7.0 (m, 3H), 7.25 (m, 1OH). Mass spectrum: (M+H)+ = 629. Example 3 20 (2S, 3S, 5S)-2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(3 oxazolidin-2-onyl)-3-methyl-butanoyll amino-1.6-diphenylhexane. A. 2S-(3-Oxazolidin-2-onyl)-3-methyl-butanoic acid methyl ester. To a solution of L-valine methyl ester hydrochloride (7.6 mmole) was added a solution of ethylene oxide in ethanol (1.5 equivalent). The solution was 25 kept at 00C for 0,5 h and then at RT for 18 h, at which time 0.01 equivalent of

BF

3 -Et 2 O was added. Fresh ethylene oxide was bubbled directly into the solution for 3 to 4 minutes. After 8 h the solution was concentrated to dryness and the residue was dissolved in CH 2

CI

2 and cooled to 00C. To this solution was added 1.2 equivalents of triethylamine and 1.0 equivalent of triphosgene.

-58 After 1 h, the solvent was removed in vacuo and the residue was washed with water (30 ml) and extracted with CH 2

CI

2 (3x50 ml), dried and concentrated. Purification of the crude product by silica gel column chromatography (5% EtOAc/CH 2 Cl 2 ) provided the desired compound (42%, 2 steps). 300 MHz 1 H NMR (CDC13) 8 0.98 (d, J = 4.0 Hz, 3H), 1.0 (d, J = 4.0 Hz, 3H), 2.16 (m, 1H), 3.60 (m, 2H), 3.73 (s, 3H), 4.20 (d, J = 10 Hz, 1H), 4.37 (m, 2H). Mass spectrum: (M+H)+ = 202. B. 2S-(3-Oxazolidin-2-onyl)-3-methyl-butanoic acid. Hydrolysis of the methyl ester from Example 3A, using the procedure to described in Example 1 M provided the desired compound. 300 MHz 1 H NMR (DMSO-d6) 8 0.90 (d, J = 6 Hz, 3H), 0.95 (d, J = 6 Hz, 3H), 2.1 (m, 1 H), 3.55 (m, 1 H), 3.70 (m, 1 H), 3.88 (d, J = 9 Hz, 1 H), 4.30 (m, 2H), 13.0 (br s, 1 H). Mass spectrum: (M+NH 4 )+ = 205. C. (2S. 3S, 5S)-2-(2.6-Diimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(3 is oxazolidin-2-onyl)-3-methyl-butanoyll amino-1.6-diphenylhexane. Coupling of the amine from Example 1N with the acid from Example 3B using standard coupling procedures (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDCI3) 8 0.83 (d, J = 4.5 Hz, 3H), 0.87 (d, J = 4.5 Hz, 3H), 1.75 (m, 1H), 2.10 (m, 1 H), 2.20 (s, 6H), 2.65 (m, 1H), 2.85 (m, 1H), 20 3.0 (m, 3H), 3.30 (m, 1 H), 3.60 (m, 2H), 3.77 (m, 1 H), 4.20 (m, 4H), 6.25 (br d, J = 6 Hz, 1H), 7.0 (m, 3H), 7.25 (m, 1OH). Mass spectrum: (M+H)+ = 616. Example 4 (2S.3S,5S)-2-[(3R. 3aS. 6aR)-Bis-tetrahydrofuranyloxyl amino-3-hydroxy-5-[2S (3-methyl-1-imidazolidin-2-onyl)-3-methyl butanoyll amino- 1,6-diphenylhexane. 25 A. 2S-(3-Methyl-1-imidazolidin-2-onyl)-3-methyl butanoic acid methyl ester. To a suspension of 45 mg (60% oil dispersion) of sodium hydride in 0.5 ml of DMF was added a solution of 150 mg of the compound from Example 1 L in 4.5 ml of DMF. After 20 minutes at RT, (1.5 equivalent, 0.07 ml) methyl iodide was added. Reaction was complete in 1 h. The reaction was quenched with -59 satd. NH 4 CI solution and extracted with ether (100 ml + 50 ml x 2), dried and concentrated in vacuo. The crude product was purified by silica gel column chromatography (20% EtOAc/CH 2 Cl 2 ) to provide the desired compound (61 %). 300 MHz 1 H NMR (CDCI3) 5 0.95 (d, J = 6 Hz, 3H), 0.97 (d, J = 6 Hz, 3H, 2.15 s (m, 1 H), 2.80 (s, 3H), 3.32 (m, 3H), 3.60 (m, 1 H), 3.70 (s, 3H), 4.25 (d, J = 10.5 Hz, 1 H). Mass spectrum: (M+H)+ = 215. B. 2S-(3-Methyl-1-imidazolidin-2-onvl)-3-methyl butanoic acid. Hydrolysis of the methyl ester from Example 4A using the procedure described in Example 1 M provided the desired compound. 300 MHz 1 H NMR 10 (DMSO-d 6 ) 8 0.85 (d, J = 6 Hz, 3H), 0.92 (d, J = 6 Hz, 3H), 2.05 (m, 1 H), 2.65 (s, 3H), 3.25 (m, 3H), 3.42 (m, 1H), 3.90 (d, J = 10 Hz, 1H). Mass spectrum: (M+H)+ = 201. C. (3R,3aS.6aR)-Bis-tetrahydrofuranyl-(4-nirophenyl) carbonate. To a solution of 3R-hydroxy-(3aS,6aR)-bis-tetrahydrofuran [J. Med. 1s Chem. 37, 2506-2508 (1994)] (200 mg, 1.54 mmole) in 10 ml of CH 2

CI

2 was added triethylamine (0.26 ml, 1.85 molee, and p-nitrophenyl chloroformate (341 mg, 1.69 mmole). The solution was kept at RT for 3 days, diluted with

CH

2

CI

2 (100 ml) and washed with satd. NaHCO 3 (15 ml). The organic layer was dried and concentrated in vacuo. Purification by silica gel column 20 chromatography (5% EtOAc/CH 2

CI

2 ) provided the desired compound (42%). 300 MHz 1 H NMR (CDCl3) 8 2.0 (m, 1H), 2.20 (m, 1H), 3.18 (m, 1H), 4.0 (m, 3H), 4.17 (m, 1 H), 5.27 (m, 1 H), 5.80 (d, J = 6 Hz), 7.40 (d, J = 7.5 Hz, 2H), 8.30 (d, J = 7.5 Hz, 2H). Mass spectrum: (M+NH 4 )+ = 313. D. ( 2

S

3 S5S)-2-(3R.3aS6aR)-Bis-tetrahydrofuranvloxvl amino-3-hydroxv-5-(t 25 butvloxv carbonvl) amino-1.6-diohenvihexane. To a solution of the carbonate from Example 4C (100 mg, 0.34 mmole) in 3.4 ml of DMF was added the compound from Example 1 F (130 mg, 0.34 mmole). The solution was kept at RT overnight and then concentrated in vacuo. Purification of the crude product by silica gel column chromatography (2% to 5% 30 MeOH/CH 2

CI

2 ) provided the desired compound (93%). 300 MHz 1 H NMR -60 (CDCI3) 8 1.40 (s, 9H), 1.64 (m, 3H), 2.76 (m, 2H), 2.87 (m, 2H), 3.66-4.0 (m, 7H), 4.53 (m, 1 H), 5.06 (m, 2H), 5.68 (d, J = 6 HZ, 1 H), 7.10-7.28 (m, 1 OH). Mass spectrum: (M+NH 4 )+ = 558. E. (2S.3S.5S)-2-[(3R.3aS.6aR)-Bis-tetrahydrofuranvloxyl amino-3-hvdroxv-5 5 amino-1.6-diphenylhexane. To a solution of the compound from Example 4D (170 mg, 0.31 mmole) in 5 ml of CH 2

CI

2 was added 5 ml of trifluoroacetic acid. After 0.25 h, the solvent was removed in vacuo. The residue was dissolved in 100 ml of EtOAc and washed with satd. NaHCO 3 and then brine, dried and concentrated to provide 10 the desired compound (91%). 300 MHz 1 H NMR (CDCl3) 8 1.27-1.60 (m, 4H), 1.75 (m, 2H), 2.47 (m, 1 H), 2.80 (m, 1 H), 2.88 (m, 2H), 3.0 (m, 2H),3.80 (m, 4H), 4.0 (m, 1 H), 5.10 (m, 1 H), 5.30 (d, J = 10.5 Hz, 1 H), 5.70 (d, J = 6 Hz, 1 H), 7.05 7.25 (m, 10H). Mass spectrum: (M+H)+ = 441. F. (2S.3S,5S)-2-[(3R. 3aS. 6aR)-Bis-tetrahydrofuranyloxyl amino-3-hydroxy-5 15 [2S-(3-methyl-1 .'midazolidin-2-onyl)-3-methyl butanoyll amino-1.6 diphenylhexane. Coupling of the carboxylic acid from Example 4B with the amino compound from Example 4E using standard procedure (EDAC in DMF) 20 provided the desired compound. 300 MHz 1 H NMR (CDCI3) 8 0.82 (d, J = 3H, 3H), 0.85 (d, J = Hz, 3H), 1.65 (m, 1H), 2.77 (s, 3H), 2.85 (m, 3H), 3.17 (m, 2H) 3.47 (m, 1 H), 3.60 (m, 2H), 3.75 (m, 1 H), 3.87 (m, 1 H), 4.0 (m, 1 H), 4.20 (m, 1 H), 5.05 (m, 2H), 5.68 (d, J = 6 Hz, 1 H), 6.45 (br d, J = 7.5 Hz, 1 H), 7.20 (m, 1 OH). Mass spectrum: (M+H)+ = 623. 25 Examgle. (2S.3S.5S)-2-[(3R.3aS.6aR)-Bis-tetrahydrofuranvloxvl amino-3-hydroxv-5-[2S (1-imidazolidin-2-onyl)-3-methyl butanoyll amino-1.6-diphenylhexane. Coupling of the amino compound from Example 4E with the carboxylic acid from Example 1 M using standard procedure (EDAC/DMF) provided the 30 desired compound. 300 MHz 1 H NMR (CDCl3) 8 0.85 (d, J = 7 Hz, 3H), 0.88 (d, J = Hz, 3H), 1.70 (m, 2H, 2.18 (m, 1H), 2.80 (m, 3H), 2.95 (m, 1H), 3.20 (m, -61 4H), 3.60 (m, 3H), 3.75 (m, 2H), 4.0 (m, 1 H), 4.20 (m, 1 H), 4.45 (s, 1 H), 5.10 (m, 2H), 5.67 (d, J = 6 Hz, 1H) 6.60 (d, J = 7.5 Hz, 1 H), 7.20 (m, 1 OH). Mass spectrum: (M+H)+ = 609. Example 6 5 (2S.3S.5S)-2-(N-((5-Thiazolyl)methoxvcarbonvl)amino)-5-((2S-(1 -imidazolidin 2-onvl)-3-methyl-butanovl)-amino)-3-hydroxv-1.6-di1henvlhexane. A. Ethyl 2-Chloro-2-formvlacetate. To a three neck 2L round bottom flask charged with potassium t-butoxide (0.5 mol, 500 mL of a 1 M solution in THF) and 500 mL of dry THF cooled to 0*C 10 was added dropwise from an addition funnel a solution of ethyl chloroacetate (0.5 mol, 53.5 mL) and ethyl formate (0.5 mol, 40.4 mL), in 200 mL of THF over 3 hours. After completion of addition, the reaction mixture was stirred for 1 hour and allowed to stand overnight. The resulting solid was diluted with diethyl ether and cooled in an ice bath. Then, the pH was lowered to approximately 3 is using 6N HCI. The organic phase was separated, and the aqueous layer was washed 3 times with diethyl ether. The combined ethereal portions were dried over NaSO 4 , and concentrated in vacuo. The crude desired compound was stored at -30"C and used without further purification. B. Ethyl Thiazole-5-carboxylpte. 20 To a round bottom flask was added 250 mL of dry acetone, 7.5 g (0.123 mol) of thioformamide, and 18.54 g (0.123 mol) of ethyl 2-chloro-2 formylacetate. The reaction was heated at reflux for 2 hours. The solvent was removed in vacuo, and the residue was purified by chromatography (SiO 2 , 6 cm 25 o.d. column, 100% CHCl3, Rf = 0.25) to provide 11.6 g (60%) of the desired compound as a light yellow oil. NMR (CDCl3 5 1.39 (t, J = 7 Hz, 3H), 4.38 (q, J = 7 Hz, 2H), 8.50 (s, 1H), 8.95 (s, 1H). C. 5-(Hvdroxvmethyl)thiazole. To a precooled (ice bath) three neck 500 mL flask containing lithium 30 aluminum hydride (2.89 g, 76 mmol) in 250 mL of THF was added ethyl -62 thiazole-5-carboxylate (11.82 g, 75.68 mmol) in 100 mL of THF dropwise over 1.5 hours to avoid excess foaming. The reaction was stirred for an additional hour, and treated cautiously with 2.9 mL of water, 2.9 mL of 15% NaOH, and 8.7 mL of water. The solid salts were filtered, and the filtrate set aside. The crude salts were heated at reflux in 100 mL of ethyl acetate for 30 minutes. The resulting mixture was filtered, and the two filtrates were combined, dried over Na 2

SO

4 , and concentrated in vacuo. The product was purified by silica gel chromatography eluting sequentially with 0% - 2% - 4% methanol in chloroform, to provide the desired compound, Rf - 0.3 (4% methanol in chloroform), which 1o solidified upon standing in 75% yield. NMR (CDCl 3 ) 8 4.92 (s, 2H), 7.78 (s, 1 H), 8.77 (s, 1 H). Mass spectrum: (M+H)+ = 116. D. ((5-Thiazolyl)methyl)-(4-nitrophenyl)carbonate. A solution of 3.11 g (27 mmol) of 5-(hydroxymethyl)thiazole and excess N-methyl morpholine in 100 ml of methylene chloride was cooled to OOC and is treated with 8.2 g (41 mmol) of 4-nitrophenyl chloroformate. After being stirred for 1 h, the reaction mixture was diluted with CHCl 3 , washed successively with 1N HCI, saturated aqueous NaHCO3, and saturated brine, dried over NaSO 4 , and concentrated in vacuo. The residue was purified by silica gel chromatography (SiO 2 , 1-2% MeOH/CHC 3 , Rf = 0.5 in 4% MeOH/CHCl 3 ) to 20 yield 5.9 g (78%) of the desired compound as a yellow solid. NMR (CDCl 3 ) 6 5.53 (s, 2H), 7.39 (dt, J = 9, 3 Hz, 2H), 8.01 (s, 1 H), 8.29 (dt, J = 9, 3 Hz, 2H), 8.90 (s, 1 H). Mass spectrum: (M+H)+ = 281. E. (2S.3S.5S)-5-Amino-2-(N-((5-thiazolyl)-methoxycarbonyl)amino)-3-hydroxv 1.6-diphenylhexane. 25 Coupling of the amino compound from Example 1 F with the carbonate from Example 6D using the procedure from Example 4D, followed by removal of the Boc-protecting group using TFA/CH 2

CI

2 provided the desired compound. 300 MHz 1 H NMR (CDCl3) 6 1.3-1.6 (m, 2H), 2.40 (dd, J = 14, 8 Hz, 1 H), 2.78 (dd, J = 5 Hz, 1 H), 2.88 (d, J = 7 Hz, 2H), 3.01 (m, 1 H), 3.72 (br q, 1 H), 3.81 (br d, 30 J = 10 Hz, 1H), 5.28 (s, 2H), 5.34 (br d, J = 9 Hz, 1H), 7.07 (br d, J = 7 Hz, 2H), 7.15-7.35 (m, 8H), 7.87 (s, 1 H), 8.80 (s, 1 H). Mass spectrum: (M+H)+ = 426.

-63 F. (2S.3S.5S)-2-(N-((5-thiazolyl)methoxycarbonyl)amino)-5-((2S-(1 imidazolidin-2-onyl)-3-methyl-butanoyl)-amino)-3-hydroxy-1.6-diphenvlhexane. Coupling of the amino compound from Example 6E with the carboxylic 5 acid from Example 1M using standard procedure (EDAC in DMF) provided the desired compound (52%). 300 MHz 1 H NMR (CDCI3) 8 0.82 (d, J = 7.5 Hz, 3H), 0.85 (d, J = 7.5 Hz, 3H), 1.65 (m, 2H), 2.15 (m, 1H), 2.70 (m, 3H), 2.85 (d, 7.5 Hz, 2H), 3.08 (m, 1 H), 3.18 (m, 1H), 3.30 (M, 2H), 3.60 (m, 3H), 3.80 (m, 1H), 4.16 (m, 1H), 4.40 (s, 1H), 5.16 (d, J = 9 Hz, 1H), 5.24 (s, 2H), 6.60 (d, J = 9 Hz, 1H), 1o 7.20 (m, 1 OH), 7.83 (s, 1 H), 8.80 (s, 1 H). Mass spectrum: (M+H)+ = 594. Example 7 (2S,3S.5S)-2-(N-((5-Thiazolyl)-methoxycarbonyl)amino)-3-hydroxv-5-(2S-(1 imidazolidin-2-onyl)-3,3-dimethyl butanoyl)amino-1.6-diphenylhexane. A. 2S-(1 -1midazolidin-2-onyl)-3.3-di methyl butanoic acid. Is Using the procedures described in Example 1J to 1M, but replacing L valine methyl ester with L-t-butyl-leucine methyl ester provided the desired compound. 300 MHz 1 H NMR (DMSO-d6) 8 1.0 (s, 9H), 3.22 (t, J = 7.5 Hz, 2H), 3.55 (q, J = 7.5 Hz, 1H), 3.65 (q, J = 7.5 Hz, 1H), 4.14 (s, 1H), 6.40 (s, 1H), 12.62 (br s, 1 H). Mass spectrum: (M+H)+ = 201. 20 B. (2S.3S 5S)-2-(N-((5-Thiazolvl)-methoxycarbonvllamino)-3-hydroxy-5-(2S (1-imidazolidin-2-onyl)-3,3-dimethyl butanoyl)amino-1.6-diphenylhexane. Coupling of the amino compound from Example 6E with the carboxylic acid from Example 7A using standard procedure (EDAC in DMF) provided the desired compound (77%). 300 MHz 1 H NMR (CDCI3) 6 1.0 (s, 9H), 1.68 (m, 25 2H), 2.60-2.80 (m, 3H), 2.85 (d, J = 7.5 Hz, 1H), 3.10 (m, 1H), 3.30 (m, 1H), 3.50 (m, 1 H), 4.56 (s, 1 H), 5.15 (d, J = 7.5 Hz, 1 H), 5.25 (ABq, 1 H), 6.50 (d, J = 7 Hz, 1H), 7.20 (m, 1OH), 7.83 (s, 1H), 8.80 (s, 1H). Mass spectrum: (M+H)+ = 609.

-64 Examole 8 (2S.3S.5S)-2-(2.6-Dimethvlohenoxyacetyl)amino-3-hydroxv-5-(2S-(1 imidazolidin-2-onyl)-3.3-dimethyl butanoyl)amino-1.6-diohenvlhexane. Coupling of the amino compound from Example 1 N with the carboxylic 5 acid irom Example 7A using standard procedure (EDAC in DMF) provided the desired compound (80%). 300 MHz 1 H NMR (CDCl3) 8 1.0 (s, 9H), 2.18 (s, 6H), 2.68 (m, 1 H), 2.80 (m, 1H), 2.98 (m, 3H), 3.10 (m, 1 H), 3.27 (q, J = 7 Hz, 1H), 3.53 (m, 1 H), 3.77 (m, 1 H), 4.0 (s, 1 H), 4.20 (m, 4H), 6.72 (m, 1 H), 7.0 (m, 3H), 7.10-7.25 (m, 1OH). Mass spectrum: (M+H)+ = 629. 10 Example 9 (2S.3S,5S)-2-(2.6-Dimethylphenoxyacetyl)amino-3-hydroxy-5-(2S-(1 imidazolidin-2-thionyl)-3-methyl butanoyl)amino-1 .6-diphenylhexane. A. 2S-(1-imidazolidin-2-thionyl)-3-methyl butanoic acid. Using the same procedures described in Example 1J to 1M, but replacing 15 1,1-carbonyl-diimidazole with 1,1,-thiocarbonyldiimidazole provided the desired compound. 300 MHz 1 H NMR (DMSO-d6) 6 0.87 (d, J = 6 Hz, 3H), 0.96 (d, J = 6 Hz, 3H), 2.11 (m, 1 H), 3.45 (m, 2H), 3.62 (m, 1 H), 3.80 (q, J = 9 Hz, 1 H), 4.80 (d, J = 10 Hz, 1 H), 8.30 (s, 1 H), 12.75 (br s, 1 H). B. (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetyliamino-3-hydroxy-5-(2S-(1 20 imidazolidin-2-thionyl)-3-methyl butanoyl)amino-1.6-diphenylhexane. Coupling of the amino compound from Example 1N with the carboxylic acid from Example 9A using standard procedure (EDAC in DMF) provided the desired compound (53%). 300 MHz 1 H NMR (CDCI3) 5 0.82 (d, J = 6 Hz. 3H), 0.93 (d, J = 6 Hz, 3H), 1.75 (m, 1 H), 2.20 (s, 6H), 2.65 (m, 1 H), 2.84 (m, 1 H), 3.0 25 (m, 3H), 3.25 (m, 1H), 3.40 (m, 2H), 3.54 (d, J = Hz, 1H), 3.78 (m, 1H), 4.22 (m, 4H), 4.56 (d, J = 10.5 Hz, 1H), 5.65 (s, 1H), 6.60 (d, J = Hz, 1H), 7.0 (m, 3H), 7.2 (m, 10H). Mass spectrum: (M+H)4 = 631.

-65 Example 10 (23S.5S)-2-(4-Amino-2,6-dimethylghenoxvacetyl amino-3-hydroxv-5-(2S-(1 imidazolidin-2-onyl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. A. 2.6-Dimethyl-4-nitro phenoxyacetic acid ethyl ester. 5 To a solution of 10.5 g (54.6 mmole) of ethyl 2,6-dimethylphenoxy acetate and 7.5 g (109 mmole) of sodium nitrite in 100 ml of methylene chloride was added 50 ml of trifluoroacetic acid slowly. The reaction mixture became solid after addition. Additional 35 ml of trifluoroacetic acid was added. After the reaction mixture was stirred at room temperature for 3 h, it was carefully 1o partitioned between saturated sodium bicarbonate solution and methylene chloride. The combined organic extracts were washed with brine and dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure. The residue was recrystalized in 30% ethyl acetate and hexanes to give 4.75 g (36%) of ethyl 2,6-dimethyl-4-nitro phenoxyacetate as '5 light yellow prisms. 300 MHz 1 H NMR (CDCl3) 8 1.34 (3H, t, J = 7.5 Hz), 2.39 (6H, s), 4.31 (2H, q, J = 7.5 Hz), 7.93 (2H, s). B. 2,6-Dimethyl-4-nitro-phenoxyacetic acid. To a solution of 0.962 g (4.06 mmole) of ethyl 2,6-dimethyl-4-nitro phenoxy acetate in 10 ml of methanol was added 1 ml of 3 N sodium hydroxide. 20 After the reaction mixture was stirred at room temperature for 30 minutes it was acidified with 3 N HCI and partitioned between water and methylene chloride. The combined organic extracts were washed with brine and dried over anhydrous sodium sulfate, filtered and evaporated to dryness under recduced pressure to give 0.82 g (97%) of 2,6-dimethyl-4-nitro phenoxy acetic acid as 25 light yellow solid. 300 MHz 1 H NMR (d3-DMSO) 5 2.35 (6H, s), 4.55 (2H, s) 7.97 (2H, s), 13.02 (1H, bs).

