CA1270350A - Amino thio dipeptides - Google Patents

Abstract

ABSTRACT
AMINO THIOL DIPEPTIDES

Amino thiol substituted dipeptides of the formula are disclosed. These compounds are useful as hypotensive agents due to their angiotensin converting enzyme inhibition activity and are also useful as analgesics due to enkephalinase inhibition activity when X is

Description

-AMINO THIOL DIPEPTIDES
This invention is directed to the amino thiol dipeptide compounds of formula I and salts thereof (I) * I I 1 11 R3-CH - CH-CH~-N - C~ - C-X
N~ * ~L) C=O

X is an amino or imino acid of the formula 2f 1 2 ' ~2C

I(L~ l(L~ I(L) H H H

, .

E~315 ~21C IC52 f?~ S~ 12 -N--C-COOR6 -N--C-COOR6 -N--c-cod~2 I (L) I (L) l (L~
H H H

( L ~ ¦ ( L ) -N--C -COOR
~I H I (L) -N--C-COOR -~
( L ~ 6 : H ( L ~ ~
:, -N--CH-COOR6 ~ Nl 1 4 R5 :-N C-COOR6 .

., ' . ' ,~ .

;: ,...

35~

~tL) N ) OOR6, (L) H H H

OC~3 ~Y ' ~ ' -N J -N Y
L ~ ~f COOR6 H H

~L) 6 f ~OOR6 H H
n is zero, one, or two.
:: Rz5 is lower alkyl of 1 to 4 carbons or : - ( CH2 ) ~ ~ ~

:

.

, ~:

: '' ';

1~7~S~ HA315 R7 is hydrogen, lower alkyl~ halogen, ~, ~Rlg hydroxy, -NH-C-lower alkyl, amino, -N\

-NH-C-(CH2~m ~ (R14~ 2)m ~ ( 13)p ( CH 2 ) m~1 , ~ ( CH 2 ) m~3 ' - ( CH 2 ) a 1- or 2-naphthyl of the formula 21m~ (CH2)m-cycloalkyl, ~(R14~ p -O-C-N , -O-lower alkyl, -O-ICH~

a l- or 2~naphthyloxy of the formula -O-(CH2)m ~ , -S-lower alkyl, ~R14)p -S-(CH2)m ~or a l- or 2-naphthylthio ~R13)p ~, ~
:.^ :.
:: -: .

.. ..

~27~3S~ HA315 sf.the formula ~S~ (CH2)m~ , .
~( 14)E, R
R8 is halogen , -O-C-N /

-O-(CH2)m ~ , -O-lower alkyl, a 1- or 13 p

2-naphthyloxy of the formula -O-(CH2)m ~ ( 14)p -S-lower alkyl, -S-ICH2)m ~ (R13)p or a 1- or 2-naphthylthlo of the formula S ~CH2) ~ (R14)E~
Rg is keto or -(CH2lm ~ ( 13)p , .. . .
~ ' ' ' ` .

,; :, , ,, ~ :"
.~ .

~7~

is halogen or -Y-Rl6 R~R12 and 12 P
selected from hydrogen and lower alkyl or R'll, R12 and R'12 are hydrogen and Rll is ( 14 p R13 is hydrogen, lower alkyl of l to 4 caxbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl.
R14 i5 hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylth.io of l to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, or hydroxy.
m is zero, one, two, three, or foux.
p is one, two or three provided that p is more than one only if Rl3 or R14 is hydrogen, methyl, methoxy, chloro, or fluoro.
R15 is hydrogen or lower alkyl of 1 to 4 carbons.
Y is oxygen or sulfur.
Rl6 is lower alkyl of l to 4 carbons, ( 2)m ~ , or the Rl6 groups joln to P
complete an unsubstituted 5- or 6-membered ring .~ . .

.......
;.
.. ,, ~ ... .

.,: ~ .~. ..

5~

or said ring in which one or more of the carbons has a lower alkyl of 1 to 4 carbons or a di(lower alkyl of l to 4 carbons) substituent.
R4 is hydrogen, lower alkyl, -(CH2)m-cycloalkyl~ ~(CH2)mt ~ , ( 2)m (CH2)m ~ , ~ , or ~ .

R5 ia hydrogen, lower alkyl, -(CH2)r ~ , -(CH2)x ~ - OH, -(CH2)r-OH, (CH2)r ~ OH , OEI

~(CH2)r ~ ' ( 2) ~ ~ ~ -(CH2)r-NH2 ,~

H H

-(CH2)r-SH, -~CH2)r-S-lower alkyl7 ~ NH ll ( 2~r ~ , or -(CH2)~-C-NH2 ~ , . .

, ,~, -:

7 HA3l5 -8- ~

r is an integer from 1 to 4.
Rlg is lower alkyl, benzyl, or phenethyl.
R20 is hydrogen, lower alkyl, benzyl or phenethyl.
R is hydrogen, lower alkyl, cycloalkyl, (CH2)m ~ , -(CH2~2-NH2~ -(cH2)3 NH2 ' (CH ) -NH2, -(CH232-OH, (CH2)3 -(CH2)4-OH, -(c~2)2-sH~ (C 2 3 (CH2)4 Rl is hydrogen, lower alkyl, halo substitut d lower al]syl, ~-~
( 2)r ~ ~(CH2)r ~ -OH

-(CH2)r ~ OH , -(CH2) OH
H
~~CH2)r ~ 3 , -(CH2)r-NH2, (CH2)r N
: H

-(CH2) -0~, -(CH2)r-S-lo~ alkyl, (CH2)2 ~ 2 2 2 o NH
( 2)r ~ , or -1CH23r-C-NH2 : NH2 ' ' ' '' ' ' ' ...
,. .:. ~ -, : ~ .
''.:. ;,.,, ' ~ ::
.,: . .

~2~

R2 is ~(CH2)m~(R14)p , (CH2)m (CH2)mt~ , or - (cH2~mtoJ

R3 is hydrogen, lower alkyl, ~(CH2)m~ ~R14)p ' ( 2~mff~3 ' ~(cH2)mff~ (CH2)m t~ , halo s~bstituted lower alkyl, - (CH2)m-cycloalkyl, - (CH2) r~0H , OH

(C 2)~) ' ~ (CH2) r~OH' (CH2) r~
H H

- ' .. . .
:. , , , ~ ~

: . ,~,

3 l s 2 r H2~ (CH2)r-SH, -(CX2~r-S-lower alkyl ~ NH O
-~CH2)~-NH-c , or -~CH2)r-C-NH2 S \ NH2 wherein m, R14, p and r are as defined a~ove.
R6 is h~x~n,l~ alk~l,~-metho:xyb~2yl,b~hyd~yl, O R O
~ ~21 -CH-O-C Rl8 -C - C-O-R23 , -CH-lCH2-0~)2, -cH2-cH-cH2 , -~CH2)2 N(CM3)2 ~r ~ 2 r OH OH

R17 is hydrogen, lower alkyl, cycloalkyl, o:r phenyl.
Rl~ is hydrogen, lower alkyl, lower alko~y, or phenyl or R17 and R18 taken together are -(CM2)2-, -ICH2)3-, -CH=CH-, or ~

R21 and R22 are independently selected ~rom hydrogen and lower alkyl.
R23 is lower alkyl.
R24 is hydrogen, lower alkyl, ~ R
14 p , ~ ~ , or ~

~ ,, .

.~, . .

-: ., ; ~ :

.,, ~ ~ `' " '-.

~2~35~
~ HA315 This invention in its broadest aspects relates to the amino thiol dipeptide compounds of formula I above, intermediates useful in the preparation of such compounds, compositions containing such compounds and the me~hod of using such compounds as pharmaceutical agents.
The term lower alkyl used in defining various s~mbols refers to straight or branched chain radicals ha~ing up to seven carbons. The preferred lower alkyl groups are up to four carbo~s with methyl and ethyl most preferred Similarly the terms lower alkoxy and lower alkylthio refer to such lower alkyl groups attached to an oxygen or sulfur.
The term cycloalkyl refers to saturated rings of 3 to 7 carbon atoms with cyclopentyl and cyclohexyl being most preferred.
The term halogen refers to chloro, bromo and fluoro.
The term halo substituted lower alkyl refers to such lower alXyl groups described above in which one or more hydrogens have been replaced by chloro, bromo or ~luoro groups such as trifluoro-methyl, which is preferred, penta~luoroethyl,2,2,2-trichloroethyl, chlorome~hyl, bromomethyl, etc.

., , .
,~

,, ~
. . ~. ; :, . . ~

..::

The symbols ~(CH2)m~ ~ 2 m ~O 3 and (CH2)m ~ represent that ~he alkylene bridg~ is attached to an available carbon atom.
~ he compounds of formula I can be prepared according to the following procedure. An aldehyde of the formula 15 (II) o NH S
C=O C~2 oc~3 is reductively coupled with a dipeptide ester of the formula (III) HN--C~-- C--X

;''' ~ ' ' '' ~ ~ .
. ~ . ,.

