Di- or tripeptide renin inhibitors containing lactam conformational restriction in ACHPA

Enzyme di- or tripeptides of the formula: ##STR1## and analogs thereof which inhibit renin and are useful for treating various forms of renin-associated hypertension, hyperaldosteronism and congestive heart failure; compositions containing these renin-inhibitory peptides, optionally with other antihypertensive agents; and methods of treating hypertension, hyperaldosteronism or congestive heart failure or of establishing renin as a causative factor in these problems which employ these novel peptides.

The present invention is concerned with novel di or tripeptides which 
inhibit the angiotensinogen cleaving action of the proteolytic enzyme, 
renin, with pharmaceutical compositions containing the novel peptides of 
the present invention as active ingredients, with methods of treating 
renin-associated hypertension, hyperaldosteronism, and congestive heart 
failure, with diagnostic methods which utilize the novel peptides of the 
present invention, and with methods of preparing the novel peptides of the 
present invention. 
BACKGROUND OF THE INVENTION 
Renin is an endopeptidase (molecular weight about 40,000) produced and 
secreted by the juxtaglomerular cells of the kidney. Renin has a high 
specificity for and cleaves the naturally-occurring plasma glycoprotein, 
angiotensinogen, at only the 10, 11 peptide bond, i.e., between the 10th 
(Leu) and 11th (Leu) amino acid residues in the equine substrate, as 
described by Skeggs et al, J. Exper. Med. 1957, 106, 439, or between Leu 
10 and Val 11 in the human renin substrate, as elucidated by Tewksbury et 
al., Circulation 59, 60, Supp. II: 132, Oct. 1979. 
This cleavage of its tetradecapeptide substrate, angiotensinogen, by renin 
splits off the decapeptide, angiotensin I, which is thought to be 
hemodynamically-inactive, but which is converted in the lungs, kidney or 
other tissue by angiotensinconverting enzyme (ACE) to the potent pressor 
octapeptide, angiotensin II. Angiotensin II then causes constriction of 
the arterioles and is also believed to stimulate release of the 
sodium-retaining hormone, aldosterone, from the adrenal gland, thereby 
causing a rise in extra cellular fluid volume. Thus, the renin-angiotensin 
system plays an important role in normal cardiovascular homeostasis and in 
some forms of elevated blood pressure (hypertension). 
Inhibitors of angiotensin I converting enzyme have proven useful in the 
modulation of the renin angiotensin system. Consequently, specific 
inhibitors of the catalytic and rate-limiting enzymatic step that 
ultimately regulates angiotensin II production, the action of renin on its 
substrate, have also been sought as effective investigative tools, as well 
as therapeutic agents in the treatment of hypertension and congestive 
heart failure. 
Renin antibody, pepstatin (another aspartic proteinase, like renin), 
phospholipids, and substrate analogs, including tetrapeptides and octa- to 
tridecapeptides, with inhibition constants (K.sub.i) in the 10.sup.--3 
10.sup.--6 M region, have been studied. 
Umezawa et al., in J. Antibiot. (Tokyo) 23: 259-262, 1970, reported the 
isolation of a peptide, pepstatin, from actinomyces that was an inhibitor 
of aspartyl proteases such as pepsin, cathepsin D, and renin. Gross et 
al., Science 175:656, 1972, reported that pepstatin reduces blood pressure 
in vivo after the injection of hog renin into nephrectomized rats. 
However, pepstatin has not found very wide application as an experimental 
agent because of its limited solubility and its inhibition of a variety of 
other acid proteases in addition to renin. 
Many efforts have been made to prepare a specific renin inhibitor based on 
pig renin substrate analogy, since such analogy has been shown to 
correlate well with and predict human renin inhibitor activity. The 
octapeptide amino acid sequence extending from histidine-6 through 
tyrosine 13 
##STR2## 
has been shown to have kinetic parameters essentially the same as those of 
the full tetradecapeptide renin substrate. 
Kokubu et al., Biochem. Pharmacol., 22, 3217-3223, 1973, synthesized a 
number of analogs of the tetrapeptide found between residues 10 to 13, but 
while inhibition could be shown, inhibitory constants were only of the 
order of 10.sup.--3 M. Analogs of a larger segment of renin substrate have 
been also synthesized, e.g., Burton et al., Biochemistry 14: 892-3898, 
1975, and Poulsen et al., Biochemistry 12: 3882, 1973, but a lack of 
solubility and weak binding (large inhibitory constant) generally 
resulted. 
Modifications to increase solubility soon established that the inhibitory 
properties of the peptides are markedly dependent on the hydrophobicity of 
various amino acid residues. These modifications also established that 
increasing solubility by replacing lipophilic amino acids with hydrophilic 
isosteric residues can become counter-productive. Other approaches to 
increasing solubility have also had limited success. 
Modifications designed to increase binding to renin have also been made, 
but here too, with mixed results. 
A series of inhibitors of renin have been disclosed which contain the 
unnatural amino acid, statine: see, e.g., Veber et al, U.S. Pat. Nos. 
4,384,994 and 4,478,826; Evans et al, U.S. Pat. No. 4,397,786; Boger et 
al, Nature, 1983, 303, 81-84 and U.S. Pat. Nos. 4,470,971; 4,485,099; 
4,663,310 and 4,668,770; Matsueda et al, EP-A 128 762, 152 255; Morisawa 
et al., EP-A 186 977; Riniker et al, EP-A 111 266; Bindra et al, EP-A 155 
809; Stein et al, Fed. Proc. 1986, 45, 869; and Holzemann et al, German 
Offenlegungsschrift DE 3438545. Attempting to explain the effect of 
statine, Powers et al., in Acid Proteases, Structure, Function and 
Biology, Plenum Press, 1977, 141-157, observed that in pepstatin, statine 
occupies the space of the two amino acids on either side of the cleavage 
site of a pepsin substrate and Tang et al., in Trends in Biochem. Sci., 
1:205-208 (1976) and J. Biol. Chem., 251:7088-94, 1976, pointed out that 
the statine residue of pepstatin resembles the transition state for pepsin 
hydrolysis of peptide bonds. 
Renin inhibitors containing other peptide bond isosteres, including a 
reduced carbonyl isostere have been disclosed by M. Szelke et al, in work 
described in published European Patent Applications 45 665 and 104 041; in 
U.S. Pat. No. 4,424,207, and in PCT Int. Appl. WO 84/03044; in Nature, 
299, 555 (1982); Hypertension, 4, Supp. 2, 59, 1981; and British Patent 
1,587,809. In Peptides, Structure and Function: Proceedings of the Eighth 
American Peptide Symposium, ed. V. J. Hruby and D. H. Rich, p. 579, Pierce 
Chemical Co., Rockford, IL., 1983, Szelke et al also showed isosteric 
substitutions at the Leu-Leu site of cleavage, resulting in compounds with 
excellent potency. 
Other peptide bond isosteres have then been disclosed in Buhlmayer et al in 
EP-A 144 290 and 184 550; Hester et al, EP-A 173 481; Raddatz, EP-A 161 
588; Dann et al, Biochem. Biophys Res. Commun. 1986, 134, 71-77; Fuhrer et 
al, EP-A 143 746; Kamijo et al, EP-A 181 110; Thaisrivongs et al, J. Med. 
Chem., 1985, 28, 1553-1555; Ryono et al., EP A 181 071; and Evans et al, 
U.S. Pat. No. 4,609,641. 
Other modifications which have been tried include preparing renin 
inhibitors with non peptide C-termini, such as disclosed in European 
Published Applications 172 346 and 172 347; Evans et al, J. Med. Chem., 
1985, 28, 1755-1756; Bock et al, Peptides, Structure and Function: 
Proceedings of the Ninth American Peptide Symposium, ed. C. M. Deber et 
al, pp.751-754, Pierce Chemical Co., Rockford, IL, 1985; and Plattner et 
al, in Abstracts from the 191st National Meeting of the Anerican Chemical 
Society, April, 1986. Kokubu et al, in Hypertension, 1985, 7, Suppl. I, p. 
8-10 and Matsueda et al, in Chemistry Letters, 1985, 1041-1044 and in 
European Published Applications 128 762 and 152 255 disclosed peptide 
aldehyde renin inhibitors, and Hanson et al in Biochem. Biophys. Res. 
Commun. 1985, 132, 155-161, reported peptide glycol inhibitors. 
These various renin inhibitors all generally comprise peptide-based 
inhibitors in which a sequence of the type: 
...A--B--D--E--F--G--J--K--L... , where G is a peptide bond mimic and 
A,B,D,E,F,J,K, and L may individually be absent or may represent 
naturally-occurring or modified amino acids. Typical sequences of this 
type include: 
##STR3## 
where the N-terminus typically comprises an amino acid protecting group 
such as BOC or CBZ, and the N-terminal amino acids are Pro--Phe--His or 
Phe--His. 
Lower molecular weight renin-inhibitory di-or tripeptides comprising 
acyclic 2-substituted-4-amino-5 cycl-ohexyl-3 hydroxy-pentanoic acid 
(ACHPA) have been disclosed in U.S. Pat. application 45,941, filed May 4, 
1987, and other lower molecular weight peptides have been disclosed in 
Sham, EP 184 855, Bindra et al, EP 155 809, and Matsueda et al, EP 152 
255. 