-66 C. (2S.33.5S -2-(t-Butvloxvcarbonyl) amino-3-hydroxv-5-(2S-(1 -imidazolidin-2 onlv)-3-methyl-butanovylamino-1.6-diohenvlhexane. Coupling of (2S,3S,5S)-2-(t-butyloxycarbonyl) amino-3-hydroxy-5 amino-1,6-diphenylhexane with the carboxylic acid from Example 1 M using s standard procedure (EDAC in DMF) provided the desired compound (100%). 300 MHz 1 H NMR (CDCI3) 5 0.83 (d, J = 6 Hz, 3H), 0.87 (d, J = 6 Hz, 3H), 1.40 (s, 9H), 1.70 (m, 2H), 2.16 (m, 1 H), 2.58-2.80 (m, 4H), 3.10-3.30 (m, 4H), 3.65 (m, 2H), 4.20 (m, 1 H), 4.38 (s, 1 H), 4,83 (d, J= Hz, 1 H), 6.53 (d, J = 9 Hz, 1 H), 7.20 (m, 10H). Mass spectrum: (M+H)+ = 553. 10 D. (2S.3S.5S)-2-Amino-3-hydroxy-5-(2S-(1-imidazolidin-2-onyl)-3-methyl butanoyl) amino-1.6-diphenylhexane. Deprotection of the Boc-protecting group of the compound from Example 10C by standard procedure (TFA/CH 2

CI

2 ) provided the desired compound. 300 is MHz 1 H NMR (CDCI3) 6 0.87 (d, J = 6 Hz, 3H), 0.90 (d, J = 6 Hz, 3H), 1.33 (dd, J = 4.5, 9.0 Hz, 1H) 2.18 (m, 1H), 2.50 (m, 1H), 2.80 (m, 5H), 3.20 (m, 4H) 3.72 (d, J = 10 Hz, 1 H), 4.30 (m, 1 H), 4.50 (s, 1 H), 6.67 (d, J = 7 Hz, 1 H), 7.20 (m, 1 OH). Mass spectrum: (M+H)+ = 453. E. (2S.3S.5S)-2-(4-Nitro-2.6-dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S 20 (1 -imidazolidin-2-onyll-3-methyl-butanoyl) amino-1.6-diphenylhexane. Coupling of the amino compound from Example 10D with the carboxylic acid from Example 10B using standard procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDCI3) 6 0.83 (d, 7 = Hz, 3H), 0.86 (d, J = 7 Hz, 3H), 1.70 (m, 3H), 2.18 (m, 2H), 2.28 (s, 6H) 2.75 (m, 3H), 2.95-3.30 (m, 25 6H), 3.67 (d, J = 10.5 Hz, 1H), 3.75 (m, 1H), 3.82 (d, J = 4 Hz, 1H), 4.25 (m, 5H), 6.55 (d, J = 7 Hz, 1H), 7.20 (m, 1OH), 7.92 (s, 2H). Mass spectrum: (M+H)+ = 660.

-67 F, (2S.3S.5S)-2-(4-Amino-2,6-dimethylphenoxvacetvl) amino-3-hydroxv-5-(2S (1-imidazolidin-2-onvl)-3-methyl-butanovl) amino-1.6-diohenvlhexane. To a suspension of 7 mg of 10% Pd/C in 5 ml of methanol was added a solution of 69 mg of the compound from Example 10E. The reaction mixture s was stirred vigorously under a hydrogen atmosphere (balloon filled with hydrogen attached to a 3-way stopcock). After 1 h, reaction was complete by TLC analysis; the catalyst was filtered off and the filtrate was concentrated in vacuo. The crude product was purified by silica gel column chromatography (2% to 5% MeOH/CH 2 Cl 2 ) to provide the desired compound (65%). 300 MHz 10 1 H NMR (CDCl 3 ) 5 0.82 (d, J = Hz, 3H), 0.87 (d, J = 6 Hz, 3H), 1.70 (m, 2H), 2.10 (s, 6H), 2.15 (m, 2H), 2.72 (m, 2H), 2.97 (d, J = 7.5 Hz, 2H), 3.08 (m, 1 H), 3.15 ( , 1 H), 3.30 (m, 2H), 3.45 (br s, 2H), 3.66 (d, J = 10 Hz, 1 H), 3.72 (m, 1 H), 3.90 (d, J = 3 Hz, 1 H), 4.10-4.20 (m, 4H), 4.30 (s, 1 H), 6.33 (s, 2H), 6.57 (d, J = 9 Hz, 1H), 7.20 (m, 1OH). Mass spectrum: (M+H)+ = 630. Example 11 (2S.3S.5S)-2-(2.4.6-Trimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 imidazolidin-2-onyl)-3-methylbutanoyl) amino-1.6-diphenylhexane. A. 2.4.6-Trimethylphenoxyacetic acid. Using the procedures from Example 1G and 1H, but replacing 2,6 20 dimethylphenol with 2,4,6-trimethylphenol provided the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 8 2.25 (s, 9H), 4.43 (s, 2H), 6.84 (s, 2H). Mass spectrum: (M+H)+ = 195. B. (2S.3S5S)-2-(2.4.6-Trimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 i midazolidin-2-onyl)-3-methylbutanoyl) amino-1.6-diphenylhexane. 25 Coupling of the amino compound from Example 10D with the carboxylic acid from Example 11 A using standard procedure (EDAC in DMF) provided the desired compound (51%). 300 MHz 1 H NMR (CDC1 3 ) 5 0.82 (d, J = 6 Hz, 3H), 0.85 (d, J = 6 Hz, 3H), 1.70 (m, 4H), 2.13 (s, 6H), 2.25 (s, 3H), 2.75 (m, 2H), 2.97 (d. J = 7 Hz, 1 H), 3.13 (m, 2H), 3.28 (m, 2H), 3.68 (d, J = 10 Hz, 1 H), 3.72 (m, -68 1 H), 4.16 (m, 4H), 4.40 ( br s, 1H), 6.67 (d, J = 8 Hz, 1 H), 6.80 (s, 2H), 7.20 (m, 10H). Mass spectrum: (M+H)+ = 629. Example 12 (2S.3S.5S)-2-(4-Fluoro-2.6-dimethylohenoxvacetvl) amino-3-hydroxv-5-(2S-(1 5 imidazolidin-2-onyl)-3- met hyl-butanoyl) amino-1 .6-diphenvlhexane. A. 4-Fluoro-2.6-dimethylphenoxyacetic acid. Using the procedure from Example 1G and 1H, but replacing 2,6 dimethylphenol with 4-fluoro-2,6-dimethylphenol provided the desired compound. 300 MHz 1 H NMR (CD30D) 8 2.26 (s, 6H), 4.37 (s, 2H), 6.73 (d, J = ,o 9 Hz, 2H). Mass spectrum: M+ = 198. B. (2S.3S.5S)-2-(4-Fluoro-2.6-dimethylphenoxvacetyl) amino-3-hydroxy-5-(2S (1-imidazolidin-2-onyll-3-methyl-butanoyl) amino-1 .6-diphenvlhexane. Coupling of the amino compound from Example 10D with the carboxylic acid from Example 12A provided the desired compound. 300 MHz 1 H NMR 1s (CDCl 3 ) 5 0.83 (d, J = 6 Hz, 3H), 0.86 (d, J = 6 Hz, 3H), 1.72 (m, 2H), 2.15 (s, 6H), 2.20 (m, 1H), 2.76 (m, 2H), 2.98 (d, J = 7 Hz, 2H), 3.12 (m, 2H), 3.30 (m, 2H), 3.67 (d, J = 10 Hz, 1 H), 3.72 (m, 1 H), 4.13 (AB q, J = 8, 9 Hz, 2H), 4.20 (m, 2H), 4.37 (s, 1H), 6.64 (d, J = 9 Hz, 1H), 6.70 (d, J = Hz, 2H), 7.20 (m, 1OH). Mass spectrum: (M+H)+ = 633. Example 13 20 (2S,3S,5S)-2-(4,6-Dimethyl pyrimidin-5-oxy-acetyl) amino-3-hydroxy-5-(2S-(1 imidazolidin-2-onyl)-3- methyl-butanoyl) amino-1.6-diphenvlhexane. A. 4.6-Dimethyl pyrimidin-5-oxy-acetic acid. Using the procedures from Example 1G and 1H, but replacing 2,6 dimethylphenol with 5-hydroxy-4,6-dimethylpyrimidine (prepared according to 25 Chem. Ber. 93 pg. 1998, 1960) provided the desired compound. 300 MHz 1 H NMR (DMSO-d 6 ) 5 2.45 (s, 6H), 4.55 (s, 2H), 8.50 (s, 1 H). Mass spectrum: (M+H)+ = 183.

-69 B. (2S.3S.5S)-2-(4.6-Dimethyl Dyrimidin-5-oxv-acetvl) amino-3-hydroxv-5-(2S (1-imidazolidin-2-onvl)-3-methyl-butanoyl) amino-1.6-diphenvlhexane. Coupling of the amino compound from Example 1 OD with the carboxylic acid from Example 13A provided the desired compound. 300 MHz 1 H NMR 5 (CDCl3) 6 0.82 (d, J = 6 Hz, 3H), 0.85 (d, J = 6 Hz, 3H), 1.70 (m, 2H), 2.15 (in, 1H), 2.40 (s, 6H), 2.75 (m, 2H),2.97 (d, J = 7 Hz, 2H), 3.12 (m, 2H), 3.30 (m, 2H), 3.66 (d, J = 10 Hz, 1 H), 3.74 (m, 1 H), 3.88 (d, J = Hz, 1 H), 4.20 (m, 4H, 6.62 (d, J = 9 Hz, 1 H), 7.0 (d, J = 9 Hz, 1 H), 7.20 (m, 1 OH), 8.70 (s, 1 H). Mass spectrum: (M+H)+ = 617. 10 Example 14 D. (2S.3S.5S)-2-(2,4-Dimethyl-pyridin-3-oxy-acetyl) amino-3-hydroxy-5-(2S-(1 imidazolidin-2-onyl)-3.3-dimethyl butanoyl) amino-1.6-diphenylhexane. A. 2,4-Dimethyl-pyridin-3-oxy-acetic acid. Using the procedures from Example 1 G and 1 H, but replacing 2,6 15 dimethylphenol with 2,4 dimethyl-3-hydroxypyridine (prepared according to J. Med. Chem. 35, pg. 3667-3671, 1992) provided the desired compound. 300 MHz 1 H NMR (DMSO-d6) 8 2.26 (s, 3H), 2.42 (s, 3H), 4.44 (s, 2H), 7.08 (d, J = 5 Hz, 1 H), 8.07 (d, J = 5 Hz, 1 H). Mass spectrum: (M+H)+ = 182. B. (2S,3S.5S)-2-(2,4-Dimethyl-pyridin-3-oxy- acetyl) amino-3-hydroxy-5-(t 20 butyloxycarbonyl) amino-1 .6-diphenylhexane. Coupling of the amino compound from Example1 F with the carboxylic acid from Example 14A using standard procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDC13) 5 1.40 (s, 9H), 1.70 (m, 2H), 2.18 (s, 3H), 2.40 (s, 3H), 2.77 (m, 2H), 2.98 (d, J = 7 Hz, 2H), 3.75-3.95 (m, 3H), 25 4.20 (s, 2H), 4.22 (m, 1 H), 4.60 (br d, 1 H), 7.0 (d, J = 5H, 1 H), 7.10 (m, 3H), 7.25 (m, 7H), 8.16 (d, J = 5 Hz, 1 H). Mass spectrum: (M+H)+ = 548.

-70 C. (2S.3S .5S)-2-(2.4-Dimethyl-Dyridin-3-oxy-acetvl) amino-3-hydroxy-5-amino 1.6-diohenvlhexane. Deprotection of the Boc-group in the compound from Example 14B using standard procedure (TFA/CH 2

CI

2 ) provided the desired compound. 300 MHz 5 1H NMR (CDCI3) 8 1.45 (m, 1H), 1.62 (m, 1H), 2.23 (s, 3H), 2.45 (s, 3H), 2.50 (m, 1 H), 2.80 (m, 1H), 3.0 (m, 2H), 3.12 (m, 1H), 3.90 (m, 1 H), 4.18 (m, 1 H), 4.25 (ABq, J = 9, 12 Hz, 2H), 6.98 (d, J = 5 Hz, 1H), 7.10 (m, 2H), 7.30 (m, 8H), 8.17 (d, J = 5 Hz, 1 H). Mass spectrum: (M+H)+ = 448. D. (2S.3S.5S)-2-(2.4-Dimethyl-1vridin-3-oxy-acetyl) amino-3-hydroxv-5-(2S-(1 to imidazolidin-2-onyl)-3.3-dimethyl butanoyl) amino-1 .6-diphenvlhexane. Coupling of the amino compound from Example 14C with the carboxylic acid from Example 7A using standard procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDCI3) 6 1.0 (s, 9H), 1.70 (m. 3H), 2.18 (s, 3H), 2.42 (s, 3H), 2.75 (m, 2H), 3.0 (m, 4H), 3.30 (m, 1 H), 3.55 (m, 1 H), 3.80 is (m, 1 H), 4.05 (s, 1 H), 4.20 (m, 4H), 4.60 (s, 1 H), 6.70 (d, J = 7 Hz, 1 H), 6.97 (d, J 5 Hz, 1 H), 7.15 (m, 3H), 7.25 (m, 7H), 8.17 (d, J = Hz, 1H), Mass spectrum: (M+H)+ = 630. Example 15 (2S.3S.5S)-2-(2.4-Dimethyl-pyridin-3-oxy-.8ptyl) amino-3-hydroxy-5-(2S-(1 20 imidazolidin-2-onyl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. Coupling of the amino compound from Example 14C with the carboxylic acid from Example 1M using standard procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDCI3) 6 0.82 (d, J = 6 Hz, 3H), 0.86 (d, J = 6 Hz, 3H), 1.75 (m, 3H), 2.15 (m, 1 H), 2.18 (s, 3H), 2.40 (s, 3H), 2.75 (m, 2H), 25 2.97 (d, J = 7.5 Hz, 2H), 3.20 (m, 4H), 3.70 (d, J - 10 Hz, 1 H), 3.75 (m, 1 H), 4.20 (m, 6H), 4.52 (s, 1H), 3.75 (m, 1H), 4.20 (m, 6H), 4.52 (s, 1H), 6.80 (d, J - 7 Hz, 1 H), 6.96 (d, J = 4.5 Hz, 1 H), 7.20 (m, 10 H), 8.17 (d, J = 4.5 Hz, 1 H). Mass spectrum: (M+H)+ = 616.

-71 Examoie 16 (2S,3S .5S)-2-(2,6-Dimethylthiophenoxvacetyl) amino-3-hydroxv-5(2S-(1 imidazolidin-2-onyl)-3-methyl-butanoVl) amino- 1,6-diDhenvlhexane. A. 2.6-Dimethylthiophenoxy acetic acid. 5 Using the procedures from Example 1G and 1H, but replacing 2.6 dimethylphenol with 2,6-dimethylthiophenol provided the desired compound. 300 MHz 1 H NMR (CDCI3) 8 2.56 (s, 6H), 3.40 (s, 2H), 7.10 (m. 3H). Mass spectrum: (M+H)+ = 197. B. (2S,3S,5S)-2-(2.6-Dimethylthiophenoxyacetyl) amino-3-hydroxv-5-(2S-( 1 10 imidazolidin-2-onyl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. Coupling of the carboxylic acid from Example 16A with the amino compound from Example 10D provided the desired compound. 300 MHz 1 H NMR (CDCI3) 5 0.82 (d, J = 6 Hz, 3H), 0.86 (d, J = 6 Hz, 3H), 2.15 (m, 1 H), 2.52 (s, 6H), 2.70 (m, 4H), 3.10 (m, 2H), 3.30 (m, 4H), 3.60 (m, 2H), 4.0 (m, 1H), 4.10 15 (m, 1 H), 4.22 (s, 1 H), 6.39 (d, J = 7 Hz, 1 H), 6.58 (d, J = 9 Hz, 1 H), 7.20 (m, 13H). Mass spectrum: (M+H)+ = 631. Example 17 (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(2S-(1 pyrrolidin-2-onyl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. A 4-Bromobutanoyl-L-valine methyl ester. To a solution of 1.08 g (8.4 mmole) of L-valine methyl ester in 30 ml of

CH

2

CI

2 was added 1.36 ml (16.8 mmole) of pyridine, cooled to 0*C and 1.55 g (8.4 mmole) of 4-bromobutanoyl chloride added. The solution was stirred at OC for 40 minutes and at RT for 1 h. The solution was washed with satd. 25 NaHCO 3 , brine and dried with anhy. Na 2

SO

4 ; filtered and concentrated in vacuo. The crude product was purified by silica gel column chromatography (5% EtOAc/CH 2

CI

2 ) to provide 1.82 g (77%) of desired product. 300 MHz 1 H NMR (CDCl 3 ) 8 0.92 (d, J = 6 Hz, 3H), 0.96 (d, J = 6 Hz, 3H) 2.20 (m, 3H), 2.46 -72 (m, 2H), 3.50 (m, 2H), 3.76 (s, 3H), 4.58 (dd, J = 4,7 Hz, 1 H), 5.97 (br d, J = 7 Hz, 1 H). Mass spectrum: (M+H)+ = 297. B. 2S-(1 -Pyrrolidin-2-onyl)-3-methyl-butanoic acid. To a solution of 1.49 g (5.3 mmole) of the compound from Example 17A 5 in a mixture of DMF/CH 2

CI

2 cooled to 0*C was added 0.234 g (1.1 equivalent) of 60% sodium hydride in mineral oil. The mixture was slowly warmed up to RT and stirred overnight. The mixture was poured into satd. ammonium chloride and extracted with ethyl acetate, dried and concentrated in vacuo. The crude product was hydrolyzed using lithuim hydroxide as in Example 1 H to provide 10 the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 8 0.96 (d, J = 7 Hz, 3H), 1.06 (d. J = 7 Hz, 3H), 2.10 (m, 2H), 2.40 (m, 1H), 2.50 (t, J = 7 Hz, 2H), 3.56 (m, 2H), 4.14 (d, J = 10 Hz, 1H). Mass spectrum: (M+H)+ = 186. C. ( 2 S3S5S)-2-(26-Dimethylphenoxyacetyl) amino-3-hvdroxy-5-(2S-(1 pyrrolidin-2-onvl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. Coupling of the carboxylic acid from Example 17B with the amine from Example 1N using standard procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDC13) 8 0.77 (d, J = 7 Hz, 3H), 0.83 (d, J = 7 Hz, 3H), 1.75 (m, 3H), 2.10 (m, 1 H), 2.20 (s, 6H), 2.25 (m, 1 H), 2.65 (m, 1 H), 2.85 (m, 1 H), 3.0 (d, J = 7 Hz, 2H), 3.20 (m, 1 H), 3.77 (m, 2H), 3.88 (d, J = 10 Hz, 1 H), 20 4.20 (m, 3H), 6.30 (d, J = 7 Hz, 1H), 6.98 (m, 3H), 7.20 (m, 10 H). Mass spectrum: (M+H)+ = 614. Example 18 (2S.3S.5S)-2-(2.6-Dimethylphenoxvacetvl) amino-3-hydroxv-5-(2S-(1 pyrrolidin-2,5-dionvl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. 25 A. 2S-(1-Pyrrolidin-25-dionyl)-3-methyl-butanoic acid benzyl ester. To a solution of 700 mg (3.38 mmole) of L-valine benzyl ester in 6 ml of chloroform was added 1 equivalent of succinic anhydride. After 1 h at RT, the solvent was removed in vacuo and the residue was dissolved in 20 ml of DMF. To this solution was added 0.52 g of N-hydroxy-benzotriazole, 0.68 g of EDAC -73 and 0.52 ml of triethylamine. After 24 h at RT, 20 mg of 4-dimethylaminopyridine was added. The solution was left at RT for 3 days. After standard work-up, the crude product was purified by silica gel column chromatography to provide 0.25 g of desired product (26%). 300 MHz 1 H NMR (CDCI3) 8 0.84 (d, J = 7 Hz, 3H), 5 1.12 (d, J = 7 Hz, 3H), 2.70 (m, 1H), 2.71 (s, 4H), 4.45 (d, J = 9 Hz, 1H), 5.15 (s, 2H), 7.30 (m, 5H). B. 2S-(1-Pyrrolidin-2.5-dionyl)-3-methyl-butanoic acid. A mixture of 0.245 of the product from Example 18A, 30 mg of 10% palladium on charcoal in 50 ml of methanol was stirred vigorously under 10 hydrogen atmosphere (balloon filled with hydrogen) for 1 h. The catalyst was filtered off and the solvent was removed under vacuum to provide 168 mg of the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 6 0.84 (d, J = 6 Hz, 3H), 1.13 (d, J = 6 Hz, 3H), 2.65 (m, 1 H), 2.80 (s, 4H), 4.45 (d, J = 8 Hz, 1 H). Mass spectrum: (M+H)4 = 200. 15 C. (2S.3S.5S)-2-(2.6-Dimethvlohenoxvacetvl) amino-3-hydroxv-5-(2S-(1 pyrrolidin-2.5-dionyl)-3-methyl-butanoyl) amino-1.6-diphenylhexane. Coupling of the carboxylic acid from Example 1 BB with the amine from Example 1N using standard procedure (EDAC in DMF) provided the desired product (75%). 300 MHz 1 H NMR (CDCl3) 8 0.70 (d, J = 4 Hz, 3H), 0.72 (d, J = 20 4 Hz. 3H), 1.70 (m, 1H), 2.20 (s, 6H), 2.45 (m, 2H), 2.60 (s, 4H), 2.80 (m, 2H), 3.0 (m, 2H), 3.76 (m, 1H), 4.20 (m, 6H), 7.0 (m, 3H), 7.20 (m, 1OH). Mass spectrum: (M+H)+ = 628. Example 19 (2S.