~'7~`3~D
~ ~ HA315 wherein R6 in the definition of X is an acid cleavable protecting group such as t-butyl, benzhydryl, or p-methoxybenzyl.
The resulting ~-methoxy~enzyl pro~ected S compound of the formula ~IV) R R1 O

R3-~H - C~-CH~-N-CH- C X
NH S
C=O CH2 oc~3 is treated with trifluoroacetic acid and anisole to remove the R6 ester group and mercuric trifluoroacetic acid to remove the p-methoxybenzyl sulfur protecting group and give the amino thiol product of formula I.
The aldehyde intermediate of formula II can be prepared as follows. An N-protected carboxylic acid of the formula (V) : 25 o N~
prot .

: ' , .

. . .

5~

wherein prot is a prote~ting group such as benzyl-oxycarbonyl is treated with diazomethane in the presence of N-methylmorpholi~e and isobutylchloro-formate to yield (VI) R3-CH-C-CH2-N~
N~
Irot The diazo compound of formula VI in methanol is treated with silver benzoate and triethylamine to yield the methyl ester of the formula (VI}) NH
prot Removal of the N-protecting group such as by hydroyenation followed by reaction with the acid chloride of the formula (VIII) O
~1 R -C-Cl z .

: ~ . .
~ .

.
. ::
:
: .

7~t~
~ HA315 yields the methyl ester of the formula (IX) R3 - CH - CH2 C -OC~3 NH
C=O

The methyl ester of formula IX is treated with lithium diisopropylamine and the disulfide of the formula (X~

( 3 ~ CH -3) at low temperature to yield the protected sulfide of the formula (XI) O
R3 C~ C~ - C- OC~3 NH S
C=O CH~
12 ~ .

:; OC~3 ' ~ :'' ' '~:
'' .:
. ~ ' "' '~

~Z7~5g3 The me~hyl ester of formula XI is treated with lithium chloride and sodium borohydride to yield the alcohol of the formula (XII) R3- C~ - C~ CH2 - OH
N~ S
C=O CH2 R2 ~, The alcohol of formula XII is treated with pyridin-ium-l-sulfonate and dimethylsuloxide in the presence of diisopropylethylamine to yield the aldehyde of formula II.
The dipeptides of formula III are described in the literature. They can be obtained by reacting the N-protected amino acid of the formula (XIII) R R O
I 11 11 :
Prot-N- C~ - C-OH
wherein the N-protecting group is benæyloxy-carbonyl, t-butoxycarbonyl, or ~-methoxybenzyl-oxycarbonyl with the imino or amino acid ester of the fonmula (XIV) H-X

.. . .

~;' ' :~: - ., . ;

3~

Removal of the N protecting group yields the intermediate of formula III. When the imino or amino acid of formula XIV is known in the acid foxm it can be readily converted to the ester by conventional means. For example, the esters where R6 is t-butyl can be obtained by treating the corresponding N-carbobenzyloxy imino or amino acid with isobutylene under acidic conditions and then removing the N-carbobenzyloxy protecting group by catalytic hydrogenation.
In the above reactions if any or all of R, R1, R3 and R5 are 15 (CH2)r ~ OH , -(CH2)r ~ OH
OH

~(CH2)r~NH2 ' (,CH2~r~,~ (CH2)r-SH

H
~(CH2)r~H ~ or ~ NH
(CH2)r NH C ~

then the hydroxyl, amino, imidazolyl, mercaptan or guanidinyl unction should be protected during the reaction. Suitable pxotecting groups include . ~ .

.

~f~35~

benzyloxycarbonyl, t-butoxycarbonyl, benzyl, benz-hydryl, trityl, etc., and nitro in the case of guanidinyl. The protecting group is removed by hydrogenation, treatment with acid, or other known methods following completion of the reaction.
The ester products of formula I wherein R6 is ~CH-0-C-R

may be obtained by employing the dipeptide of formula III in the above reactions with such ester group already in place. Such ester reactants can be prepared by treating the dipeptide of formula III wherein R6 is hydrogen with an acid chloride such as Il 11 ~ CH2 0-C-Cl or (H3C)3-C O-C-Cl so as to protect the N atom. The protected compound is then reacted in th~ presence of a base with a compound of formula (X~) .

O

, ~ .
....

~L2~35~

wherein L is a leaving group such as chlorine, bromine, tolylsulfonyl, etc., followed by removal of the N-protecting group such as by treatment with acid or hydrogenation.
The ester products of formula I wherein R6 is -c~-O-C-R18 can also b~ obtained by treating the product of formula I wherein R6 is hydrogen with a molar excess of the compound of formula XV.
The ester products of formula I wherein R6 is ~ C--~23 can be prepared by treating the product of formula I wherein R6 is hydrogen with a molar excess of the compound of the formula (XVI) R O

The ester products of formula I wherein R6 iS -C~-(CH2-OH)2 or -CH2--CH - C~2 can OH OH
be prepared by coupling the product of formula I

~7~ 3~

wherein R6 is hydrogen with a molar excess of the compound of the formula (XVII) CH-(CH~-OProt)2 OH

or the formula (XVIII) OH Prot OProt in the presence of a coupling agent such as dicyclohexylcarbodiimide followed by removal of the hydroxyl protecting groups.
Similarly, the ester products of formula I
wherein R6 is -~CH2)2 N(C~3~2 -CH2 ~ can be prepared by coupling the product of formula I wherein R6 is hydrogen with a molar excess o the compound of the formula ~XIX) .~ , ~o-CH2-C~2~N~(CH3~2 .
.
' :

~.

.

. . .
.

~7~3~3 or the formula (~X) HO (CH2~r ~

in the presence of a coupling agent such as dicyclohexylcarbodiimide.
The products of formula I wherein R7 is amino may be obtained by reducing the correspond-ing products of formula I wherein R7 is azido.
Preferred compounds of this invention with respect to the peptide part of the structure of formula I are those wherein:
R is hydrogen or straight or branched chain lower alkyl of 1 to 4 carbons.
R1 is hydrogen, straight or branched chain lower alkyl or 1 to 4 carbons,-CF3, (CH2)r-NH2 wherein r is an integer from : 1 to 4, ' .. . .
' ' ''' ' " ' :'' .

3~
-22~ HA315 -CH2~, -CH2~0H , -CH2~--OH
OH

-CH2~ , -CH2~ N ~ -CH2-SH~ - (CH2) 2 S (CH2) 2 2 H H

NH
2 ) 2 S CH3, - ( t H2 ) 3N~C I -CH2 -OH, O O
Il 11 2 C NH2, or -(CH2)2-C-NH

R4 is hydrogen, cyclohexyl or phenyl.
R5 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, -CH20H, -CH2~, -CH2~0H, -CH2~0H
OH

-CH2~ , -CH2~J~ ~ -(CH2) 4 N 2 H H
NH
CH -SH - (CH2) 2-S-CH3 ~ (CH2 j 3 ~

~L2~7~ 35q3 O O
l !

-CH -C-NH ( 2)2 2 R6 is hydrogen, straight or branched chain lower alkyl of l to 4 carbons, alkali metal salt, O O
Il ll -CH~O-C-R18 -CH2-C-OR 23 -CH-~CH2-O~)2 ,-CH2-CH- CH2 , -(CH2)2-N~CH3)2, OH O~
: or -(CH2)r ~

r is an integer from l to 4.
R23 is straight or branched chain lower alkyl of l to 4 carbons, especiallv -C(C~3)3 .

R17 is hydrogen, straight or branched chain lower alkyl of l to 4 carbons, or cyclohexyl.
: Rl8 is straight or branched chain lower alkyl of 1 to 4 carbons or phenyl.

R7 is hydrogen.
R7 is hydroxy.
R7 is straight or branched chain lower alkyl of l to 4 carbons or cyclohexyl.

-, A ' .

'~, ' ;; ' ~' ~

' ' ~ "
'. , .
.~.' .~ .

~LZ'7~S~
. - - RA315 R7 is amino.
R7 is -O-lower alkyl wherein lower alkyl is stralght or branched chain of 1 to 4 carbons.
R7 is S ~ ~CH2)m~

wherein m is zero, one or two and R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R7 is -O- ~ CH2 3 m ~

1-naphthyloxy or 2-naphthyloxy wherein m is zero, one, or two and R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R7 is -S-lower alkyl wherein lower alkyl is straight or branched chain of l to 4 carbons.

~S~ (CH2)m~

l-naphthylthio, or 2-naphthylthio wherein m is zero, one, or two and Rl3 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R8 is -O-lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons.

: . , . ~:
.; ~

~3~ HA3l5 -O- (CH2)~ R13 wherein m is zero, one, or two and R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
~8 is -S-lower alkyl wherein lower alkyl is straight or branched chain of l to 4 carbons.
R8 is -S-lCH2)m ~ 13 wherein m is zero, one or two and Rl3 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro or hydroxy.
Rg is phenyl, 2-hydroxyphenyl, or 4-hydroxy-phenyl.
Rlo are both fluoro or chloro.
Rlo are both Y R16 he 2~ Rl6 is straight or branched chain lower alkyl of l to 4 carbons or the R16 groups join to complete an unsubstituted 5- or 6 membered ring or said ring in which one or more o the available carbons has a methyl or dimethyl substituent.
2S Rll, Ril, R12 and R12 are all hydrogen, or Rll is phenyl, 2-hydroxyphenyl, or 4-hydroxy-phenyl and Rll, Rl2 and R12 are hydrogen.
R24 iS phenYl .
Most preferred compounds of this invention with res2ect to the peptide part of the structure of formula I ar- those wherein:

.. , ..
.'` ' ~ ~7~ 35~ ~A315 X is -N - CH-COOR6 , l7

4 5 H~C CH2 2)t~ H

10 Hzl I H2 ~(~
-N C-COOR6 , or -N

El COOR6 R is hydrogen or methyl.
Rl is hydrogen, methyl, or -(CH2)~NH2 R6 is hydrogen, straight or branched chain lower alkyl o 1 to 4 carbons, or an alkali metal salt.
R4 i~ cyclohexyl or phenyl and R5 i~ hydrogen.
R4 is hyd~ogen and R5 i9 methyl, -CH2-C~(cH3~Z' CH2 ~ , -C~2 ~ OH , -C32 ~ OH , -CH2 ~ ~ , or -CH

H H

.