It was an object of this invention to prepare lower molecular weight 
peptides which have enhanced biological potency in inhibiting the renin 
enzyme. It was also an object to prepare shortened peptide sequences which 
incorporate at the C terminus a stabilizing, conformationally constrained 
dipeptide mimic to replace the 10- and 11-position amino acids in the 
analogous natural substrate. It was a further object to include 
strategically-located substituents at the C- and/or N-terminii of a 
shortened peptide which confer increased potency while constructively 
altering the physical properties of these peptides. It was an additional 
object of this invention to prepare peptides which have greater oral 
bioavailability and increased duration of action. It was still a further 
object of this invention to prepare novel peptides which are more useful 
antihypertensive agents, and compounds useful in treating 
hyperaldosteronism and congestive heart failure. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention is directed to renin-inhibitory di and tripeptides of 
the structure: 
##STR4## 
wherein: A is hydrogen; C.sub.1 -C.sub.6 -alkyl; aryl, where aryl is 
unsubstituted or mono-, di or trisubstituted phenyl, wherein the 
substituent(s) is/are independently selected from the group consisting of 
C.sub.1 -C.sub.7 -alkyl, amino, mono- or di-C.sub.1 -C.sub.4 -alkylamino, 
amino-C.sub.1 -C.sub.4 -alkyl, hydroxy-C.sub.1 -C.sub.4 -alkyl, 
phenyl-C.sub.1 -C.sub.4 -alkyl, mono- or di-C.sub.1 -C.sub.4 
aklylamino-C.sub.1 -C.sub.4 -alkyl, guanidyl, guanidylC.sub.1 -C.sub.4 - 
alkyl, hydroxyl, C.sub.1 -C.sub.4 -alkoxy, trifluoromethyl, halo, CHO, 
--CO.sub.2 H, --CONH.sub.2, --CONH-C.sub.1 -C.sub.4 -alkyl, --CON(C.sub.1 
-C.sub.4 -alkyl).sub.2, --CO-C.sub.1 -C.sub.4 -alkyl, --(CH.sub.2)hd m-13 
.sup.+ N(R.sup.3).sub.2 R.sup.4 A.sup..crclbar., where R.sup.3 is C.sub.1 
-C.sub.4 alkyl, --(CH.sub.2).sub.4 -, --(CH.sub.2).sub.5 --or 
--(CH.sub.2).sub.2 -O-(CH.sub.2).sub.2 --;R.sup.4 is C.sub.1 -C.sub.4 
-alkyl, C.sub.1 -C.sub.4 -hydroxyalkyl, C.sub.1 - C.sub.4 -carboxyalkyl, 
or --CH.sub.2 -phenyl; A.sup..crclbar. is a counterion selected from the 
group consisting of single negatively-charged ions, such as chloride, 
bromide, perchlorate, benzoate, benzene sulfonate, tartrate, maleate, 
hemitartrate, and acetate; and m is 0-to-3; --CO.sub.2 -C.sub.1 -C.sub.4 
-alkyl, --CO.sub.2 -C.sub.1 -C.sub.4 -alkoxy-C.sub.2 -C.sub.4 --alkyl, 
##STR5## 
where A.sup..crclbar. and m are as defined above, and --NR.sup.5 R.sup.6, 
where R.sup.5 and R.sup.6 are independently hydrogen, unsubstituted or 
monosubstituted C.sub.1 -C.sub.4 -alkyl, wherein the substituent is amino, 
mono- or di--C.sub.1 -C.sub.4 --alkylamino or .sup..sym. N(R.sup.3).sub.2 
R.sup.4 A.sup..crclbar., where R.sup.3, R.sup.4 and are as defined above; 
Het, where Het is an unsubstituted or mono-or disubstituted 5- or 
6-membered mono or bicyclic or benzofused 5 or 6 membered heterocyclic 
ring, where the one or two heteroatoms are independently selected from the 
group consisting of N, O, S, NO, SO, SO.sub.2 or quaternized N, and the 
substituent(s) is/are independently selected from the group consisting of 
hydroxyl, thiol, C.sub.1 -C.sub.6 -alkyl, CF.sub.3, C.sub.1 -C.sub.4 
-alkoxy, halo, aryl, as defined above, aryl-C.sub.1 -C.sub.4 -alkyl, amino 
mono- or di C.sub.1 -C.sub.4 -alkylamino, amino-C.sub.1 -C.sub.4 -alkyl, 
hydroxy-C.sub.1 -C.sub.4 -alkyl, mono or di-C.sub.1 -C.sub.4 
-alkylamino-C.sub.1 -C.sub.4 -alkyl, guanidyl, guanidylC.sub.1 -C.sub.4 
-alkyl, CHO, CO.sub.2 H, CO.sub.2 -C.sub.1 -C.sub.3 -alkyl, CONH.sub.2, 
CONH-C.sub.1 -C.sub.4 -alkyl, CON(C.sub.1 -C.sub.4 -alkyl).sub.2, NR.sup.5 
R.sup.6, 
##STR6## 
and -(CH.sub.2).sub.m --.sup..sym. N(R.sup.3).sub.2 R.sup.4 
A.sup..crclbar., wherein R.sup.5, R.sup.6, A.sup..crclbar., m, R.sup.3 and 
R.sup.4 are as defined above, or when the heteroatom is N, the 
substituents are alternatively (CH.sub.2)q or --(CH.sub.2).sub.2 
--O--(CH.sub.2).sub.2 - and form a ring with the N-atom, wherein q is 
3-to-6; where R.sup.2 is C.sub.1 -C.sub.7 -alkyl; hydrogen; Het, as 
defined above; aryl, as defined above; mono substituted C.sub.1 -C.sub.5 
-alkyl, wherein the substituent is selected from the group consisting of 
aryl, as defined above; Het, as defined above; hydroxyl; -CO.sub.2 H; 
CO.sub.2 R.sup.7, where R.sup.7 is C.sub.1 -C.sub.5 -alkyl, aryl, as 
defined above, and aryl-C.sub.1 -C.sub.4 -alkyl; CONH.sub.2 ; 
--CONH-R.sup.7 or --S(O).sub.n --R.sup.7, wherein n is 0-to-2 and R.sup.7 
is as defined above; C.sub.1 -C.sub.4 -alkoxy; C.sub.3 -C.sub.7 
-cycloalkyl; amino; mono- or di--C.sub.1 -C.sub.4 -alkylamino; NH-aryl, 
--NH-CH.sub.2 -aryl or --CO-aryl, where aryl is as defined above; and 
--NH-Het, --NH-CH.sub.2 -Het or --CO-Het, where Het is as defined above; 
##STR7## 
where R.sup.7 is as defined above; or 
##STR8## 
where R.sup.9 is C.sub.1 -C.sub.5 -alkyl, aryl, as defined above, or Het, 
as defined above; 
B and D are independently 
##STR9## 
where R.sup.12 is hydrogen, C.sub.1 -C.sub.5 -alkyl or CH.sub.2 -aryl, 
wherein aryl is as defined above; and R.sup.2 is as defined above; 
##STR10## 
where R.sup.2 is as defined above; or either B or D, but not both 
simultaneously, is absent; 
R.sup.1 is hydrogen; C.sub.3 -C.sub.6 -alkyl; aryl, as defined above; 
unsubstituted, mono-, di- or trisubstituted C.sub.3 -C.sub.7 -cycloalkyl, 
where the substituent(s) is/are selected from the group consisting of 
C.sub.1 -C.sub.4 -alkyl, trifluoromethyl, hydroxyl, C.sub.1 -C.sub.4 
-alkoxy and halo; or unsubstituted or 4-monosubstituted 1,3-dithiolan-2-yl 
or unsubstituted or 4-mono-substituted 1,3-dithian-2-yl, where the 
substituent is (CH.sub.2).sub.m aryl, where m and aryl are as defined 
above; 
##STR11## 
where R.sup.13 and R.sup.14 are independently hydrogen; C.sub.1 -C.sub.7 
-alkyl; C.sub.2 -C.sub.7 -alkenyl; -CO.sub.2 H; -CONH.sub.2 ; CO.sub.2 
R.sup.7, --CO--NH--R.sup.7 or --CO--N(R.sup.7) , wherein R.sup.7 is as 
defined above; mono-substituted C.sub.1 -C.sub.5 -alkyl, wherein the 
substituent is selected from the group consisting of azido; halo; hydroxy; 
C.sub.1 -C.sub.5 -alkoxy; aryl, aryl--CH.sub.2 O, aryloxy, aryl--COO--, 
aryl--CH.sub.2 --NH--or arylamino, where aryl is as defined above; C.sub.1 
-C.sub.5 -alkyl--CO.sub.2 --; R.sup.7 NH--COO--, R.sup.7 --CO--NH--, 
R.sup.7 --NH--CO--NH--or R.sup.7 --S(O).sub.n, where n and R.sup.7 are as 
defined above; amino; mono or di-C.sub.1 -C.sub.4 -alkylamino; and Het, as 
defined above; or R.sup.13 and R.sup.14 are connected to form a 
polymethylene chain of the formula, --(CH.sub.2).sub.p, where p is 2 to 6; 
or 
##STR12## 
where R.sup.13 and R.sup.14 are as defined above; Y is CH.sub.2, O, S, SO 
or SO.sub.2 ; or 
Y--X is --(CH.sub.2).sub.4 --; and 
E is hydrogen; aryl, as defined above; Het, as defined above; C.sub.2 
-C.sub.7 -alkenyl; or unsubstituted or mono- substituted C.sub.1 -C.sub.7 
-alkyl or unsubstituted or mono-substituted C.sub.3 -C.sub.7 -cycloalkyl, 
where the substituent is selected from the group consisting of aryl, --CO 
aryl, --NH--aryl or --O--aryl, wherein aryl is as defined above; Het, 
--NH--Het, --O--Het, --CO--Het, --NH--CO--Het, CO--NH--Het, 
--CO--NH--CH.sub.2 --Het or --O--CO--Het, wherein Het is as defined above; 
azido; C.sub.3 -C.sub.7 -cycloalkyl; halo; hydroxyl; C.sub.1 -C.sub.4 
-alkoxy; --COOH; --O--CO--R.sup.7, --O--CO--NH R.sup.7, --NH--CO--R.sup.7, 
--NH--CO--NH R.sup.7, --S(O).sub.n --R.sup.7, --CO.sub.2 R.sup.7 or 
--CO--NH--R.sup.7, wherein R.sup.7 and n are as defined above; amino; 
mono- or di C.sub.1 -C.sub.4 -alkylamino; CHO; and --.sup..sym. 