3 S.5S)-2-(Trans-3-(2.6-dimethylohenvl) Dropenovl) amino-3-hydroxv-5 25 (2S-1 -tetrahydrovrimidin-2-onyl)-3-methyl-butanovl) amino-1.6 diphenylhexane. A. 26-Dimethyl benzaldehyde. Oxidation of 2,6-dimethyl benzyl alcohol by standard Swern oxidation procedure (oxalyl chloride/DMSO) provided the desired compound. 300 MHz -74 1 H NMR (CDCI3) 62.62 (s, 6H), 7.10 (m, 2H), 7.33 (t, J = 7 Hz, 1H), 10.63 (s, 1H), Mass spectrum: (M+H)+ = 135. B. Trans-3-(2.6-dimethylphenyl)-rooenoic acid methyl ester. To a solution of trimethyl phosphonoacetate (149 mg, 0.82 mmole) in 15 5 ml of THF was added 36 mg of sodium hydride (60% in oil). After 15 minutes 100 mg of the compound from Example 19A in 2 ml of THF was added. After 2 h, the reaction was quenched carefully with water and extracted with ethyl acetate (70 ml), dried and concentrated. Purification of the crude product by silica gel column chromatography (hexane/EtOAc 95:5) provided the desired io compound (75%). 300 MHz 1 H NMR (CDCI3) 8 2.35 (s, 6 H), 3.82 (s, 3H), 6.07 (d, J = 16 Hz, 1 H). 7.10 (m, 3H), 7.85 (d, J = 16 Hz, 1H). Mass spectrum:

(M+NH

4 )+ = 191. C. Trans-3-(2.6-dimethylphenyl)-propenoic acid. Hydrolys , of the methyl ester from Example 198 using lithium hydroxide 15 in a mixture of methanol and water provided the desired compound (84%). 300 MHz 1 H NMR (CDCl3) 5 2.38 (s, 6H), 6.13 (d, J = 16 Hz, 1H), 7.10 (m, 3H), 7.96 (d. J = 16 Hz, 1H). Mass spectrum: (M+H)+ = 194. D. (2S,3S,5S)-2-(Trans-3-(2.6-dimethylphenyl) propenoyll amino-3-hydroxy-5 (t-butyloxvcarbonyl) amino-1.6-diphenylhexane. 20 Coupling of the carboxylic acid from Example 19C with the amine from Example 1 F using standard procedure (EDAC/DMF) provided the desired compound (84%). 300 MHz 1 H NMR (CDC1 3 ) 6 1.40 (s, 9H), 1.68 (m, 1H), 2.34 (s, 6H), 2.75 (m, 2H), 2.96 (m, 2H), 3.72 (m, 1 H), 3.85 (m, 1 H), 4.08 (m, 2H), 4.60 (m, 1 H), 5.88 (d, J = 10 Hz, 1 H), 5.94 (d, J = 16 Hz, 1 H), 7.10 (m, 5H), 7.25 (m, 8H), 7.72 (d, J = 16 Hz, 1H). Mass spectrum: (M+H)+ = 543 -75 E. (2S .3S.5S1-2-(Trans-3-(2.6-dimethvlphenvl) propenoyl amino-3-hvdroxY-5 (2S-1 -tetrahvdropvrimidin-2-onvl)-3-methyl-butanovl) amino-1.6 diphenvihexane. Removal of the Boc-protecting group of the compound from Example 19D 5 (TFA/CH 2

CI

2 ) and coupling of the resulting amine with the carboxylic acid from Example 2A using standard procedure (EDAC/DMF) provided the desired compound (73%). 300 MHz 1H NMR (CDCI3) 6 0.82 (d, J = 6 Hz, 3H), 0.87 (d, J = 6 Hz, 3H), 1.50 (m, 1 H), 1.70 (m, 2H), 2.20 (m, 1 H), 2.33 (s, 6H), 2.68 (m, 1 H), 2.78 (m, 1 H), 2.85 (m. 1 H), 3.05 (m, 5H), 3.73 (m, 1 H), 4.17 (m, 1 H), 4.30 (d, J = 10 3 Hz, 1H), 4.60 (s, 1H), 5.95 (d, J = 15 Hz, 1H), 6.0 ( d, J = 9 Hz, 1H), 6.80 (d, J = 7 Hz, 1H), 7.25 (m, 13H), 7.70 (d, J = 15 Hz, 1H). Mass spectrum: (M+H)+= 625. Example20 (2S.3S.5S)-2-(3-(2.6-Dimethylphenvl) proanovl) amino-3-hvdroxY-5-(2S-(1 is tetrahvdropyrimidin-2-onvl)-3-methyl-butanoyl) amino-1.6-diphenvlhexane. A. 3-(2.6-Dimethylohenvl) prooanoic acid methyl ester. A solution of 400 mg of the compound from Example 19B in 25 mi of methanol and 40 mg of 10% Pd/C was stirred vigorously under a hydrogen atmosphere (balloon pressure) for 3 h. The catalyst was filtered off and 20 concentration of the filtrate in vacuo provided the desired compound (98%). 300 MHz 1 H NMR (CDCl3) 8 2.35 (s, 6H), 2.45 (m, 2H), 2.98 (m, 2H), 3.22 (s, 3H), 7.02 (s. 3H). Mass spectrum: (M+H)+ = 210. B. 3-(2.6-Dimethylohenyl) ropanoic acid. Hydrolysis of the methyl ester from Example 20A, using lithium hydroxide 25 in methanol and water provided the desired compound (93%). 300 MHz 1 H NMR (CDCI 3 ) 5 2.36 (s, 6H), 2.50 (m, 2H), 3.0 (m, 2H), 7.03 (s, 3H). Mass spectrum. (M+NH 4 )+ = 196.

-76 C. (2S.3S.5S)-2-(3-2.6-Dimethylphenvl) pronanovl) amino-3-hydroxv-5-(t butyloxycarbonyl) amino-1 .6-diphenylhexane. Coupling of the carboxylic acid from Example 20B with the amine from Example 1 F using standard coupling procedure (EDAC/DMF) provided the 5 desired compound. 300 MHz 1 H NMR (CDCI3) 6 1.40 (s, 9H), 1.55 (m, 2H), 2.20 (m, 2H), 2.30 (s, 6H), 2.74 (m, 2H), 2.85 (m, 4H), 3.66 (m, 1 H), 3.82 (m, 1 H), 3.95 (m, 2H), 4.57 (br d, 1 H), 5.66 (d, J = 9 Hz, 1 H), 7.0 (s, 3H), 7.22 (m, 1 OH). Mass spectrum: (M+H)+ = 545. 'D. (2S.3S.5S)-2-(3-(2.6-Dimethylohenyl) Dropanoyl) amino-3-hvdroxy-5-(2S 1o (1-tetrahvdrovriimidin-2-onvl)-3-methyl-butanovl) amino-1.6-dinhenvlhexane. Removal of the Boc-protecting group of the compound from Example 20C using trifluoroacetic acid in CH 2

CI

2 and coupling of the resulting amine with the carboxylic acid from Example 2A using standard coupling procedure (EDAC/DMF) provided the desired compound. 300 MHz 1 H NMR (CDC13) 5 "5 0.82 (d, J = 6 Hz, 3H), 0.86 (d, J = 6 Hz, 3H), 1.55 (m, 2H), 1.65 (m, 1 H), 1.70 (s, 3H), 2.20 (m. 3H), 2.30 (s, 6H), 2.65 (m, 1H), 2.75 (m, 1H), 2.86 (m, 5H), 3.10 (m, 3H), 3.68 (m, 1H), 4.10 (m, 4H), 4.63 (s, 1H), 5.75 (d, J = 7 Hz, 1H), 6.76 (d, J = 7 Hz, 1 H), 7.0 (m, 3H), 7.20 (m, 10H). Mass spectrum: (M+H)+ = 627. Example 21 20 (2S.3S.5S)-2-(2.6-DimDethyl-4-hvdroxv-Dhenoxvacetvl) amino-3-hvdroxy-5-(2S (1-tetrahvdropyrimidin-2-onyl)-3-methyl-butanovl) amino-1.6-diphenvlhexane. A. 2.6-Dimethyl-4-tert-butvidimethylsilyloxy phenol To a solution of 2.5 g (14.7 mmole) of 2,6-dimethylquinone in 5 ml of methanol was added 200 mg of Pd/C (20%). The reaction mixture was stirred 25 under 1 atmosphere of hydrogen for overnight. The Pd/C was removed over a celite pad, and the solvent was evaporated to dryness under reduced pressure to give 2.0 g (100%) of 2,6-dimethyldihydroquinone as a light yellow oil. To a solution of 2.0 g (14.7 mole) of 2,6-dimethyldihydroquinone in 10 ml of methylene chloride was added 1.2 g (17.6 mmole) of imidazole and 2.2 g 30 (14.7 mmol) of tert-butyldimethylsilyl chloride subsequently at 0*C. After the -77 reaction was complete as indicated by TLC, it was partitioned between methylene chloride and 1:1 mixture of 3 N hydrogen chloride and brine. The organic layer was washed with brine, dried over sodium sulfate, filtered and evaporated to dryness under reduced pressure. Silica gel chromatography s using 5% ethyl acetate:hexanes gave 1.8 g (49%) of 2,6-dimethyl-4-tert butyldimethylsilyloxy phenol as a white solid. 300 MHz 1 H NMR (CDCl3) 6 0.16 (s, 6H), 0.98 (s, 9H), 2.19 (s, 6H), 4.22 (s, 1H), 6.48 (s, 2H). Mass spectrum: (M+H)4 = 253. B. Ethyl 2.6-Dimethyl-4-tert-Butvldimethylsilvloxv phenoxvl acetate 1o A solution of 1.8 g (7.1 mmole) of 2,6-dimethyl-4-tert-butydimethylsilyloxy phenol in 5 ml of dimethylformamide was treated with 2.0 g (1.43 mmole) of potassium carbonate and 830 ul (7.5 mmole) of ethyl bromoacetate. The resulting solution was healed at 70"C for 4 hr. After cooled to room temperature, the reaction mixture was partitioned between ethyl acetate and 3 N 1s hydrogen chloride. The combined organic layer was washed with diluted brine, dried over magnesium sulfate, filtered, and evaporated in vacuo. Silica gel chromatography using 5% ethyl acetate:hexanes gave 2.03 g (85%) of ethyl 2,6-dimethyl-4-tert-butyldimethylsilyloxy phenoxyl acetate as a light yellow oil. 300 MHz 1 H NMR (CDCI3) 6 0.17 (s, 6H), 0.97 s, 9H), 1.33 (t, 3H, J = 6.3 Hz), 20 2.22 (s, 6H), 4.30 (q, 2H, J = 6.3 Hz), 4.35 (s, 2H), 6.57 (s, 2H). Mass spectrum: (M+H)4 = 356. C. 2.6-Dimethvl-4-Hvdroxyl phenoxyacetic acid To a solution of 2.03 g (6.0 mmole) of ethyl 2,6-dimethyl-4-tert butyldimethysilyloxy phenoxy acetate in 10 ml of methanol was added 4 ml of 3 25 N sodium hydroxide. After the reaction mixture was stirred at room temperature for 30 minutes it was acidified with 3 N HCI. The reaction was allowed to stir for additional 1 h, and then partitioned between water and methylene chloride. The combined organic extracts were washed with brine and dried over anhydrous sodium sulfate, filtered, and evaporated to dryness under reduced pressure. 30 Trituration with hexanes gave 910 mg (77%) of 2,6-dimethyl-4-hydroxyl phenoxyacetic acid as a white solid. 300 MHz 1 H NMR (CD30D) 8 2.18 (s, 6H), 4.31 (s. 2H), 6.41 (s, 2H). Mass spectrum: (M+H)+ = 214.

-78 D. (2S.3S.5S)-2-(2.6-Dimethyl-4-hydroxy-phenoxvacetvl) amino-3-hydroxv-5 (t-butvloxvcarbonyl) amino-1 .6-diphenvlhexane. Coupling of the carboxylic acid from Example 21 C with the amine from Example 1 F using standard coupling procedure (EDAC/DMF) provided the 5 desired compound. 300 MHz 1 H NMR (CDCI3) 8 1.40 (s, 9H), 1.68 (m, 2H), 2.07 (s, 6H), 2.77 (d, J = 6 Hz, 2H), 2.98 (m, 2H), 3.74 (m, 1 H), 3.90 (m, 1 H), 4.10 (m, 3H), 4.58 (m, 1H), 5.20 (m, 1H), 6.44 (s, 2H), 7.10-7.30 (m, 10H). E. (2S.3S.5S)-2-(2.6-Dimethyl-4-hydroxv-phenoxyacetyl) amino-3-hydroxv-5 (2S-(1-tetrahydroovrimidin-2-onyl)-3-methyl-butanoyl) amino-1.6 10 dip~henvihexane. Removal of the Boc-protecting group of the compound from Example 21 D using TFA/CH 2

CI

2 and coupling of the resulting amine with the carboxylic acid from Example 2A using standard procedure (EDAC/DMF) provided the desired compound. 300 MHz 1H NMR (CDCI3) 8 0.78 (d, J = 5 Hz, 3H), 0.81 (d, J = 5 15 Hz, 3H), 1.47 (m, 1H), 2.03 (s, 6H), 2.18 (m, 1H), 2.62 (m, 1H), 2.80 (m, 2H), 3.05 (m, 6H), 3.78 (m, 1H), 4.12 (M, 6H), 4.37 (M, 1H), 4.71 (s, 1H), 6.47 (s, 2H), 6.94 (br d, 1 H), 7.20 (m, 1 OH). Mass spectrum: (M+H)4 = 645. Example 22 (2S.3S.5S)-2-(cis()-1.1-dioxo-2-isopropv-3-tetrahvdrothiophenoxv)amino-3 20 hydroxv-5-(2S-(1-tetrahvdropvrimid-2-onyl-3-methyl butanoyliamino-1.6 diphenylhexane. A. Cis (+)-2-isopropvl-3-hydroxy-tetrahydrothiophene. To a solution of ethyl-3-mercaptopropionate (27.25 ml, 0.246 mole) in 200 ml of ethanol was added carefully sodium ethoxide (16.75 g, 0.246 mole) in 25 several portions. The resulting suspension was then cooled to -20 0 C and ethyl 2-bromoisovalerate (50 g, 0.239 mole) in 50 ml of ethanol was added dropwise over 2 h. After addition was complete, the reaction was warmed to ambient temperature and stirred for 3 h. The mixture was poured into 600 ml of ethyl acetate and 600 ml of saturated NH 4 CI. The ethyl acetate layer was removed 30 and the aqueous layer extracted (2 - 200 ml) with ethyl acetate. The combined -79 organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to give an orange oil. The oil was dissolved in 500 ml of toluene and sodium ethoxide (16.75 g, 0.246 mole) was added. The reaction mixture was heated to reflux for 6 h, cooled to RT, and then poured into an ice-cold solution of 1 N HCI s (235 ml) and extracted with ethyl acetate (3 x 150 ml). The combined organic layers were dried over sodium sulfate, filtered and concentrated to an oil that was used in the next step without purification. The crude product was added to 500 ml of aqueous 10% sulfuric acid and the resulting mixture heated to reflux for several hours, and then cooled to lo RT and neutralized with 6N sodium hydroxide and extracted with ethyl acetate (3 x 300 ml). The combined organic layer was dried, filtered and concentrated in vacuo to give a dark burgundy oil. The crude product (ketone) was purified by vacuum distillation at 75 0 -80"C. 300 MHz 1 H NMR (CDCI3) 8 0.93 (d, J = 9 Hz, 3H), 1.03 (d, J = 9 Hz, 3H), 2.32 (m, 1H), 2.55-2.70 (m, 2H), 2.93 (t, J = 7.5 is Hz, 2H), 3.38 (d, J = 4 Hz, 1 H). Mass spectrum: (M+H)+ = 145. To a stirred solution of the above ketone in 125 ml of CH 2

CI

2 at 0*C was added diisobutylaluminum hydride (86 ml, 1M in THF) dropwise over 20 minutes. The reaction mixture was allowed to warm to room temperature and then was quenched by cautious addition of 1N HCI (255 ml). The reaction 20 mixture was extracted with ether (3 x 150 ml) and the combined ether solution was washed with satd. sodium bicarbonate, brine and dried over magnesium sulfate. The solution was concentrated in vacuo and the resulting oil was purified by silica gel column chromatography (10% EtOAc/hexane). 300 MHz 1 H NMR (CDC1 3 ) 8 1.03 (d, J = 7 Hz, 3H), 1.08 (d, J = 7 Hz, 3H), 1.80 (d, J = 9 25 Hz, 1H), 1.90 (m, 2H), 2.24 (m, 1H), 2.90-3.10 (m, 3H), 4.36 (m, 1H). Mass spectrum: (M+H)+ = 147. B. Cis(+( 2 --isorovl-3-th'ophen- .2(2-pridvlarbonate, To the product from Example 22A (2.29 g, 15.7 mmole) in 40 ml of

CH

2 Cl 2 was added diisopropylethyl amine (4.65 ml, 26.7 mmole) and di-(2 30 pyridyl)carbonate (5.42 g, 25.1 molee. After 18 h at RT, the reaction mixture was diluted with chloroform and washed sequentially with 10% citric acid, satd.

-80 sodium bicarbonate, brine and then dried over sodium sulfate; filtered and concentrated in vacuo. Purification of the crude product by silica gel column chromatography (20% EtOAc/hexane) provided the desired compound. 300 MHz 1 H NMR (CDCl3) 8 1.05 (d, J = 7 Hz, 3H), 1.08 (d, J = 7 Hz, 3H), 1.90 (m, 5 1 H), 2.05 (m, 2H), 2.58 (dd, J = 6, 15 Hz, 2H), 3.10 (m, 2H), 3.28 (dd, J = 3, 12 Hz, 1H), 5.47 (m, 1H), 7.12 (m, 1H), 7.27 (m, 1H), 7.80 (m, 1H), 8.41 (m, 1H). Mass spectrum: (M+H)+ = 268. C. (2S. 3S. 5S)-2-(cis(+)-2-Isooropvl-3-tetrahvdrothioohenoxy)amino-3 hvdroxy-5-(t-butyloxvcarbonvilamino-1.6-diohenylhexane. < To a solution of the compound from Example 22B (500 mg, 1.87 mmole) in 5 ml of CH 2

CI

2 was added the amine from Example 1 F (791 mg, 2.06 mmole). The reaction was stirred at RT until all the compound from Example 22B was consumed. The reaction mixture was diluted with chloroform and washed with 10% citric acid, satd. sodium bicarbonate, brine and then dried 15 with sodium sulfate; filtered and concentrated in vacuo. Purification of the crude product by silica gel column chromatography (2% MeOH/CH 2

CI

2 ) provided the desired compound (73%). 300 MHz 1 H NMR (CDCl3) 8 0.83-1.05 (m, 6H), 1.40 (s, 9H), 1.90 (m, 3H), 2.20 (m, 1H), 2.75 (m, 2H), 2.85 (m, 4H), 2.95-3.15 (m, 3H), 3.67-3.90 (m, 4H), 4.55 (m, 1H), 5.10 (m, 1H), 5.30 (m, 1H), 7.10-7.26 (m, 1OH). 20 Mass spectrum: (M+H)+ = 557. D. (2S.3S.5S)-2-(cis(+)-1 .1 -Dioxo-2-isoprooyl-3-tetrahydrothiophenoxyiamino 3-hvdroxv-5-(t-butvloxvcarbonyl)amino-1 .6-diphenvlhexane. To the compound from Example 22C (523 mg, 0.91 mmole) in 10 ml of acetone and 0.5 ml of water was added Oxone (839 mg, 1.37 mmole) and 25 sodium bicarbonate (152 mg, 1.82 mmole). The resulting solution was stirred for 2 h, at which time a white precipitate appeared. The reaction was quenched with aqueous sodium bisulfite and extracted with ethyl acetate (2 x 100 ml), dried with sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by silica gel column chromatography (2% MeOH/CH 2

CI

2 ) to 30 provide 422 mg of product. 300 MHz 1 H NMR (CDCI3) 5 1.20 (m, 6H), 1.40 (s, 9H), 1.60 (m, 4H), 2.10-2.32 (m, 4H), 2.67 (m, 2H), 2.75 (m, 2H), 2.85 (m, 2H), 3.15 (m, 2H), 3.70-3.90 (m, 3H), 4.56 (m, 1H), 5.30 (m, 2H), 7.10-7.30 (m, 10H).