~''.,"''' : ~ ' :. ' , '' .

3 ~ ~

R7 is hydrogen, cyclohexyl, lower alkoxy of l to 4 carbons, -(CH2) ].3 -O~(CH2) ~ Rl3 ' or -S-(CH2)m ~ R13 wherein m is zero, one, or two and R13 is hydrogen, methyl, methoxy, methylthio, Cl, Br, F, or hydroxy, especially preferred wherein R7 is hydrogen.
t is two or three, especially where t is two.
Preferred compounds of this invention with respect to the thiol substituted portion of the structure of formula I are those wherein:
R is 2 -(CH2) ~ R
1~
wherein m is zero, one, or two and Rl4 is hydrogen, methyl, methoxy, methylthio, Cl, Br, F, or hydroxy, es~ecially phenyl.
R3 is straight or branched chain lower alkyl of l to 4 carbons, -(CH2~r-NH2, ~(CH2)m ~ , or -ICH2)m ~

wherein m is zero, one, or two, Rl4 is hydrogen,methyl, methoxy, methylthio, Cl, Br, F, or hydroxy, and r is an integer from l to 4, especially ~enzyl.

.

, .. . . .
~ ' ..

.. . .
'', ~ ~ , . ' ' :, ~ - ,. :

".. ' s~

-2~-The compounds of formula I wherein R6 is hydrogen form salts with a variety of inorganic or organic bases. The nontoxic, pharmaceutically acceptable salts are pref~rred, although other salts are also useful in isolating or purifying the product. Such pharmaceutically acceptable salts include metal salts such as sodium, potassium or lithium, alkaline earth metal salts such as calcium or magnesium, and salts derived from amino acids such as arginine, lysine, etc.
The salts are obtained by reacting the acid form of the compound with an equivalent of the base supplying the desired ion in a medium in which the salt precipitates or in aqueous medium and then lyophilizing.
Similarly, the compounds of formula I
form salts with a variety of inorganic and organic acids. ~gain, the non-toxic pharmaceutically acceptable salts are preferred, although other salts are also useul in isolating ar purifying the product.
Such pharmaceutically acceptable salts include those formed with hydrochloric acid, 35~

~29-methanesulfonic acid, sulfuric acld, maleic acid, etc. The salts are obtained by reacting the product with an equivalent amount of the acid in a medium in which the salt precipitates.
As shown above, the peptide portion of the molecule of the products of forml1la I
represen~ed by R Rl -N - C~ - C-X
(L) is in the L-configuration tRl is other than hydrogen). One or two asymmetric centers are also present in the t~iol substituted portion o ~he molecule as represented by the * in formula I.
Of course, if R3 is hydrogen, then only one centex is present. Thus, the compounds of formula I
can exist in diastereoisometric forms-or in mixtures thereof. The above described processes can utilize racemates, enantiomers or diastereomers as starting materials. When diastereomeric products are prepared, they can be separated by conventional chromatographic or fractional crystallization methods.

`

,~
:
, :: :

' u~

he products of formula I wherein the imino acid ring is monosubstituted give rise to cis-trans isomerism. The configuratiorl of the final product will depend upon the configuration S of the R7, R8 and Rg substituent in the starting material of formulaxIv The comDounds of fo~nula I, and the pharma-ceutically acceptable salts thereof, are hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II
and, therefore, are useful in reducing or relieving angiotensin related hypertension.
The action of the enzyme renin on angiotensinogen, a pseudoglubulin in blood plasma, produces angiotensin I. Angiotensin I is converted by angiotensin converting enz~ne ~ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causa-tive agent in several forms of hypertension in various marnmalian species, e.g., humans.
The com~ounds of this invention intervene in the angiotensinogen } (renin) ~ angiotensin I ~
angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angio-tensin II. Thus by the administration of a composition containing one (or a cornbination) of the compounds of this invention, angiotensin dependent hypertension in a species of marnrnal (e.g., hurnans) suffering therefrom is alleviated.

. .
.
. ... .
.. . .. .. .
'~

~2~ 5~3 . ~ ~A315 single dose, or preferably two to four divided da~y doses, provided on a basis of about 0.1 to 100 mg., prefera~ly about 1 to 50 mg., per kg. of body weight per day is ap~roDriate to reduce blood pressure.
S The substance is preferably admin:istered orally, but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this inventlon can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effecti~e amount which comprises a total daily dosage of about 30 to 600 mg., pre~erably about 30 to 330 mg. of a comDouna of this invention, and about lS to 300 mg., preferably about 15 to 200 mg.
of the diuretic, to a mammalian species in need thereof. Exemp~ary of the diuretics contemplated for use in combination with a compound of this invention are the thiazide diuretics,~e.g., chlorothiazide, hydrochlorothiazide, flumethia-zide, hydroflumethiazide, bendroflumethiazide, methyclothiazide, trichloromethiazide, poly-thiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spiro-nolactone and salts of such compounds.
The comoounds of formula ~ can be formulated for use in the reduction of blood :

:

.

:, ~
., ~ .
.: :
.;:, ~ :, ;
:. .
~ "` .

2 7f~
~ HA315 _32_ pressure in compositions such as tablets, capsules or elixirs for oral administration, or in sterile solutions or susPensions for parenteral administration. About lO to 500 mg.
of a compound of formula I is compounded with physiologically accepta~le vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage fo~n as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosaye in the range indicated is obtained.
The compounds of formula I wherein X is -NH-CH-COOR6 aiso possess enkephalinase inhibition activity and are useful as analgesic agents. Thus, by the administration of a composition containi~g one or a combination of such compounds of formula I or a pharmaceutically acceptable salt thereof, pain is alleviated in the mammalian host. A single dose, or preferably two to four divided daily doses, provided on a hasis of about 0.1 to about lO0 mg. per kilogram of body weight per day, preferably about l to about 50 mg. per kilogram per day, produces the desired analgesic activity.
The composition is preferably administered orally but parenteral routes such as sùbcutaneous can also be employed.

~ Z ~ ~ S ~ HA315 /

The following examples are illustrative of the invention. Temperatures are given in degrees centigrade. LH-20 refers to a Sephadex chromatography gel commercially available from Pharmacia Fine Chemicals.

:: :

: :

, :

:

* Trade Mark , ~: ~ , , ,:

- ,.~:: ~- , , .
. .~, . .
:. :

~27~35~

Example 1 1-[N-[(3S)-3-(Benzoylamino)-2~mercapto-4-phenyl-butyll-L-alany~i-L-prol~ isomer A) a~ 4-Metho~yphen~L~thyl disulfide A benzene solution of iodine is added to a stirred mixture of 4-methoxybenzenemethanethiol ~25 g., 0.162 mole) in benzene (300 ml.) and water (300 ml.) containing sodium bicarbonate (29.4 g., 0.35 mole) until the color of iodine persists.
After stirring for 15 minutes, the excess iodine is quenched with sodium thiosulfate. The benzene fraction is washed with water, aqueous sodium thiosulfate, lN sodium bicarbonate, and brine.
After drying over anhydrous MgSO4, the solvent is removed at reduced pressure to give a brown solid that is washed with ether to give a light tan solid. This material is dissolved in hot ethyl acetate for recrystallization and while cooling the coloxless solution turns dark brown which is indicative of iodine. The resulting solution is cooled in an ice bath and the resulting solid is collected by filtration. This solid is then recry tallized from ethyl acetate and washed with ether to give 15.1 g. of (4-methoxyphenyl)methyl disulide as a colorless solid; m.p. 98 - 100.
Anal. calc'd. for C16~1802S2.
C, 62.71; H, 5.92; S, 20.92 Found: C, 62.60; H, 5.97; S, 20.86.

, . .

.

~7~
~ ~ HA315 b~ (S~-3 [~Benzyloxycarbonyl)amino]-1-diazo-4-Isobutyl chloroformate (23.4 ml., 180 mmole) is added to a solution of N-benzyloxycarbonyl-L-phenylalanine (53.9 g., 180 mmole) and N-methyl-morpholine (19.8 ml., 180 mmole) in dry tetrahydrofuran ~250 ml.) at 20 under argon.
Afker stirring for 15 minutes, the N-methyl-morpholine hydrochloride is removed by filtration and the filtrate is treated with a cold (0), etheral solution of diazomethane. The resulting mixture is allowed to warm to room temperature and stirred f or 2 hours. The excess diazomethane is removed by bubbling a stream of nitrogen through th~ reaction mixture for 30 minutes. The solvent is removed at reduced pressure and the residue is dissolved in ethyl acetate. The resulting solution is washed with water (twice), lN ~odium ~icarbonate (twica), 0.25 M citric acid ~t~ice), and brine. After drying over anhydrous MgSO4, the solvent is removed at reduced pressure and the residue is dissolved in isopropyl e~her. The resulting precipitate is collected by filtration to give 41.07 g. of (S)-3-[(benzylo~ycarbonyl)-amino}-1-diazo-4-phenyl-2-butanone as a light yellow solid. TLC(silica gel, hexane:ethyl acetate; (3:1) Rf = 0.12.

' ~27~35~ HA315 c) ~ uBenzyloxycarbonyl~amlno~benzenebutanoic ~c~
To a solution of (S~3-[(benz~yloxycarbonyl)-amino] l-diazo-4-phenyl-2-butanone (}0 g., 30.8 mmole) in methanol (loa ml. ) is added 0.5 ml.
of a solution of silver benzoate ~l.0 g.) in ~ri-ethylamine (12.5 ml. ) . After nitrogen evolution ceases, an additional O.S mL. o~ th~ silver benzoate/triethylamine solution is added and stirring ~ontinuPd for an additional 15 minutes.
The reaction mixture is treated Wi~l activated charcoal and filtered ~hrough Celite. The filtrate 15 concentrated at reduced pressure and the residue is dissolved in ethyl acetate. This solu~ion is washed with water, lN hydrochloric acid, l~ sodium bicarbonate (twice~, and brlne.
After drying over anhydrous MgS04, the solvent is remo~ed at reduced pressure and th~ xesidue is chromatographed ~Flori-cil~ ether) to give 9.43 g. of (S~-B ~[(benzyloxycarbonyl)amino]-benzenebutanoic acid, methyl e~ter as a waxy yellow solid.
TLC (silica gel; hexane:ethyl acetate; 4:1) Rf = 0.25.
O ~-~ ~= ~
methyl ester A mixture of (S)-3 -[(benzyloxycarbo~yl)-amino] benzenebutanoic acid, methyl estex (10.O g., 30.5 mmole), ~-toluenesulfonic acid monohydrate ~5.8 g., 30.5 mmole), and palladium hydroxide carbon catalyst ~1.0 g.) in 95% ~thanol * Trade Mark (170 ml.) is stirred under a hydrogen atmosphere (balloon). The system is evacuatPd and refilled with fresh hydrogen every 20 minutes. After 1.5 hours, the catalyst is removed by filtration and the filtrate is concentrated at reduced pressure to give a colorless solid.
To a solution of the above colorless solid and diisopropylethylamine (8.23 ml., 47.2 mmole) in anhydrous tetrahydrofuran (150 ml.) at 0 is added benæoyl chloride (6.27 ml., 54 mmole). After stirring for 30 minutes, the mixture is warmed to room temperature and stirring continued or 45 minutes. The reaction mixture is then treated with lN sodium bicarbonate (150 ml.). After stirring for 3~ minùtes, the bulk of the tetrahydrofuran is removed at reduced pressure and the residue is extracted with ethyl acetate. The ethyl acetate fraction is washed with water (twice), lN hydrochloric acid (twice), lN sodium bicarbonate (twice), and brine. After drying over anhydrous MgS04, the solvent is removed at reduced pressure and the residue is washed wi~h hexane to give 8.15 g. of (S)~ benzoylamino)-benzene-butanQic acid, methyl ester as a colorless solid.
TLC (silica gel; hexane:ethyl acetate, 1:1) Rf = 0.38.
e) 1~- a -(Benzoylamino ? - ~ - [ L( 4-methoxyPhenyl)-methyl]thio]-benzenebutanoic acid, methyl ester To a solution of fxeshly distilled diiso-propylamine (2.07 ml., 14.8 mmole) in dry tetra-... . .
- :
'':

... .....

s~
~ HA315 hydrofuran (20 ml.) at 0 under argon is added a hexane solution of n-butyl lithium (6.02 ml. of a 2.4 M solution, 14.5 mmole~. After stirrlng at 0 for 30 minutes, the resulting solution of lithium diisopropylamide is cooled to -78 ~nd a solution of (s)- B -(benzoylamino)-benzenebutanoic acid, methyl ester (2.0 g., 6.72 mmole) in tetrahydrofuran t20 ml.) is added dropwise over a period of 5 minutes. ~fter stirrins at -7~ for 15 minutes, a solution of (4-methoxyphenyl)methyl disulfide (2.5 g., 8.07 mmole) in tetrahydrofuran (9 ml.) is added. After 5 minutes a~ -78, the mixture is warmed to 0 and stirring continued for 45 minutes. The reaction is quenched with lN
hydrochloric acid and diluted with ethyl acetate.
The resulting solukion is washed with water, lN
hydrochloric acid, lN sodium bicarbonate, and brine. After drying over anhydrous NgS04, the solvent is removed at reduced pressure and the residue is flash chromatographed ~silica gel LPS-l;
benzene:ethyl ace~ate, 93:7) to give 1.~5 g. of pale yellow solid tS)- ~ -(benzoylamino)- ~ -[~(4-methoxyphenyl)methyl]thio]-benzenebutanoic acid, methyl ester as a mixture of diastereomers.
TLC (silica gel; benzene:ethyl acetate, 9:1) Rf = 0.29 and 0.26.

" . . . .

3~
~ ~ HA315 f) (S)- ~ -(Benzoylamino)- -[[(4-methox ~henyl ? ~
methyllthiol-~enzenebutanol (isomer A~
Lithium chloride (0.7 g~, 4 eq.) and sodium borohydride (0.62 g., 4 eq.) are added to a solution of (S)-~ -(benzoylamino)- ~[[(4-methoxyphenyl)methyl]thio]-benzenebutanoic acid, methyl ester (1.85 g., 4.11 mmole) in tetra-hydrofuran (2S ml.) and absolute ethanol (25 ml.). After stirring at room temperature for 21 hours, the mixture is quenched with lN hydro chloric acid and diluted with e~hyl ~cetate. The resulting solution is washed with water, lN hydro-chloric acid, lN sodium bicarbonate, and brine.
After drying over anhydrous MgS04, the solvent is removed at reduced pressure and the residue flash chromatographed (silica gel LPS-l; benzene:acetone, 91:9) to give the separated diastereomers of (S)-~ -(benzoylamino)- a ~ E [ ( 4-methoxyphenyl)-methyl]thio]-benze~ebutanol as colorless solids.
Isomer ~; 0.48 g.; TLC (silica gel; benzene:
acetone, 9:1) Rf = 0.27; and isomer B; 0.52 g.;
TLC (silica gel; benzene:acetone, 9:1) R~ = 0.16.
g) ~S)-~ -(Benzoylamino)- a - L[ ( 4-methoxy-~henyl)methYl]thio~benzenebutanal (isomer ~) A mi~ture of anhydrous dimethylsulfoxide (5 ml.) and pyridinium-l-sulfonate (0.91 g.,

5.65 ml. ) at room temperature under argon is stirred for 15 m.inutes and then diluted with dry methylene chloride (5 ml.). To the resulting 3G solution is added a solution of (S)-~ -(benzoyl-... . . . .
" .
;

: -' ' .
. ;.
. '"'~" ' ~ .
" ~

~ ~ HA315 amino)~ ~ -[[(4-methoxyphenyl)methyl]thio3-benzene-bu-tanol (isomer A) (0.48 g., 1.13 mmole~ and diisopropylethylamine (1.98 ml., 11.3 mmole) in methylene chloride (7 ml.). After stirring for 15 minutes, the mixture is diluted with ethyl acetate and washed with water (twice), lN sodium bicar-bonate (twice), and brine. Af~er drying over anhydrous MgS04, the solvent is removed at reduced pressure to give 0.45 g. of (S)- ~ -(benzoylamino)-10 a - [ [ ( 4-methoxyphenyl]methyl]thio]-benzenebutanal (isomer A) as a pale yellow solid. TLC (silica gel; benzene:acetone, 9:1) R~ - 0.44.
h) 1-[N-~(3S)-3-(Benzoylamino)-2-[[(4-methoxy-phenYl)methyl]thiol-4-phenylbutyll-L-alanYll-L-proline, l,l-dimethylet_yl ester (isomer A) A mixture of (S)- ~ -(benzoylamino)-~ -[~(4-methoxyphenyl)methyl~thio]-benzenebutanal (isomer A) (0.45 g., 1.07 mmole~, L-alanyl-L-proline, l,l-dimethylethyl ester (0.78 g., 3.21 mmole), and crushed 3A molecular sieves (2 g.) in tetrahydrofuran (5 ml.) and absolute ethanol (5 ml.) is stirred at room temperature under argon. After 2.5 hours, sodium cyano-borohydride (0.20 g., 3 eq,~ .is added and stirring continued for 15 hours. The reaction mixture is filtered to remove the sieves and the filtrate is diluted with ethyl acetate and washed with water, lN hydrochloric acid (twice), lN sodium bicarbonate, and brine. After drying over anhydrous ~gSO4, the solvent is removad to give ... .

:
''`

. :.

- ~ H~315 the desired product, as a ~ixture of diastereomers, as a pale yellow oil. TLC (silica gel, benzene:acetone, 4:1) isomer A at Rf = 0.30 and isomer B at Rf = 0.13. ~lash chroma~ography (silica gel LPS-1; benzene:acetone, 7:3) affords impure product ~isomer A~. Repeated flash chroma-tography (silica gel LPS-li ethyl acetate:benzene,

6:4) gives 0.20 g. of 1-[N-t(3S)-3-(benzoylamino)-2-[[(4-methoxyphenyl)methyl]thio]-4-phenylbutyl]-L-alanyl]-L-proline, 1,1-dimethylethyl ester (isomer A) as a nearly colorless oil.
i) 1-[~-[(3S~-3-~enzo~yla ino~-2~mercapto-4-~henyl-butyll-L-alanyl]-L-proline (isomer A) A solution of the 1,l-dimethylethyl ester product from part (h) (0.57 g., 0.88 mmole) and anisole (1.0 ml.) in tri~luoroacetic acid (19 ml.) is stirred at room temperature~for 1 hour. After cooling to Q, mercuric trifluoro-acetate (376 mg., 0.88 mmole) is added. After s~irring for 1 hour, the bulk of the tri~luoroace~ic acid is removed at reduced pressure. The residue is treated with ether to afford a colorless solid which is collected by filtration (535 mg.).
The above solid (535 mg.) is dissolved in 80% acetic acid (20 ml.) a~d hydrogen sulfide is bubbled through the solution for 3Q minutes. The resulting black mercuric sulfide is xemoved by filtration through Celite. The filtrate is - , .
. .
., : . -~7~`~5g~
~ HA315 refiltered through a Teflon milllpore filter and concentrated a~ reduced pressure. The residue is chased twice with absolute ethanol, dissolved in water (8 ml.), treated with lN hydrochloric acid (O.S ml.~, and lyophilized to give 0.33 g. of 1- [N- ~ ( 3S ) -3~ (benzoylamino)-2-mercapto-4-phenyl-butyl]-L-alanyl3-L-proline (isomer A) as a colorless solid; m.p. 142-176 (de~.); [ y]20 = -89.6 (c = 1.07, methanol). TLC (silica gel, n-butanol:
acetic acid:water, 4:1:1~ Rf = 0.50.
Anal. calc d. for C25H31~304S HCl 0.38 H20 C, 58.54; H, 6.44; N, 8.19; Cl, 6.91;
S, 6.25; SH, 6.45.
Found: C, 58.S4; ~, 6.44; N, 8.15; Cl, 6.91;
S, 6.15; SH, 6.26.
Example 2 l-~N-~3S~-3-(Benzoylamino)-2-mercaE~o-4-phenvl-butyl3-L-alanY1]-L proline, monohydrochloride (isomer B) a) 1-[N-t(3S)-3-(Benzoylamino)-2-~[(4-methoxyph~yl)methyl~thiol-4-phenylbutyll-L-isomer B) The partially pllrified mixture of diastereo-mers from Example 1(h), in which isomer B is the major component, is rechxomatographed (flash, silica gel LPS-l; chloroform:methanol, 99:1) to give 0.26 g. of l-~N-[(3S)-3-(benzoylamino)-2-.

, ~
.
:.

35~

~3_ [[(4~methoxyphenyl)methyl]thio]-4-phenylbutyl]-L-alanyl]~L-prollne, l,l-dimethylethyl ester (isomer B) as a colorless oil. TLC (silica gel;
chloroform:methanol, 96:4) Rf = 0.28.
5 b ) 1~ LN- t(3S~-3~(Benzoylamino ? -2 -mer. cap to-4-phenYlbutyll-L-alanyll-L-proline, monohydro-chloride (isomer Bl A solution of the 1,l-dimethylethyl ester product from part (a~ ~0.26 g., 0.40 mmole) and anisole (0.5 ml.) in trifluoroacetic acid (9.5 ml.) is stirred at room temperature for one hour.
After cooling to 0, mercuric trifluoroacetate (171 mg.,l eq.) is added. After stirring for 45 minutes, the bulk of the trifluoroacetic acid lS is removed at reduced pressure. The residue is treated with ether to ~ive a colorless product which is collected by filtration (260 mg.).
The above colorless solid (260 mg.) is dissolved in 80% acetic acid (lO ml.) and hydrogen sulfide is bubbled through this solution for 30 minutes. The r~sulting black mercuric sulfide is removed by filtration through Celite. The product is refiltered (Teflon millipor~3 ~nd the filtrate is conce~trated at reduced pres~ure. The residue i~ chased once with absolute athanol, dissolved i~
water ~10 ml.), and the~ treated with lN hydro-chloric acid. The resulting solution is lyophi-liz~d to give a white fluffy solid (150 mg.).
This material i5 disso}ved in water (9 ml.~, 39 filtered (Teflo~ millipore), ~ld relyophilized * Trade Mark ,:, ~

.: . : . , :
,.:

..
..... :.,:;. ,;: ..
' ::

' ' , : .

~7~5~
~ ' HA315 -4~-to a white fluffy solid which is then dxied under vacuum over phosphorus pentoxide to give 136 mg.
of l-[N [(3S)-3-(benzoylamino)-2-mercapto~4-phenylbu~yl]-L-alanyl]-L-proline, monohydro-chloride (isomer B); m.p. 147-162; ~a ]D
= -64.5 (c = 1.06, methanol). TLC (silica gel;
n-butanol:acetic acid:water, 4:1:1) Rf = 0.47.
. r 25~31N~O4S HCl 0.36 H~O:
C, 58.58; H, 6.44; N, 8~20; S, 6.25;
Cl, 6.92; SH, 6.45 Found: C, 58.58; ~, 6.50; N, 8.14; S, 6.15;
Cl, 6.71; SH, 6.10.
Example 3 l-[N-~(3S)-3-(BenzoYlamino)-2-mercapto-4-phenyl-butvlL~L-lvsyl]-L-proline~ monohydrochloride (isomer A~
a) 1-[N2-[(BenzYloxy)carbonylL-N6-t(l~l-dimethyl-ethoxy~arbonyl~-L lysy~l~L_proline, 1,1-dimethyl-ethyl ester A suspension of N2-[(benzyloxy)carbonyl~-N6-[(1,1-dimethylethoxy)carbonyl]-L-lysine, dicyclohexylami~e salt ~10.0 g., 17.8 mmole) in ethyl acetate (300 ml.) is extracted with lN
hydrochloric acid ~three times~. The organic phase is then washed with water and brine. After drying over anhydrous MgS04, the solvent is removed to give 5.81 g. of N -[(benzyloxy)-carbonyl~-N6-[(1,1-dimethylethoxy)carbonyl]~L-lysine as a pale yellow oil.

.

~, ..

35~
~315 To a solution of N2-[~benzyloxy)carbonyl] N6-[(1,1-dimethylethoxy)carbonyl]-L-lysine ~5.81 g., 15.3 mmole) and L-proline, l,l-dim~thylethyl ester (2.80 g., 16.4 mmole) in dry methyle:ne chloride (70 ml.~ is added 1-hydroxybenzotriazole (2.02 g., 14.95 mmole) and dicyclohexylcarbodiimide (3.09g., 14.98 mmole). After stirring at room temperature for 15 hours, the mixture is filtered to remove the dicyclohexylurea. The filtrate is concentrated at reduced pressure and the residue is dissolved in ether and refiltered. The filtrate is washed with water (twice), lN hydro-chloric acid (twice), lN sodium bicarbonate, and brine. After drying over anhydrous MgS04, the solvent is removed at reduced pressure and the residue is flash chromatographed (silica gel LPS-1; hexane-ethyl acetate, 1:1) to give 8.13 g. of 1-[N2-[(benzyloxy)carbonyl]-N6- L ( 1, dimethylethoxy)carbonyl]-L-lysyl~-L-proline, l,l-dimethylethyl ester as a colorless oil.
TLC (silica gel; hexane:ethyl acetate, 1 Rf - 0.21.
b) l-~N6~f(1,1-Dlmethylethoxy)carbonyl]-L-lysyl~-L-proline, 1,1-dimethylethyl ester A mixture of the l,l-dimethylethyl ester product from part (a) (4.13 g., 7.73 mmole) and palladium hydroxide/carbon catalyst (400 mg.) in ethyl acetate (90 ml.) and ethano~ (10 ml.) is stirred under a hydrogen atmosphere (balloon).
The system is evacuated and refilled with fresh . .:

~ ~ . ., -.,: '', , .

O~f.
R ~ ~ ~ HA315 hydrogen every 30 minutes. After stirring for 3 hours, the catalyst is removed by ~iltration (Teflon millipore~ and the filtrate is concen-trated at reduced pressure to give 3.15 g. of 1-[N6-[(l,l~dimethylethoxy)carbonyl]-L lysyl~-L-proline, l,1-dimethylethyl ester as a colorless solid.
c3 1-[N-[(3SL~-(Benzoylamino)~2-[~(4-methoxy-phenyllmethyllthiol-4 phen~lbutyll-N6~
dlmethylethox~)carbonyl]-L-lysy~J-L-proline, 1,1-dimeth~lethyl ester (isomer A) A mixture of ~Sj~ benzoylamino)~
~ -[[(4-methoxyphenyl)methyl]thio]-benzene-butanal (isomer A) (O.59 g. 1.40 mmole), 1-15 [N6-[(l,l~dimethylethoxy)carbonyl]-L-lysyl~-L-proline, 1,1-dimethylethyl ester (1.55 g., 3.88 mmole), and crushed 3A molecular sieves (2.0 g.) in tetrahydrofuran (5 ml.) and absolute ethanol (5 ml.) is stirred at room temperature under argon. After stirring for 2 hours, sodium cyanoborohydride (0.27 g., 3 eq.) is added and stirring continued for 18 hours. The reaction mixture is filtered through Celite to remove the sie~es. The filtrate is ~hen diluted with ethyl 2s acetate and washed with water, lN hydrochloric acid (twice), lN sodium bicarbonate, and brine.
After drying over anhydrous MgS04, the solvent is removed at reduced pressure to give the desired product, a mixture of dias~ereomers, as a pale yellow oil. TLC (silica gel,b~nzene:aretone .,.. ~

., .

. .
.. . .

12~r35~

4:1) isomer A at ~f = 0.31, and isomer B at Rf =
0.15. Repeated chromatography (flash, silica gel LPS-l; chloroform:methanol, 98:2; hexane:acetone, 65:35; benzene:acetone, 4:1; ethyl acetate:hexane, 6:4; ethyl acetate:hexane, 6:4) gives 0.41 g. of l-[N-[~3S)~3-(benzoylamino)-2-[~(4~methoxyphenyl) methyl]thio]-4-phenylbutyl~-M6-[(l,l~dimethyl-ethoxy)carbonyl]~L-lysyl]~L-prolin~,l,l-dimethyl-ethyl ester (isomer A) as a colorless oil.
d) 1-[N-~(3S)-3-(Benzoylamino)-2-mercapto-4-phenylbutyll~L-lysyl]-L-Proline, monohydro-chloride (isomer A) A solution of the l,l-dimethylethyl este:r product from part (c) (0.41 g., 0.51 mmole) and anisole (0.6 ml.) in trifluoroacetic acid (12 ml.
is stirred at room temperature for o~e hour.
After cooling to 0, mercuric trifluoroacetate (217 mg., 1.0 e~.) is added. After stirring for one hour at 0, the bulk o~ the trifluoroacetic acid is removed at xeduced pr~ssure. The residue is treated with ether to give a colorless solid which is collected by filtration (0.49 g.).
This solid (0.49 g.) is dissolved in 80%
acetic acid (17 ml.) and hydrogen sulfide is bubbled through the solution for 30 minutes. The resulting black m~rcuric sulfide is removed by filtration through Celite. The filtrate is, refiltered (Teflon millipore) and then concentrated at reduced pressure. The residue is ~, . . . .

':

;

,:

35~

dissolved in water (lO ml.~ and treated with lN
hydrochloric acid (1.5 ml.~ and then lyophilized.
The material is xedissolved in water containing a small amount of hydrochloric acid and relyophilized. The material is finally lyophilized rom water to give 290 mg. of l-~N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenyl-butyl]-L-lysyl]-L-proline, monohydrochlorida ~isomer A); m.p. 157 - 180; [ ~ ]20 = -60.0 (c = 1.15, methanol). TLC (silica gel; n-butanol:
acetic acid:water, 4:1:1) Rf = 0.16.
Anal.calc d- for C28H38N404S 2HCl 2 C, 54.45; H, 6.85; N, 9.07; S, 5.19;
Cl, 11.48; SH, 5.35 Found: C, 54.35; H, ~.67; N, 8.97; Sr 5.20 Cl, 11.36; S~, 5.23.
Examples 4 - 42 Following the procadure of Examples 1 to 3 the carboxylic acid methyl ester shown in Col. I
is reacted with (4-methoxyphenyl)me~hyl disulfide to yield the carboxylic acid methyl ester shown in Col. II. This is then converted to the corresponding alcohol and then the aldehyde shown in Col. III. The aldehyde is then reacted with the peptidyl ester shown in Col. IV to yield the protected sulfide product shown in Col. V.
Re~oval of the S-protecting group and the car~oxylic acid ester group yields the final product shown in Col. VI.

~7~

Col R3 CH C~12 3 NEI
C--O

Col. II

3 ! CH - COCH3 NH S

~3 ~27~35~

~IA315 --50~

Col. III

N~ S
C=O ,CH2 R2 ~
oc~3 Col. IV

HN--CH--C--X
(L) : , : .
- ' :

. .

.

~. "' ~:`: ., ' '' -~27~3~

Col V

I 1 11 , R3 CH CE~--CH2 N- CH--C -X
NH S ( L ) C=O l H2 Col. VI

:: NH SH ( ) C=O
~2 :

' ~ ` . ..

~7~35~

-52- H~315 ~" 'T' S -- N c) U ~

~c t u~
Z

~ U,~, r~

N
C

~p ` U7 ~9 ' ~`

., ' "` ' ,. ' ,~''"'~ '"

'~' ' ~7~35~
E~a3 1 5 ~a ~-'1 N ~ ~ t) ~1 I oo cr~ o .

.;

:
'',,~

' "" ~ , ~', ' `
"

35~

~t ~ ~ U ~

Z Z

t U~ , N

N ~ I

:1 ~ .

.. . .
, .~ . .

,,, " :~ , ' ', ', ~
:, . ' ~ .:
. . .~ , . .
' . , ' ': ' ' ' ' ' . .: ' ' '. ' ' :: ' ' :
. : . . .
',":"; ~' ',.~ ' ~
:' : -: .

`3S~

V~ ~: ' ~cZ' li' sr' :c~
:

~.

' .':,. ;

~ , ' .: `
' ` ' '~:

~76:~35~

~ ^,~, .

X I
C~

N

:

1 =,, , , .

''' " " ' ~'':', ~'"' `' ' ~
'; ` . ' ; ~
~ , "' ~' ' , .

~2~7~135~

(~) /
U ~ U U
s s ~`I U~ ~ U~
O = o Z~
:;:

~ ~ ~ . ~ U
U~

~ o,1 ~
~ . ~, ,~, ~ ~

'` ,~.
' - i' ' '~

~.7~
H~315 ,~

J ~ [o ~

U
N N

~1 ~æ

N
N U
~r _ ~U
~1 t , , . - . ...

~, ,. ' ~2~5!:~'~

~s U~
~ ~ V"
C~

~ Ci U ,1_ 5 ~:: ,. ~
~,:: ' .;
:: ' .

~7$35q~
. _ HA315 ~ -- .
~ U U
8 ~ ~ u~
~ U _ C,) K ~
.

U~

U~

,,~
.
, ::. ::::' ' : ` : : - :
~::
.:
, : ,:
`~ ~': ' :
' ~2 7~ ~5~ HA3 15 --Zl--X :~:
(~ , ~3 s u- u X I Z Z ~

U
U

~: (`',t l uu~ U
2 3:

U' ~

.
'', , t '" ;"';~

5g~

$ :~

L~ ~ U'~

~ ~ ~ ~1 0--~

C~

5:

.

a~
~D 1-- CO
' ~ '~

' -- ' , .. . .

':'. ': ~ .
:' ~ ' ' :
~; .,; ', , '' s~

\
~; I $ , o~

Y~
o--V ,~ 5~ ~ ~
V ~N
Q ~5 Z

t~
~J

O
x ~ ~r ~
~ .

, ,., .'' . ;:
,`' '' ' ~'~ '' .. ~
: ~' _64--I ~

~î
r~c ~
.
x I --ta I

lY

~ .
. . .. . . . .

.. --.. ~ :

... .

3~2~7~ 3 _65-The R1 protecting groups in Examples 20 to 26, the R3 protecting group in Example 29, and R5 protecting group in Example 35 are removed as the last step in the synthesis. The 4-azidoproline of Example 30 when treated wlth the reducing agent will yield a 4-aminoproline product. The R6 es~er groups shown in Examples 37 to 42 are not removed.
Examples 43 - 55 1-[N-[(3S)-3-(Benzoylamino)-2-[[(4-methoxy-phenyl)methyl]thio]-4-phenylbutyl]-L-aianyl]-L-proline (isomer A) is treated with the reagent listed below in Col. I to give the product shown in Col. II.
Col. II

S-CH2 ~ -OCH3 1 ~ ~
~ C- NH- CH -CH -CH2- NH - C,H - C ~ N ~ C~OR6 ~3 Deprotection by treatment with mercuric trifluoro-acetate yields the desired final product.

.
, ': ` '`"

.

3~

ExampLe Col~ I 6 O O
tl . Il 43Cl-CH-O-C-C2H5 -CH-O-C-C H
bo (~o 44Cl-C~-O C-C2H5 -CH-O-C-C H
CH(CH3)2 CH(CH3)2 O O
Il 11 45Cl-CH2-0-C-C(CH3)3-CH -O-C-C(CH ) O O
. Il 11 46Br-CH -O-C-CH -CH2-0-C-CH3 O O
47Cl-CH2-o-c ~ -C~2-0-C

O O
:~ 48I-CH2-C-O-CtCH3)3-CH2-C-O-C(C~3)3 11 ~ 11 I
~ CH3 ~ CH3 ''; ,' . . .
..~ :,, .