N(R.sup.3).sub.2 R.sup.8 A.sup..crclbar., 
##STR13## 
where R.sup.8 is C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 hydroxyalkyl, 
C.sub.1 -C.sub.4 -carboxyalkyl, --CH.sub.2 -aryl, wherein aryl is as 
defined above, or --CH.sub.2 --Het, wherein Het is as defined above, and 
R.sup.3 and A.sup..crclbar. are as defined above; 
and pharmaceutically acceptable salts thereof. 
In the peptides of the present invention, the components having asymmetric 
centers occur as racemates, racemic mixtures and as individual 
diastereomers, with all isomeric forms generally being included in the 
present invention. In particular, asymmetric carbon atoms at the 2, 3 and 
4 positions in peptides of Formula I preferably have an S configuration. 
When any variable (e.g., aryl, Het, m, n, R.sup.2, R.sup.3, R.sup.7, 
A.sup.-, etc.) occurs more than one time in any variable or in formula I, 
its definition on each ocurrence is independent of its definition at every 
other occurrence. 
As used herein, "alkyl" is intended to include both branched- and straight 
chain saturated aliphatic hydrocarbon groups having the specified number 
of carbon atoms (Me is methyl, Et is ethyl); "alkoxy" represents an alkyl 
group of indicated number of carbon atoms attached through an oxygen 
bridge; and "C.sub.3 -C.sub.7 -cycloalkyl" is intended to include 
saturated ring groups, such as cyclopropyl, cyclobutyl, cyclopentyl, 
cyclohexyl and cycloheptyl. "Alkanoyl" is intended to include those 
alkylcarbonyl groups of specified number of carbon atoms, which are 
exemplified by formyl, acetyl, propanoyl and butanoyl; "alkenyl" is 
intended to include hydrocarbon chains of either a straight or branched- 
configuration and one unsaturation, which may occur at any point along the 
chain, such as ethenyl, propenyl, butenyl, pentenyl, and the like, and 
includes E and Z forms, where applicable; and "arylalkyl" represents aryl 
groups as herein defined which are attached through a straight- or 
branched- chain alkyl group of specified number of carbon atoms, such as, 
for example, benzyl, phenethyl, 3,3-diphenylpropyl, 3-indolymethyl, and 
the like. "Halo", as used herein, means fluoro, chloro, bromo and iodo, 
and "counterion" is used to represent a small, single negatively-charged 
specie, such as chloride, bromide, hydroxide, nitrate, acetate, benzoate, 
perchlorate, benzene sulfonate, tartrate, hemitartrate, maleate, and the 
like. 
As used herein, with exceptions as noted, "aryl" is intended to mean phenyl 
(Ph), which is optionally-substituted by from one- to three- members 
independently selected from the group consisting of C.sub.1 -C.sub.7 
-alkyl, amino (Am), mono- or di-C.sub.1 -C.sub.4 -alkylamino, phenyl 
C.sub.1 -C.sub.4 -alkyl, amino-C.sub.1 -C.sub.4 alkyl, hydroxy-C.sub.1 
-C.sub.4 -alkyl, mono or di-C.sub.1 -C.sub.4 -alkylamino-C.sub.1 -C.sub.4 
-alkyl, hydroxyl, guanidyl, guanidyl-C.sub.1 -C.sub.4 -alkyl, C.sub.1 
-C.sub.4 -alkoxy, CF.sub.3, halo, CHO, CO.sub.2 H, CONH.sub.2, 
CONH--C.sub.1 -C.sub.4 -alkyl, CON(C.sub.1 -C.sub.4).sub.2, CO--C.sub.1 
-C.sub.4 -alkyl or (CH.sub.2).sub.m --.sup..sym. N(R.sup.3).sub.2 R.sup.4 
A.sup..crclbar., wherein R.sup.3, R.sup.4 and m are as defined above and 
A.sup..crclbar. is counterion, as defined herein. "Aroyl" is intended to 
include those aryl carbonyl groups which are exemplified by phenoyl. 
The term "Het", as used herein, represents a 5- to 7-membered mono- or 
bicyclic heterocyclic ring which is either saturated or unsaturated, and 
which consists of carbon atoms and one or two heteroatoms selected from 
the group consisting of N, O and S, and wherein the nitrogen and sulfur 
heteroatoms may optionally be oxidized, and the nitrogen heteroatom may 
optionally be quaternized, and including any bicyclic group in which any 
of the above defined heterocyclic rings is fused to a benzene ring. 
Heterocycles which contain nitrogen are preferred. In the case of a 
heterocyclic ring containing one or more nitrogen atoms, the point of 
attachment may be at one of the nitrogen atoms, or at any carbon atom. 
Examples of such heterocyclic elements include piperidyl, piperidinyl, 
piperazinyl, 2-oxopiperazinyl, 2 oxopyrolodinal, 2-oxopiperidinyl, 
2-oxoazepinyl, azepinyl, pyrryl, pyrrolinyl, 4-piperidonyl, pyrrolidinyl, 
pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl, 
imidazolidinyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, oxazolyl, 
oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl, thiazolyl, 
thiazolidinyl, isothiazolyl, quinucli-dinyl, isothiazolidinyl, indolyl, 
guinolinyl, isoguinolinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, 
furyl, thienyl, benzothienyl, thiamorpholinyl, thiamorpholinyl sulfoxide, 
and thiamorpholinyl sulfone. The heterocyclic moiety is further 
optionally-substituted by from one to four- members independently selected 
from the group consisting of hydroxyl, thiol, C.sub.1 -C.sub.6 -alkyl, 
CF.sub.3, C.sub.1 -C.sub.4 -alkoxy, halo, aryl, aryl-C.sub.1 -C.sub.4 
-alkyl, amino, mono- or di-C.sub.1 -C.sub.4 -alkylamino, amino-C.sub.1 
-C.sub.4 -alkylamino, amino-C.sub.1 -C.sub.4 -alkyl, hydroxy-C.sub.1 
-C.sub.4 -alkyl, di-C.sub.1 -C.sub.4 -alkylamino-C.sub.1 -C.sub.4 -alkyl, 
guanidyl, guanidyl C.sub.1 -C.sub.4 -alkyl, CHO, CO.sub.2 H, CO.sub.2 
-C.sub.1 -C.sub.4 -alkyl, CONH.sub.2, CONH-C.sub.1 -C.sub.4 -alkyl, 
CON(C.sub.1 -C.sub.4 -alkyl).sub.2, --NR.sup.5 R.sup.6, 
##STR14## 
or --(CH.sub.2).sub.m --.sup..sym. N(R.sup.3).sub.2 R.sup.8 
A.sup..crclbar., 
wherein R.sup.5, R.sup.6, A.sup..crclbar., m, R.sup.3 and R.sup.8 are as 
defined above, or when the heteroatom is N, the substituents on the N-atom 
are -13 (CH.sub.2).sub.q --or --(CH.sub.2).sub.2 --O--(CH.sub.2).sub.2 
--and form a ring with the N-atom, wherein q is as defined above. 
The following additional abbreviations have also been used herein: 
______________________________________ 
Abbreviated 
Designation Amino Acid/Residue 
______________________________________ 
ACHPA (3S,4S)-4-amino-5-cyclohexyl-3- 
hydroxypentanoic acid 
Ala L-alanine 
Arg L-arginine 
Cys cysteine 
Gly L-glycine 
His D- or L-histidine 
HomoPhe homologated phenylalanine 
HomoTrp homologated tryptophan 
HomoTyr homologated tyrosine 
Ile L-isoleucine 
Leu L-leucine 
Lys L-lysine 
Met L-methionine 
Nle norleucine 
Nva norvaline 
Orn L-ornithine 
(p-MeO)Phe L-para-methoxyphenylalanine 
Phe L-phenylalanine 
Pro proline 
Sar L-sarcosine (N-methylglycine) 
Ser L-serine 
Sta statine 
Thr L-threonine 
Trp L-tryptophan 
Tyr L-tyrosine 
Val L-valine 
Protecting Group 
BOC .sub.- t-butyloxycarbonyl 
CBZ benzyloxycarbonyl(carbobenzoxy) 
DNP 2,4-dinitrophenyl 
IPOC isopropoxycarbonyl 
Activating Group 
HBT(HOBt) 1-hydroxybenzotriazole hydrate 
HOSU N-hydroxysuccinimide 
Condensing Agent 
DCCI (DCC) dicyclohexylcarbodiimide 
DPPA diphenylphosphorylazide 
EDC 1-(3-dimethylaminopropyl)-3-ethyl 
carbodiimide hydrochloride 
Reagent 
(BOC).sub.20 di- .sub.- t-butyl dicarbonate 
DIBAL diisobutylaluminum hydride 
DIPEA diisopropylethylamine 
DMAP 4-(dimethylamino)pyridine 
TEA triethylamine 
TFA trifluoroacetic acid 
LAH lithium aluminum hydride 
LDA lithium diisopropylamide 
MCPBA 3-chloroperoxybenzoic acid 
NMM N-methyl morpholine 
PPTS pyridinium para-toluenesulfonate 
TBAF tetra- -n-butylammonium fluoride 
Solvent 
HOAc (AcOH) acetic acid 
DMF dimethylformamide 
DMSO dimethyl sulfoxide 
EtOAc ethyl acetate 
EtOH ethanol 
Et.sub.2 O ether 
MeOH methanol 
THF tetrahydrofuran 
______________________________________ 
The novel renin inhibitory peptides of the present invention may be 
generalized and alternately described in terms of common amino acid 
components and closely-related analogs thereof, in accordance with formula 
I, wherein A, R.sup.1, X and E are as defined under Formula I; 
B is Absent, Ala, Leu, Phe, HomoPhe, (p--MeO)Phe, Tyr, Trp, HomoTrp or 
##STR15## 
where R.sup.2 is as defined above; and D is Absent, Ala, Ser, Met, Thr, 
Phe, Tyr, Trp, His, Lys, Orn, Arg or Val, such that B and D are not 
simultaneously absent. 
In terms of substrate analogy, a unique aspect and essential feature of the 
present invention is the substitution of the 
##STR16## 
component for the double amino acid sequence, Leu.sup.10 -Val.sup.11 in 
the endogenous human renin substrate 
##STR17## 
which substitution for both amino acids at the cleavage site rather than 
just one is believed to result in an improved substrate analogy. This 
invention's peptides particularly comprise novel lactam versions of rigid 
4-amino-5-cyclohexyl-3-hydroxy-pentanoic acid (ACHPA), which enables 
stereo-specific placement of substituents, and allows the 
##STR18## 
component to better mimic the Leu.sup.10 -Val.sup.11 dipeptide moiety in 
the natural substrate. 
It will be understood that closely-related analogs of the above common 
amino acids, for example, aliphatic amino acids in addition to Ala, Val, 
Leu, and Ile, such as .alpha.-aminobutyric acid (Abu), substituted phenyl 
derivatives of Phe, and N.sup..alpha. -methyl amino acids, are included in 
the broad description of the novel inhibitory peptides of the present 
invention represented by Formula I and related definitions. 
Preferred renin-inhibitory peptides are those wherein A is R.sup.2 --CO--, 
R.sup.9 --SO.sub.2 --, C.sub.1 -C.sub.4 -alkyl-O-CO--or R.sup.7 
--NH--CO--, wherein R.sup.2, R.sup.7 and R.sup.9 are as defined above; B 
is absent (when D is present), L-phenylalanyl or derivatives thereof 
substituted on the aromatic ring by para-methoxy or 
##STR19## 
D is absent (when B is present), L-histidyl or L valinyl; R.sup.1 is 
cyclohexyl; Y is O or CH.sub.2 ; R.sup.13 and R.sup.14 in either 
definition of X are simultaneously or independently hydrogen or methyl; 
and E is C.sub.1 -C.sub.6 -alkyl, --(CH.sub.2).sub.r --.sup..sym. 
N(R.sup.3).sub.2 R.sup.8 CH.sub.3 CO.sup..crclbar..sub.2, wherein r is 2 
or 3 and R.sup.3 and R.sup.8 are as defined above, 
##STR20## 
wherein R.sup.8 is as defined above. The preferred stereochemistry at the 
2,3 and 4 positions is S. 
Representative preferred renin-inhibitory peptides of the present invention 
include the following compounds having the structure: 
##STR21## 
wherein in the structures: 
__________________________________________________________________________ 
A B D Y X E 
__________________________________________________________________________ 
.circle.1 
Boc Phe His 
CH.sub.2 
CH.sub.2 CH.sub.2 
n-Bu 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR22## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.5 
-- 
##STR23## " " " " 
Boc Phe His 
CH.sub.2 
CH.sub.2 C(CH.sub.3).sub.2 
n-Bu 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR24## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.10 
-- 
##STR25## " " " " 
Boc " " " CH.sub.2 CH.sub.2 
##STR26## 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR27## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
His 
CH.sub.2 
CH.sub.2 CH.sub.2 
##STR28## 
.circle.15 
-- 
##STR29## " " " " 
Boc Phe " O " " 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR30## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.20 
-- 
##STR31## " " " " 
Boc Phe His 
CH.sub.2 
C(CH.sub.3).sub.2 CH.sub.2 
##STR32## 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR33## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.25 
-- 
##STR34## " " " " 
Boc Phe His 
CH.sub.2 
CH.sub.2 CH.sub.2 
##STR35## 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR36## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.30 
-- 
##STR37## " " " " 
Boc Phe His 
CH.sub.2 
CH.sub.2 CH.sub.2 
##STR38## 
(CH.sub.3).sub.2 CHSO.sub.2 
" " " " " 
##STR39## 
" " " " " 
(CH.sub.3).sub.2 CHSO.sub.2 
CH.sub.2 CH(CH.sub.2 Ph)CO 
" " " " 
.circle.35 
-- 
##STR40## " " " ". 
__________________________________________________________________________ 
The pharmaceutically-acceptable salts of the peptides of Formula I (in th 
form of water- or oil-soluble or dispersible products) include the 
conventional non-toxic salts or the quarternary ammonium salts of these 
peptides which are formed, e.g., from inorganic or organic acids or bases. 
Examples of such acid addition salts include acetate, adipate, alginate, 
aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, 
camphorate, camphorsulfonate, c-cylopentan-epropionate, digluconate, 
dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, 
glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, 
hydrobromide, hydroiodide, 2 hydroxyethanesulfonate, lactate, maleate, 
methanesulfonate, 2 naphthalenesulfonate, nicotinate, oxalate, pamoate, 
pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, 
succinate, tartrate, thiocyanate, tosylate, and undecanoate. Base salts 
include ammonium salts, alkali metal salts such as sodium and potassium 
salts, alkaline earth metal salts such as calcium and magnesium salts, 
salts with organic bases such as dicyclohexylamine salts, N-methyl-D 
glucamine, and salts with amino acids such as arginine, lysine, and so 
forth. Also, the basic nitrogen-containing groups may be quaternized with 
such agents as lower alkyl halides, such as methyl, ethyl, propyl, and 
butyl chloride, bromides and iodides; dialkyl 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. 
Chemical synthesis of the compounds with the general structure given in 
formula I may be accomplished in several ways as illustrated by the 
following generalized procedures (wherein "ACHP", an abbreviation of 
2-Amino-3-Cyclohexyl 1-HydroxyPropyl, is used in describing the structural 
segment which joins the A-B D and 
##STR41## 
portions of the invention as shown in formula I. The ACHP segment is 
connected through the 1-position of the propyl chain to the 3-position of 
the piperidinone or caprolactam, to the 2-position of the morpholinone or 
thiamorpholinone, and through the amino group to the A-B-D segment.) 
Method A: 
Step A1. A derivative of 2-piperidinone, caprolactam, 3 morpholinone or 
3-thiamorpholinone is obtained through commercial sources or is prepared 
using well known chemical methods for preparation of members in these 
classes (see Example 1); 
Step A2. The enolate of the 2 piperidinone, caprolactam, 3-morpholinone or 
3-thiamorpholinone derivative is generated, such as by using LDA as the 
base, and is added to a nitrogen-protected (e.g., N--Boc or N--CBZ 
protected) .alpha.-amino-aldehyde (e.g., N-tert butyloxycarbonyl 
cyclohexylalaninal) to give a Boc- or CBZ-protected amino alcohol 
derivative (see Example 2B); 
Step A3. The nitrogen protecting group of the amino alcohol derivative from 
step A2 is removed (e.g., by hydrogenolysis for CBZ protection, or TFA 
treatment for Boc protection) and the amine is coupled using standard 
peptide methodology to one or two amino acids, or to an appropriate 
carboxylic acid, the structure(s) of which is/are described by A, B, and D 
in the general formula I (e.g., see Example 3A steps 1 and 2); and 
Step A4. Removal of any protecting groups which may have been used, e.g., 
on the lactam substituent(s) R.sup.13, R.sup.14, or E), or on the amino 
acid side chains (see Example 3A, step 3), gives the final products. 
Method B: 
Steps A1 and A2 are followed. 
Step B3. Modification of the lactam substituent(s) (R.sup.13, R.sup.14, and 
E in generic formula I) is/are performed, as shown in Examples 2V-2PP. 
Then Steps A3 and A4 are followed. 
Method C: 
Steps A1, A2 and A3 are followed. 
Step C4: Modification of the lactam substituent(s) R.sup.13, R.sup.14, and 
E in generic formula I) is/are performed, as shown in Examples 3D. 
Step A4 is then followed. 
The novel peptides of the present invention possess a high degree of 
activity in treating renin-associated hypertension, hyperald-osteronism 
and/or congestive heart failure in humans, as well as in other 
warm-blooded animals such as mice, rats, horses, dogs and cats. 
For these purposes, the peptides of the present invention may be 
administered orally, parenterally (including subcutaneous injections, 
intravenous, intramuscular, intrasternal injection or infusion 
techniques), by inhalation spray, or rectally, in dosage unit formulations 
containing conventional non-toxic, pharmaceutically acceptable carriers, 
adjuvants and vehicles. 
Thus, in accordance with the present invention there is further provided a 
method of treating and a pharmaceutical composition for treating 
renin-associated hypertension, hyperaldosteronism, and/or congestive heart 
failure. This treatment involves administering to a patient in need of 
such treatment a pharmaceutical composition comprising a -pharmaceutical 
carrier, optionally with an adjuvant, and a therapeutically-effective 
amount of a peptide of the formula: 
##STR42## 
wherein A, B, D, R.sup.1, X, Y and E are defined above, or a 
pharmaceutically-acceptable salt thereof. 
These pharmaceutical compositions may be in the form of 
orally-administrable suspensions or tablets; nasal sprays; sterile 
injectable preparations, for example, as sterile injectable aqueous or 
oleagenous suspensions; or suppositories. 
When administered orally as a suspension, these compositions may contain 
microcrystalline cellulose for imparting bulk, alginic acid or sodium 
alginate as a suspending agent, methylcellulose as a viscosity enhancer, 
and sweetners/flavoring agents known in the art. As immediate release 
tablets, these compositions may contain microcrystalline cellulose, 
dicalcium phosphate, starch, magnesium stearate and lactose and/or other 
excipients, binders, extenders, disintegrants, diluents and lubricants 
known in the art. 
When administered by nasal aerosol or inhalation, these compositions may be 
prepared as solutions in saline, employing benzyl alcohol or other 
suitable preservatives, absorption promoters to enhance bioavailability, 
flourocarbons, and/or other solubilizinq or dispersing agents known in the 
art. 
The injectable solutions or suspensions may be formulated according to 
known art, using suitable non-toxic, -parenterally-acceptable diluents or 
solvents, such as mannitol, 1,3 butanediol, water, Ringer's solution or 
isotonic sodium chloride solution, or suitable dispersing or wetting and 
suspending agents, such as sterile, bland, fixed oils, including synthetic 
mono- or diglycerides, and fatty acids, including oleic acid. 
When rectally administered in the form of suppositories, these compositions 
may be prepared by mixing the drug with a suitable non irritating 
excipient, such as cocoa butter, synthetic glyceride esters or 
polyethylene glycols, which are solid at ordinary temperatures, but 
liquify and/or dissolve in the rectal cavity to release the drug. 
Dosage levels of the order of 0.02 to 2.0 grams-per-day are useful in the 
treatment of the above-indicated conditions, with oral doses two-to five 
times higher. For example, renin-associated hypertension and 
hyperaldosteronism are effectively treated by the administration of from 
10 to 50 milligrams of the compound per kilogram of body weight from one 
to three times per day. It will be understood, however, that the specific 
dose level and frequency of dosage for any particular patient will depend 
upon a variety of factors including the activity of the specific compound 
employed, the metabolic stability and length of action of that compound, 
the age, body weight, general health, sex, diet, mode and time of 
administration, rate of excretion, drug combination the severity of the 
particular condition, and the host undergoing therapy. 
The present invention is also directed to combinations of the novel 
renin-inhibitory peptides of Formula I with one or more antihypertensive 
agents selected from the group consisting of diuretics, .alpha.-and/or 
.beta.-adrenergic blocking agents, CNS-acting agents, adrenergic neuron 
blocking agents, vasodilators, angiotensin I converting enzyme inhibitors, 
calcium channel blockers, and other antihypertensive agents. 
For example, the compounds of this invention can be given in combination 
with such compounds or salt or other derivative forms thereof as: 
Diuretics: acetazolamide; amiloride; bendro flumethiazide; benzthiazide; 
bumetanide; chlorothiazide; chlorthalidone; cyclothiazide; ethacrynic 
acid; furosemide; hydrochlorothiazide; hydro flumethiazide; indacrinone 
(racemic mixture, or as either the (+) or (-) enantiomer alone, or a 
manipulated ratio, e.g., 9:1 of said enantiomers, respectively); 
metolazone; methyclothiazide; muzolimine; polythiazide; guinethazone; 
sodium ethacrynate; sodium nitroprusside; spironolactone; ticrynafen; 
triamterene; trichlormethiazide; .alpha.-Adrenergic Blocking Agents: 
dibenamine; phentolamine; -phenoxybenzamine; prazosin; tolazoline; 
.beta.-Adrenergic Blocking Agents: atenolol; metoprolol; nadolol; 
propranolol; timolol; 
((+)-2-[3-(tert-butylamino) 2-hydroxypropoxy]-2-furananilide) (ancarolol); 
(2 acetyl-7-(2-hydroxy-3-isopropy-lamincpropoxy)benzofuran HCl) 
(befunolol); 
((.+-.; 1-(isopropylamino) 
3-(p-(2-cyclopropylmethoxyethyl)-phenoxy)-2-propranol HCl) (betaxolol); 
(1-[(3,4-dimethoxyphenethyl)amino]-3-(m-tolyloxy)-2-propanol HCl) 
(bevantolol); 
((.+-.)-1-(4-((2-isopropoxyethoxy)methyl)phenoxy)-3-isopropylamino-2-propan 
ol)fumarate) (bisoprolol); 
(4-(2-hydroxy-3-[4-(phenoxymethyl)-piperidino]-propoxy)-indole); 
(carbazolyl-4-oxy-5,2-(2-methoxyphenoxy)-ethylamino-2-propanol); 
(1-((1,1-dimethylethyl)amino)-3-((2-methyl-1H-indol-4-yl)oxy)-2-propanol 
benzoate) (bopindolol); 
(1-(2-exobicyclo[2.2.1]-hept-2-ylphenoxy)3-[(1-methylethyl)amino]-2-propano 
l HCl) (bornaprolol); 
(o [2-hydroxy-3-[(2-indol-3-yl-1,1-dimethylethyl)amino]propoxy]benzonitrile 
HCl) (bucindolol); 
(.alpha.[(tert.butylamino)methyl]-7-ethyl-2-benzofuranmethanol) 
(bufuralol); 
(3-[3-acetyl-4-[3-(tert.butylamino)-2-hydroxypropyl]phenyl]1,1-diethylurea 
HCl) (celiprolol); 
((.+-.)-2-[2-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]phenoxy]-N-meth 
ylacetamide HCl) (cetamolol); 
(2-benzimidazolyl-phenyl(2-isopropylaminopropanol)); 
((.+-.) 3'-acetyl-4'-(2-hydroxy-3-isopropylaminopropoxy)acetanilide HCl) 
(diacetolol); 
(methyl-4-[2-hydroxy3-[(1-methylethyl)aminopropoxy]]-benzenepropanoate HCl) 
(esmolol); 
(erythro DL-1-(7-methylindan4-yloxy)-3-isopropylaminobutan 2 ol); 
(1-(tert.butylamino)-3-[O-(2-propynyloxy)phenoxy]-2-propanol (pargolol); 
(1-(tert.butylamino)-3-[o-(6-hydrazino-3-pyridazinyl)-phenoxy]-2-propanol 
diHCl) (prizidilol); 
((-)-2-hydroxy-5-[(R)-1-hydroxy-2-[(R)-(1-methyl-3-phenylpropyl)amino]ethyl 
]benzamide); 
(4-hydroxy-9-[2-hydroxy-3-(isopropylamino)-propoxy]-7-methyl-5H-furo[3,2-g] 
[1]benzopyran-5-one) (iprocrolol); 
((-)-5-(tert.butylaaino)-2-hydroxypropoxy]-3,4-dihydro1-(2H)-naphthalenone 
HCl) (levobunolol); 
(4-(2-hydroxy-3-isopropylamino-propoxy)-1,2-benzisothiazole HCl); 
(4-[3-(tert.butylamino)-2-hydroxypropoxy]-N-methylisocarbostyril HCl); 
((.+-.)-N-2-[4-(2-hydroxy-3-isopropyl aminopropoxy)-phenyl]ethyl 
N'-isopropylurea) (pafenolol); 
(3-[[(2-trifluoroacetamido)ethyl]amino]-1-phenoxypropan-2-ol); 
(N-(3-(o -chlorophenoxy)-2-hydroxypropyl)-N'-(4'-chloro2,3 
-dihydro-3-oxo-5-pyridazinyl) ethylenediamine); 
((.+-.) 
N-[3-acetyl-4-[2-hydroxy-3-[(1-methylethyl)amino]-propoxy]phenyl]butanamid 
e) (acebutolol); 
((.+-.)-4'-[3-(tert-butylamino)-2-hydroxypropoxy]spiro[cyclohexane 
1,2'-indan]-1'-one) (spirendolol); 
(7-[3-[[2-hydroxy-3-[(2-methylindol-4-yl)oxy]propyl]amino]butyl]thiophyllin 
e) (teoprolol); 
((.+-.) 1-tert.butylamino-3-(thiochroman-8-yloxy)-2-propanol) (tertatolol); 
((.+-.)-1-tert.butylamino-3-(2,3-xylyloxy)-2-propanol HCl) (xibenolol); 
(8-[3-(tert.butylamino)-2-hydroxypropoxy]-5-methylcoumarin) (bucumolol); 
(2-(3-(tert.butylamino)-2-hydroxy-propoxy)benzonitrile HCl) (bunitrolol); 
((.+-.)-2'-[3-(tert-butylamino)-2-hydroxypropoxy-5'-fluorobutyrophenone) 
(butofilolol); 
(1-(carbazol-4-yloxy)-3-(isopropylamino)-2-propanol) (carazolol); 
(5-(3-tert.butylamino-2-hydroxy)propoxy-3,4-dihydrocarbostyril HCl) 
(carteolol); 
(1 (tert.butylamino)-3-(2,5-dichlorophenoxy)-2-propanol) (cloranolol); 
(1-(inden-4(or 7)-yloxy)-3-(isopropylamino)-2-propanol HCl) (indenolol); 
(1-isopropylamino-3-[(2-methylindol-4-yl)oxy]-2-propanol) (mepindolol); 
(1-(4-acetoxy-2,3,5-trimethylphenoxy)-3-isopropylaminopropan-2-ol) 
(metipranolol); 
(1-(isopropylamino)-3-(o-methoxyphenoxy)-3-[(1-methylethyl)amino]-2-propano 
l) (moprolol); 
((1-tert.butylamino)-3-[(5,6,7,8-tetrahydro-cis 
6,7-dihydroxy-1-naphthyl)oxy]-2-propanol) (nadolol) 
((S)-1-(2-cyclopentylphenoxy)-3-[(1,1-dimethylethyl)amino]-2-propanol 
sulfate (2:1)) (penbutolol); 
(4'-[1-hydroxy-2-(amino)ethyl]methanesulfonanilide) (sotalol); 
(2-methyl-3-[4-(2-hydroxy-3-tert.butylaminopropoxy)-phenyl]-7-methoxy-isoqu 
inolin-1-(2H)-one); 
(1-(4-(2-(4-fluorophenyloxy)ethoxy)phenoxy)-3-isopropylamino-2-propanol 
HCl); 
((-)-p-[3-[(3,4-dimethoxyphenethyl)amino]-2-hydroxypropoxy]-.beta.-methylci 
nnamonitrile) (pacrinolol); 
((.+-.)-2-(3'-tert.butylamino-2'-hydroxypropylthio)-4-(5'-carbamoyl-2'-thie 
nyl) thiazole HCl) (arotinolol); 
((.+-.) 
1-[p-[2-(cyclopropylmethoxy)ethoxy]phenoxy]-3-(isopropylamino)-2-propanol) 
(cicloprolol); 
((.+-.)-1-[(3-chloro-2-methylindol-4-yl)oxy]-3-[(2-phenoxyethyl)amino]-2-pr 
opanol) (indopanolol); 
((.+-.) 6-[[2-[[3-(p-butoxyphenoxy)-2-hydroxypropyl]amino]ethyl]amino]-1,3 
dimethyluracil) (pirepolcl); 
(4-(cyclohexylamino)-1-(1-naphtholenyloxy)-2-butanol); 
(1-phenyl-3-2-[3-(2-cyanophenoxy)-2-hydroxypropyl]-aminoethyl]hydantoin 
HCl); 
(3,4-dihydro-8-(2-hydroxy-3-isopropylaminopropoxy)-3-nitroxy-2H-1-benzopyra 
n) (nipradolol); 
.alpha.- and .beta.-Adrenergic Blocking Agents: 
((.+-.)-1-tert-butylamino)-3-[o-[2-(3-methyl 
5-iso-xazolyl)vinyl]phenoxy]-2-propanol) (isoxaprolol); 
(1-isopropylamino-3-(4-(2-nitroxyethoxy)phenoxy)-2-propanol HCl); 
(4-hydroxy-.alpha.-[[3-(4-methoxyphenyl)-1-methylpropyl]-aminomethyl]-3-(me 
thylsulfinyl)-benzmethanol HCl) (sulfinalol); 
(5-[1-hydroxy-2-[[2-(o-methoxyphenoxy)ethyl]amino]-ethyl]-2-methylbenzenesu 
lfonamide HCl); 
(5-[1-hydroxy-2-[(1-methyl-3-phenylpropyl)amino]ethyl]-salicylamide HCl) 
(labetalol); 
(1-((3-chloro-2-methyl-1H-indol-4-yl)oxy)-3-((2-phenoxyethyl)amino)-2-propa 
nol -hydrogenmalonate) (ifendolol); 
(4-(2-hydroxy-3-[(1-methyl-3-phenylpropyl)amino]-propoxy)benzeneacetamide); 
(1-[3-[[3-(1-naphthoxy)-2-hydroxypropyl]-amino]-3,3-dimethyl-propyl]-2-benz 
imidazolinone); 
(3-(1-(2-hydroxy-2-(4-chlorophenylethyl)-4-piperidyl)-3,4-dihydroxy)quinoxo 
lin-2-(1H) -one); 
CNS-Acting Agents: clonidine; methyldopa; 
Adrenergic Neuron Blocking Agents: quanethidine; reserpine and other 
rauwolfia alkaloids such as rescinnamine; 
Vasodilators: diazoxide; hydralazine; minoxidil; 
Angiotensin I Converting Enzyme Inhibitors: 
1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline (captopril); 
(1-(4-ethoxycarbonyl-2,4-(R,R)-dimethylbutanoyl)-indoline-2(S)-carboxylic 
acid); 
(2-[2-[[1-(ethoxycarbonyl)-3-phenyl 
propyl]amino]-1-oxopropyl]-1,2,3,4-tetrahydro-3-isoquinoline carboxylic 
acid); 
((S)-1-[2-[[1-(ethoxycarbonyl)-3-phenylpropyl]amino]-1-oxopropyl]octahydro- 
1H-indole-2-carboxylic acid HCl); 
(N 
cyclopentyl-N-(3-(2,2-dimethyl-1-oxopropyl)thiol-2-methyl-1-oxopropyl)glyc 
ine) (pivalopril); 
((2R,4R)-2-(2-hydroxyphenyl)-3-(3-mercaptopropionyl)-4-thiazolidinecarboxyl 
ic acid); 
(1-(N[1-(S)-ethoxycarbonyl-3-phenylpropyl]-(S)-alanyl)-cis,syn-octahydroind 
ol-2(S) carboxylic acid HCl); 
((-)-(S)-1-[(S)-3-mercapto-2-methyl-1-oxopropyl]-indoline-2-carboxylic 
acid); 
([1(S),4S]-1-[3-(benzoylthio)-2-methyl-1-oxopropyl]-4-phenylthio L-proline; 
(3-([1-ethoxycarbonyl-3-phenyl-(1S)-propyl]amino)-2,3,4,5-tetrahydro-2-oxo- 
1-(3S) -benzazepine-1-acetic acid HCl); 
(N-(2-benzyl-3-mercaptopropanoyl)-S-ethyl-L-cysteine) and the S methyl 
analogue; 
(N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-proline maleate) 
(enalapril); 
N-[1-(S)-carboxy-3-phenylpropyl]-L-alanyl-1-proline; 
N.sup.2 -[1-(S)-carboxy-3-phenylpropyl]-L-lysyl-L-proline (lysinopril); 
Calcium Channel Blockers: 
.alpha.3-[[2-(3,4-dimethoxyphenyl)ethyl]methylamino]propyl]-3,4-dimethoxy- 
.alpha.-(1-methylethyl) benzeneacetonitrile (verapamil); 
1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinedicarboxylic acid 
dimethyl ester (nifedipine); 
2-(2,2-dicyclohexylethyl)piperidine (perhexiline); 
N-(1-methyl-2-phenylethyl)- -phenylbenzenepropanamine (prenylamine); 
3-(aminosulfonyl)-4-chloro-N-(2,3-dihydro-2-methyl-1H-indol-1-yl)benzamide 
(indapamide); 
(2'-(2-diethylaminoethoxy)-3-phenylpropiophenone (etafenone); 
(4-[4,4-bis-(4-fluorophenyl)butyl]-N-(2,6-dimethylphenyl)-1-piperazineaceta 
mide) (lidoflazine); 
(2-(N-benzyl-N-methylamino)ethylmethyl-2,6 
dimethyl-4-(m-nitrophenyl)-1,4-dihydro-3,5-pyridinedicarboxylate HCl) 
(nicardipine); 
(N-(3,4-dimethoxyphenethyl)-2-(3,4-dimethoxyphenyl)-N-methyl-m-dithiane-2-p 
ropylamine-1,1,3,3-tetraoxide) (tiapamil); 
(5,6-dimethoxy-2-(3-[(.alpha.-(3,4-dimethoxy)phenylethyl)-methylamino]propy 
l)phthalimidine) (falipamil); 
(.beta.-[(2-methylpropoxy)methyl]-N-phenyl-N-phenylmethyl-1-pyrrolidineetha 
namine HCl monohydrate) (bepridil); 
((+)-cis-3-(acetyloxy)-5-[2-(dimethylamino)ethyl]-2,3-dihydro-2-(4-methoxyp 
henyl)-1,5-benzothiazepin-4-(5H)-one) (diltiazem); 
((E)-1-[bis-(p fluorophenyl)methyl]-4-cinnamylpiperazine di HCl) 
(flunarizine); 
(5-[(3,4-dimethoxyphenethyl)methylamino]-2-isopropyl-2-(3,4,5-trimethoxyphe 
nyl)valeronitrile (gallopamil); 
(ethylmethyl(2,3-dichlorophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicar 
boxylate (felodipine); 
(isopropyl-2-methoxyethyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-py 
ridinecarboxylate) (nimodipine); 
(3-ethyl-5-methyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridine-d 
icarboxylate) (nitrendipine); 
Other Antihypertensive Agents: aminophylline; cryptenamine acetates and 
tannates; deserpidine; meremethoxylline procaine; pargyline; trimethaphan 
camsylate; and the like, as well as admixtures and combinations thereof. 
Typically, the individual daily dosages for these combinations can range 
from about one-fifth of the minimally-recommended clinical dosages to the 
maximum recommended levels for the entities when they are given alone. 
Coadministration is most readily accomplished by combining the active 
ingredients into a suitable unit dosage form containing the proper dosages 
of each. Other methods of coadministration are, of course, possible. 
The renin inhibitory novel peptides of the present invention may also be 
utilized in in vivo or in vitro diagnostic methods for the purpose of 
establishing the significance of renin as a causative or contributory 
factor in hypertension, hyperaldo steronism or congestive heart failure in 
a particular patient. 
In the in vivo method, a novel peptide of the present invention is 
administered to a patient, preferably by intravenous injection, although 
parenteral administration is also suitable, at a hypotensive dosage level 
in a single dose of from 0.1 to 10 mg per kg of body weight, and the 
resulting transitory fall in blood pressure, if it occurs, indicates 
supranormal plasma renin levels. 
In vitro methods which may be employed involve incubating a body fluid, 
preferably plasma, with a novel peptide of the present invention according 
to methods described in Boger et al., J. Med. Chem., 1985, 28, 1779-1790. 
The following are intended to exemplify the present invention, without, 
however, limiting it.

EXAMPLE 1 
SYNTHESIS OF STARTING LACTAMS 
A. Preparation of 1-Methylcaprolactam 
Caprolactam (25 g; 0.22 mol) was added portionwise over a period of 15 
minutes to a suspension of NaH (10.6 g of a 60% suspension in mineral oil; 
0.265 mol) in degassed DMF (500 mL). The mixture was stirred for 3 hours 
at room temperature under an atmosphere of nitrogen and was then cooled to 
0.degree. C. Methyl iodide (39.5 g; 0.275 mol) was added dropwise to the 
cold suspension over a period of 30 minutes, and stirring was continued 
overnight, allowing the cooling bath to warm to room temperature. 
Acetic acid (ca. 2 mL) was added to quench any remaining NaH, and the 
suspension was filtered, with the bulk of the DMF being removed by 
distillation at reducted pressure (ca. 20 torr), until NaI had formed a 
heavy precipitate. Ether was added and the mixture was cooled for several 
hours in a refrigerator. 
The NaI was removed by filtration, and after the ether had been removed 
under reduced pressure on the rotovap, distillation under reduced pressure 
was resumed. 1 Methylcaprolactam (20 g; 71% yield) was collected, boiling 
at 110-115.degree. C. (10 torr). 
B. Preparation of 4-Methyl-3 Morpholinone 
The title compound was prepared from 2 (methylamino)ethanol nd chloroacetyl 
chloride in basic ethanol using the procedure of Surry, et. al., J. Am. 
Chem. Soc. (1955) 77, 633. The product was purified by vacuum distillation 
from calcium hydride, bp 108-112.degree. C. (10 torr). 
C. Preparation of 1-Butyl 2-Piperidinone 
2-Piperidinone is deprotonated with NaH in DMF solution and butylated with 
n-butyl iodide to give the title compound. 
D. Preparation of 1-Butyl-6,6-Dimethyl-2-Piperidinone 
The oxime of 2,2 dimethylcyclopentanone is prepared by reaction of the 
ketone with hydroxylamine hydrochloride in EtOH, and treated with 
p-toluenesulfonyl chloride and DMAP. Heating then effects Beckmann 
rearrangement to give 6,6-dimethyl-2-piperidinone which is deprotonated 
with NaH in DMF solution. Reaction with n-butyl iodide then gives the 
title compound. 
E. Preparation of 1-(2-Diethylaminoethyl)-2-Piperidinon 
2-Piperidinone is deprotonated with NaH in DMF solution and reaction with 
allyl bromide, and 1-allyl-2-piperidinone is obtained by distillation. 
Ozonolysis in MeOH solution at -78.degree. C., followed by reductive 
workup with Me.sub.2 S, gives the aldehyde derivative, which is 
reductively aminated using diethylamine hydrochloride and NaBH.sub.4 to 
give the title compound. 
F. Preparation of 1.5.5 Trimethyl-2-Piperidinone 
The oxime of 3,3 dimethylcyclopentanone is prepared by treatment of the 
ketone with hydroxylamine hydrochloride in EtOH. Heating the oxime with 
p-toluenesulfonyl chloride and DMAP effects Beckmann rearrangement to give 
a mixture of 4,4-dimethyl 2-piperidinone and the desired 
5,5-dimethyl-2-piperidinone. 
This mixture is separated chromatographically and the 
5,5-dimethyl-2-piperidinone is methylated by reaction with NaH in DMF 
solution followed by treatment with methyl iodide to give the title 
compound. 
G. Preparation of 4 Methyl-5-(2-Propyl)-3-Morpholinone 
Treatment of valinol in basic ethanol with chloroacetyl chloride using the 
procedure of Surry, et. al., J. Am. Chem. Soc. (1955) 77, 633, gives 
5-(2-propyl)-3-morpholinone. Deprotonation of the latter with NaH in DMF 
solution and reaction with methyl iodide gives the title compound. 
H. Preparation of 4-Methyl-3-Thiamorpholinone 
Heating N methylaziridine with ethyl mercaptoacetate gives the title 
compound. 
EXAMPLE 2 
SYNTHESIS OF BOC-(ACHP)-LACTAMS 
A. Preparation of Boc-(ACHP)-1-Methyl-2-Piperidinone using a Typical Lactam 
Aldol Addition Procedure 
To a 0.degree. C. solution of diisopropylamine (4.11 g; 40.7 mmol) in dry 
THF (120 mL) under an atmosphere of nitrogen was added n-butyllithium 
(25.1 mL of a 1.6 M solution in hexane: 40.1 mmol). After being stirred 
for 10 minutes, the resulting solution was cooled to -78.degree. C., at 
which time a solution of 1-methyl2-piperidinone (4.52 g, 40.0 mmol) in dry 
THF (10 mL) was added dropwise over a period of 5 minutes. 
The resulting solution was stirred at -78.degree. C. for 1.5 hour, when a 
78.degree. C. solution of N-Boc-L-cyclohexylalaninal (10.2 g; 40.0 mmol), 
prepared according to the method of Boger, et. al., J. Med. Chem., (1985) 
28, 1779, in dry THF (60 mL) was added rapidly via cannula. After being 
stirred for 5 minutes at -78.degree. C., the reaction was quenched by the 
addition of 10 mL of water, and the cooling bath was removed and more 
water (25 mL) and ether (200 mL) were added. 
The mixture was extracted with 5% aqueous HCl (200 mL), saturated with 
aqueous NaHCO.sub.3 (200 mL), and dried (MgSO.sub.4) and filtered. Removal 
of the solvents under reduced pressure gave a viscous oil, from which the 
diasteriomeric aldol products was separated by flash chromatography 
(SiO.sub.2 ; 2%-5% MeOH/CH.sub.2 Cl.sub.2). 
The 2S,3S,4S diasteriomer was obtained as a viscous oil (2.80 g; 19% 
yield). 
B. Preparation of Boc (ACHP)-4-Methyl-3-Morpholinone 
The title compound (2S,3S,4S diasteriomer) was obtained by aldol reaction 
of Boc-L-cyclohexylalaninal and 4 methyl 3 morpholinone using the 
procedure described in Example 2A. 
C. Preparation of Boc-(ACHP)-1-Methylcaprolactam 
The title compound (2S,3S,4S, diasteriomer) was obtained by aldol reaction 
of Boc-L cyclohexylalaninal and 1-methylcaprolactam using the procedure 
described in Example 2A. 
The following Boc--(ACHP)--lactams are prepared using the aldol procedure 
described in Example 2A 
D. Boc-(ACHP 1-Butyl-2-Piperidinone 
E. Boc-(ACHP)-1-(2-Diethylaminoethyl)-2-Piperidinone 
F. Boc-(ACHP) 1-Butyl-6,6-Dimethyl-2-Piperidinone 
G. Boc-(ACHP)-1,5,5 Trimethyl-2-piperidinone 
H. Boc-(ACHP)-4-Methyl-3-thiamorpholinone 
I. Boc-(ACHP)-4-Methyl-5-(2-Propyl)-3-Morpholinone 
EXAMPLE 3 
AMINO ACID COUPLING PROCEDURES AND SUBSEQUENT TRANSFORMATIONS 
A. Preparation of Boc-Phe-His-(ACHP)-1-Methyl-2-Piperidinone 
Step 1. Boc-(DNP)His-(ACHP)-1-Methyl-2-Piperidinone 
To a solution of Boc (ACHP) 1 methyl 2-piperidinone (2.20 g; 5.98 mmol) in 
CH.sub.2 Cl.sub.2 (4 mL) was added TFA (4 mL) and the solution was stored 
under an atmosphere of nitrogen at ambient temperature for 45 minutes. 
Excess TFA and solvent were removed under reduced pressure and the oil so 
obtained was triturated in ether, giving a white solid which was collected 
by filtration, washed with ether, and dried under reduced pressure. 
The TFA salt (2.10 g; 92% yield) was dissolved under an atmosphere of 
nitrogen in a minimum amount (5-6 mL) of DMF (more ideally in EtOAc if the 
salt had been soluble) and stored while the activation of Boc(DNP)His--OH 
was accomplished by in situ formation of a mixed anhydride, as described 
immediately below. 
(Activation of Boc(DNP)His--OH) To a suspension of Boc(DNP)His OH (3.23 g; 
7.69 mmol) in dry EtOAc (30 mL) under an atmosphere of nitrogen was added 
NMM (930 ul; 8.45 mmol), which caused dissolution of any remaining solid. 
The solution was cooled to -23.degree. C. at which point isobutyl 
chloroformte (957 ul; 7.38 mmol) was added, and the resulting solution was 
stirred at -23.degree. C. for 25 minutes. 
After completion of the activation, the DMF solution of the TFA salt was 
neutralized by the addition of NMM (812 ul; 7.38 mmol) and was added via 
cannula to the cold solution of the mixed anhydride. After being stirred 
for 1 hour at -23.degree. C., the reaction mixture was warmed to 0.degree. 
C. and was stirred for 1.5 hour. The cooling bath was removed and stirring 
of the mixture was continued for another 3 hours, at which time the 
reaction was quenched by the addition of water (50 mL). 
The mixture was diluted with EtOAc (125 mL) and was washed successively 
with 5% aqueous HCl (150 mL), water (20 mL), and saturated aqueous 
NaHCO.sub.3 (200 mL). The organic layer was dried (MgSO.sub.4), filtered, 
and concentrated under reduced pressure to give an orange solid which was 
flash chromatographed (SiO.sub.2 ; 3%-5% MeOH/CH.sub.2 Cl.sub.2). 
The coupling product was obtained as a yellow solid (3.05 g; 75% yield). 
Step 2 Boc-Phe-(DNP)His (ACHP)-1-Methyl-2-Piperidinone 
To a solution of the coupling product obtained from Step 1 (3.05 g; 4.55 
mmol) in CH.sub.2 Cl.sub.2 (4 mL) was added TFA (4 mL), and the mixture 
was stored under an atmosphere of nitrogen for 45 minutes, at which time 
the solvent and excess TFA were removed under reduced pressure. The yellow 
oil so obtained was triturated in ether and the solid which resulted was 
collected by filtration, washed with ether, and dried under reduced 
pressure. 
The resulting orange yellow solid (2.99 g; 96% yield) was dissolved, under 
an atmosphere of nitrogen, in dry EtOAc (20 mL) and stored while the 
activation of Boc-Phe-Oh was accomplished by in situ formation of a mixed 
anhydride as described below. 
(Activation of Boc--Phe--OH) To a suspension of Boc--Phe--OH (1.52 g; 5.74 
mmol) in dry EtOAc (25 mL) under an atmosphere of nitrogen was added NMM 
(695 .mu.l; 6.31 mmol). The resulting solution was cooled to -23.degree. 
C., isobutyl chloroformate (715 ul; 5.51 mmol) was added, and the solution 
was stirred for 25 minutes. 
After completion of the activation, the solution of the TFA salt was 
neutralized by the addition of NMM (555 .mu.l; 5.06 mmol) and was added 
via cannula to the cold solution of the mixed anhydride. The resulting 
mixture was stirred at -23.degree. C. for 1 hour, at 0.degree. C. for 1.5 
hour, and then at room temperature for 3.5 hours, and the reaction was 
quenched by the addition of water (50 mL), and was diluted with EtOAc (125 
mL). 
The organic phase was washed successively with 5% aqueous HCl (150 mL), 
water (20 mL) and saturated aqueous NaHCO.sub.3 (150 mL), then dried 
(MgSO.sub.4), and filtered. Removal of the solvent under reduced pressure 
gave a solid which was flash-chromatographed (SiO.sub.2 ; 4%-7% 
MeOH/CH.sub.2 Cl.sub.2). The coupling product was obtained as a yellow 
solid (3.24 g; 87% yield). 
Step 3. Boc-Phe-His-(ACHP)-1-Methyl-2-Piperidinone 
The coupling product obtained from Step 2 (3.24 g; 3.96 mmol) was dissolved 
under an atmosphere of nitrogen in dry CH.sub.2 Cl.sub.2 (8 mL), then 
thiophenol (4 mL) and NMM (60 .mu.l; 0.54 mmol) were added. The mixture 
was stirred at room temperature for 5 hours, at which time the solvent and 
excess thiophenol were removed under reduced pressure (0.2 torr) at 
30.degree. C. The residue was flash chromatoqraphed (SiO.sub.2 ; 5%-10% 
MeOH/CH.sub.2 Cl.sub.2), giving the title compound as an off-white powder 
(2.27 g; 88% yield). 
The product exhibited satisfactory NMR spectral properties, was analzyed 
for purity by reverse phase HPLC, and was anlyzed for composition using C, 
H, and N combustion analysis. Inhibition of human plasma renin was assayed 
using the in vitro method described by Boger, et. al., J. Med. Chem. 
(1985) 28, 1779. IC.sub.50 =47 nM. 
B. Preparation of Boc-Phe His-(ACHP)-4-Methyl-3-Morpholinone 
Amino acid coupling was accomplished as described in Example 3A. IC.sub.50 
=31 nM. 
C. Preparation of Boc Phe His-(ACHP) 1-Methylcaprolactam 
Amino acid coupling was accomplished as described in Example 3A. IC.sub.50 
=203 nM. 
D. Preparation of 
Boc-Phe-His-(ACHP)-1-(N-Benzyl-2-Diethylaminoethyl)-2-Piperidinone Acetate 
Boc-Phe-His-(ACHP)-1-(Diethylaminoethyl)-2-piperidinone is protected on the 
histidine side chain by reaction with (BOC).sub.2 O in DMF solution. An 
excess of benzyl bromide is added and the mixture is warmed to effect 
quaternization of the diethylaminoethyl substituent. The Boc group on the 
histidine side chain is removed in situ by the addition of water and 
triethylamine. 
The crude product is purified by preparative reverse phase HPLC and is 
passed through an ion exchange column (Bio Rad AG3-X4A resin, acetate 
form) to produce the title compound. Ipoc--Phe--His--peptides are made 
using sequential coupling, using Ipoc--Phe instead of Boc--Phe, in the 
method according to Example 3A, or by fragment coupling, using 
Ipoc--Phe--His in place of Boc--Phe--His, in the method according to 
Example 3B. 
##STR43## 
peptides are made by sequential coupling using mixed anhydride coupling 
(according to Example 3A) for the histidine group, and using mixed 
anhydride or DCC/HOBT coupling for the 
##STR44## 
group. (CH.sub.3).sub.2 CH--SO.sub.2 --Phe--His--peptides are made by 
sequential coupling using mixed anhydride coupling (according to Example 
3A) for the histidine group, and using mixed anhydride or DCC/HOBT 
coupling for the (CH.sub.3).sub.2 CH-SO.sub.2 -Phe group. 
(CH.sub.3).sub.2 CH--SO.sub.2 --CH.sub.2 -CH(CH.sub.2 
Ph)--CO--His--peptides are made by sequential coupling using mixed 
anhydride coupling (according to Example 3A) for the histidine group and 
DCC/HOBT or DCC/HOSU coupling for the (CH.sub.3).sub.2 CH--SO.sub.2 
--CH.sub.2 -CH(CH.sub.2 Ph)--CO--group. 
2-Indolyl-CO His peptides are made by sequential coupling using mixed 
anhydride coupling (according to Example 3A) for the histidine group, and 
DCC or EDC coupling of indole-2-carboxylic acid. 
These methods are applied to any of the 9 Boc-(ACHP)-lactams described in 
Example 2. 
Claims to the Invention follow.