-81 E. (2S.3S.5S)-2-(cs(+)-1.1-Dioxo-2-isopropyl-3-tetrahydrothiophenoxv)amino 3-hydroxv-5-(2S-(1-tetrahvdropyrimid-2-onyl-3-methyl butanovlamino-1.6 diphenvlhexane. Removal of the Boc-protecting group of the compound from Example 22D s using TFA/CH 2

CI

2 and coupling of the resulting amine with the carboxylic acid from Example 2A provided the desired compound (82%). 300 MHz 1 H NMR (CDCl3) 8 0.82 (m, 6H), 1.0-1.20 (m, 6H), 1.60 (, 2H), 2.07 (m, 1 H), 2.25 (m, 2H), 2.65-3.20 (m, 12H), 3.70 (m, 1H), 3.90 (m, 1H), 4.10-4.20 (m, 2H), 5.07 (m, 1 H), 5.37 (m, 1 H), 5.87-5.98 (m, 1 H), 6.95-7.05 (m, 1 H), 7.20 (m, 10H). Mass io spectrum: (M+H)+ = 671. Example 23 (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetvl) amino-3-hydroxv-5-(2S-(1 dihydropvrimid-2.4-dionyl)-3-methyl-butanoy) amino-1.6-diphenvlhexane. A. N-(2-Ethoxvacrvlovl)-N'-(1S-carbomethoxv-2-methyl-propyl)-urea. To 1.74 g (0.013 mole) of 2-ethoxy-acryloyl chloride in 18 ml of toluene was added 3.90 g (0.026 mole) of silver cyanate. The mixture was heated to reflux for 0.75 h. The mixture was allowed to cool to RT and the precipitate allowed to settle. The supernatant (9.6 ml) was withdrawn and added to 18 ml of dry DMF and 5 ml of Et20, cooled to -15"C for 45 minutes and left in freezer 20 overnight. The solvent was evaporated in vacuo and the residue was purified by silica gel column chromatography (2% MeOH/CH 2

CI

2 ) to provide 1.59 g of desired compound (90.2%). 300 MHz 1 H NMR (CDCI3) 8 0.96 (d, J = 7 Hz, 3H), 1.0 (d, J = 7 Hz, 3H), 1.37 (t, J = 7.5 Hz, 3H), 2.25 (m, 1 H), 3.74 (s, 3H), 3.97 (q, J ='7.5 Hz, 2H), 4.42 (dd, J = 4.5, 8.0 Hz, 1 H), 5.25 (d, J = 12 Hz, 1 H), 7.68 (d, J = 25 12 Hz, 1H), 8.55 (s, 1H), 9.10 (d, J = 8 Hz, 1H). Mass spectrum: (M+H)+ = 273. B. 2S-(1-Dihvdropvrimid-2.4-dionvl)-3-methvl butanoic acid. A solution of 174 mg (0.64 mole) of the compound from Example 23A in 10 ml of 2N sulfuric acid was refluxed for 2 h, cooled to RT and left in freezer overnight. The mixture was concentrated and the residue was extracted with 30 ethyl acetate (2 x 100 ml), dried and concentrated in vacuo to give 122 mg of -82 desired compound. 300 MHz 1 H NMR (CDCI3) S 1.06 (d, J = 7Hz, 3H), 1.13 (d, J = 7 Hz, 3H), 2.25 (m, 1H), 5.04 (d, J = 10 Hz, 1H), 5.74 (d, J = 7 Hz, 1H), 7.50 (d, J = 10 Hz, 1 H), 8.43 (s, 1 H). C. (2S.3S.5S)-2-(2.6-Dimethvlohenoxyacetvl) amino-3-hydroxv-5-(2S-(1 s dihvdroovrimid-2.4-dionvil-3-methyl-butanoyl) amino-1.6-diohenylhexane. Coupling of the carboxylic acid from Example 23B with the amine from Example 1 N using standard coupling procedure (EDAC in DMF) provided the desired compound. 300 MHz 1 H NMR (CDCI3) 8 0.81 (d, J = 7 Hz, 3H), 0.92 (d, J = 7 Hz, 3H), 2.18 (s, 6H), 2.23 (m, 1H), 2.63 (m, 1H), 2.85 (m, 1H), 3.0 (m, 2H), 10 3.78 (m, 1 H), 4.20 (m, 4H), 4.58 (d, J = 10 Hz, 1 H), 5.68 (dd, J = 1.5, 7.5 Hz, 1 H), 7.0-7.25 (m, 13H), 7.50 (d, J = 7.5 Hz, 1H), 9.50 (s, 1H). Mass spectrum: (M+H)+ = 640. Example 24 Alternate Preparation of (2S. 3S. 5S)-2-(2.6-Dimethylphenoxyacetyl) amino-3 is hydroxv-5-42S-(1-tetrahydro-pyrimid-2-onyl-3-methyl butanoyl amino-1.6 diphenvlhexane. A. 2.6-DimethylDhenoxyacetic acid 2,6-Dimethylphenol (102.8 g, 0.842 mol) and chloroacetic acid (159.6 g, 1.68 mol) in 1000 ml of H 2 0 was added to a 3-L, 3-necked round bottom flask 20 with mechanical stirring and a water-cooled condenser. A solution of NaOH (134.9 g, 3.37 mol) dissolved in 500 ml of water was slowly added to the above mixture via addition funnel and heat to reflux. After 2 hours, additional chloroacetic acid (79.4 g, 0.84 mol) and NaOH solution (67.2 g, 1.68 mol in in 200 ml water) was added to the reaction mixture. After 19 hours, additional 25 chloroacetic acid (39.8 g, 0.42 mol) and NaOH solution (33.6 g, .84 mol in in 100 ml water) was added to the reaction mixture and refluxing was continued until starting phenol was consumed. The reaction flask was cooled in and ice water bath and acidified to pH=1 with conc. HCI, causing a precipitate to form. The resulting slurry was stirred in the ice bath for 1 hour then filtered. The solid -83 was dissolved in hot (100*C) water and cooled to crystallize the product as white plates, mp= 136-137"C, yield = 78.8 g, 52%. B. (2S. 3S. 5S) -2-(2.6-Dimethvlphenoxvacetyl) amino-3-hydroxy-5-(t butvloxycarbonylamino)-1 .6-diphenvlhexane. s Oxallyl chloride (36.3 ml, 0.42 mol) was added to a slurry of 2-6 dimethylphenoxyacetic acid (50 g, 0.28 mol) in 500 ml toluene followed by addition of 5 drops of DMF and stirred at room temperature for 30 min, then at 55 0 C for 1.5 hours. The toluene was removed on a rotary evaporator and remaining volatiles were removed in vacuo to afford 2,6-dimethyl io phenoxyacetyl chloride as an amber oil, 55 grams, 100%. [2S,3S,5SJ-2-Amino-3-hydroxy-5-t-butyloxycarbonylamino-1,6 diphenylhexane x 0.5 succinate (111.9 g, 0.25 mol) was charged to a 2L, 3 necked round-bottomed flask with mechanical stirring. NaHCO3 (106 g, 1.26 mol), 600 ml H20 and 600 ml EtOAc were added and stirred vigorously until all is solids were dissolved (15 minutes). Stirring was slowed and a solution of the 2,6-dimethyl-phenoxyacetyl chloride and EtOAc (100 ml) was added in a narrow stream via addition funnel. After 30 min of stirring, starting materials were consumed (HPLC analysis) and the layers were separated. The aqueous layer was extracted with EtOAc, the organic layers were combined and washed 20 with 200 ml of 1 M NaOH, 200 ml of 10% HC[, 200 ml of brine, dried over MgSO 4 , filtered and concentrated to provide the desired product as a white solid. C. (2S. 3S. 5S) -2-(2.6-Dimethylohenoxyacetvl) amino-3-hvdroxv-5-amino-1 .6 diyhenvlhexane. 25 (2S, 3S, 5S) -2-(2,6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-(t butyloxycarbonylamino)-1,6-diphenylhexane (175.1 g, 0.32 mol) and 500 ml CH2CI2 were mixed with stirring. CF3CO2H (249 ml, 3.2 mol) was added and stirred 20-25 minutes, then the reaction mixture was poured into a separatory funnel containing 1000 ml of water and 200 ml of CH2CI2. The resulting -84 mixture was shaken carefully and the layers were separated. The organic layer was washed again with 500 ml of water, then 3x 500 ml of NaHCO3 and finally 500 ml of brine. The organic solution was dried over MgSO4, filtered and concentrated to a golden oil that pulled into a foam 300 ml of diethyl ether 5 was added to the crude product and shaken vigorously to dissolve. Within minutes solid began to crystallize and the mixture became thick. Enough diethyl ether was added to make the mixture stirrable and the mixture was stirred at room temperature for 1 hour. The solid was filtered and air dried to give the desired product as 115 g of white needles, 81% yield. 10 A solution of HCI/diethyl ether was added to the filtrate td precipitate the remaining product as the HCI salt. This pinkish solid was collected by filtration, taking care to keep the solid flooded with N2 while it was wet with ether. When dry, transfered the amine salt to a separatory funnel and extracted with CH2Ci2 and NaHCO3 (aq). The organic layer was washed with brine, dried over 15 MgSO4, concentrated and treated as above to afford an additional 15 g of the desired product, the total yield is 91%. D. N-Carbonylbenzvloxy-3-aminopropanol To a 12L 3-neck round bottom flask was added isopropyl acetate (6.5L). The solvent was cooled to 0OC in an ice-water bath and 3-amino-1-propanol 20 (1.14Kg, 15.1mol, 2.15eq) was added in one portion. To this rapidly stirring solution, benzyl chloroformate (1.20Kg, 7.03mol, 1.Oeq) was added dropwise over 2h while maintaining the internal temperature of the flask between 100C and 150C. After the addition was complete, the reaction mixture was allowed to stir between 10CC and 150C for an additional 0.3h after which time water 25 (3.5L) was added in one portion. The solution was then partitioned and washed with an additional 2X3.5L of water. The organic layer was dried over potassium carbonate and concentrated to give a solid that was dissolved in excess isopropyl acetate and precipitated from solution by adding the compound to heptane. The solid was filtered under nitrogen to yield 1.20Kg 30 (82%) of the desired product as a colorless solid.

-85 E. N-Carbonylbenzyloxv-3-aminopropanal 335 mL of dimethylsulfoxide and 9L of methylene chloride were combined and chilled to -480C. 313 mL of oxalyl chloride was added over 25 minutes so that the temperature remained below -400C. Cooled to -480C, and 5 added 500 grams of N-Cbz-3-amino-1 -propanol dissolved in 1 L of methylene chloride so that the temperature remained below -400C. Stirred for an additional hour at -450C. 1325 mL of triethylamine was added at such a rate that the temperature remained below -400C. After stirring an additional 15 minutes at -400C, the mixture was allowed to warm to -30 0 C, then added 2.5L 10 of 20% aqueous potassium dihydrogen phosphate. Stirred for one hour, then separated the layers, washed the organic layer with brine, and dried with magnesium sulfate. The resulting aldehyde was kept in solution at -200C until needed. F. N-(N-(Benzvloxvcarbonyl-3-amino)-propvl) valine methyl ester. 15 To a 5L 3-neck round bottom flask was added the crude (unchromatographed) product of Example 24E (115g, 0.555mol, 1.Oeq) followed by addition of water (400mL) and methanol (1 600mL). The reaction mixture was maintained at 250C throughout the course of the reaction. After the solution became homogeneous, (S)-Valine methyl ester hydrochloride 20 (90.2g, 0.538mol, 0.97eq) was added in one portion followed by rapid addition of sodium acetate trihydrate (151g, 1.11mol, 2.Oeq) and sodium cycanoborohydride (73.2g, 1.17mol, 2.1eq) in said order. The reaction mixture was allowed to stir at room temperature for 0.5h and was concentrated in vacuo to remove all methanol present. To this solution, saturated aq sodium 25 bicarbonate (400mL) was added and the mixture was extracted with isopropyl acetate (1 L). The organic layer was washed with water (2X400mL), dried over sodium sulfate, and concentrated to yield 150g of crude product, which was dissolved in isopropyl acetate (300mL) and heptane (2400mL). Dry HCI was bubbled in and an oily solid precipitated out of solution. The liquid was 30 decanted away from the solid and was dissolved in dichloromethane (3L). The solution was washed with water (600mL) and saturated aq sodium bicarbonate -86 (600mL) and dried over sodium sulfate. It was concentrated in vacuo to yield 105g (59%) of the desired product as a light yellow oil. G. N-(3-amino)-propyl) valine methyl ester. To a 3L flask was added the product of Example 24F (1 20g, 0.372mol) 5 and methanol (1 L). This solution was allowed to stir in the presence of Raney Nickel (180g) for 1h . After removal of Raney Nickel by filtration, Pd(OH)2 (24g) was added and the solution was allowed to stir under 60 psi of a hydrogen atmosphere for 12h. The solution was purged with nitrogen and repressurized with 60 psi of hydrogen for an additional 1 h. The solution was filtered and to concentrated to give 63g of an oil (90%). To this oil toluene (120mL) was added and the solution was again concentrated in vacuo to give the desired product. H. 2S-(1-tetrahydro-pyrimid-2-onyl)-3-methy butanoic acid methyl ester. To a 5L 3-neck round bottom flask with stir bar was added the crude 1s product of Example 24G (150g, 0.8mol) and dichloromethane (3.2L). Carbonyldiimidazole (232g, 1.44mol, 1 .8eq) was added slowly in portions over 25 min. The solution was allowed to stir at ambient temperature for 40h. Water (200mL) was added over 1h with careful stirring until no more gas evolution occurred. A solution of 35% HCI was slowly added to the stirring solution until 20 the solution became acidic. The solution was then partitioned and was washed with water (2X300mL). The organic layer was dried over sodium sulfate and was concentrated to yield 126g (74%) of the desired product as a colorless solid. 1. 2S-(1-tetrahvdro-pyrimid-2-onyl-3-methyl butanoic acid methyl ester. 25 To a 12L 3-neck round bottom flask with stir bar was added the product of Example 24H (126g, 0.588mol), water (1.3L), and THF(3.9L). The solution was cooled to 00C in an ice-water bath and lithium hydroxide monohydrate (74g, -87 1.76mol, 3.Oeq) was added in one portion with rapid stirring. The solution was allowed to stir at 0 0 C for 14h. It was then acidified to pH 11 by slow addition of 50% aq phosphoric acid and the THF was removed in vacuo. The aqueous phase was washed with isopropyl acetate (2L) and was subsequently acidified 5 to pH by slow addition of 35% aq HCI. The aqueous layer was then extracted with ethyl acetate (5X2.2L). The combined organic layers were concentrated to give the desired product (105g) as a white solid. The compound was then purified by addition of isopropyl acetate (500mL) and ethanol (1 5mL) and bringing the solution to a boil with rapid stirring until 50mL of solvent had 10 evaporated. The solution was cooled to 0 0 C and filered to give 92g (75%) of pure desired product. J. (2S. 3S. 5S)-2-(2.6-Dimethylphenoxyacetyl) amino-3 hvdroxv-5-[2S-(1 -tetrahydro-pvrimd-2-onvl)-3-methvl butanovll amino-1.6-diphenylhexane. 5 In a 2L, 3-necked round-bottomed flask were combined the product of Example 24C (100 g, 0.22 mol), the product of Example 241 (44.8 g, 0.22 mol) and 750 ml DMF and the mixture was cooled in an ice/water bath. HOBT (90.9 g, 0.67 mol), EDAC (86 g, 0.45 mol) and triethylamine (62.5 ml, 0.45 mol) were added and the ice bath was removed, allowing the reaction mixture to stir with 20 warming to room temperature for 5h. The reaction was diluted with 1000 ml of IPAC and quenched with 1000 ml of water. The mixture was shaken and separated, the aq. layer was extracted 1x 400 ml IPAC, the organics were washed with 1x 400 ml 10% HCI, 1x 500 ml NaHCO3, diluted with 100 ml hexanes, then washed 4x 500 ml water, and 1x 500 ml brine, dried over 25 MgSO4, filtered and concentrated to provide the desired product as a white foam.

-88 (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetvl) amino-3-hydroxy-5-[2S-(1 tetrahvdro-ovrimid-2.4-dionyl)-3-methylbutanovllamino-1.6-dihenvlhe xane A. N-(2-Carbomethoxy) ethyl-L-Valine t-butyl ester. s To a solution of 1.73 g of L-Valine t-butyl ester in 10 ml of methanol was added 9.0 ml of methyl acrylate. The solution was heated to reflux overnight. Another 9.0 ml of methyl acrylate was added and continued the reflux for 24 h. The solvent was evaporated in vacuo and the crude product was purified by ,silica gel column chromatography (20% ethyl acetate in hexane) to provide 10 2.435 g of desired compound (93.9%). 300 MHz 1 H NMR (CDCl 3 ) 8 0.91 (d, J=3.5 Hz, 3H), 0.93 (d, J=3.5 Hz, 3H), 1.47 (s, 9H), 1.85 (m, 1 H), 2.47 (t, J=7 Hz, 2H), 2.68 (m, 1H), 2.81 (d, J=6 Hz, 1H), 2.95 (m, 1H), 3.68 (s, 3H). Mass spectrum: (M+H)+ = 260. B. N-(2-Carboxamido) ethyl-L-Valine t-butyl ester. '5 To a solution of 1.86 g of the product from Example 25A in 5 ml of THF was added 0.415 g of lithium hydroxide monohydrate in 10.8 ml of water. After 40 min, 10.8 ml of 1N HCI was added. The reaction mixture was evaporated to dryness and dry pyridine was added and evaporated to dryness two times. The residue was dissolved in 25 ml of acetonitrile and 0.62 ml of dry pyridine 20 added. To this solution was added 2.02 g of N,N'-disuccinimidyl carbonate. The reaction mixture was stirred for 3.5 h. The solvent was removed in vacuo and 90 ml of THF added followed by 1.43 ml of conc. ammonium hydroxide. The reaction was allowed to go overnight. The reaction mixture was filtered and the filtrate concentrated in vacuo. The residue was dissolved in ethyl acetate 25 and washed with sodium bicarbonate, brine and dried with anhy. sodium sulfate. After filtering off the drying agent, the filtrate was conc. in vacuo and the crude product was purified by silica gel column chromatography (5% MeOH in

CH

2 Cl 2 ) to give 1.19 g (68%) of desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 0.95 (d, J=7 Hz, 3H), 0.97 (d, J=7 Hz, 3H), 1.48 (s, 9H), 1.93 (m, 30 1 H), 2.37 (m, 2H), 2.65 (m, 1 H), 2.95 (m, 2H), 5.30 (br s, 1 H), 7.85 (br s, 1 H). Mass spectrum: (M+H)+=245.

-89 C. 2S-(1-Tetrahydro-pyrimid-2.4-dionyl)-3-methylbutanoic acid t-butvl ester. A solution of 0.92 g of the product from Example 25B in 10 ml of THF and 1.83 g of carbonyldiimidazole (CDI) was refluxed for 26 h. Then 1.83 g of CDI was again added and the solution was refluxed for 72 h more. The solvent 5 was evaporated in vacuo and the residue was dissolved in ethyl acetate and washed with water, satd. sodium bicarbonate, dilute hydrochloric acid and then brine. The organic layer was dried, filtered and conc. in vacuo. The crude product was purified by silica gel column chromatography (2% to 5% MeOH in

CH

2

CI

2 ) to give 0.54 g (52%) of desired compound. 300 MHz 1 H NMR 10 (CDCl 3 ) 5 0.96 (d, J=7 Hz, 3H), 1.05 (d, J=7 Hz, 3H), 1.48 (s, 9H), 2.20 (m, 1H), 2.66 (m, 2H), 3.43 (m, 1H), 3.75 (m, 1H), 4.63 (d, J=9 Hz, 1H), 7.35 (br s, 1H). Mass spectrum: (M+H)+=271. D. 2S-(1-Tetrahydro-pyrimid-2.4-dionvl)-3-methvlbutanoic acid. A solution of 0.53 g of the compound from Example 25C in 5 ml of is trifluoroacetic acid was stirred at 0*C for 1.25 h. Solvent was evaporated in vacuo, dried and purified by silica gel column chromatography (2% MeOH/4% HOAc in CH 2

CI

2 ) to give 0.36 g of desired compound. 300 MHz 1 H NMR (DMSO-d 6 ) 8 0.86 (d, J=7 Hz, 3H), 0.97 (d, J=7 Hz, 3H), 2.15 (m, 1H), 3.40 (m, 4H), 4.39 (d, J=10 Hz, 1H). Mass spectrum: (M+H)+=215. 20 E. (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetvl) amino-3-hydroxv-5-[2S-(1 tetrahvdro-pyri mid-2.4-dionvl)-3-methylbutanovl amino-1.6-diphenvlhexane. Coupling of the amino compound from Example 1 N with the acid from Example 25D using standard coupling procedure (EDAC in DMF) provided the desired compound (68%). 300 MHz 1 H NMR (CDCl 3 ) 6 0.83 (d, J=7Hz, 3H), 25 0.88 (d, J=7Hz, 3H), 1.80 (m, 2H), 2.20 (s, 6H), 2.40 (m, 1 H), 2.58 (m, 1 H), 2.80 (m,- 1H), 2.92 (m, 1H), 3.05 (m, 3H), 3.65 (d, J=5Hz, 1H), 3.83 (m, 1H), 4.20 (m, 5H), 6.18 (d, J=9Hz, 1H), 7.0-7.38 (m, 14H). Mass spectrum: (M+H)+=643.

-90 Examole 26a (2S.3S.5S)-2-(2.6-Dimethylohenoxvacetvl) amino-3-hydroxy-5[2S-(4-aza-1 tetrahydro-ovrimid-2-onyl-3-methyl-butanoyllamno-1.6-dinhenylhexane. A. N(1 -t-butvloxycarbonyl-N(2)-allyl hydrazine. s To a solution of 18.18 g of 1-butyloxycarbonyl protected hydrazine in 50 ml of acetonitrile was added 19.0 g of potassium carbonate, followed by 11.9 ml of allyl bromide. The reaction mixture was heated at reflux for a total of 3 h , filtered and conc. in vacuo. The residue was dissolved in ethyl acetate and washed with satd. sodium bicarbonate and dried with anhydrous sodium lo ,sulfate and filtered. After concentration in vacuo, the crude product was purified by silica gel column chromatography (20% EtOAc/hexane) to give 4.47 g of desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 1.45 (s, 9H), 3.46 (m, 2H), 4.0 (br s, 1H), 5.10 (m, 2H), 5.83 (m, 1H), 6.0 (br s, 1H). Mass spectrum: (M+H)+=173. is B. N(1)-t-butvloxvcarbonvl-N(2)-allyi-N(2)-benzyloxvcarbonyl hydrazine. To a solution of 4.8 g of the compound from Example 26A in 15 ml of DMF was added 4.69 g of benzyloxycarbonyloxy-succinimide. The reaction mixture was stirred at RT for 72 h and the solvent was evaporated in vacuo. The residue was dissolved in ethyl acetate, washed with satd. sodium 20 bicarbonate and dried with anhydrous sodium sulfate. The crude product obtained after concentration was purified by silica gel column chromatography (20% to 50% EtOAc in hexane) and provided 5.27 g of desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 1.43 (br s, 9H), 4.15 (br s, 2H), 5.18 (s, 2H), 5.20 (m, 2H), 5.82 (m, 1 H), 6.39 (br s, 1 H), 7.36 (m, 5H). Mass spectrum: 25 (M+H)+=307. C. N(1)-t-butvloxvcarbonyl-N(2)-formvlimethyl-N(2)-benzyloxvcarbonyl hydrazine. A solution of 6.5 g of the compound from Example 26B in 100 ml of methanol was cooled with a dry ice/acetone bath. Ozone was bubbled in for 30 1.75 h until a pale blue color persisted. Air was passed through the solution for 10 min and then 15.6 ml of dimethyl sulfide was added and the reaction -91 mixture was allowed to warm gradually to RT overnight. Solvent was evaporated in vacuo and the residue was dissolved in ethyl acetate and washed with water, then brine several times. The organic layer was dried with anhydrous sodium sulfate, filtered and conc. in vacuo to provide 7.2 g of the 5 desired compound. 300 MHz 1 H NMR (CDC1 3 ) 5 1.40 (br s, 9H), 4.35 (m, 2H), 5.20 (s, 2H), 6.65 (br s, 1 H), 7.36 (s, 5H), 9.70 (br s, 1 H). Mass spectrum:

(M+NH

4 )+=326. D. N-[2-(N-(2)-benxyloxvcarbonyl-N-(1)-t-butyloxvcarbonvlhydrazinvl) ethyl-L Valine methyl ester. 10 To a solution of 7.2 g of the compound from Example 26C in 100 ml of methanol was added 3.55 g of L-valine methyl ester hydrochloride, followed by 3.48 g of sodium acetate and 1.33 g of sodium cyanoborohydride. The reaction mixture was stirred at RT overnight. The mixture was filtered and concentrated in vacuo. The crude product was purified by silica gel column is chromatography (2% MeOH in CH 2

CI

2 ) to provide 5.8 g of desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 0.90 (d, J=6Hz, 6H), 1.43 (br s, 9H), 1.87 (m, 1H), 2.60-3.0 (m, 4H), 3.72 (s, 3H), 5.18 (s, 2H), 7.37 (m, 5H). Mass spectrum: (M+H)+=424. E. 2S-[4-benzyloxycarbonylaza-1-tetrahydro-nvrimid-2-onvil-3-methvl-butanoic acid methyl ester. A solution of 2.4 g of the compound from Example 26D in 20 ml of HCI in dioxane was stirred at RT under argon for 1 h. Solvent was evaporated in vacuo and the residue was washed with satd. sodium bicarbonate and extracted with ethyl acetate. The organic layer was dried, filtered and 25 concentrated in vacuo. The crude product was dissolved in 28 ml of CH 2

CI

2 and 0.56 g of carbonyldiimidazole was added. The solution was left at RT for 48 h. The solvent was removed and the residue was purified by silica gel column chromatography (10% to 30% EtOAc in CH 2

CI

2 ) to give 0.78 g of desired compound. 300 MHz 1 H NMR (CDC13) 5 0.90 (d, J=7Hz, 3H), 0.98 (d. 30 J=7Hz, 3H), 2.17 (m, 1H), 3.34 (m, 1H), 3.61 (m, 2H), 3.72 (s, 3H), 3.98 (m, 1H), 4.71 (d, J=1OHz, 1H), 5.20 (s, 2H), 6.72 (br s, 1H), 7.38 (m, 5H). Mass spectrum: (M+H)+=350.