~L~7~5~

Example Col. I R

CEI-- ¦ CH2--CH ~ 2¦ CH (CH2 OH) 2 OH

OH O o OH OH
HC~))2t(~) 2 52 H-CH2-CH2-N (CH3) 2 -CH2-CH2-N (C~3) 2 53 HO- (CH2) 2~32 2~) 54 E!O- (CH2) 3~N( 2) 3~N

HO- (CF~2) 2~) ~) In the case of Examples 50 to 55, the reaction with the reagent listed in Col. I is performed in the presence of a coupling agent such as dlcyclohexyLcarbodlimide.

, ~27~3~

~ [~35 butyll-L-alanyl]-L-prol ~e! sodium salt ~lsomer A~
l-[N-~(3S)-3-(Benzoylamino)-2-mercapto-~5 phenylbutyl~-L-alanyl~-L-proline (isom~r A) (1 mmole) is dissolved in water (50 ml.). Aqueous ~odium bicarbonate (0.1 N, 20 ml.) is added and the aqueous solution is lyophilized. It is then dissolved in water (lO ml.~ and applied on a column (5 cm. x 60 cm.~ of Sephadex chromatography gel G-10 and eluted with water. Fractions containing the de~ired product are pooled and lyophilized to give 1-tN-~(3$)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline, sodium salt (isomer A~.
Example 57 1000 tablets each containing the followin~
ingredients l-[N~[(3S)-3-(Benxoyl~mi~o)-2-mercapto-4~phanylbutyl]-L-alanyl 3 -~proline, sodium salt ( isomer A ) 100 mg .
Cor~ starch 50 mg.
Gelatin 7.5 mg.
25 Avicel(~icrocrystalli~e cellulose) 25 mg.
Magnesium stearate ~
185 mg.
are prepared from ~ufficient bulk quantities by : mixing ~he 1- tN-t(35)-3~(benzoylamino)-2-mercapto-4 phenylbutyl]-L-alanyl~-L-proline, sodium salt * Trade Mark ' ~ :

~ , .

~7~1 ~5~

~A315 (isomer A) and corn starch with an aLqueous soIution of the gelatin. The mixture! is dried and ground to a fine powder. The Avicel and then the ma~nesium stearate are admixed with granulation.
This mixture is then compressed in a tablet press to form lOQ0 tablets each containing 100 mg. of active ingredient.
In a similar manner, tablets containing 100 mg. of the product of any of Examples 1 to 55 can be prepared.
A similar procedure can be employed to form tablets containing 50 mg. o active ingredient.
Example 58 Two piece #l gelatin capsules each containing 50 mg. of 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-lysyl]-L-proline, monohydrochloride (isomer A) are filled with a mixture of the following ingredients:
l-~N-~3S)-3-(benzoylamino)-2-mercap~o-4-phenylbutyl]-L-l~syl]-L-proline, monohydro-chloride (isomer A) 50 mg.
Magnesium stearate 7 mg.
Lactose 193 mq.
250 mg.
In a similar manner capsules containing 50 mg. of the product of any of Examples 1,2 and 4 to 56 can be prepared.

.
~, .

, ~
.

51~

Example 59 An injectable solution is prepared as follows:
1-EN-[(3S)-3-(Benzoylamino)-2-5 mercapto-4-phenylbutyl]-L-alanyl~-L-proline, sodium salt (isomer A) 500 g.
Methyl parahen 5 g.
Propyl paraben l g.
10 Sodium chloride 25 g.
Water for injection 5 The active substance, preservatives, and sodium chloride are dissolved in 3 liters of water for injection and the~ the volume is brought up to 5 liters. The solution is filtered through a stexile filter and aseptically filled into pre-sterilized vials which are closes with presterilized rubber closures. Each vial contains 5 ml. of solution in a concentra~ion of 100 mg. of active ingredient per ml. of solution for injection.
In a similar manner, an injectable solution containing 100 mg. of active ingredient per ml. of solution can be prepared for the product of any of Examples l to 56.

- .

.

':
.; ,.

~27~35(~
~ HA315 Example 60 1000 tablets each containing t;he following ingredients:
l-[N-[~3S)-3-(senzoylamino)-5 2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline, sodium salt (isomer A) 100 mg.
Avicel 100 mg.
Hydrochlorothiazide 12.5 mg.
10 Lactose 113 mg.
Cornstarch 17.5 mg.
Stearic Acid 7 mg.
350 mg.
are prepared from sufficient bulk quantitites by slugging the 1-[N-[(3S)-3~(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline, sodium salt (isomer A), Avicel, and a portion of the stearic acid. The slugs are ground and passed through a #2 screen, then mixed with the hydro-chlorothiazide, lactose, cornstarch, and remainder of the stearic acid. The mixture is compressed - into 350 mg. capsule shaped tablets in a tablet press. The tablats are scored for dividing in half.
In a similar manner, tablets can be prepared containing 100 mg. of the product of any of Examples 1 to 55.

, ., ~' .

Claims (28)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A compound of the formula or a pharmaceutically acceptable salt thereof wherein X is n is zero, one, or two.
R25 is lower alkyl of 1 to 4 carbons or R is hydrogen, lower alkyl, cycloalkyl, -(CH2)2-NH2, -(CH2)3-NH2 , -(CH2)4-NH2, -(CH2)2-OH , -(CH2)3-OH , -(CH2)4-OH, -(CH2)2-SH, -(CH2)3-SH, or -(CH2)4-SH;

R1 is hydrogen, lower alkyl, halo substituted lower alkyl, - (CH2)r-OH , -(CH2)r-NH2 , -(CH2)r-SH, -(CH2)r-S-lower alkyl, -(CH2)2-S-(CH2)2-NH2, or R2 is R3 is hydrogen, lower alkyl, halo substituted lower alkyl, - (CH2)m-cycloalkyl, -(CH2)r-NH2 , -(CH2)r-SH , (CH2)r-S-lower alkyl, or R4 is hydrogen, lower alkyl, - (CH2)m-cycloalkyl, or R5 is hydrogen, lower alkyl, R5 is hydrogen, lower alkyl, -(CH2)r-OH , -(CH2)r-NH2, -(CH2)r-SH, -(CH2)r-S-lower alkyl, , or ;

r is an integer from 1 to 4;
R7 is hydrogen, lower alkyl, halogen, hydroxy, -NH-?-lower alkyl, amino, a 1- or 2-naphthyl of the formula , -(CH2)m-cycloalkyl, -O-lower alkyl, a 1- or 2-naphthyloxy of the formula -S-lower alkyl, , or a 1- or 2-naphthylthio of the formula R8 is halogen, , -O-lower alkyl, a 1- or 2-naphthyloxy of the formula -S-lower alkyl, , or a 1- or 2- naphthylthio of the formula R9 is keto or R10 is halogen or -Y-R16;
R11, R'11, R12 and R'12 are independently selected from hydrogen and lower alkyl or R'11, R12 and R'12 are hydrogen and R11 is R13 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl;
R14 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, or hydroxy;
m is zero, one, two, three, or four;
p is one, two or three provided that p is more than one only if R13 or R14 is hydrogen, methyl, methoxyr chloro, or fluoro;
R15 is hydrogen or lower alkyl of 1 to 4 carbons;
Y is oxygen or sulfur;
R16 is lower alkyl of 1 to 4 carbons, or the R16 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a lower alkyl of 1 to 4 carbons or a di(lower alkyl of 1 to 4 carbons) substituent;
R19 is lower alkyl, benzyl, or phenethyl;
R20 is hydrogen, lower alkyl, benzyl or phenethyl;
R20 is hydrogen, lower alkyl p-methoxybenxyl, benzhydryl, -CH-(CH2-OH)2 , R17 is hydrogen, lower alkyl, cycloalkyl or phenyl;
R18 is hydrogen, lower alkyl, lower alkoxy, phenyl, or R17 and R18 taken together are -(CH2)2-, -(CH2)3- , -CH=CH, or R24 is hydrogen, lower alkyl, R21 and R22 are independently selected from the group consisting of hydrogen and lower alkyl; and R23 is lower alkyl.

2. A compound of Claim 1 wherein:
R is hydrogen, straight or branched chain lower alkyl of l to 4 carbons, or phenyl, R1 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, CF3, -(CH2)r-NH2, -CH2-SH, -(CH2)2-S-(CH2)2-NH2, -(CH2)2-S-CH3, -CH2-OH, or R4 is hydrogen, cyclohexyl, or phenyl;

R5 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, -CH2-OH, -(CH2)4-NH, -CH2-SH, -(CH2)2-S-CH3 , or R6 is hydrogen, straight or branched chain lower alkyl of l to 4 carbons, an alkali metal salt ion, -CH-(CH2-OH)2, -(CH2)2-N(CH3)2, or R17 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or cyclohexyl;
R18 is straight or branched chain lower alkyl of 1 to 4 carbons or phenyl;
R23 is straight or branched chain lower alkyl of 1 to 4 carbons;
R2 is R3 is straight or branched chain lower alkyl of 1 to 4 carbons, -(CH2)r-NH2, R7 is hydrogen, hydroxy, straight or branched chain lower alkyl of 1 to 4 carbons, cyclohexyl, amino, -O-lower alkyl wherein lower alkyl is straight or brançhed chain of 1 to 4 carbons, 1-naphthyloxy, 2 naphthyloxy, -S-lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons, 1 naphthylthio, or 2-naphthylthio;
R8 is -O-lower alkyl, -S-lower alkyl, or wherein lower alkyl is straight or branched chain of 1 to 4 carbons, R9 is phenyl, 2-hydroxyphenyl or 4-hydroxyphenyl;
R10 are both fluoro, both chloro, or both -Y-R16;
Y is O or S;
R16 is straight or branched chain lower alkyl of 1 to 4 carbons or the R16 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the available carbons has a methyl or dimethyl substituent;
R11, R11', R12 and R12' are all hydrogen or R11 is phenyl, 2-hydroxyphenyl, or 4-hydroxyphenyl and R11', R12 and 12' are all hydrogen;
r is an integer from 1 to 4;
m is zero, one, or two;
R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy;
R14 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy; and R24 is phenyl.

3. A compound of Claim 2 wherein:
X is or R is hydrogen or methyl;
R1 is hydroyen, methyl, or - (CH2)4-NH2;
R6 is hydrogen, straight or branched chain lower alkyl o f 1 to 4 carbons, or an alkali metal salt ion;
R4 is cyclohexyl or phenyl and R5 is hydrogen or R4 is hydrogen and R5 is methyl, -CH2-CH(CH3)2, or R7 is hydrogen, cyclohexyl, lower alkoxy of 1 to 4 carbons, or m is zero, one or two;
R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy; and t is 2 or 3.

4. A compound of Claim 3 wherein X is wherein R5 and R6 are defined as in claim 3.

5. A compound of Claim 3 wherein X is wherein R6 is defined as in claim 3.

6. A compound of Claim 3 wherein X is wherein R6 is defined as in claim 3.

7. A compound of Claim 3 wherein X is wherein R6 and R7 are defined as in claim 3.

8. A compound of Claim 7 wherein R2 is phenyl; and R3 is

9. A compound of Claim 8 wherein R7 is hydrogen.

10. A compound of Claim 9 wherein R6 is hydrogen;
R is hydrogen; and R1 is methyl.

11. Ths compound of Claim 10, 1-[N-((3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline (isomer A).

12. The compound of Claim 10, 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline (isomer B).

13. A compound of Claim 9 wherein R6 is hydrogen;
R is hydrogen; and R1 is -(CH2)4-NH2.

14. The compound of Claim 13, 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-lysyl]-L-proline, monohydrochloride (isomer A).

15, A pharmaceutical composition com-prising a compound of the formula or a pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically accept-able carrier therefor, wherein X is or n is zero, one, or two.
R25 is lower alkyl of 1 to 4 carbons or R is hydrogen, lower alkyl, cycloalkyl, -(CH2)2-NH2, -(CH2)3-NH2 , -(CH2)4-NH2, -(CH2)2-OH , (CH2)3-OH , -(CH2)4-OH, -(CH2)2-SH, -(CH2)3-SH, or -(CH2)4-SH;
R1 is hydrogen, lower alkyl, halo substituted lower alkyl, -(CH2)r-OH , -(CH2)r-NH2 , -(CH2)r-SH,-(CH2)r-S-lower alkyl,-(CH2)2-S-(CH2)2-NH2 , or R2 is or R3 is hydrogen, lowor alkyl, halo substituted lower alkyl, -(CH2)m-cycloalkyl, -(CH2)r-OH , -(CH2)rNH2 , -(CH2)r-SH , -(CH2)r-S-lower alkyl, R4 is hydrogen, lower alkyl, -(CH2)m-cycloallcyl, or R5 is hydrogen, lower alkyl, -(CH)r-OH , -(CH2)r-NH, -(CH2)r-SH, -(CH2)r-S-lower alkyl, or r is an integer from 1 to 4:
R7 is hydrogen, lower alkyl, halogen, hydroxy, alkyl, amino, a 1- or 2-naphthyl of the formula -(CH2)m-cycloalkyl, lower alkyl, a 1- or 2-naphthyloxy of the formula -S-lower alkyl, or a 1- or 2-naphthylthio of the formula R8 is halogen, , -O-lower alkyl, a 1- or 2-naphthyloxy of the formula -S- lower alkyl, , or a 1- or 2-naphthylthio of the formula R9 is keto or R10 is halogen or -Y-R16;
R11, R'11, R12 and R'12 are independently selected from hydrogen and lower alkyl or R'11, R12 and R'12 are hydrogen and R11 is R13 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl;
R14 is hydrogen, lower alkyl or 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, or hydroxy;
m is zero, one, two, three, or four;
p is one, two or three provided that p is more than one only if R13 or R14 is hydrogen, methyl, methoxy, chloro, or fluoro;
R15 is hydrogen or lower alkyl of 1 to 4 carbons;
Y is oxygen or sulfur;
R16 is lower alkyl of 1 to 4 carbons, or the R16 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a lowr alkyl of 1 to 4 carbons or a di(lower alkyl of 1 to 4 carbons) substituent;
R19 is lower alkyl, benxyl, or phenethyl;
R20 is hydrogen, lower alkyl, benzyl or phenethyl;
R6 is hydrogen,lower alkyl,p-methoxybenzyl,benxhydryl, -CH-(CH2-OH)2 , R17 is hydrogen, lower alkyl, cycloalkyl or phenyl;
R18 is hydrogen, lower alkyl, lower alkoxy, phenyl, or R17 and R18 taken together are -(CH2)2-, -(CH2)3- , -CH=CH, or R24 is hydrogen, lower alkyl, or R21 and R22 are independently selected from the group consisting of hydrogen and lower alkyl; and R23 is lower alkyl.

16. A composition of Claim 15 wherein:
R is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or phenyl;
R1 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, CF3, -(CH2)r-NH2, -CH2-SH, -(CH2)2-S-(CH2)2-NH, -(CH2)2-S=CH3, -CH2-OH , or R4 is hydrogen, cyclohexyl, or phenyl;

R5 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, -CH2-OH, -(CH2)4-NH2 , -CH2-SH, -(CH2)2-S-CH3 , or R6 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, an alkali metal salt ion, -CH-(CH2-OH)2 , -(CH2)2-N(CH3)2 , or R17 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or cyclohexyl;
R18 is straight or branched chain lower alkyl of 1 to 4 carbons or phenyl;
R23 is straight or branched chain lower alkyl of 1 to 4 carbons;
R2 is R3 is straight or branched chain lower alkyl of 1 to 4 carbons, -(CH2)r-NH, or R7 is hydrogen, hydroxy, straight or branched chain lower alkyl of 1 to 4 carbons, cyclohexyl, amino, -O-lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons, 1-naphthyloxy, 2-naphthyloxy, -S-lower alkyl wherein lower alkyl is straight or branched chain of 1 to 4 carbons, 1-naphthylthio, or 2-naphthylthio;
R8 is -O-lower alkyl, -S-lower alkyl, or wherein lower alkyl is straight or branched chain of 1 to 4 carbons, R9 is phenyl, 2-hydroxyphenyl or 4-hydroxyphenyl;
R10 are bother fluoro, both chloro, or both -Y-R16;
Y is O or S;
R 16 is straight or branched chain lower alkyl of 1 to 4 carbons or the R16 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the available carbons has a methyl or dimethyl substituent;
R11, R11', R12, R12', are all hydrogen or R11 is phenyl, 2-hydroxyphenyl, or 4-hydroxyphenyl and R11', R12 and R12' are all hydrogen;
r is an integer from 1 to 4;
m is zero, one, or two;
R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy;
R14 is hydrogen, methyl, methoxy, methlthio, chloro, bromo, fluoro, or hydroxy; and R24 is phenyl.

17. A composition of Claim 16 wherein:
X is R is hydrogen or methyl;
R1 is hydrogen, methyl, or -(CH2)4-NH2;
R6 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or an alkali metal salt ion;
R4 is cyclohexyl or phenyl and R5 is hydrogen or R4 is hydrogen and R5 is methyl, -CH2-CH(CH3)2, , or M is zero, one or two;
R13 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy; and t is 2 or 3.

18. A composition of Claim 17 wherein:
X is wherein R5 and R6 are defined as in claim 17.

19. A composition of Claim 17 wherein X is wherein R6 is defined as in claim 17.

20. A composition of Claim 17 wherein X is wherein R6 is defined as in claim 17.

21. A composition of Claim 17 wherein X is wherein R6 and R7 are defined as in claim 17.

22. A composition of Claim 21 wherein R2 is phenyl; and R3 is

23. A composition of Claim 22 wherein R7 is hydrogen.

24. A composition of Claim 23 wherein R6 is hydrogen;
R is hydrogen; and Rl is methyl.

25. A composition of Claim 15 wherein the com-pound is 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline (isomer A).

26. A composition of Claim 15 wherein the com-pound is 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-alanyl]-L-proline (isomer B).

27. A composition of Claim 23 wherein R6 is hydrogen;
R is hydrogen; and R1 is -(CH2)4 NH2

28. A composition of Claim 15 wherein the com-pound is 1-[N-[(3S)-3-(benzoylamino)-2-mercapto-4-phenylbutyl]-L-lysyl]-L-proline, monohydrochloride (isomer A).