-92 F. 2S-(4-Benzvloxycarbonvlaza-1-tetrahydro-pvrimid-2-onvl-3-methyl-butanoic 2cid Hydrolysis of 0.78 g of the compound from Example 26E using lithium hydroxide in aqueous dioxane provided 0.35 g of desired compound. 5 300 MHz 1 H NMR (CDCI 3 ) 5 0.85 (d, J=7Hz, 3H), 1.04 (d, J=7Hz, 3H), 2.40 (m, 1H), 3.40 (m, 1H), 3.50 (m, 1 H), 3.80 (m, 2H), 3.95 (d, J=10Hz, 1 H), 5.20 (s, 2H), 7.30 (s, 1H), 7.36 (s, 5H). Mass spectrum: (M+H)+=336. G. (2S.3S.5S)-2-(2.6-Dimethvlphenoxyacetvl) amino-3-hydroxv-5[2S (benzyloxvcarbonvlaza-1 -tetrahydro-pyrimid-2-onvl)-3-methyl-butanvllamino 1o 1.6-diphenvlhexane. Coupling of the amino compound from Example 1 N with the acid from Example 26F using standard coupling procedure (EDAC/DMF) provided the desired compound (36%). 300 MHz 1 H NMR (CDCl 3 ) 5 0.72 (d, J=7Hz, 3H), 0.83 (d, J=7Hz, 3H), 2.20 (s, 6H), 2.65 (m, 1H), 2.83 (m, 1H), 3.0-3.10 (m, 4H), is 3.90 (m, 1H), 6.65 (m, 1H), 7.0-7.35 (m, 18H). Mass spectrum: (M+H)+=764. H. (2S.3S.5S)-2-(2.6-Dimethylhenoxyacetvl) amino-3-hvdroxv-5r2S-(4-aza-1 tetrahydro-pvri mid-2-oxyl)-3-methyl-butanoylamino-1 .6-diphenvlhexane. Removal of the benzyloxycarbonyl protecting group of the compound from Example 26G by hydrogenolysis using 10% palladium on carbon as 20 catalyst provided the desired compound. 300 MHz 1 H NMR (CDCI 3 ) 6 0.83 (d, J=4.5Hz, 3H), 0.86 (d, J=4.5Hz, 3H), 1.80 (m, 1 H), 2.20 (s, 6H), 2.58 (m, 1 H), 2.67 (m, 1H), 2.90 (m, 2H), 3.0 (m, 2H), 3.80 (m, 1H), 4.20 (m, 3H), 6.72 (m, 1H), 7.0 (m, 2H), 7.20 (m, 11 H). Mass spectrum: (M+H)+=630.

-93 Example 27 (2S.3S.5S)-2-(2.6-Dmethylphenoxvacetvl) amino-3-hydroxy-5-[2S-(1 tetrahydro-Dvrimid-2-onvl)-3-methylbutanoyllamino-1 -nhenvl-6-methylheotane A. (2S.3S.5S)-2-Amino-3-hydroxy-5-(t-butyloxvcarbonvlamino)-1 -phenvl-6 5 methylhetane. Following the procedures described in Example 1A to Example 1F-1, but substituting isopropylmagnesium chloride for benzylmagnesium chloride in Example 1C provided the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 8 0.88 (d, J=7Hz, 3H), 0.92 (d, J=7Hz, 3H), 1.43 (s, 9H), 1.50-1.80 (m, 4H), 2.55 1o (m, 1H), 2.90 (m, 1H), 3.0 (m, 1H), 3.54 (m, 2H), 4.62 (m, 1H), 7.30 (m, 5H). Mass spectrum: (M+H)+=337. B. (2S.3S.5S)-2-(2.6-Dimethylohenoxvacetyl) amino-3-hvdroxy-5-(t butvloxvcarbonvlamino)-1 -nhenvl-6-methylheptane. Coupling of the amino compound from Example 27A with the acid from "5 Example 1H using standard EDAC coupling procedure provided the desired compound. 300 MHz 1 H NMR (CDC1 3 ) 8 0.85 (d, J=7Hz, 3H), 0.90 (d, J=7Hz, 3H), 1.43 (s, 9H), 1.70 (m, 2H), 2.20 (s, 6H), 3.03 (d, J=8Hz, 2H), 3.42 (m, 1H), 3.80 (m, 1 H), 4.20 (m, 2H), 4.22 (s, 2H), 4.55 (m, 1 H), 7.0 (m, 3H), 7.30 (m, 5H). Mass spectrum: (M+H)+=499. 20 C. (2S.3S.5S)-2-(2.6-Di methylohenoxvacetvll amino-3-hydroxy-5-amino-1 phenvl-6-methylheptane. Removal of the t-butyloxycarbonyl protecting group of the compound from Example 27B using the procedure of Example 1 N provided the desired compound. 300 MHz 1 H NMR (CDC1 3 ) 8 0.90 (d, J=3Hz, 3H), 0.94 (d, J=3Hz, 25 3H), 1.60 (m, 4H), 2.20 (s, 6H), 2.85 (m, 2H), 3.0 (m, 1 H), 3.85 (m, 1 H), 4.20 (m, 2H), 7.0 (m, 2H), 7.35 (m, 6H). Mass spectrum: (M+H)+=399. D. (2S.3S.5S)-2-(2.6-Di methvlohenoxvacetvl) amino-3-hvdroxv-5-[2S.(1 tetrahydro-pyriid-2-onyl- 3-methylbutanovilami no-1 -ohenvl-6-methylheotane. Coupling of the amino compound from Example 27C with the acid from 30 Example 2A using standard coupling procedure (EDAC/DMF) provided the -94 desired compound. 300 MHz 1 H NMR (CDCI 3 ) 8 0.88 (m, 12H), 1.67 (m, 2H), 1.90 (m, 1 H), 2.20 (s, 6H), 3.0 (d, J=8Hz, 2H), 3.22 (m, 4H), 3.67 (m, 1 H), 3.77 (m, 1 H), 4.20 (s, 2H), 4.40 (m, 1 H), 4.76 (m, 1 H), 7.0 (m, 3H), 7.30 (m, 5H). Mass spectrum: (M+H)+=581. Examlole 28 (2S.3S.5S)-2-(2.6-Dimethylphenoxvacetvl) amino-3-hydroxy-5-[2S-(1 tetrahydro-pvrimid-2.4-dionyl)-3-methylbutanoyllamino-1 -phenvl-6 methylhep~tane. Coupling of the amino compound from Example 27C with the acid from 1o Example 25D using standard coupling procedure (EDAC/DMF) provided the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 8 0.83 (d, J=7Hz, 6H), 0.92 (t, J=7Hz, 6H), 1.73 (m, 2H), 2.18 (s, 6H), 2.30 (m, 1H), 2.62 (m, 2H), 3.03 (m, 2H), 3.45 (m, 1 H), 3.55 (m, 1 H), 4.72 (m, 2H), 4.20 (m, 4H), 6.40 (br d, J=9Hz, 1 H), 7.0 (m, 3H), 7.30 (m, 5H), 7.62 (br s, 1H). Mass spectrum: (M+H)+=595. 15 Example 29. (2S.3S.5S)-2-(2.6-Dimethylphenoxyacetylamino-3-hydroxy-5-[2S-(1 -Diperazin 2.3-dionvf)-3-methvlbutanovllamino-1.6-diohenvlhexane. A. 2S-(4-benzvloxvcarbonyl-1 -piperazin-2.3-dionvl)-3-methvlbutanoic acid methyl ester. 20 To a solution of 0.77 g of N-(benzyloxycarbonylamino)-ethyl-L-Valine methyl ester in 20 ml of toluene and 10 ml of acetonitrile was added 0.79 g of oxalyl diimiidazole. The reaction mixture was kept at 50 0 C for 24 h and 0.2 g of oxalyl diimidazole was added. The reaction mixture was kept at 50 0 C for another 72 h. Evaporation of solvent in vacuo and purification of the crude 25 product by silica gel column chromatography (10% EtOAc in CH 2

CI

2 ) provided the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 0.95 (d, J=7 Hz, 3H), 1.03 (d, J=7Hz, 3H), 2.20 (m, 1H), 3.60 (m, 1H), 3.73 (s, 3H), 3.85 (m, 1H), 4.0 (m, 1H), 4.10 (m, 1H), 4.90 (d, J=10 Hz, 1H), 5.36 (s, 2H), 7.20 (m, 5H). Mass spectrum: (M+NH 4 )+=380. 30 B. 2S-(1 -Diperazin-2.3-dionvl)-3-methylbutanoic acid methyl ester.

-95 Removal of the benzyloxycarbonyl protecting group of the compound from Example 29A by hydrogenolysis using 10% Pd/C as catalyst provided the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 0.95 (d, J=7 Hz, 3H), 1.03 (d, J=7 Hz, 3H), 2.20 (m, 1H), 3.50 (m, 3H), 3.74 (s, 3H), 3.83 (m, 1H), 5.0 (d, 5 J=10 Jz, 1 H), 7.30 (br s, 1 H). Mass spectrum: (M+H)+=229. C. (2S.3S.5S)-2-(2.6-Dimethylohenoxvacetvl) amino-3-hvdroxv-5[2S-(1 piperazin-2.3-dionyl)-3-methylbutanoyllamino-1.6-diohenyhexane. The methyl ester from Example 29B was hydrolyzed using the procedure of Example 1M and the resulting acid was coupled to the amino compound 1o from Example 1 N using standard EDAC coupling procedure to provide the desired compound. 300 MHz 1 H NMR (CDCl 3 ) 5 0.82 (d, J=6 Hz, 3H), 0.85 (d, J=6 Hz, 3H), 1.80 (m, 2H), 2.18 (m, 1H), 2.20 (s, 6H), 2.65 (m, 1H), 2.82-3.0 (m, 4H), 3.30 (m, 3H), 3.70 (m, 1H), 3.82 (m, 1H), 4.22 (m, 3H), 4.54 (d, J=1 0 Hz, 1 H), 6.30 (br s, 1 H), 6.65 (br d, 1 H), 7.0-7.30 (m, 13H). Mass is spectrum: (M+H)+=643. E xample 30Q (2S.3S.5S)-2-(2.6-Di methylohenoxvacetvl) amino-3-hydroxv-5[2S-(4-aza-4.5 dehvdro-1 -pvrimid-2-onyl)-3-methyl-butanovllamino- 1.6-diohenylhexane. 20 A. 2S-(4-Aza-4.5-dehydro-1-oyrimid-2-onvyl-3-methyl-butanoic acid. From the hydroysis product mixture of Example 26F, the desired product was isolated after column chromatography (5% MeOH/5% AcOH in CH 2

CI

2 ) in 12.5% yield. 300 MHz 1 H NMR (CD 3 0D) 5 0.93 (d, J=7Hz, 3H), 1.04 (d, J=7Hz, 3H), 2.20 (m, 1H), 3.92 (dd, J=15, 3 Hz,, 1H), 4.09 (dd, J=15, 3 Hz, 1H), 4.50 (d, J=10 Hz, 1H), 6.95 (t, J=3Hz, 1H). Mass spectrum: (M+H)+=334. 25 B. (2S.3S.5S)-2-(2.6-Dimethvlohenoxvacetvl) amino-3-hydroxy-5[2S-(4-aza 4.5-dehydro-1-pvrimid-2-oxvl)-3-methyl-butanoyllamino-1 .6-diohenylhexane. Coupling of the compound from Example 1N with the acid from Example 30A using standard coupling procedure (EDAC/DMF) provided the desired compound (70%). 300 MHz 1 H NMR (CDCl 3 ) 8 0.80 (d, J=7Hz, 3H), 0.85 (d, 30 J=7Hz, 3H), 1.75 (m, 2H), 2.15 (m, 1H), 2.20 (s, 6H), 2.62 (m, 1H), 2.85 (m, 1H), -96 3.02 (m, 2H), 3.55 (m, 2H), 3.80 (m, 1 H), 4.20 (m, 4H), 6.38 (br d, 1 H), 6.72 (t, J=3 Hz,1H), 7.0 (m, 3H), 7.22 (m, 1OH), 7.63 (s, 1H). Mass spectrum: (M+H)+=628. E xample 31 cis-N-tert-butvl-decahydro-2-[ 2(R)-hydroxy-4-phenyl-3(S)-(2S-(1 tetrahvdropyrimid-2-onvl)-3-methylbutanoylaminobutyll-(4aS .8aS) isoouinoline-3(S)-carboxamide The title compound can be prepared by coupling the product of Example 2A with cis-N-tert-butyl-decahydro-2-[ 2(R)-hydroxy-4-phenyl-3(S)-aminobutyl) 1o (4aS,8aS)-isoquinoline-3(S)-carboxamide (disclosed in PCT Patent Application No. W09426749 and U.S. Patent No. 5,196,438, issued March 23, 1993, both of which are incorporated herein by reference) using a standard coupling procedure (EDAC in DMF). E xample 32 is cis-N-tert-butvl-decahydro-2-[ 2(R)-hydroxv-4-thiophenvl-3(S)-(2S-(1 tetrahvdropyrimid-2-onvl)-3-methylbutanovlIaminobutyll-(4aS.8aS) isoguinoline-3(S)-carboxamide The title compound can be prepared by coupling the product of Example 2A with cis-N-tert-butyl-decahydro-2-[ 2(R)-hydroxy-4-thiophenyl-3(S) 20 aminobutyl]-(4aS,8aS)-isoquinoline-3(S)-carboxamide (disclosed in PCT Patent Application No. W095/09843, published April 13, 1995 and U.S. Patent No. 5,484,926, issued January 16, 1996, both of which are incorporated herein by reference) using a standard coupling procedure (EDAC in DMF). E xample 33 25 4-Amino-N-(( 2syn. 3S)-2-hydroxy-4-phenyl-3-(2S-( 1 -tetrahydropyrimid-2 onyl-3-methylbutanovlamino)-butyl)-N-isobutyl-benzenesulfona mide The title compound can be prepared by coupling the product of Example 2A with 4-Amino-N-(( 2syn, 3S)-2-hydroxy-4-phenyl-3-amino)-butyl)-N-isobutyl benzenesulfonamide (disclosed in PCT Patent Application No. W094/05639, 30 published March 17, 1994, which is incorporated herein by reference) using a standard coupling procedure (EDAC in DMF).

-97 Example 34 A. Alternative Preparation of (2S, 3S. 5S) -2-(2,6-Dimethvlrhenoxvacetvl) amino- 3-hydroxy-5-amino-1 .6-diphenylhexane To a 1 liter 3-necked flask equipped with a mechanical stirrer, J-Kem@ 5 temperature probe. dropping addition funnel, and dry nitrogen line was charged 30.0 g (54.87 mmol) of the product of Example 11 and 120 mL of acetonitrile. The resultant slurry was cooled to 0-50C and 54.1 g (549 mmol) of 37% aqueous hydrochloric acid was slowly added, maintaining an internal temperature of not more than +5*C during the addition. The reaction mixture 10 was stirred at 0-50C and samples were taken periodically to analyze for consumption of starting material by HPLC (Zorbax C-8 column, mobile phase = 1:1 acetonitile/0.1% aqueous phosphoric acid, flow rate = 1.5 mL/minute, detection at 205 nm). After stirring for 3 hours the reaction was complete. The reaction was 15 quenched by the slow addition of 105 mL of 20% aqueous sodium hydroxide, again maintaining an internal temperature of not more than +5"C during the addition. Once the pH of the reaction mixture was confirmed to be basic, the solution was warmed to room temperature. Ethyl acetate (180 mL) was added with mixing and. after settling, the lower aqueous phase was separated and 20 discarded. The organic phase was then washed once with 105 mL of 10% aqueous sodium chloride. The title compound was crystallized from 12 mL/g of 1:2 ethyl acetate/heptane (yield 80-85%). 25 B. Alternative Preparation of (2S. 3S. 5S) -2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-amino-1.6-diphenylhexane To a round-bottom 3-neck 1 L flask with attached mechanical stirbar and thermometer was added the product of Example 11 (51.6 g, 0.095 mol) and 100 mL of glacial acetic acid. To the resulting suspension was added 35% aqueous HCI (10.5 mL. 0.103 mol) in 1 portion. The solution was allowed to stir under a 30 N 2 atmosphere for 3h, at which time an additional 10.5 mL of 35% aqueous HCI was added. After an additional 1.5h. the reaction flask was immersed in an ice -98 bath and a NaOH solution (16 mL, 0.198 mol) was added at a rate to maintain the internal temperature of the flask below 30 OC. Water (200 mL) was added and the mixture extracted with 4 x 200 mL of isopropyl Acetate. The combined organic layers were washed with 2.5M NaOH (2 x 200 mL), 100 mL H 2 0, brine, 5 dried over Na 2

SO

4 , filtered and evaporated in vacuo to yield 39.7g (94% crude) of product as a colorless solid in greater than 95% purity by HPLC. The product could be further purified by dissolving in 200 mL isopropanol heated over a steam bath, allowed to cool with stirring to 0-5 0C to yield 32.2g (76%) of the desired product, m.p. = 131 OC. 10 Example 35 Alternative Preparation of 2S-(1-Tetrahydro-Pyrimid-2-onyl)-3-methvl butanoic A. N-phenoxycarbonyl-L-valine N-phenoxycarbonyl-L-valine may be prepared according to the 15 procedures disclosed in U.S. Patent Application No. 08/08/671,893, filed June 28, 1996, which is incorporated herein by reference, and which include the following method. Into a reactor equipped with an overhead stirrer, chiller, pH probe and thermocouple was added lithium chloride (15.6 kg, 368 moles), L-valine (26.0 20 kg, 222 moles), neutral alumina (8.1 kg, 150 mesh, Aldrich) and 156 kg of distilled water. The heterogeneous mixture was stirred and cooled to -14CC + 50C. The pH was adjusted to 10.1 with 10% aqueous lithium hydroxide. Precooled (-20*C) phenyichlorformate (36.6 kg, 234 moles) was added while maintaining a temperature of not more than -9 0C and the pH was 25 controlled during the reaction (maintaining a pH within the range of 9.5 to 10.5 with a target of 10.0) using a continuous addition of 10% aqueous lithium hydroxide. The reaction was stirred for 2 hours at about -14 0C. The reaction mixture was filtered through Celite and the filter cake was washed with 42 kg of distilled 30 water. The aqueous filtrate was extracted with methyl t-butyl ether (65 kg) to remove residual phenol. The aqueous phase was then cooled to 0-50C and mixed with 200 kg of toluene. The stirred biphasic solution was adjusted to -99 pH 1.8-2.0 with 25% (w/w) sulfuric acid. The toluene layer was concentrated at not more than 40 0C to approximately 120 L, filtered (30 kg rinse of toluene) and then concentrated again at not more than 40 0C to approximately 120 L. To the resulting solution was added 44.2 kg of heptane and the resulting 5 solution was heated to 40 *C ± 10 C for 15 minutes. The heat was removed and the solution was seeded and stirred overnight. The product crystallized on the walls of the reactor and was resuspended in 80 kg of toluene, reconcentrated at not more than 50 *C to approximately 130 L, then 45.2 kg of heptane was added. The resulting solution was then heated to 40 *C ± 10"C io for not less than 15 minutes and then cooled at not more than 20 OC/hour to 18 0 C - 5'C. After not less than 12 hours, the resulting white slurry was cooled to 14 *C ± 50C and stirred for not less than 3 hours. The white slurry was filtered and the solid washed with 41 kg of 1:1 toluene/heptane. The solid product was dried at not more than 50 0C to provide the desired product (47.8 1s kg) as a white powder. B. 2S-(1-Tetrahvdro-pyrimid-2-onvl)-3-methyl butanoic acid A mixture of N-phenoxycarbonyl-L-valine (25 g, 0.106 mol) and 3-chloropropylamine hydrochloride (15.2 g, 0.116 mol) in THF (250 mL) was cooled to 20C. Sodium hydroxide (12.7 g, 0.318 mol) was added to the stirring 20 suspension. After about 35 minutes, a slow exotherm to 100C occurred. The reaction was stirred at less than 10 C for 2 hours. A solution of potassium t butoxide (29.6 g, 0.265 mol) in 125 mL of THF was added over 10 minutes, followed by a 20 mL THF rinse. The temperature of the reaction mixture was allowed to rise to 200C during the addition. The reaction mixture was stirred at 25 room temperature for 19 hours. The reaction mixture was quenched with 200 mL of distilled water and then acidified to pH 9 using 26.2 g of concentrated hydrochloric acid, keeping the temperature below 300C. The aqueous layer was separated and washed with another 125 mL of THF. Ethanol 3A (75 mL) was added to the separated 30 aqueous layer and the mixture was acidified to pH < 3 with 12.3 g of concentrated hydrochloric acid, keeping the temperature below 250C. The acidified mixture was extracted twice with ethyl acetate (250 mL and 150 mL). The combined organic layers were evaporated to dryness on a rotary -100 evaporator at a temperature below 500C. The residual solids were flushed with 250 mL of ethyl acetate. The residual solid was dissolved in 150 mL of ethanol 3A at reflux temperature and filtered through a 5 g Darco-G60 bed over filteraid, followed by a 50 mL hot ethanol rinse. The filtrate was evaporated to dryness 5 on a rotary evaporator at a temperature below 50"C. Ethyl acetate (75 mL) was added to the residue and refluxed for 30 minutes. The suspension was cooled to below 1 0 0 C for 2 hours. The solid was collected by filtration and washed with 20 mL of cold ethyl acetate (5-81C). After drying at 400C for 72 hours the desired product was obtained as a white solid (15.6 g, 74%). 0 Example 36 Alternative Preparation of 2S-(1 -Tetrahydro-pvrimid-2-onvl)-3-methvl butanoic acid A mixture of phenoxycarbonyl-L-valine (250 g, 1.05 mol; prepared according to the procedure disclosed in U.S. Patent Application No. 08/671,893, 15 filed June 28, 1996, which is incorporated herein by reference) and 3 chloropropylamine hydrochloride (151 g, 1.16 mol) in THF (2.5 L) is cooled to 20C. Sodium hydroxide (127 g, 3.2 mol) is added to the stirring suspension. After about 45 minutes, a rapid exotherm to 10C occurrs. The reaction is stirred at 1-5 0 C for 2 hours. Additional 3-chloropropylamine (10 g, 0.08 mol) is added 20 and stirring is continued for 1 hour. A solution of potassium t-butoxide (296 g, 2.6 mol) in 1.25 L of THF is then added over 30 minutes, followed by a 100 mL THF rinse. The temperature of the reaction mixture was allowed to rise to 20 0 C during the addition. The reaction mixture is stirred at room temperature for 12 16 hours. 25 The reaction mixture is quenched with 2 L of distilled water and cooled to 12"C and then acidified to pH 9 using 258 g (2.6 mol) of concentrated hydrochloric acid, keeping the temperature below 30*C. The aqueous layer is separated. Ethanol 3A (625 mL) is added to the separated aqueous layer and the mixture was acidified to pH < 3 with 116 g (1.2 mol) of concentrated 30 hydrochloric acid, keeping the temperature below 250C. The acidified mixture is extracted twice with ethyl acetate (2.5 L and 1.5 L). The combined organic layers are evaproated to dryness on a rotary evaporator at a temperature below -101 50 0 C. The residual solids are dried by repeated distillation with ethyl acetate (4 x 1 L). The residual solid is dissolved in 750 mL of methanol and treated with decolorizing carbon (10 g Darco-G60 bed) at room temperature overnight. The carbon is removed by filtration through diatomaceous earth. The filtrate is 5 evaporated to dryness on a rotary evaporator at a temperature below 50 0 C. Ethyl acetate (1.5 L) is added to the residue and approximately 500 mL is removed on the rotary evaporator. The suspension is cooled to below 1 0*C for > 1 hour. The solid is collected by filtration and washed with 2 x 100 mL of cold ethyl acetate (5-8"C). After drying at 50 0 C for 72 hours the desired product is 10 obtained. Example 37 Alternative Preparation of 2S-(1-Tetrahydro-pvrimid-2-onyl)-3-methyl butanoic agid A. (S-(-)-N-carboxvmethyl-N(B(cyanoethyl Valine '5 To a 5L 3-neck round bottom flask with a mechanical stirrer was added (S)-valine (170.1g, 1.45mol) and water 145mL. The solution was cooled to 0 0 C with an ice-water bath and a solution of 1.Oeq of KOH (93g of 88% solid KOH) in 180mL water was added dropwise over 20 minutes. After the addition was complete. acrylonitrile 1.Oeq (95.5mL) was added dropwise with vigorous 20 stirring while maintaining the internal temperature of the flask below 50C. The solution was allowed to stir between 0-50C for 4.5h. Water (600mL) was added and a pH meter was inserted into the solution. Methyl chloroformate 1.Oeq (112mL) was added dropwise while maintaining the pH of the solution between 9.5 and 10.5, with solution of 10% aq KOH. The addition took place 25 over 0.5h. The solution was then acidified with conc. HCI and phosphoric acid to pH 2 and was subsequently extracted with 2L of isopropyl acetate. The organic layer was concentrated under vacuum to give 201 g (60%) of a colorless oil that solidified on standing. mp 65-660C. Optical rotation sodium D line at 25 0 C -0.44 (c=4.3, ethanol). IR (cm-1, CDCI3) 2960, 1740, 1710,1470. 30 1 H NMR (300 MHz,CDCI 3 ); (6 TMS, 0.00) ppm 0.93 (d,3H J=7Hz); 1.07 (d,3H J=6Hz); 2.16-2.36 (m,1H); 2.62-2.86 (m,2H); 3.62 (t,2H. J=7.5Hz); 3.77 (s,1.2H -102 rotamer); 3.82 (s,1.8H rotamer); 4.15-4.30 (m,1H); 9.76-9.96 (brs,1H). ms (DCI/NH3) 246, 185, 146, 125. FAB hrms: cal for (M+H+): 229.1188; found: 229.1185. B. 2S-(1 -Tetrahydro-pyrimid-2-onyl)-3-methyl butanoic acid 5 To a 2L pressure vial was added the product of Example 37A (190g, 0.833 mol), water (900mL) and KOH (3eq, 140g). To this solution at ambient 'temperature was added Nickel Aluminum alloy (Raney-Type) 75g. Note that this is the unactivated form. The solution was sealed in a pressure bomb and was placed under 60 psi of hydrogen. The resulting solution was heated to 10 1000C for 4h. After cooling the solution to ambient temperature, it was filtered, washed with 900mL of dichloromethane and subsequently acidified to pH 1. The aqueous solution was extracted with 2 X 900mL of dichloromethane. The combined organic layers were concentrated to give 120g of crude product which was slurried in isopropyl acetate to give 70g of the title compound. 1s E xample 38 Alternative Preparation of (2S. 3S. 5S)-2-(2.6-Dimethylohenoxvacetvl) amino-3 hvdroxv-5-[2S-(1 -tetrahydro-Dyrimid-2-ony)-3-methyl butanovll amino-1 .6 diphenlhexane A-1. 2S-(1-Tetrahydro--pyrimid-2-onyll-3-methvl butanoyl chloride 20 2S-(1-Tetrahydro-pyrimid-2-onyl)-3-methyl butanoic acid (17.6 g, 87.9 mmole) was slurried in THF (240 mL) and cooled to <5 0 C. Thionyl chloride (14.3 g, 120 mmole) was added over 5 minutes (exothermic). The slurry was stirred at 20 OC for 70 min. until complete by HPLC (samples quenched into methanol). THF was removed by rotary evaporation; heptane (90 mL) was 25 added and removed by rotary evaporation, yielding a wet solid mass. The material was slurried in DMF (85 mL). A-2. Alternative Preoaration of 2S-(1-Tetrahydro-ovrimid-2-onyll-3-methyl butanoyl chloride 2S-(1-Tetrahydro-pyrimid-2-onyl)-3-methyl butanoic acid (39.6 g, 198 30 mmole) was slurried in THF (590 mL) and cooled to 1 *C. Thionyl chloride -103 (28.3 g, 238 mmole) was added over 5 minutes (exothermic). The slurry was stirred at 20 C for 2 hours. THF was removed on the rotary evaporator; THF (200 mL) was added and removed on the rotary evaporator, yielding a wet solid mass. The material was slurried in DMF (225 mL). 5 B-1. (2S. 3S. 5S) -2-N.N-dibenzylamino-3-hydroxv-542S-(1 -tetrahvdro-rirrmid 2-onvl)-3-methyl butanovil amino-1.6-diphenylhexane (2S, 3S, 5S)-2-N,N-dibenzylamino-3-hydroxy-5-amino-1,6 diphenylhexane (ca. 83 mmole; U.S. Patent No. 5,491,253, issued February 13, 1996, which is incorporated herein by reference) and imidazole (8.2 g, 120 1o mmole) were dissolved in ethyl acetate (350 mL, KF < 0.1%) and cooled to 2 OC. The slurried product of Example 38A-1 was added (exothermic, maximum temp. was 10 "C), followed by a DMF rinse (15 mL). The reaction was stirred cold initially then allowed to slowly warm to room temperature and stirred overnig ht. The reaction was quenched with 100 mL water and stirred 30 minutes. The organic layer was separated and washed with 3 x 125 mL 5% NaCl. The organic solution was filtered and concentrated on rotary evaporator to a thick syrup, 62 g. HPLC purity approx. 85% (peak area). Isomer content approx. 11.2%. 20 CIMS (NH 3 ) m/z 647 (M + H)+. 1 H NMR (300 MHz, CDC13) 8 7.35-7.13 (m, 10H), 7.13-7.06 (m, 1H), 6.87 (br d, 1H), 5.22 (br s, 1H), 4.28 (d, 1H), 4.20-4.05 (m, 1H), 3.95 (d, 2H), 3.65-3.56 (m, 1 H), 3.37, (d, 2H), 3.12-2.89 (m, 5H), 2.83-2.53 (m, 4H), 2.23-2.08 (m, 1H), 1.74-1.40 (m, 4H), 0.87-0.75 (m, 6H). 25 13C NMR (75 MHz, CDC13) 8 170.0, 156.6, 140.2, 139.1, 138.4, 129.3, 129.1, 128.9, 128.4, 128.3, 128.0, 127.1, 126.0, 125.8, 69.1, 64.0, 63.1 (br), 54.2, 49.2, 41.2, 40.5, 40.0, 39.7, 31.5, 25.4, 21.6, 19.5, 18.6.

-104 B-2. Alternative Preparation of (2S. 3S. 5S)-2-NN-dibenzylamino-3-hydroxv-5 f2S-(1-tetrahydro-Dyrimid-2-onyl)-3-riethYl butanoyll amino-1.6-diphenvlhexane (2S, 3S, 5S)-2-N,N-dibenzylamino-3-hydroxy-5-amino-1,6 diphenylhexane (ca. 180 mmole; U.S. Patent No. 5,491,253, issued February 5 13, 1996, which is incorporated herein by reference) and imidazole (38.1 g, 560 mmole) were dissolved in ethyl acetate (675 mL, KF < 0.1%) and cooled to 1 *C. The slurried product of Example 38A-2 was added slowly over 30 minutes (exothermic, maximum temp. was 6 *C), followed by an ethyl acetate rinse (225 mL). The reaction was stirred cold for 1. 5 hours, then allowed to 10 slowly warm to about 27 0 C and stirred for about 20 hours. The reaction was quenched with a dilute solution of HCI (36.75 g concentrated HCI in 225 mL of water) and stirred 20 minutes. The biphasic mixture was filtered with a 100 mL ethyl acetate rinse. The organic layer was separated and washed with 3 x 125 mL 5% NaCl. The organic layer was is separated and washed with 3 x 225 mL 5% NaCI and 2 x 225 mL 5% NaHCO 3 . The organic solution was concentrated by rotary evaporation to provide the desired product as a thick syrup. C. (2S. 3S. 5S)-2-Amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2-onvl)-3 methyl butanoyll amino-1.6-diphenylhexane 20 The crude product of Example 38B (ca. 83 mmole) was dissolved in methanol (260 mL). Pd/C (50% wet Pearleman's catalyst, 10.4 g wet weight) and ammonium formate (15.1 g, 239 mmole) were added and the mixture was warmed to 50 *C. After 2.5 hours the reaction was complete by TLC. The mixture was cooled to 35 0C and catalyst was removed by filtration through 25 diatomaceous earth. followed by a methanol rinse (250 mL). The combined filtrate was concentrated on the rotary evaporator. The residue was dissolved in dioxane (150 mL) with warming. Dioxane was removed on the rotary evaporator to yield 60 g of yellow oil. HPLC purity approx. 88.2% (peak area). Isomer content 27.9% (however, one isomer does not separate from the main 30 peak).

-105 CIMS (NH 3 ) m/z 467 (M + H)+ 1 H NMR (300 MHz, CD 3 0D) 5 7.35-7.10 (m, 10H), 4.40-4.20 (m, 1H), 4.25 (d, 1 H), 3.68-3.57 (m, 1 H), 3.20-3.09 (m, 2H), 3.08-2.90 (m, 3H), 2.90-2.74 (m, 2H), 2.65-2.49 (m, 2H), 2.20-2.04 (m, 1 H), 1.92-1.78 (m, 1 H), 1.78-1.60 (m, 2H), 5 1.60-1.45 (m. 1 H), 0.88-0.77 (m, 6H) 13 C NMR (75 MHz, CD 3 0D) 6 171.3, 158.4, 140.5, 139.8, 130.6, 130.4. 129.5, 129.3, 127.3, 127.0, 71.5, 63.9. 57.1, 49.1, 41.8, 41.6, 41.4, 40.7, 40.5, 26.9, 22.5, 20.0, 18.9 1 H NMR (300 MHz, CDCl 3 ) 5 7.35-7.13 (m, 1OH). 5.35 (s, 1H), 4.40-4.23 (m, 10 2H), 3.60-3.52 (M. 1 H), 3.25-2.65 (m, 8H), 2.58-2.45 (dd, 1H), 2.30-2.10 (m, 1H), 1.90-1.65 (m, 3H), 1.65-1.50 (m, 1H), 0. 91 (d, 3H), 0.84 (d, 3H) 13C NMR (75 MHz, CDCl 3 ) 6 171.2, 156.6, 139.1, 138.5, 129.3, 129.2, 128.5, 128.2, 126.3, 126.0, 71.6, 63.1 (br), 56.3, 48.7, 41.6, 41.0, 40.6, 40.0, 39.6, 25.5, 21.7, 19.7, 18.7 5 D, (2S. 3S. 5S)-2-Amino-3-hydroxy-5-[2S-(1-tetrahydro-pyrimid-2-onyl)-3 methyl butanoyll amino-1.6-diphenylhexane (S)-Pyroglutamic acid salt The crude product of Example 38C was dissolved in dioxane (370 mL, KF = 0.07% moisture). S-Pyroglutamic acid (10.3 g, 80 mmole) was added and the suspension was warmed to 50 0C to give a clear solution. After stirring 1 20 hour the solution was seeded with a few crystals of the product salt. The salt slowly precipitated. The slurry was slowly cooled and stirred overnight at room temperature. The product was isolated by filtration and washed with dioxane (100 mL). Wet cake weight was 120 g. Product was dried at 60 *C in a vacuum oven with nitrogen purge. Yield 35.2 g off-white powder. HPLC purity: >98% 25 (peak area including pyroglutamic acid). Isomer content approx. 1% (however, one isomer does not separate from the main peak). mp = 135-141 OC -106 [a]D 2 5 = -21.90 (c=2.5, CH 3 0H) CIMS (NH 3 ) m/z 467 (M + H for base)+, 147 (M + NH 4 for pyroglutamic acid)+, 130 (M + H for pyroglutamic acid)+ IR (KBr) 1586, 1655, 1682 cm- 1 s 1H NMR (400 MHz, DMSO-d 6 ) 6 7.62 (s, 1H), 7.54 (d, 1H), 7.32-7.06 (m, 10 H), 6.33 (s, 1H), 4.26 (d, 1H), 4.11-3.99 (m, 1H), 3.82 (dd, 1H), 3.57-3.48 (m, 1H), 3.27-3.19 (m, 1 H), 3.08-2.95 (m, 2H), 2.92-2.70 (m, 5H), 2.53-2.43 (m, 1 H), 2.26-2.14 (m, 1H), 2.13-1.99 (m, 2H), 1.99-1.87 (m, 2H), 1.72-1.61 (m, 2H), 1.61-1.49 (m, 1H), 1.46-1.35 (m, 1 H), 0.70 (d, 3H), 0.64 (d. 3H). io 13 C NMR (100 MHz, DMSO-d 6 ) 8 176.9, 176.1, 169.2, 155.5, 138.8, 137.7, 129.3, 129.3, 128.3, 127.8, 126.4, 125.5, 66.9, 61.5, 56.9, 55.3, 46.8, 40.2, 39.6, 39.4, 38.8, 37.4, 29.8, 25.4, 25.3, 21.6, 19.6, 18.7. 1 H NMR (300 MHz, CD 3 OD) 5 7.32-7.03 (m, 1OH), 4.23-4.12 (m, 1H), 4.12 (d, 1H), 3.98 (dd, 1 H), 3.71-3.63 (m, 1H), 3.46-3.37 (m, 1H), 3.11-2.98 (m, 2H), s5 2.97-2.80 (m, 4H), 2.70-2.59 (m, 1H), 2.49-2.38 (m, 1H), 2.38-2.12 (m, 3H), 2.07-1.92 (m, 2H), 1.75-1.63 (m, 2H), 1.63-1.50 (m, 1H), 1.45-1.32 (m, 1 H), 0.74-0.65 (m, 6H). 13C NMR (75 MHz, CD 3 0D) 5 181.0, 179.6, 171.6, 158.4, 139.5, 137.3, 130.5, 130.0, 129.4, 128.3, 127.2, 68.1, 64.0, 59.6, 57.7, 48.8, 41.7, 41.1, 40.7, 40.6, 20 37.9, 31.1, 26.9, 26.9, 22.5, 20.1, 18.9. 1 H NMR (300 MHz, D 2 0) 8 7.30-6.97 (m, 10H), 4.16-4.03 (m, 1H), 3.99-3.91 (m, 2H). 3.71-3.63 (m, 1 H), 3.43-3.35 (m, 1 H), 3.00-2.68 (m, 6H), 2.40-2.13 (m, 5H), 1.88-1.72 (m, 3H), 1.68-1.56 (m, 1H), 1.52-1.37 (m, 1H), 1.32-1.18 (m, 1H), 0.60-0.52 (m. 6H).

-107 13 C NMR (75 MHz, D 2 0) 5 181.6, 180.1, 171.0, 157.3, 137.9, 135.2, 129.3, 129.2, 129.1, 128.4, 127.6, 126.4, 67.3, 62.6, 58.2, 56.7, 47.5, 40.1, 39.4, 39.2, 38.7, 35.7, 29.6. 25.3, 25.2, 20.5, 18.5, 17.6. E. (2S, 3S. 5S)-2-(2.6-Dimethylphenoxyacetvyl amino-3-hydroxv-5-42S-(1 5 tetrahydro-pvrimid-2-onv i)-3-methyI butanovll amino-1 .6-diphenvihexane The product of Example 1H (7.26 g, 40.3 mmole) was slurried in ethyl acetate (22 mL) and thionyl chloride (5.75 g, 48.3 mmole) was added, followed by 1 drop DMF. The mixture was warmed to 50 *C and stirred 5 hours. The solution of the resulting acid chloride was cooled to 22 *C and held for the 10 subsequent coupling reaction. The product of Example 38D (20 g, 31.7 mmole, corrected for dioxane contend), sodium bicarbonate (16.5 g, 197 mmole), ethyl acetate (150 mL) and water (150 mL) were combined in a flask and stirred until the product of Example 38D had dissolved (some salt remains undissolved). The solution of is acid chloride prepared above was added over 5 minutes, followed by an ethyl acetate rinse (5 mL). Addition was mildly exothermic (maximum temperature 23 *C). The mixture was stirred overnight. The organic layer was separated and washed with 5% sodium bicarbonate (100 mL) and water (100 mL). Solvent was removed on the rotary 20 evaporator. The residue was dissolved in ethyl acetate (100 mL) and filtered, rinsing with ethyl acetate (50 mL). The solvent was removed from the combined filtrate on the rotary evaporator. The residue was dissolved in hot ethyl acetate (105 mL) and heptane (105 mL) was added; product began to crystallize rapidly. The slurry was cooled and stirred at 20-23 *C for 5 hours. Product was 25 collected by filtration and washed with 1/1 (v/v) ethyl acetate/heptane (30 mL). Product was dried under vacuum oven at 70 0 C to provide 18.8 g of the desired product as a white powder. Example 39 -108 Preparation of Amorphous (2S. 3S. 5S)-2-(2.6-Dimethylphenoxvacetvl) amino 3-hydroxv-5-r2S-( -tetrahydro-DYrimid-2-ony l)-3-methyl butanovil amino-1.6 diohenvlhexane A. The product of Example 38E (2.5 g) was dissolved in 8 mL of absolute 5 ethanol. This solution was added slowly dropwise to 250 mL of chilled water at 90C with vigorous stirring. A white solid immediately appeared. The stirring was continued for 15 minutes and the solids were collected by filtration. Vacuum drying at 500C for 12 hours provided 2.32 g of the desired product as an amorphous solid. 10 B. The product of Example 38E (2.5 g) was dissolved in 6 mL of absolute ethanol. This solution was added slowly dropwise to 31 mL of chilled water at 7-90C with vigorous stirring. A white solid appeared. The stirring was continued for 20 minutes and the solids were collected by filtration. Vacuum drying at 500C for 12 hours provided 2.24 g of the desired product as an amorphous 15 solid. C. The product of Example 38E (0.5 g) was dissolved in 8 mL of isopropanol. This solution was added slowly dropwise to 100 mL of chilled water at 10-15*C with vigorous stirring. A white solid appeared. The stirring was continued for 20 minutes and the solids were collected by filtration. Air 20 drying provided 0.48 g of the desired product as an amorphous solid. D. The product of Example 38E (0.5 g) was dissolved in 8 mL of acetone and 0.2 mL of absolute ethanol. This solution was added slowly dropwise to 100 mL of chilled water at 10-15 0 C with vigorous stirring. A white solid appeared. The stirring was continued for 10 minutes and the solids were 25 collected by filtration. Air drying provided 0.46 g of the desired product as an amorphous solid. E. The product of Example 38E (0.5 g) was dissolved in 2 mL of acetonitrile. This solution was added slowly dropwise to 100 mL of chilled water -109 at 10-15'C with vigorous stirring. A white solid appeared. The stirring was continued for 20 minutes and the solids were collected by filtration. Air drying provided 0.46 g of the desired product as an amorphous solid. E example 40 N-(3-Chloropropylaminocarbonyl)-valing methyl ester 3-Chloropropylisocyanate (0.31 mL, 3.0 mmol) was added to a slurry of L-valine methyl ester hydrochloride (0.5 g, 3.0 mmol) and triethylamine (0.42 mL, 3.0 mmol) in THF (10 mL). The reaction mixture was stirred for 4 hours at room temperature and was then quenched with the addition of aqueous sodium o0 bicarbonate. The quenched reaction mixture was extracted with ethyl acetate. The organic layer was separated, dried and evaporated to give the desired product. Example 41 (2S. 3S. 5S)-2-(2.6-Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1 is tetrahydro-4-hydroxy-pyrimid-2-onyl)-3-methyl butanoyll amino-1.6 diphenylhexane Reaction of a solution of the product of Example 25E in methylene chloride with sodium borohydride provides the desired product. Example 42 20 (2S. 3S. 5S)-2-(2.6-Dimethylphenoxvacetvl) amino-3-hydroxv-5-[2S-(1 tetrahydro-6-hydroxy-pyrimid-2-onyl)-3-methyl butanoyll amino-1 .6 diphenvlhexane A 300-mL incubation of (2S, 3S, 5S)-2-(2,6 Dimethylphenoxyacetyl) amino-3-hydroxy-5-[2S-(1 -tetrahydro-6 25 hydroxy-pyrimid-2-onyl)-3-methyl butanoyl] amino- 1,6-diphenylhexane labelled with 14C in the carbonyl group of the acetyl moiety (50 gM, 6.0 pCi) was performed with ral liver microsomes (0.5 mg/mL microsomal protein) and an NADPH-generating system for 60 minutes at 370C. The metabolic reaction was stopped by adding 300 mL of acetonitrile. The 30 supernatant obtained after centrifugation at 3000 RPM for 10 minutes -110 was evaporated to dryness in vacuo. The residue was reconstituted in 2 mL of HPLC mobile phase. Isolation of the desired product was achieved at ambient temperature with a Beckman Ultrasphere 5 pm 10 x 150 mm C18 column connected to an Alltech Ultrasphere 5 pm s C18 cartridge guard column. A linear gradient of 25-55% acetonitrile in buffer (25 mM ammonium acetate, pH adjusted to 4.8 with formic acid) over 57 minutes was used as column eluent at a flow rate of 2.8 mL/minute. Fluoronenic Assay for Screenin, Inhibitors of HIV Protease 10 The inhibitory potency of the compound of the invention can be determined by the following method. The compound of the invention is dissolved in DMSO and a small aliquot further diluted with DMSO to 100 times the final concentration desired for testing. The reaction is carried out in a 6 X 50 mm tube in a total volume of 300 15 microliters. The final concentrations of the components in the reaction buffer are: 125 mM sodium acetate, 1 M sodium chloride, 5 mM dithiothreitol, 0.5 mg/ml bovine serum albumin, 1.3 pM fluorogenic substrate, 2% (v/v) dimethylsulfoxide, pH 4.5. After addition of inhibitor, the reaction mixture is placed in the fluorometer cell holder and incubated at 300C for several minutes. 20 The reaction is initiated by the addition of a small aliquot of cold HIV protease. The fluorescence intensity (excitation 340 nM, emmision 490 nM) is recorded as a function of time. The reaction rate is determined for the first six to eight minutes. The observed rate is directly proportional to the moles of substrate cleaved per unit time. The percent inhibition is 100 X (1 - (rate in presence of 25 inhibitor)/(rate in absence of inhibitor)). Fluorogenic substrate: Dabcyl-Gaba-Ser-Gln-Asn-Tyr-Pro-lie-Val-Gln EDANS wherein DABCYL = 4-(4-dimethylamino-phenyl)azobenzoic acid, Gaba = y-aminobutyric acid, and EDANS = 5-((2-aminoethyl)amino) naphthalene-1-sulfonic acid.

-111 Table 1 Compound of Percent Inhibitor Concentration Example inhibition (nanomolal 1P 92.6 0.5 s 2B 93.2 0.5 3C 86.9 0.5 4F 49.7 0.5 5 80.8 0.5 6F 61.4 0.5 10 7B 67.1 0.5 8 55.6 0.5 9B 62.6 0.5 1OF 81.0 0.5 15 11B 91.1 0.5 12B 76.8 0.5 13B 56.2 1.0 14D 52.7 0.5 15 48 0.5 20 17C 87.2 0.5 18C 57.8 0.5 19E 68.5 0.5 22E 71.8 0.5 23C 86.0 0.5 25 25E 100 0.5 26H 94.6 0.5 27D 92.9 0.5 28 86.6 0.5 29C 72.6 0.5 30B 91.0 0.5 -112 Antiviral Activity The anti-HIV activity of the compound of the invention can be determined in MT4 cells according to the following procedure. MT4 cells were infected with cell-free supernatant of HIVIIIB (previously frozen with known 50% tissue culture 5 infectious dose (TCID 50 ) at 0.003 multiplicity of infection (MOI) for one hour. After one hour infection, cells were washed twice to remove residual viruses, resuspended in culture media and seeded into 96-well tissue culture plates at 1x1 0A4 cells per well with various half-log dilutions of compounds. Uninfected cells are included as toxicity and cell controls. RPMI 1640 media (Gibco ) with 10 10% fetal bovine serum were used as culture media. Various concentrations of human serum (Sigma) 50%, 25% and 12.5% were added to culture media resulting in final concentration of 60%. 35% and 22.5% total serum All assay plates were incubated in 37 deg. cent. incubator for 5 days. MTT (sigma. 5 mg/ml stock in PBS) was added to all wells at 25 ul per well, incubate for 4 is hours. 20%SDS with 0.02 N HCI in water was added at 50 ul per well to lyse cells. Plates incubated overnight for complete lyses were read on a microtitre plate reader at 570/650 nm wavelengths to determine cell optical density (O.D.). Raw data were analysed for percent inhibition by the following formula: O.D. test well - O.D. virus control x1OO 20 O.D. cell control -0.D. virus control The 50% effective concentration (EC 5 0) was calculated by the median effect equation (Chou, 1975,Proc. Int. Cong. Pharmacol. 6th p. 619) to determine the efficacy of compound. The 50% lethal concentration (LC 5 o) was calculated using uninfected MT4 cells. 25 Under these conditions, the following data were obtained (n = 4 duplicate determinations: -113 Table 2 Compound of

IC

50 LC 50 Example (pIM._0% Ulasma) .(M) 1 P 0.01 41.32 5 2B 0.016 17.78 3C 0.025 49.5 4F 0.101 >100 5 0.368 >100 6F 0.193 >100 10 7B 0.204 >100 8 0.019 17.78 98 0.272 19.33 1OF 0.047 91.97 118 0.19 18.16 15 12B 0.093 19.11 14D 0.053 >100 15 0.119 >100 17C 0.051 18.96 18C 0.329 19.1 20 19E 0.395 17.95 20D 0.283 24.08 25E 0.012 22.88 26H 0.015 33.0 27D 0.03 56.23 25 28 0.011 72.2 29C 0.427 56 30B 0.003 18 The compounds of the present invention can be used in the form of salts derived from inorganic or organic acids. These salts include but are not limited 30 to the following: acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate, -114 digluconate, cyclopentanepropionate, dodecylsulfate, ethanesulfonate, glucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxy ethanesulfonate (isethionate), lactate, maleate, methanesulfonate, nicotinate, 5 2-naphthalenesulfonate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, p-toluenesulfonate and undecanoate. Also, the basic nitrogen containing groups can be quaternized with such agents as loweralkyl halides, such as methyl, ethyl, propyl, and butyl chloride, bromides, and iodides: dialkyl 10 sulfates like dimethyl, diethyl, dibutyl, and diamyl sulfates, long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides, aralkyl halides like benzyl and phenethyl bromides. and others. Water or oil soluble or dispersible products are thereby obtained. Examples of acids which may be employed to form pharmaceutically 15 acceptable acid addition salts include such inorganic acids as hydrochloric acid, sulphuric acid and phosphoric acid and such organic acids as oxalic acid, maleic acid, succinic acid and citric acid. Other salts include salts with alkali metals or alkaline earth metals, such as sodium, potassium, calcium or magnesium or with organic bases. 20 Preferred salts of the compounds of the invention include hydrochloride, methanesulfonate, sulfonate, phosphonate and isethionate. The compounds of the present invention can also be used in the form of esters. Examples of such esters include compounds wherein a hydroxyl group in the compound of this invention has been acylated with an N-protected or 25 unprotected amino acid residue, a phosphate function, a hemisuccinate residue, an acyl residue of the formula R*C(O)- or R*C(S)- wherein R* is hydrogen. loweralkyl, haloalkyl, alkoxy, thioalkoxy, alkoxyalkyl, thioalkoxyalkyl or haloalkoxy, or an acyl residue of the formula Ra-C(Rb)(Rd)-C(O)- or Ra-C(Rb)(Rd)-C(S)- wherein Rb and Rd are independently selected from 30 hydrogen or loweralkyl and Ra is -N(Re)(Rf), ORe or -SRe wherein Re and Rf are independently selected from hydrogen. loweralkyl and haloalkyl, or an amino-acyl residue of the formula R18oNH(CH 2

)

2

NHCH

2 C(O)- or R1 8 oNH(CH 2

)

2 0CH 2 C(O)- wherein R1 8 is hydrogen, loweralkyl, arylalkyl, 35 cycloalkylalkyl, alkanoyl, benzoyl or an a-amino acyl group. The amino acid -115 esters of particular interest are glycine and lysine; however, other amino acid residues can also be used, including those wherein the amino acyl group is

-C(O)CH

2

NR

20 0

R

201 wherein R 200 and R201 are independently selected from hydrogen and loweralkyl or the group -NR 20 0

R

201 forms a nitrogen containing 5 heterocyclic ring. These esters serve as pro-drugs of the compound of the present invention and serve to increase the solubility of these substances in the gastrointestinal tract. These esters also serve to increase solubility for intravenous administration of the compound. Other prodrugs include compounds wherein a hydroxyl group in the compound of this invention is lo functionalized with a substituent of the formula -CH(Rg)OC(O)R 1 1 or -CH(Rg)OC(S)R1 8 1 wherein R 181 is loweralkyl, haloalkyl, alkoxy. thioalkoxy or haloalkoxy and Rg is hydrogen, loweralkyl, haloalkyl, alkoxycarbonyl, aminocarbonyl. alkylaminocarbonyl or dialkylaminocarbonyl. Such prodrugs can be prepared according to the procedure of Schreiber (Tetrahedron Lett. ' 1983, 24, 2363) by ozonolysis of the corresponding methallyl ether in methanol followed by treatment with acetic anhydride. The prodrugs of this invention are metabolized in vivo to provide the compound of this invention . The preparation of the prodrug esters is carried out by reacting the compound of the invention with an activated amino acyl, 20 phosphoryl, hemisuccinyl or acyl derivative as defined above. The resulting product is then deprotected to provide the desired pro-drug ester. Prodrugs of the invention can also be prepared by alkylation of the hydroxyl group with (haloalkyl)esters. transacetalization with bis-(alkanoyl)acetals or condensation of the hydroxyl group with an activated aldehyde followed by acylation of the 25 intermediate hemiacetal. The compounds of the invention are useful for inhibiting retroviral protease. in particular HIV protease, in vitro or in vivo (especially in mammals and in particular in humans). The compounds of the present invention are also useful for the inhibition of retroviruses in vivo, especially human 30 immunodeficiency virus (HIV). The compounds of the present invention are also useful for the treatment or prophylaxis of diseases caused by retroviruses, especially acquired immune deficiency syndrome or an HIV infection in a human or other mammal.

-116 Total daily dose administered to a human or other mammal host in single or divided doses may be in amounts, for example, from 0.001 to 300 mg/kg body weight daily and more usually 0.1 to 20 mg/kg body weight daily. Dosage unit compositions may contain such amounts of submultiples thereof to make up the 5 daily dose. The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. It will be understood, however, that the specific dose level for any 10 particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination, and the severity of the particular disease undergoing therapy. The compounds of the present invention may be administered orally, 15 parenterally, sublingually, by inhalation spray, rectally, or topically in dosage unit formulations containing conventional nontoxic pharmaceutically acceptable carriers, adjuvants, and vehicles as desired. Topical administration may also involve the use of transdermal administration such as transdermal patches or iontophoresis devices. The term parenteral as used herein includes 20 . subcutaneous injections, intravenous, intramuscular, intrasternal injection, or infusion techniques. Injectable preparations, for example, sterile injectable aqueous or oleagenous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile 25 injectable preparation may also be a sterile injectable solution or suspension in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-propanediol. Among the acceptable vehicles and solvents that may be employed are water. Ringer's solution, and isotonic sodium chloride solution. In addition. sterile, fixed oils are conventionally employed as a solvent or 30 suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables. Suppositories for rectal administration of the drug can be prepared by mixing the drug with a suitable nonirritating excipient such as cocoa butter and -117 polyethylene glycols which are solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum and release the drug, Solid dosage forms for oral administration may include capsules. tablets, pills, powders, and granules. In such solid dosage forms, the active compound 5 may be admixed with at least one inert diluent such as sucrose lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets, and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be 1o prepared with enteric coatings. Liquid dosage forms for oral administration may include pharmaceutically acceptable emulsions, solutions, suspensions, syrups. and elixirs containing inert diluents commonly used in the art, such as water. Such compositions may also comprise adjuvants, such as wetting agents, emulsifying and suspending is agents, and sweetening, flavoring, and perfuming agents. The compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous 20 medium. Any non-toxic, physiologically aceptable and metabolizable lipid capabale of forming liposomes can be used. The present compositions in liposome form can contain. in addition to the compound of the present invention. stabilizers. preservatives, excipients, and the like. The preferred lipids are the phospholipids and phosphatidyl cholines (lecithins), both natureal and 25 synthetic. Methods to form liposomes are known in the art. See, for example, Prescott. Ed., Methods in Cell Biologv, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq. Some preferred dosage forms for the compounds of this invention are disclosed in U.S. Patent Application No. 08/754,390, filed November 21, 1996, in the names of J. Lipari, L.A. Al-Razzak, S. Ghosh and R. Gao and which is entitled Pharmaceutical Composition, which is incorporated herein by reference. A preferred dosage form for the compounds of this invention comprises -118 a solution of (a) a compound of the formula I in the amount of from about 1% to about 50% (preferably, from about 5% to about 30%) by weight of the total solution and (b) polyoxyl 35 castor oil in the amount of from about 0% to about 20% (preferably, from about 5% to about 10%) by weight of the total solution, in 5 a pharmaceutically acceptable organic solvent which comprises (i) oleic acid in the amount of from about 20% to about 99% (preferably, from about 30% to about 70%; more preferably, from about 40% to about 65%) by weight of the total solution or (ii) a mixture of (1) oleic acid in the amount of from about 20% to about 99% (preferably, from about 30% to about 70%; more preferably, from 1o about 40% to about 65%) by weight of the total solution and (2) ethanol or propylene glycol or a mixture thereof in the amount of from about 0% to about 12% (preferably. about 10%) by weight of the total solution. In an even more preferred embodiment of the invention. the solution is encapsulated in a soft elastic gelatin capsule (SEC) or a hard gelatin capsule. 15 A most preferred composition of the invention comprises a solution of (a) a compound of the formula I in the amount of about 30% by weight of the total solution and (b) polyoxyl 35 castor oil in the amount of about 10% by weight of the total solution, in a pharmaceutically acceptable organic solvent which comprises a mixture of (1) oleic acid in the amount of about 50% by 20 weight of the total solution and (2) ethanol in the amount of about 10% by weight of the total solution. In a most preferred embodiment of the invention, the solution is encapsulated in a soft elastic gelatin capsule (SEC) or a hard gelatin capsule and the solution also comprises an antioxidant (preferably, BHT (butylated hydroxytoluene)) in the amount of from about 0.01% to about 0.08% 25 by weight of the total solution (preferably, from about 0.01% to about 0.05% by weight of the total solution). An example of such a composition and its preparation is provided below.

-119 Comlponent % Bv Weight compound of Example 2B (free base) 30 Ethanol (USP, 200 proof) 10 polyoxyl 35 castor oil (Cremophor@ EL) 10 5 Oleic acid, 6321, NF 50 Butylated hydroxy toluene (BHT), NF 0.01 Preparation of the above composition: The mixing tank was purged with nitrogen. Oleic acid (499.9 g) and ethanol (100g) were mixed in the tank. The butylated hydroxytoluene (0.1 g) 10 was charged into the tank and mixed until the solution was clear. The Compound of Example 2B (300 g) was slowly charged into the tank and mixed until the solution was clear. The polyoxyl 35 castor oil (100 g)was added to the tank and mixed. The resulting solution was filled into soft elastic capsules (0.333 g of solution/SEC) to provide a dosage of 100 mg of compound of 15 Example 2B/SEC or 0.667 g/SEC to provide a dosage of 200 mg of compound of Example 2B/SEC. While the compound of the invention can be administered as the sole active pharmaceutical agent, it can also be used in combination with one or more immunomodulators, antiviral agents, other antiinfective agents or 20 vaccines. Other antiviral agents to be administered in combination with a compound of the present invention include AL-721, beta interferon, polymannoacetate, reverse transcriptase inhibitors ( for example, dideoxycytidine (ddC; zalcitabine), dideoxyinosine (ddl; didanosine), BCH-189, AzdU, carbovir, ddA, d4C, d4T (stavudine), 3TC (lamivudine) DP-AZT, FLT 25 (fluorothymidine), BCH-189, 5-halo-3'-thia-dideoxycytidine, PMEA, bis POMPMEA, zidovudine (AZT), nevirapine, delviridine, MSA-300, trovirdine and the like), non-nucleoside reverse transcriptase inhibitors (for example, R82193, L-697,661, BI-RG-587 (nevirapine), retroviral protease inhibitors (for example, HIV protease inhibitors such as ritonavir, Ro 31-8959 (saquinavir), SC-52151, 30 VX-478, AG1343 (nelfinavir), BMS 186,318, SC-55389a, BILA 1096 BS, DMP 323, DMP-450, KNI-227, KNI-272, U-140690, N-(2(R)-hydroxy-1(S)-indanyl) 2(R)-phenylmethyl-4(S)-hydroxy-5-(1-(4-(3-pyridylmethyl)-2(S)-N'-(t- -120 butylcarboxamido)-piperazinyl))-pentaneamide (MK-639: indinavir), 5(S)-Boc amino-4(S)-hydroxy-6-phenyl-2(R)-phenylmethylhexanoyl-(L)-Val-(L)-Phe morpholin-4-ylamide, 1-Naphthoxyacetyl-beta-methylthio-Ala-(2S.3S)-3-amino 2-hydroxy-4-butanoyl-1,3-thiazolidine-4-1-butylamide (i.e., 1-Naphthoxyacetyl 5 Mta-(2S,3S)-AHPBA-Thz-NH-tBu), 5-isoquinolinoxyacetyl-beta-methylthio-Ala (2S,3S)-3-amino-2-hydroxy-4-butanoyl-1,3-thiazolidine-4-t-butylamide (i.e., iQoa-Mta-Apns-Thz-NHtBu) and the like), HEPT compounds, L,697,639, R82150, U-87201 E and the like), HIV integrase inhibitors (Zintevir and the like), TAT inhibitors (for example, RO-24-7429 and the like), trisodium 10 phosphonoformate, HPA-23, eflonithine, Peptide T, Reticulose (nucleophosphoprotein), ansamycin LM 427, trimetrexate. UA001, ribavirin, alpha interferon, oxetanocin, oxetanocin-G, cylobut-G, cyclobut-A. ara-M. BW882C87, foscarnet, BW256U87, BW348U87, L-693,989, BV ara-U, CMV triclonal antibodies. FIAC, HOE-602, HPMPC, MSL-109. TI-23, trifluridine, 15 vidarabine, famciclovir, penciclovir, acyclovir, ganciclovir, castanospermine, rCD4/CD4-IgG, CD4-PE40, butyl-DNJ, hypericin, oxamyristic acid, dextran sulfate and pentosan polysulfate. Immunomodulators that can be administered in combination with the compound of the present invention include bropirimine, Ampligen, anti-human alpha interferon antibody, colony stimulting factor, 20 CL246,738, lmreg-1, Imreg-2, diethydithiocarbamate, interleukin-2, alpha interferon, inosine pranobex, methionine enkephalin, muramyl-tripeptide. TP-5, erythropoietin, naltrexone, tumor necrosis factor, beta interferon, gamma interferon, interleukin-3, interleukin-4, autologous CD8+ infusion, alpha interferon immunoglobulin, IGF-1, anti-Leu-3A, autovaccination, biostimulation, 25 extracorporeal photophoresis, cyclosporin, rapamycin, FK-565, FK-506, G-CSF. GM-CSF, hyperthermia, isopinosine, IVIG, HIVIG, passive immunotherapy and polio vaccine hyperimmunization. Other antiinfective agents that can be administered in combination with the compound of the present invention include pentamidine isethionate. Any of a variety of HIV or AIDS vaccines (for example, 30 gp120 (recombinant), Env 2-3 (gp120), HIVAC-le (gp120), gp160 (recombinant), VaxSyn HIV-1 (gp160), Immuno-Ag (gp160), HGP-30, HIV Immunogen. p24 (recombinant), VaxSyn HIV-1 (p24) can be used in combination with the compound of the present invention.

-121 Other agents that can be used in combination with the compound of this invention are ansamycin LM 427, apurinic acid, ABPP, AI-721, carrisyn, AS-1o, avarol, azimexon. cotchicine, compound 0, CS-85, N-acetyl cysteine, (2 oxothiazolidine-4-carboxylate), D-penicillamine, diphenylhydantoin, EL-10, s erythropoieten, fusidic acid, glucan, HPA-23, human growth hormone, hydroxchloroquine, iscador, L-ofloxacin or other quinolone antibiotics, lentinan, lithium carbonate. MM-1, monolaurin, MTP-PE, naltrexone, neurotropin, ozone, PAl, panax ginseng, pentofylline, pentoxifylline, Peptide T, pine cone extract, polymannoacetate, reticulose, retrogen, ribavirin, ribozymes, RS-47, Sdc-28, 10 silicotungstate. THA, thymic humoral factor, thymopentin, thymosin fraction 5, thymosin alpha one, thymostimulin, UA001, uridine, vitamin B12 and wobemugos. Other agents that can be used in combination with the compound of this invention are antifungals such as amphotericin B, clotrimazole, flucytosine, '5 fluconazole, itraconazole, ketoconazole and nystatin and the like. Other agents that can be used in combination with the compound of this invention are antibacterials such as amikacin sulfate, azithromycin, ciprofloxacin, tosufloxacin, clarithromycin, clofazimine, ethambutol, isoniazid, pyrazinamide. rifabutin. rifampin, streptomycin and TLC G-65 and the like. 20 Other agents that can be used in combination with the compound of this invention are anti-neoplastics such as alpha interferon, COMP (cyclophosphamide, vincristine, methotrexate and prednisone). etoposide, mBACOD (methotrexate, bleomycin, doxorubicin, cyclophosphamide. vincristine and dexamethasone), PRO-MACE/MOPP(prednisone, methotrexate (w/leucovin 25 rescue), doxorubicin, cyclophosphamide, taxol, etoposide/mechlorethamine, vincristine, prednisone and procarbazine), vincristine, vinblastine, angioinhibins, pentosan polysulfate, platelet factor 4 and SP-PG and the like. Other agents that can be used in combination with the compound of this invention are drugs for treating neurological disease such as peptide T. ritalin, 30 lithium, elavil, phenytoin. carbamazipine, mexitetine, heparin and cytosine arabinoside and the like. Other agents that can be used in combination with the compound of this invention are anti-protozoals such as albendazole, azithromycin. clarithromycin, clindamycin. corticosteroids. dapsone, DIMP, eflornithine, 566C80, fansidar, -122 furazolidone, L,671,329, letrazuril, metronidazole, paromycin, pefloxacin, pentamidine, piritrexim, primaquine, pyrimethamine, somatostatin, spiramycin, sulfadiazine, trimethoprim, TMP/SMX, trimetrexate and WR 6026 and the like. Among the preferred agents for inhibition or treatment of HIV or AIDS in s combination with the compound of this invention are reverse transcriptase inhibitors. especially, AZT (zidovudine), ddl (didanosine), ddC (zalcitabine), d4T (stavudine), 3TC (lamivudine), nevirapine, delviridine, trovirdine, PMEA, bis POMPMEA and MSA-300. Other preferred agents for inhibition or treatment of HIV or AIDS in io combination with the compound of this invention are HIV protease inhibitors, especially, ABT-538 (ritonavir) and related compounds, disclosed in U.S. Patent No. 5.541,206, issued July 30, 1996 and U.S. Patent No. 5,491.253, issued February 13, 1996 which are both incorporated by reference herein, N-(2(R)-hydroxy-1 (S)-indanyl)-2(R)-phenylmethyl-4(S)-hydroxy-5-(1-(4-(3 is pyridylmethyl)-2(S)-N'-(t-butylcarboxamido)-piperazinyl))-pentaneamide (i.e., indinavir) and related compounds, disclosed in European Patent Application No. EP541168, published May 12, 1993, and U.S. Patent No. 5,413,999, issued May 9, 1995 which are both incorporated herein by reference; N-tert-butyl-decahydro-2-(2(R)-hydroxy-4-phenyl-3(S)-[[N-(2-quinolylcarbonyl) 20 L-asparaginyl]amino]butyl]-(4aS.8aS)-isoquinoline-3(S)-carboxamide (i.e., saquinavir) and related compounds, disclosed in U.S. Patent No. 5.196.438, issued March 23, 1993, which is incorporated herein by reference: 5(S)- Boc-amino-4 (S)-hydroxy-6-phenyl-2(R)-phenylmethylhexanoyl-(L)-Val-(L) Phe-morpholin-4-ylamide and related compounds, disclosed in European 25 Patent Application No. EP532466. published March 17, 1993, which is incorporated herein by reference; 1 -Naphthoxyacetyl-beta-methylthio-Ala-(2S,3S)-3-amino-2-hydroxy-4-butanoyl 1.3-thiazolidine-4-t-butylamide (i.e., 1-Naphthoxyacetyl-Mta-(2S,3S)-AHPBA Thz-NH-tBu), 5-isoquinolinoxyacetyl-beta-methylthio-Ala-(2S.3S)-3-amino-2 30 hydroxy-4-butanoyl-1,3-thiazolidine-4-t-butylamide (i.e., iQoa-Mta-Apns-Thz NHtBu) and related compounds, disclosed in European Patent Application No. EP490667, published June 17, 1992 and Chem. Pharm. Bull. 42 (8) 2251 (1992). which are both incorporated herein by reference: -123 [1 S-J1 R*(R*),2S*]}-Nl [3-[[[(1, -dimethylethyl)amino]carbonyl](2 methylpropyl)amino]-2-hydroxy-1 -(phenylmethyl)propyl]-2-[(2 quinolinylcarbonyl)amino]-butanediamide (i.e., SC-52151) and related compounds, disclosed in PCT Patent Application No. W092/08701, published 5 May 29, 1992 and PCT Patent Application No. W093/23368, published November 25, 1993, both of which are incorporated herein by reference; OH NH 2 H = 0 N NN S Ph (i.e., VX-478) and related compounds, disclosed in PCT Patent Application No. W094/05639, published March 17, 1994, which is incorporated herein by reference; HO N N OH HOHO OH (i.e., DMP-323) or -124 0 N N H2N

NH

2 \ /HO OH (i.e., DMP-450) and related compounds, disclosed in PCT Patent Application No. W093/07128, published April 15, 1993, which is incorporated herein by reference: OH N - H HO N HOHN O N PhS H (i.e., AG1343, (nelfinavir)), 5 disclosed in PCT Patent Application No. W095/09843, published April 13, 1995 and U.S. Patent No. 5.484,926, issued January 16, 1996. which are both incorporated herein by reference; OH OH H BocNH N NHBoc Ph O 0 (i.e., BMS 186.318) disclosed in European Patent Application No. EP580402. published January 10 26. 1994. which is incorporated herein by reference: -125 0 OH H H H N N N N N N Y H Ph (i.e., SC-55389a) disclosed at 2nd National Conference on Human Retroviruses and Related Infections, (Washington, D.C., Jan. 29 - Feb. 2, 1995), Session 88: and N S SN OH Val- NH N IO H 5 (i.e., BILA 1096 BS) and related compounds disclosed in European Patent Application No. EP560268, published September 15, 1993, which is incorporated herein by reference; and OH_ 0 0 CF 3 HN N 0 0 (i.e., U-140690) and related compounds disclosed in PCT Patent Application No. WO 9530670, published i0 November 16, 1995, which is incorporated herein by reference; or a pharmaceutically acceptable salt of any of the above.

-126 In a most preferred combination, a compound of this invention is administered in combination with ritonavir. Such a combination is especially useful for inhibiting HIV protease in a human. Such a combination is also especially useful for inhibiting or treating an HIV infection in a human. When 5 used in such a combination the compound of this invention and ritonavir can be administered as separate agents at the same or different times or they can be formulated as a single composition comprising both compounds. When administered in combination with a compound of this invention, ritonavir causes an improvement in the pharmacokinetics (i.e., increases half 10 life. increases the time to peak plasma concentration, increases blood levels) of the compound of this invention. Preferred dosage forms for ritonavir include (a) a liquid dosage form for oral administration as disclosed in U.S. Patent No. 5,484,801, issued January 19, 1996, which is incorporated herein by reference, (b) an encapsulated solid 15 or semi-solid dosage form as disclosed in PCT Patent Application No. W095/07696, published March 23, 1995 and U.S. Serial No. 08/402,690, filed March 13, 1995, both of which are incorporated herein by reference and (c) an encapsulated solid dosage form as disclosed in PCT Patent Application No. W095/09614, published April 13, 1995 and U.S. Patent No. 5,559,158. issued 20 September 24. 1996, both of which are incorporated herein by reference. Other examples of preferred dosage forms for ritonavir are disclosed in U.S. Patent Application No. 08/754,390, filed November 21, 1996, in the names of J. Lipari, L.A. Al-Razzak, S. Ghosh and R. Gao and which is entitled Pharmaceutical Composition, which is incorporated herein by reference. 25 A preferred composition for ritonavir comprises a solution of (a) ritonavir in the amount of from about 1% to about 30% (preferably, from about 5% to about 25%) by weight of the total solution and (b) polyoxyl 35 castor oil in the amount of from about 0% to about 20% (preferably, from about 5% to about 10 %) by weight of the total solution, in a pharmaceutically acceptable organic 30 solvent which comprises (i) oleic acid in the amount of from about 15% to about 99% (preferably, from about 30% to about 70%; more preferably, from about 40% to about 65%) by weight of the total solution or (ii) a mixture of (1) oleic acid in the amount of from about 15% to about 99% (preferably. from -127 about 30% to about 70%: more preferably, from about 40% to about 65%) by weight of the total solution and (2) ethanol or propylene glycol or a mixture thereof in the amount of from about 0% to about 12% (preferably, about 10%) by weight of the total solution. In an even more preferred embodiment of the 5 invention, the solution is encapsulated in a soft elastic gelatin capsule (SEC) or a hard gelatin capsule and the solution also comprises an antioxidant (preferably, BHT (butylated hydroxytoluene)) in the amount of from about 0.01% to about 0.08% by weight of the total solution (preferably, from about 0.01% to about 0.05% by weight of the total solution). 10 Examples of such a composition and its preparation are provided below. Como~onent % By Weight ritonavir (free base) 20 Ethanol (USP. 200 proof) 10 polyoxyl 35 castor oil (Cremophor@ EL) 5 is Oleic acid, 6321, NF 65 Butylated hydroxy toluene (BHT), NF 0.01 Preparation of the above composition: The mixing tank was purged with nitrogen. Oleic acid (649.9 g) and ethanol (100g) were mixed in the tank. This solution was warmed to about 33 0 C 20 (29-37 0 C) and maintained at that temperature. The butylated hydroxytoluene (0.1 g) was charged into the tank and mixed until the solution was clear. The ritonavir (200 g) was slowly charged into the tank and mixed until the solution was clear. The polyoxyl 35 castor oil (50 g) was added to the tank and mixed. Heating was discontinued and the solution allowed to cool to amibient 25 temperature (20-30 0 C). The resulting solution was filled into soft elastic capsules (0.5 g of solution/SEC) to provide a dosage of 100 mg of ritonavir/SEC or 1.0 g/SEC to provide a dosage of 200 mg of ritonavir/SEC.

-126 Component % Bv W-eight ritonavir (free base) 20 Ethanol (USP, 200 proof) 10 polyoxyl 35 castor oil (Cremophor® EL) 10 s Oleic acid, 6321, NF 60 Butylated hydroxy toluene (BHT), NF 0.01 Preparation of the above composition: The mixing tank was purged with nitrogen. Oleic acid (599.9 g) and ethanol (100g) were mixed in the tank. This solution was warmed to about 33 0 C 10 (29-37"C) and maintained at that temperature. The butylated hydroxytoluene (0.1 g) was charged into the tank and mixed until the solution was clear. The ritonavir (200 g) was slowly charged into the tank and mixed until the solution was clear. The polyoxyl 35 castor oil (100 g)was added to the tank and mixed. Heating was discontinued and the solution allowed to cool to amibient 15 temperature (20-30*C). The resulting solution was filled into soft elastic capsules (0.5 g of solution/SEC) to provide a dosage of 100 mg of ritonavir/SEC or 1.0 g/SEC to provide a dosage of 200 mg of ritonavir/SEC. Examples of preferred single dosage forms comprising both ritonavir and a compound of the formula I are also disclosed in U.S. Patent Application No. 20 08/754,390, filed November 21, 1996, in the names of J. Lipari, L.A. Al-Razzak, S. Ghosh and R. Gao and which is entitled Pharmaceutical Composition, which is incorporated herein by reference. A preferred composition for a single dosage form comprising both ritonavir and a compound of the formula I comprises a solution of 25 (a) a mixture of ritonavir in the amount of from about 1% to about 30% (preferably, from about 5% to about 25%) by weight of the total solution and a compound of the formula I in the amount of from about 1% to about 50% (preferably, from about 5% to about 40%) by weight of the total solution and (b) polyoxyl 35 castor oil in the amount of about 10% by weight of the total solution, 30 in a pharmaceutically acceptable organic solvent which comprises a mixture of -129 (1) oleic acid in the amount of from about 10% to about 88% (preferably, from about 40% to about 65%) by weight of the total solution and (2) ethanol in the amount of about 10% by weight of the total solution. In a most preferred embodiment of the invention, the solution is encapsulated in a soft elastic 5 gelatin capsule (SEC) or a hard gelatin capsule and the solution also comprises an antioxidant (preferably, BHT (butylated hydroxytoluene)) in the amount of from about 0.01 % to about 0.08% by weight of the total solution (preferably, from about 0.01 % to about 0.05% by weight of the total solution). Examples of such a composition and its preparation are provided below. 10 Component '% Bv Weight ritonavir (free base) 5 compound of Example 2B (free base) 30 Ethanol (USP, 200 proof) 10 polyoxyl 35 castor oil (Cremophor@ EL) 10 15 Oleic acid, 6321, NF 45 Butylated hydroxy toluene (BHT), NF 0.01 Component % By Weight riionavir (free base) 15 compound Example 28 (free base) 15 20 Ethanol (USP, 200 proof) 10 polyoxyl 35 castor oil (Cremophor® EL) 10 Oleic acid. 6321, NF 50 Butylated hydroxy toluene (BHT), NF 0.01 Comoonent % By Weight 25 ritonavir (free base) 15 compound Example 2B (free base) 15 Ethanol (USP. 200 proof) 10 polyoxyl 35 castor oil (Cremophor* EL) 5 Oleic acid. 6321, NF 55 30 Butylated hydroxy toluene (BHT), NF 0.01 -130 Preparation of the above composition: The mixing tank was purged with nitrogen. Oleic acid (549.9 g) and ethanol (100g) were mixed in the tank. The butylated hydroxytoluene (0.1 g) was charged into the tank and mixed until the solution was clear. The ritonavir 5 (150 g) was slowly charged into the tank and mixed until the solution was clear. Compound Example 2B (150 g) was slowly charged into the tank and mixed until the solution was clear. The polyoxyl 35 castor oil (100 g) was added to the tank and mixed. The resulting solution was filled into soft elastic capsules (1.0 g of solution/SEC) to provide a dosage of 150 mg each of ritonavir and compound jo Example 2B/SEC. Component % EY Weiht ritonavir (free base) 15 compound Example 2B (free base) 5 Ethanol (USP, 200 proof) 10 i5 polyoxyl 35 castor oil (Cremophor® EL) 10 Oleic acid, 6321, NF 60 Butylated hydroxy toluene (BHT), NF 0.01 Total daily dose of ritonavir (administered in combination with a compound of this invention) to be administered to a human or other mammal 20 host in single or divided doses may be in amounts, for example, from 0.001 to 300 mg/kg body weight daily and more usually 0.1 to 10 mg of ritonavir. Dosage unit compositions may contain such amounts of submultiples thereof to make up the daily dose. In the compositions which comprise a mixture of ritonavir and the 25 compound of Example 2B, the ratio (w/w) of ritonavir to the compound of Example 2B ranges from about 1:16 to about 5:1 (preferably, from about 1:6 to about 3:1).

-131 In another most preferred combination, a compound of this invention is administered in combination with ritonavir and one or more reverse transcriptase inhibitors (preferably, one or more compounds selected from the group consisting of AZT (zidovudine), ddl (didanosine), ddC (zalcitabine), d4T 5 (stavudine) and 3TC (lamivudine)). Such a combination is especially useful for inhibiting or treating an HIV infection in a human. When used in such a combination the compound of this invention and ritonavir and one or more reverse transcriptase inhibitors can be administered as separate agents at the same or different times or they can be formulated as compositions comprising '0 two or more of the compounds. A particularly preferred therapeutic combination comprises a compound of the formula I (especially, the compound of Example 2B) in combination with ritonavir, AZT and 3TC. It will be understood that agents which can be combined with the compound of the present invention for the inhibition, treatment or prophylaxis of 15 AIDS or an HIV infection are not limited to those listed above, but include in principle any agents useful for the treatment or prophylaxis of AIDS or an HIV infection. When administered as a combination, the therapeutic agents can be formulated as separate compositions which are given at the same time or 20 different times, or the therapeutic agents can be given as a single composition. The foregoing is merely illustrative of the invention and is not intended to limit the invention to the disclosed compounds. Variations and changes which are obvious to one skilled in the art are intended to be within the scope and nature of the invention which are defined in the appended claims.

Claims (10)

1. A process for the preparation of a compound of Formula I or a pharmaceutically acceptable salt, ester or prodrug thereof, O R1 R 3 H R4 N R4 L N R5 OH R2 0 (1) said process comprising reacting a compound of the formula: R1 R3 H H 2 N R5 OH R2 0 with a compound of the formula: 0 R 4 L1 OH or a salt or activated ester derivative thereof, wherein: R 1 and R 2 are independently selected from the group consisting of loweralkyl, cycloalkylalkyl and arylalkyl; R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; R 4 is aryl or heterocyclic; R 5 is x ] a) (CH 2 )n x (CH 2 )m b) z -133 x N Y c) z, x N Y d) (CH2)m x z e) (CH 2 )m' x N Y" f) (CH 2 )m x 'Ilk N N-R6" g) N 6N-R h) OH or HO N ,kN--R6 i) H, wherein n is 1, 2 or 3, m is 1, 2 or 3, m' is 1 or 2', X is 0, S or NH, Y is -CH 2 -, -0-, -S- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y" -134 is -CH 2 - or -N(R 6 -)- wherein R 6 -is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 )- wherein R 6 -is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, and Z is 0, S or NH; and L 1 is selected from the group consisting of: a) -0-, b) -S-, c) -N(R 7 )- wherein R 7 is hydrogen, loweralkyl, cycloalkyl or cycloalkylalkyl, d) -0-alkylenyl-, e) -S-alkylenyl-, f) -S(O)-alkylenyl-, g) -S(0) 2 -alkylenyl-, h) -N(R 7 )-alkylenyl- wherein R 7 is defined as above, i) -alkylenyl-O-, j) -alkylenyl-S-, k) -alkylenyl-N(R 7 )- wherein R 7 is defined as above, 1) -alkylenyl-, and m) -alkenylenyl-.

2. A process for the preparation of a compound of Formula I or a pharmaceutically acceptable salt, ester or prodrug thereof, O R1 R3 N R5 OH R2 0 (1) said process comprising reacting a compound of the formula: R, R 3 H N H 2 N R5 OH R2 0 -135 with a compound of the formula: 0 L1 OH or a salt or activated ester derivative thereof, wherein: R 1 and R 2 are independently selected from the group consisting of loweralkyl, cycloalkylalkyl and arylalkyl; R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; R 4 is aryl; x N J R 5 is (CH 2 ) , wherein n is 1, 2 or 3, X is 0, S or NH, and Y is -0- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl; and L 1 is selected from the group consisting of: a) -0-, b) -S-, c) -N(R 7 )- wherein R 7 is hydrogen, loweralkyl, cycloalkyl or cycloalkylalkyl, d) -0-alkylenyl-, e) -S-alkylenyl-, f) -S(O)-alkylenyl-, g) -S(0) 2 -alkylenyl-, h) -N(R 7 )-alkylenyl- wherein R 7 is defined as above, i) -alkylenyl-O-, j) -alkylenyl-S-, k) -alkylenyl-N(R 7 )- wherein R 7 is defined as above, 1) -alkylenyl-, and m) -alkenylenyl-.

3. The process of claim 2, wherein R, and R 2 are arylalkyl, R 3 is loweralkyl, -136 R 4 is aryl, and L 1 is -0-alkylenyl-.

4. The process of claim 2, wherein R 1 and R 2 are benzyl or R, is benzyl and R 2 is isopropyl, R 3 is loweralkyl, R 4 is 2,6-dimethylphenyl which is optionally substituted with a substituent selected from the group consisting of loweralkyl and halo, L 1 is -0-CH 2 -, n is 1 or 2, X is 0 or S, and Y is -CH 2 - or -NH-.

5. The process of claim 2, wherein R, and R 2 are benzyl, R 3 is loweralkyl, R 4 is 2,6-dimethylphenyl, L 1 is -0-CH 2 -, n is 1 or 2, X is 0 or S, and Y is -NH-.

6. A process for the preparation of a compound of Formula I or a pharmaceutically acceptable salt, ester or prodrug thereof, O R1 R3 R4 ' L, N "J" R5 NN N OH R2 0 (I) said process comprising reacting a compound of the formula: O R1 R L NH 2 Li N H OH R2 with a compound of the formula: R 3 HOR5 0 or an activated ester derivative thereof, wherein: R 1 and R 2 are independently selected from the group consisting of loweralkyl, cycloalkylalkyl and arylalkyl; R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; R 4 is aryl or heterocyclic; R 5 is -137 x a) (CH 2 ), x (CH 2 )m x Nc) x d)(CH 2 )m11 x N z e) (CH 2 )m, x f) (CH 2 )m' N "' -6" -138 N N-R 6 h) OH or N N-R i) HO , wherein n is 1, 2 or 3, m is 1, 2 or 3, m' is 1 or 2', X is 0, S or NH, Y is -CH 2 -, -0-, -S- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -CH 2 - or -N(R 6 )- wherein R 6 " is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, Y' is -N(R 6 -)- wherein R 6 -is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl, and Z is 0, S or NH; and L 1 is selected from the group consisting of: a) -0-, b) -S-, c) -N(R 7 )- wherein R 7 is hydrogen, loweralkyl, cycloalkyl or cycloalkylalkyl, d) -0-alkylenyl-, e) -S-alkylenyl-, f) -S(O)-alkylenyl-, g) -S(0) 2 -alkylenyl-, h) -N(R 7 )-alkylenyl- wherein R 7 is defined as above, i) -alkylenyl-O-, j) -alkylenyl-S-, k) -alkylenyl-N(R 7 )- wherein R 7 is defined as above, 1) -alkylenyl-, and m) -alkenylenyl-. -139

7. A process for the preparation of a compound of Formula I or a pharmaceutically acceptable salt, ester or prodrug thereof, O R1 R3 H R4 NL N R 5 OH R2 0 (I) said process comprising reacting a compound of the formula: 0 R 1 R4',LNH 2 H OH R2 with a compound of the formula: R 3 HO 0 or an activated ester derivative thereof, wherein: R 1 and R 2 are independently selected from the group consisting of loweralkyl, cycloalkylalkyl and arylalkyl; R 3 is loweralkyl, hydroxyalkyl or cycloalkylalkyl; R 4 is aryl; x NJ R 5 is (CH 2 )n ,wherein n is 1, 2 or 3, X is 0, S or NH, and Y is -0- or -N(R 6 )- wherein R 6 is hydrogen, loweralkyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl; and L 1 is selected from the group consisting of: a) -0-, b) -S-, c) -N(R 7 )- wherein R 7 is hydrogen, loweralkyl, cycloalkyl or cycloalkylalkyl, -140 d) -0-alkylenyl-, e) -S-alkylenyl-, f) -S(O)-alkylenyl-, g) -S(0) 2 -alkylenyl-, h) -N(R 7 )-alkylenyl- wherein R 7 is defined as above, i) -alkylenyl-O-, j) -alkylenyl-S-, k) -alkylenyl-N(R 7 )- wherein R 7 is defined as above, 1) -alkylenyl-, and m) -alkenylenyl-.

8. The process of claim 7, wherein R 1 and R 2 are arylalkyl, R 3 is loweralkyl, R 4 is aryl, and L 1 is -0-alkylenyl-.

9. The process of claim 7, wherein R 1 and R 2 are benzyl or R 1 is benzyl and R 2 is isopropyl, R 3 is loweralkyl, R 4 is 2,6-dimethylphenyl which is optionally substituted with a substituent selected from the group consisting of loweralkyl and halo, L 1 is -0-CH 2 -, n is 1 or 2, X is 0 or S, and Y is -CH 2 - or -NH-.

10. The process of claim 7, wherein R 1 and R 2 are benzyl, R 3 is loweralkyl, R 4 is 2,6-dimethylphenyl, L 1 is -0-CH 2 -, n is 1 or 2, X is 0 or S, and Y is -NH-. Dated 14 October, 2009 Abbott Laboratories Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON