EP0435887A1 - Renin inhibitory peptides containing maleamide substituents - Google Patents

Abstract

The present invention relates to novel renin inhibitor peptides comprising an insert in the non-cleavable transition state which corresponds to the position 10,11 of the renin substrate (angiotensinogen), as well as a fraction derived from maleic acid or derivatives of this fraction, which is represented by the formula R20N (R30) - (O) CCH = CHC (O) - and which corresponds to the position 8.9 of the renin substrate, preferably at the level of the N termination of the peptide. Such inhibitors are used for the diagnosis and treatment of renin-dependent hypertension, congestive heart failure, renin-dependent hypertaldosterism, other cardiovascular disorders and renin-dependent eye disorders.

Description

RENIN INHIBITORY PEPTIDES CONTAINING MALEAMIDE SUBSTITUENTS

DESCRIPTION BACKGROUND OF THE INVENTION

The present invention provides novel compounds. More particularly, the present invention provides novel renin-inhibiting peptide analogs. Most particularly, the present invention provides renininhibitory peptides containing a non-cleavable transition state insert corresponding to the 10,11-position of the renin substrate (angiotensinogen) and containing a maleic acid derived moiety corresponding to the 8,9-position of the renin substrate and which is preferably at the N-terminus of the peptide. The renin inhibitors provided herein are useful for the diagnosis and control of renindependent hypertension, congestive heart failure, renin dependent hyperaldosterism, and other renin dependent cardiovascular disorders.

Renin is an endopeptidase which specifically cleaves a particular peptide bond of its substrate (angiotensinogen), of which the N- terminal sequence in equine substrate is for example:

Renin

Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-Leu-Val-Tyr-Ser- IA

1 2 3 4 5 6 7 8 9 10 11 12 13 14

as found by L.T. Skeggs et al., J. Exper. Med. 106, 439 (1957).

Human renin substrate has a different sequence as recently discovered by D.A. Tewkesbury et al., Biochem. Biophys. Res. Comm. 99, 1311 (1981). It may be represented as follows:

Renin

-Val-Ile-His-

11 12 13 IB

and having the sequence to the left of the arrow ( ) being as designated in formula IA above .

Renin cleaves angiotensinogen to produce angiotensin I, which is converted to the potent pressor angiotensin II. A number of angiotensin I converging enzyme inhibitors are known to be useful in the treatment of hypertension. Inhibitors of renin are also useful in the treatment of hypertension.

A number of renin-inhibitory peptides have been disclosed. Thus, U.S. patent 4,424,207; European published applications 45,665; 104,041; and 156,322; and European application 0173481, published 5 March 1986; disclose certain peptides with the dipeptide at the 10,11-position containing an isostere bond. A number of statine derivatives stated to be renin inhibitors have been disclosed, see, e.g., European published applications 77,028; 81,783; 114,993; 156,319; and 156,321; and U.S. patents 4,478,826; 4,470,971; 4,479,941; and 4,485,099. Terminal disulfide cycles have also been disclosed in renin inhibiting peptides; see, e.g., U.S. patents 4,477,440 and 4,477,441. Aromatic and aliphatic amino acid residues at the 10,11 position of the renin substrate are disclosed in U.S. patents 4,478,827 and 4,455,303. C-terminal amide cycles are disclosed in U.S. patent 4,485,099 and European published applications 156,320 and 156,318. Certain tetrapeptides are disclosed in European publications 111,266 and 77,027. Further, European published application No. 118.223 discloses certain renin inhibiting peptide analogs where the 10-11 peptide link is replaced by a one to four atom carbon or carbon-nitrogen link. Additionally, Holladay et al., in "Synthesis of Hydroxyethylene and Ketomethylene Dipeptide Isosteres", Tetrahedron Letters, Vol. 24, No. 41, pp. 4401-4404, 1983 disclose various intermediates in a process to prepare stereo-directed "ketomethylene" and "hydroxyethylene" dipeptide isosteric functional groups disclosed in the above noted U.S. Patent No. 4,424,207.

Additionally, published European Applications 45,161 and 53,017 disclose amide derivatives useful as inhibitors of angiotensin converting enzymes.

Certain dipeptide and tripeptides are disclosed in U.S. patents 4,514,332; 4,510,085; and 4,548,926 as well as in European published applications 128,762; 152,255; and 181,110. Pepstatin derived renin inhibitors have been disclosed in U.S. patent 4,481,192. Retroinverso bond modifications at positions 10-11 have been disclosed in U.S. patent 4,560,505 and in European published applications 127,234 and 127,235. Derivatives of isosteric bond replacements at positions 10-11 have been disclosed in European published applications 143,746 and 144,209; and PCT Application International Publication Number WO87/05302, published 11 September 1987. Isosteric bond modifications at positions 11-12 and 12-13 have been disclosed in European published application 179,352. Certain peptides containing 2-substituted statine analogues have been disclosed in European published application 157,409. Certain peptides containing 3-aminodeoxystatine have been disclosed in European published application 161,588. Certain peptides containing 1-amino-2-hydroxybutane derivatives at positions 10-11 have been disclosed in European published application 172,346. Certain peptides containing 1-amino-2-hydroxypropane derivatives at positions 10-11 have been disclosed in European published application 172,347. Certain peptides containing N-terminal amide cycles have been disclosed in PCT Application International Publication Number WO87/05909, published 8 October 1987. Certain peptides containing dihalostatine have been disclosed in European application 0218688, published 22 April 1987.

European published applications 156,322; 114,993; and 118,223; and PCT Application International Publication Number WO87/02986, published 21 May 1987; European Application 0173487, published 5 March 1986; PCT Application International Publication Number WO87/05302, published 11 September 1987; and PCT Application International Publication Number WO87/05909, published 8 October 1987; disclose hydroxamic acids or esters at the C-terminus.

INFORMATION DISCLOSURE

PCT patent application, PCT/US89/00247 , filed 27 January 1989, discloses renin inhibitory peptides having a variety of polar end groups at the N-terminus and/or the C-terminus.

PCT Application International Publication Number WO89/01488, published 23 February 1989, discloses renin inhibitory peptides having aryl acid derived moieties substituted for Phe⁸-His⁹ (angiotensinogen numbering) positions.

SUMMARY OF THE INVENTION

The present invention particularly provides:

A renin inhibitory peptide having a non-cleavable transition state insert corresponding to the 10,11-ρosition of a renin substrate (angiotensinogen) and having a moiety of the formula I at the N-terminus;

wherein R₂₀ is

(a) -C(R₂₁)(R₂₂)-C(O)-OR₂₃, or

(b) -(CH₂)_n-R₂₄:

wherein R₂₁ is

(a) hydrogen, or

(b) C₁-C₅alkyi;

wherein R₂₂ is (a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₂₃ is

(a) hydrogen, or

(b) C₁-C₁₀alkyl;

wherein R₂₄ is

(a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₃₀ is

(a) hydrogen,

(b) C ₁-C₅alkyl,

(c) - (CH₂)_p-aryl , or

(d) -(CH₂)_p-Het;

wherein n is 1 to 5, inclusive;

wherein p is 0 to 5, inclusive.

By "renin inhibitory peptide" is meant a compound capable of inhibiting the renin enzyme in mammalian metabolism and having three or more amino acid residues linked by peptidic or pseudo-peptidic bonds.

By "a non-cleavable transition state insert" is meant a transition state insert which is not cleavable by a hydrolytic enzyme in mammalian metabolism. A variety of such transition state inserts, corresponding to the 10,11-position of the renin substrate, are known in the art, including those disclosed in the following references, which are hereby incorporated by reference:

U.S. Patent 4,424,207 (Szelke); European Patent 104041A (Szelke); European Patent Application 144,290A (Ciba Geigy AG); European Patent 0.156,322 (Merck); European Patent 161-588A (Merck); European Patent 0,172,347 (Abbott); European Patent 172-346-A (Abbott); European Patent 156-318 (Merck); European Patent 157-409 (Merck); European Patent 152-255 (Sankyo); and U.S. Patent 4,548,926 (Sankyo) ; and

PCT Application International Publication Number W087/05302, published 11 September 1987; PCT Application International Publication Number WO87/05909, published 8 October 1987; European application 0218688, published 22 April 1987: PCT Application International Publication Number WO88/04664, published 30 June 1988; and European application 0173481, published 5 March 1986; and A. Spaltenstein, P. Carpino, F. Miyake and P.B. Hyskins, Tetrahedron Letters, 27:2095 (1986); D.H. Rich and M.S. Bernatowicz, J. Med. Chem., 25:791 (1982); Roger, J. Med. Chem. , 28:1062 (1985); D.M. Glick et al., Biochemistry, 21:3746 (1982); D.H. Rich, Biochemistry, 24:3165 (1985); R.L. Johnson, J. Med. Chem., 25:605 (1982); R.L. Johnson and K. Verschovor, J. Med. Chem., 26:1457 (1983); R.L. Johnson, J. Med. Chem., 27:1351 (1984); P.A. Bartlett et al., J. Am. Chem. Soc, 106:4282 (1984); and Peptides: Synthesis, Structure and Function (V.J. Hruby; D.H. Rich, eds.) Proc. 8th American Peptide Sym., Pierce Chemical Company, Rockford, l11., pp. 511-20; 587-590 (1983).

The renin inhibitory peptides of the present invention are represented by formula II. In formula II, the non-cleavable transition state insert, corresponding to the 10,11-position of the renin substrate, begins at -NHCH(CH₂) (R₂)-X₁, with the variables as defined above.

The novel renin inhibitory peptides of the present invention containing a maleic acid derived moiety are potent inhibitors of human plasma renin. The novel non-peptidogenic nature of these inhibitory peptides alters their absorption, distribution, metabolism, and excretion characteristics. The new maleic acid derived moiety makes these inhibitory peptides unrecognizable to proteinases which would normally rapidly degrade a substrate based inhibitory peptide, particularly at the position corresponding to the 8,9-position of the renin substrate (angiotensinogen).

As is apparent to those of ordinary skill in the art, the renin inhibitory peptides of the present invention can occur in several isomeric forms. All such isomeric forms are included within the scope of the present invention.

Renin inhibitory peptides commonly have protecting groups at the C-terminus. These protecting groups are known in the polypeptide art. Examples of these protecting groups are given below. Any of these protecting groups are suitable for the renin inhibitory peptides of the present invention.

Furthermore, the non α-amino acid moieties of the formula I of the present invention preferably occur at the N-terminus of the renin inhibitory peptide.

The present invention provides peptide inhibitors of renin which contain a non α-amino acid moiety and have a transition state insert. Examples of pharmaceutically acceptable acid addition salts include: acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate , ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate , hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2- hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, palmoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate, and undecanoate.

The carbon atom content of various hydrocarbon-containing moieties is indicated by a prefix designating the minimum and maximum number of carbon atoms in the moiety, i.e., the prefix (C_i-C_j) indicates a moiety of the integer "i" to the integer "j" carbon atoms, inclusive. Thus (C₁-C₄)alkyl refers to alkyl of one to 4 carbon atoms, inclusive, or methyl, ethyl, propyl, butyl, and isomeric forms thereof . C₄-C₇cyclic amino indicates a monocyclic group containing one nitrogen and 4 to 7 carbon atoms.

Examples of (C₃-C₁₀)cycloalkyl, which include alkyl-substituted cycloalkyl containing a total of up to 10 total carbon atoms, are cyclopropyl. 2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl and isomeric forms thereof.

Examples of aryl include phenyl, naphthyl, (o-, m-, or p-)tolyl, (o-, m-, or p-)ethylphenyl, 2-ethyl-tolyl, 4-ethyl-o-tolyl, 5-ethyl- m-tolyl, (o-, m-, or p-)propylphenyl, 2-propyl- (o-, m-, or p-)tolyl, 4-isopropyl-2,ό-xylyl, 3-propyl-4-ethylphenyl, (2,3,4- 2,3,6-, or 2,4,5-)trimethylphenyl, (o-, m-, or p-)fluorophenyl, (o-, m-, or p-trifluoromethyl)phenyl, 4-fIuoro-2,5-xylyl, (2,4-, 2,5-, 2,6-, 3,4- , or 3.5-)difluorophenyl, (o-, m-, or p-)chlorophenyl, 2-chloro-p- tolyl, (3-, 4-, 5- or 6-)chloro-o-tolyl, 4-chloro-2-ρropylphenyl, 2- isopropyl-4-chlorophenyl, 4-chloro-3-fIuorophenyl, (3- or 4-)chloro- 2-fluorophenyl, (o-, m-, or p-)trifluoro-methylphenyl, (o-, m-, or p-)ethoxyphenyl, (4- or 5-)chloro-2-methoxy-phenyl, and 2,4-dichloro- (5- or 6-)methylρhenyl, and the like. Examples of Het include: 2-, 3-, or 4-pyridyl, imidazolyl, indolyl, Nⁱⁿ-formyl-indolyl, Nⁱⁿ-C₁-C₅alkyl-C(O)-indolyl, 1,2,4- triazolyl, 2-, 4-, or 5-pyrimidinyl, 2- or 3-thienyl, piperidinyl, pyrryl, pyrrolinyl, pyrrolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, pyrazinyl, piperazinyl, pyridazinyl, oxazolyl, oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, furyl, thienyl, and benzothienyl. Each of these moieties may be substituted as noted above.

As would be generally recognized by those skilled in the art of organic chemistry, a heterocycle as defined herein for Het would not be bonded through oxygen or sulfur or through nitrogen which is within a ring and part of a double bond.

Halo is halogen (fluoro, chloro, bromo, or iodo) or trifluoromethyl.

Examples of pharmaceutically acceptable cations include: pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations. Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium, and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron are also within the scope of this invention. Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines.

The novel peptides herein contain both natural and synthetic amino acid residues. These residues are depicted using standard amino acid abbreviations (see, e.g., IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN) , "Nomenclature and Symbolism for Amino Acids and Peptides." Eur. J. Biochem. 138:9-37 (1984) unless otherwise indicated.

The renin inhibitors of this invention are useful for treating any medical condition for which it is beneficial to reduce the levels of active circulating renin. Examples of such conditions include renin-dependent hypertension, hypertension, hypertension under treatment with another antihypertensive and/or a diuretic agent, congestive heart failure, renin-dependent hyperaldosterism, angina, postmyocardial infarction, other renin-dependent cardiovascular disorders and ocular disorders. The renin-angiotension system may play a role in maintenance of intracellular hoπteostasis: see Clinical and Experimental Hypertension, 86, 1739-1742 (1984) at page 1740 under Discussion.

Further, the renin inhibitors of this invention may be useful in the treatment of cerebrovascular disorders and disorders of intracellular homeotasis. The possible role of the renin-angiotensin system in the maintenance of intracellular homeostasis is disclosed in Clinical and Experimental Hypertension, 86:1739-1742 (1984). Additionally, the renin inhibitors of this invention potentiate the antithrombotic activity of a thromboxane antagonist (U.S. patent 4,558,037). The antihypertensive effect of the renin inhibitors of this invention are potentiated by combination with a thromboxane synthetase inhibitor.

The compounds of the present invention are preferably orally administered to humans to effect renin inhibition for the purpose of favorably affecting blood pressure. For this purpose, the compounds are administered from 0.1 mg to 100 mg per kg per dose, administered from 1 to 4 times daily. Equivalent dosages for other routes of administration are also employed. For example, renin-associated hypertension and hyperaldosteronism are effectively treated by the administration of from 0.5 to 50 milligrams of the compound per kilogram of body weight per day.

The exact dose depends on the age, weight, and condition of the patient and on the frequency and route of administration. Such variations are within the skill of the practitioner or can readily be determined.

The compounds of the present invention may be in the form of pharmaceutically acceptable salts both those which can be produced from the free bases by methods well known in the art and those with which acids have pharmacologically acceptable conjugate bases.

Conventional forms and means for administering renin-inhibiting compounds may be employed and are described, e.g., in U.S. Patent No. 4,424,207 which is incorporated by reference herein. Likewise, the amounts disclosed in the U.S. Patent No. 4,424,207 are examples applicable to the compounds of the present invention.

The compounds of the present invention are preferably orally administered in the form of phanaacologically acceptable acid addition salts. Preferred pharmacologically acceptable salts for oral administration include the citrate and aspartate salts, although any pharmacologically acceptable salt is useful in this invention, including those listed above. These salts may be in hydrated or solvated form.

For these purposes the coαrpounds of the present invention may be administered topically, parenterally, by inhalation spray, or rectally in dosage unit forπulations containing conventional nontoxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition to the treatment of warm-blooded animals such as mice, rats, horses, dogs, cats, etc., the compounds of the invention are effective in the treatment of humans.

The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example as a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3- butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or digly- cerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

The peptides of this invention may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable nonirritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.

The renin-inhibiting compounds of this invention may be administered in combination with ocher agents used in antihypertensive therapy such as diuretics, a and/or 5-adrenergic blocking agents, CNS-acting agents, adrenergic neuron blocking agents, vasodilators, angiotensin I converting enzyme inhibitors, and the like as described for example in published European patent application 156,318.

The present invention is also directed to combinations of the novel renin-inhibitory peptides of Formula II with one or more antihypertensive agents selected from the group consisting of diuretics, a and/or β-adrenergic blocking agents, CNS-acting agents, adrenergic neuron blocking agents, vasodilators, angiotensin I converting enzyme inhibitors, 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; bendroflumethiazide; benzthiazide; bumetanide; chlorothiazide; chlorthalidone; cyclothiazide; ethacrynic acid; furosemide; hydrochlorothiazide; hydroflumethiazide; 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; quinethazone; sodium ethacrynate; sodium nitroprusside; spironol- actone; ticrynaten; trimaterene; trichlormethiazide;

α-Adrenergic Blocking Agents: dibenamine; phentolamine; phenoxyben- zamine; prazosin; tolazoline;

β-Adrenergic Blocking Agents: atenolol; metoprolol; nadolol; propranolol; timolol;

((±)-2-[3-(tert-butylamino)-2-hydroxypropoxy]-2-furananilide) (ancarolol);

(2-acetyl-7-(2-hydroxy-3-isopropylaminopropoxy)benzofuranHCl)(befunolol);

( (±) -1- (isoρropylamino)-3-(p-(2-cyciopropylmethoxyethyl)-phenoxy)-2- propranol HCl) (betaxolol);

(1-[(3,4-dimethoxyphenethyl)amino]-3-(m-tolyloxy)-2-proρanol HCl)(bevantolol);

(((±)-1-(4-((2-isopropoxyethoxy)methyl)ρhenoxy)-3-isopropylamino-2- propano l )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 Η-indol-4-yl)oxy)-2-propanol benzoate) (bopindolol); (1-(2-exobicyclo[2.2.1]-hept-2-ylphenoxy)-3-[(1-methylethyl)-amino]-

2-propanol HCl) (bornaprolol);

(o-[2-hydroxy-3-[(2-indol-3-yl-1,1-dimethylethyl)-amino]propoxy]ben- zonitrile HCl) (bucindolol);

(α-[(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- methylacetamide HCl) (cetamolol);

(2-benzimidazolyl-phenyl(2-isopropylaminopropanol));

((±)-3'-acetyl-4'-(2-hydroxy-3-isoρropylaminopropoxy)-acetanilide

HCl) (diacetolol);

(methyl-4-[2-hydroxy-3-[(1-methylethyl)aminopropoxyl]]-benzene- propanoate HCl) (esmolol);

(erythro-DL-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol);

(1-(tert.butylamino)-3-[0-(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)-(l-methyl-3-phenylpropyl)- amino]ethyl]benzaaide);

(4-hydroxy-9-[2-hydroxy-3-(isopropylamino)-propoxy]-7-methyl-5H- furo[3,2-g][1]-benzopyran-5-one) (iprocrolol);

((-)-5-(tert.butylamino)-2-hydroxypropoxy]-3,4-dihydro-1-(2H)- naphthalenone HCl) (levobunolol);

(4-(2-hydroxy-3-isopropylamino-propoxy)-1,2-benzisothiazole HCl);

(4-[3-(tert.butylamino)-2-hydroxypropoxy]-N-aethylisocarbostyril

HCl);

((±)-N-2-[4-(2-hydroxy-3-isopropylaminopropoxy)phenyljethyl-N'- isopropylurea) (pafenolol);

(3-[[(2-trifiuoroacetamido)ethyl]amino]-l-phenoxypropan-2-ol);

(N- (3-(o-chlorophenoxy)-2-hydroxypropyl)-N'-(4'-chloro-2,3-dihydro-3- oxo-5-pyridazinyl)ethylenediamine);

((±)-N-[3-acetyi-4-[2-hydroxy-3-[(1-methylethyl)amino]propoxyphenyl]- butanamide) (acebutolol);

( (±) -4'-[3-(tert-butylamino)-2-hydroxypropoxy]spiro[cyclohexane-1,2'- indan]-1'-one) (spirendolol); (7-[3-[[2-hydroxy-3-[(2-methylindol-4-yl)oxylpropyl]amino]butyl]thio- phylline) (teoprolol);

((±)-1-tert.butylamino-3-(thiochroman-8-yloxy)-2-propanol) (tertatolol);

((±)-1-tert.butylamino-3-(2,3-xylyloxy)-2-proρanol HCl) (xibenolol); (8-[3-(tert.butylamino)-2-hydroxypropoxy]-5-methylcoumarin) (bucumolol);

(2-(3-(tert.butylamino)-2-hydroxy-proρoxy)benzonitrile HCl) (bunitrolol);

((±)-2'-[3-(tert-butylamino)-2-hydroxypropoxy-5'-fluorobutyrophenone) (butofilolol);

(1-(carbazol-4-yloxy)-3-(isopropylamino)-2-ρropanol) (carazolol);

(5-(3-tert.butylamino-2-hydroxy)propoxy-3,4-dihydrocarbotyril 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-[(l-methylethyl)amino]-2- propanol) (moprolol);

((1-tert.butylamino)-3-[(5,6,7,8-tetrahydro-cis-6,7-dihydroxy-1- naphthyl)oxy]-2-propanol) (nadolol);

((S)-1-(2-cycloρentylphenoxy)-3-[(1,1-dimethylethyl)amino]-2-propanol sulfate (2:1)) (penbutolol);

(4'-[1-hydroxy-2-(amino)ethyl]methanesulfonanilide) (sotaloi);

(2-methyl-3-[4-(2-hydroxy-3-tert.butyiaminopropoxy)phenyl]-7-methoxy- isoquinoiin-1-(2H)-one);

(1-(4-(2-(4-fluorophenyIoxy)ethoxy)phenoxy)-3-isopropylamino-2- propanol HCl);

((-)-p-[3-[(3,4-dimethoxyphenethyl)amino]-2-hydroxypropoxy]-β-nstbyl- cinnamonitrile) (pacrinolol);

((±)-2-(3'-tert.butylamino-2'-hydroxypropylthio)-4-(5'-carbamoyl-2'- thienyl)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-propanol) (indopanolol);

((±)-6-[[2-[[3-(p-butoxyphenoxy)-2-hydroxypropyl]amino]ethyl]amino]- 1,3-dimethyluracil) (pirepolol);

(4-(cyclohexylamino)-1-(1-naphtholenyloxy)-2-butanol);

(1-phenyl-3-[2-[3-(2-cyanophenoxy)-2-hydroxypropylJaminoethyl]hydantoin HCl);

(3,4-dihydro-8-(2-hydroxy-3-isopropylaminopropoxy)-3-nitroxy-2H-1- benzopyran) (nipradolol);

Angiotensin I Converting Enzyme Inhibitors:

1-(3-mercapto-2-methyl-l-oxopropyl)-L-proline (captopril);

(1-(4-ethoxycarbonyl-2,4(R,R)-dimethylbutanoyl)indoline-2(S)-car- boxylic 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-oxo-propyl)glycine) (pivalopril);

((2R,4R)-2-(2-hydroxyphenyl)-3-(3-mercaptopropionyl)-4-thiazolidine-carboxylic acid);

(1-(N-[1(S)-ethoxycarbonyl-3-phenylpropyl]-(S)-alanyl)-cis,syn-octa- hydroindol-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)-propyljamino)-2,3,4,5-tetrahydro- 2-oxo-1- (3S)-benzazepine-1-acetic acid HCl);

(N-(2-benzyl-3-mercaptopropanoyl)-S-ethyl-L-cysteiήe) 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;

N²-[1-(S)-carboxy-3-phenylpropyl]-L-lysyl-L-proline (lysinopril); Other Antihypertensive Agents: aminophylline; cryptenamine acetates and tannates; deserpidine; meremethoxylline procaine; pargyline; tri methaphan 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 singly. Coadainistration is most readily accomplished by combining the active ingredients into a suitable unit dosage form containing the proper dosages of each. Other methods of coad- ministration are, of course, possible.

The novel peptides of the present invention possess an excellent degree of activity in treating renin-associated hypertension and hyperaldosteronism.

Renin inhibitors have also been disclosed to control the rise in intraocular pressure associated with the use of steroidal anti- inflammatory drugs as described in PCT International Application

PCT/US86/02291 (PCT International Publication Number WO 87/02581 dated 7 May 1987).

The compounds of the present invention are prepared as depicted in the charts and as described more fully in the Preparations and Examples.

The process of the present invention is more completely understood by reference to the charts below. In these charts, the variables are as defined above. All of the starting materials are commercially available or their preparation is described below. Variations to these procedures to prepare other compounds of the present invention would be readily known to one of ordinary skill in the art.

CHART A

The synthesis of the compound of formula A-6 is given in Chart A D-Phenylalanine of formula A-1 is esterified with isobutylene in methylene chloride using concentrated sulfuric acid as catalyst to give the compound of formula A-2. D-Phenylalanine tert-butyl ester of formula A-2 is then reacted with maleic anhydride of formula A-3 in tetrahydrofuran to give the compound of formula A-4. The compound of formula A-4 is then coupled with 2HCl-LVA-Ile-Amp of formula A-5

(as described in U.S. patent application, Serial No. 147,073, filed

20 January 1988, and in published European patent application

0173481, which are hereby incorporated by reference) using diethyl- phosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula A-6.

CHART B

The synthesis of the compound of formula B-6 is outlined in Chart B. D-Phenylalanine of formula B-1 is esterified with ethanol and gaseous hydrochloric acid to give D-phenylalanine ethyl ester hydrochloride of formula B-2. D-Phenylalanine ether ester hydro- chloride of formula B-2 is then reacted with maleic anhydride of formula B-3 in tetrahydrofuran containing triethylamine to give the compound of formula B-4. The compound of formula B-4 is coupled with 2HCl-LVA-Ile-Amp of formula B-5 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula B-6.

CHART C

The synthesis of the compound of formula C-6 is given in Chart

C. D-Phenylalanine of formula C-1 is esterified with methanol and gaseous hydrochloric acid to give D-phenylanine methyl ester hydrochloride of formula C-2, which is then reacted with maleic anhydride of formula C-3 in tetrahydrofuran containing triethylamine to give the compound of formula C-4. The compound of formula C-4 is coupled with 2HCl-LVA-Ile-Amp of formula C-5 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula C-6.

CHART D

The synthesis of the compound of formula D-2 is given in Chart

D. The compound of formula C-6 of Chart C is used as the formula D-1 starting material. The compound of formula D-1 is hydrolyzed with IN potassium hydroxide in methanol and then neutralized with aqueous hydrochloric acid to give the compound of formula D-2.

CHART E

The synthesis of the compound of formula E-5 is outlined in Chart E. L-Phenyialanine tert-butyl ester hydrochloride of formula E-l (commercially available) is reacted with maleic anhydride of formula E-2 in the presence of triethylamine and tetrahydrofuran to give the compound of formula E-3. The compound of formula E-3 is coupled with 2HCl-LVA- Iie-Amp of formula E-4 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide as solvents to give the compound of formula E-5. CHART F

The synthesis of the compound of formula F-5 is given in Chart

F. Phenethylamine of formula F-1 is reacted with maleic anhydride of formula F-2 in tetrahydrofuran as solvent to give the compound of formula F-3. The compound of formula F-3 is then coupled with 2HC1- LVA-Ile-Amp of formula F-4 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula F-5.

CHART .G

The synthesis of the compound of formula G-5 is given in Chart

G. 2-(2-Aminoethyl)pyridine of formula G-1 is reacted with maleic anhydride of formula G-2 in tetrahydrofuran as solvent to give the compound of formula G-3. The compound of formula G-3 is then coupled with 2HCl-LVA-Ile-Amp of formula G-4 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula G-5.

CHART H

The synthesis of the compound of formula H-5 is given in Chart H. Benzylamine of formula H-1 is reacted with maleic anhydride of formula H-2 in tetrahydrofuran to give the compound of formula H-3. The compound of formula H-3 is then coupled with 2HC1-LVA-Ile-Amp of formula H-4 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformaxide to give the compound of formula H-5.

CHART I

The synthesis of the compound of formula 1-9 is given in Chart I. The amine group of phenethylamine of formula 1-2 is protected as the BOC derivative using di-tert-butyldicarbonate and potassium carbonate in tetrahydrofuran to give S-Boc-phenethylamine of formula 1-2. The compound of formula 1-2 is alkylated using sodium hydride and benzyl bromide of formula 1-3 in dimethylformamide to give N-Boc- N-benzyl-phenethylamine of formula 1-4. The Boc- group of the compound of formula 1-4 is removed vith trifluoroacetic acid in methylene chloride to give N-benzylphenethylamine of formula 1-5, which is then reacted with maleic anhydride of formula 1-6 in tetrahydrofuran to give the compound of formula 1-7. The compound of formula 1-7 is coupled with 2HCl-LVA-Ile-Amp of formula 1-8 using diethylphosphrryl cyanide and triethyisaine in methylene chloride and dimethylformamide to give the compound of formula 1-9.

CHART J

The compound of formula J- 6 is prepared as shown in Chart J . Tryptamine hydrochloride of formula J- 1 is stirred in formic acid, and gaseous hydrochloric acid is bubbled in to give Nⁱⁿ-formyltrypt- amine hydrochloride of formula J -2. Biochem. et Biophys . Acta , 147 :453 (1967) . Nⁱⁿ-formyltryptamine hydrochloride of formula J-2 is stirred with maleic anhydride of formula J-3 and triethylamine in tetrahydrofuran to give the compound of formula J-4. The compound of formula J-4 is coupled with 2HCl-LVA-Ile-Amp of formula J-5 using diethylphosphoryl cyanide and triethylamine in methylene chloride and dimethylformamide to give the compound of formula J-6.

CHART K

The compound of formula K- 7 is prepared as shown in Chart K. Boc-Leuψ[CH(O-t-BDMS)CH₂]Val-OH of formula K-1 (as described in U. S . patent application, Serial No . 147 , 073 , filed 20 January 1988 , and in published European patent application 0173481 , which are hereby incorporated by reference) is coupled with S-2-methylbutylamine of formula K-2 using diethylphosphoryl cyanide and triethylamine in methylene chloride to give Boc-Leuψ[CH(O- t-BDHS)CH₂ ]Val-methyl- butylamide of formula K-3. The Boc group of the compound of formula K-3 is removed with trifluoroacetic acid in methylene chloride to give Leuψ[CH(O-t-BDMS)CH₂ ]Val-methylbutylamide of formula K-4. The compound of formula K-4 is coupled with the compound of formula K-5 (prepared as the compound of formula A-4 in Chart A) using diethylphosphoryl cyanide and triethylamine in methylene chloride to give the compound of formula K-6 . The tert-butyldimethylsilyl group of the compound of formula K- 6 is removed with tetra-n-butylammonium fluoride in tetrahydrofuran zo give the compound of formula K- 7.

CHART L

The compound of formula L-5 , which is named 4- [ (1 ' R- tert- Butoxycarbonyl)phenethylamido] -maleoyl-2S-amino-1-cyclohexyi-3R,4S- diol-6-methylheptane , is prepared as shown in Chart L. The compound of formula L-1 (as described in PCT Application International Publication Number W088/04664 , published 30 June 1988 , which is hereby incorporated by reference) is reacted with isobutylaagnesium chloride in tetrahydrofuran and ethylene oxide to give a mixrure of isomers . The isomers are separated and the isomer of formula L-2 (stereochem istry not specified at indicated center) is deprotected with acetyl chloride-methanol to give 1-cyclohexyl-2(S)-amino-3(R), 4-dihydroxy- 6-methylheρtane of formula L-3. Published European patent application 0189203 (Abbott) discloses the hydrochloride salt of the compound of formula L-3. The compound of formula L-3 is coupled with the compound of formula L-4 (prepared as the compound of formula A-4 in Chart A) using diethylphosphoryl cyanide and triethylamine in methylene chloride as solvent to give the compound of formula L-5.When tested, the compound of formula L-5 had an IC₅₀ of 1.7 x 10^-6 molar and an FAB mass spec [m + H] at m/z 545.

Generally, the renin inhibiting polypeptides may be prepared by solution phase peptide synthetic procedures analogous to those described hereinafter or to those methods known in the art. Appropriate protecting groups, reagents, and solvents for the solution phase method can be found in "The Peptides: Analysis, Synthesis, and Biology," Vols. 1-5, eds. E. Gross and T. Meienhofer , Academic Press , NY, 1979-1983 ; "The Practice of Peptide Synthesis", M. Bodansky and A. Bodansky, Springer-Verlag, New York, 1984; "The Principles of Peptide Synthesis", M. Bodansky, Springer-Verlag, New York, 1984. Thus, for example, the carboxylic moiety of N^α-t-butyloxycarbonyl (Boc) -substituted amino acid derivatives having suitable side chain protecting groups, if necessary, may be condensed with the amino functionality of a suitably protected amino acid or peptide using a conventional coupling protocol such as dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBT) or diethylphosphoryl cyanide (DEPC) and triethylamine (Et₃N) in methylene chloride or dimethylformamide. The synthetic procedures used to incorporate the novel moieties herein are analogous to those described, for example, in U.S. patents 4,424,207; 4,470,971; 4,477,440; 4,477,441; 4,478,826; 4,478,827; 4,479,941; and 4,485,099, and European application 0173481, published 5 March 1986, all of which are expressly incorporated by reference herein. See, also, published European patent applications 45,161; 45,665; 53,017; 77,028; 77,029; 81,783; 104,041; 111,266; 114,993; and 118,223.

Following coupling reaction completion, the N^α-Boc moiety may be selectively removed with 50% trifluoroacetic acid with or without 2% anisole (v/v) in methylene chloride. Neutralization of the resultant trifluoroacetate salt may be accomplished with 10% diisopropyl- ethylamine or sodium bicarbonate in methylene chloride.

Variations in the above description for starting materials, reactants, reaction conditions and required protecting groups to obtain other such N-alkylated compounds are known to an ordinarily skilled chemist or are readily available in the literature.

The compounds of the present invention may be in either free form or in protected form at one or more of the remaining (not previously protected) peptide, carboxyl, amino, hydroxy, or other reactive groups. The protecting groups may be any of those known in the polypeptide art. Examples of nitrogen and oxygen protection groups are set forth in T.W. Greene, Protecting Groups in Organic Synthesis, Wiley, New York, (1981); J.F.W. McOmie, ed. Protective Groups in Organic Chemistry, Plenum Press (1973); and J. Fuhrhop and G. Benzlin, Organic Synthesis, Verlag Chemie (1983). Included among the nitrogen protective groups are t-butoxycarbonyl (Boc), benzyloxycarbonyl, acetyl, allyl, phthalyl, benzyl, benzoyl, trityl and the like.

The following compounds of the present invention are preferred: 4-[(1'R-tert-Butoxycarbonyl)phenethylamido]maleoyl-Leu\6[CH(OH)- C₂]Val-Ile-2-(amidomethyl)pyridine;

4-[(1'R-Ethoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)CH₂]- Val-Ile-2-(amidomethyl)pyridine;

4-[(1'R-Methoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)CH₂]- Val-Ile-2-(amidomethyl)pyridine; and

4-[(1'S-(tert-Butoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)- CH2]Val-Ile-2-(amidomethyl)pyridine.

The most preferred compound is 4-[(1'R-tert-Butoxycarbonyl)phen- ethylamido]maleoyl-Leuψ[CH(OH)C2]Val-lle-2-(amidomethyl)pyridine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following Preparations and Examples illustrate the present invention.

In the Preparations and Examples below and throughout this document:

¹H-NMR is nuclear magnetic resonance

1-HOBt is 1-hydroxybenzotriazole

2-Pya is 3-(2-pyridinyl)alanine

3-Pya is 3-(3-pyridinyl)alanine

AcCl is acetyl chloride Amp is 2-(aminomethyl)pyridinyl

Bn is benzylester

BOC is t-butoxycarbonyl

Bz is benzyl

C is centigrade

Cbz is benzyloxycarbonyl

CDCI₃ is deuteriochlorofora

Celite is a filter aid.

C_pTSA is p-toluenesulfonic acid

C_pVA is Cpa[CH(OH)CH₂]Val

Dap is 2,4-diaminopyrimidin-6-yl

DCC is dicyclohexylcarbodiimide

DEPC is diethylphosphoryl cyanide

DMF is dimethylformamide

EtOAc is ethyl acetate

FAB is fast atom bombardment, a technique for obtaining mass spectra of large molecules.

FTrp is N^in-formyl-Trp

g is grams

h is hour(s)

His is histidine

HOBT is 1-hydroxybenzotriazole

HPLC is high performance liquid chromatography

Iba is isobutylamine

lle is isoleucine

IR is infrared spectra

K₂CO₃ is potassium carbonate

LVA is Leuψ(CH(OH)CH₂)Val with the S configuration at C4 (the hydroxyl-bearing carbon atom).

M or mol is mole

Me is methyl

min is minute

ml is milliliter

MPLC is medium pressure liquid chromatography

MS is mass spectroscopy

NaH is sodium hydride

NH₄OH is ammonium hydroxide

Ph is phenyl Phe is phenylalanine

Pla is L-3-phenyllactic acid

Poa is phenoxyacetyl

RIP means a compound having the formula H-Pro-His-Phe-His-Phe- Phe-Val-Tyr-Lys-0H.2(CH₃C(O)OH).XH₂O which is a known renin- inhibiting peptide.

Sta is statine

TBS is tert-butyldimethylsilyl

TBDMS is tert-butyldimethylsilyl

TEA is triethylamine

TFA is trifluoroacetic acid

THF is tetrahydrofuran

THP is tetrahydropyranyl

TLC is thin layer chromatography

Tos is p-toluenesulfonyl

TsOH is p-toluenesulfonic acid.

The wedge-shape line indicates a bond which extends above the plane of the paper relative to the plane of the compound thereon.

The dotted line indicates a bond which extends below the plane of the paper relative to the plane of the compound thereon.

In the examples below, HPLC is performed using Altex Model 110A pumps, an LDC Spectro Monitor III detector, Altex Model 420 Programmer, and a Hewlett Packard 3390A integrator. The column used is a Brownlee RP-18 Sphere-10, 250 mm x 4.0 mm. The solvent system is solvent A, 50 mM NaH₂PO₄ (6.9 g/L), 1% H₃PO₄ (1 ml/L), and 1% CH₃CN (10 ml/L) in H₂O, and solvent B, 12.5 mM NaH₂PO₄ (1.7 g/L), 0.25% H₃PO₄ (0.25 ml/L), 25% H₂O (250 ml/L), and 75% CH₃CN (750 ml/L). ¹H- NMR spectra are recorded on a Bruker 300 MHz instrument.

In the examples below, the in vitro IC₅₀ is measured in nano- molars. The in vitro test is performed as described in U.S. patent application, Serial No. 147,073, filed 20 January 1988, and in published European patent application 0173481, which are hereby incorporated by reference.

The following general method for coupling was used in the following preparations and examples:

To a solution of the acid (1.2 to 1.5 equiv), LVA-Ile-Amp-2HCl (1 equiv), methylene chloride and dimethylformamide is added first triethylamine (3.25 equiv), followed by diethylphosphorylcyanide (1.20-1.5 equiv). After stirring for 1-24 hours, solvents are removed in vacuo and the residue is partitioned two times with methylene chloride and aqueous sodium bicarbonate. The organic layers are filtered through sodium sulfate, concentrated, and chromatographed on silica gel.

Preparation 1 Maleic acid, D-Phenylalanine-tert-butyl ester amide (Formula A-4) Refer to Chart A.

A solution of 0.142 g of maleic anhydride and 0.30 g of D-Phe tert-butyl ester in 20 ml of tetrahydrofuran is stirred for 1 hr and is then partitioned between diethyl ether, aqueous hydrochloric acid and brine. The organic layers are dried over magnesium sulfate and taken to dryness to give 0.42 g of a solid. Crystallization from methylene chloride and hexane gives 0.40 of the title product.

Physical characteristics are as follows:

M.P.: 109-112ºC.

[α]D - +8.0 (0.8135, ethanol).

MS: m/z at 319.

Anal. Found: C, 63.70; H, 6.91; N, 4.28.

¹H-NMR (5, CDCl₃): 1.43, 3.19, 4.78, 6.24, 6.44, 6.90, 7.11- 7.31.

Example 1 4- [l'R-tert-Butoxycarbonyl)phenethylamido]maleoyl- LeuψCH(HOKH₂]Val-Ile-2(amidomethynpyridine (Formula A-6) Refer to Chart A.

According to the general coupling procedure given above, 0.061 g of acid of Preparation 1 and 0.0819 g of LVA-Ile-Amp-2HCl are combined to give, after chromatography with 3% methanol -+ 5% methan- ol-methylene chloride (saturated with ammonium hydroxide), 0.0644 g of the title product.

Physical characteristics are as follows:

FAB MS : [m + H] at m/z 736.

HPLC: 45% A, 55% B, k' = 5.2.

¹H-NMR (S , CDCI₃) : 0.34-0.94 , 1.40 , 3.10 , 3.56 , 3.92 , 3 .99 , 4.43 , 4.54, 4.72 , 6.02 , 6.19 . 6.59 , 7.16-8.50.

Anal . Found: C , 66.41; H, 8.48 ; ST, 9.53.

IC₅₀: 5.4 x 10 ^{- 9} molar.

Example 2 4- [ (1 ' R- tert-Butoxycarbonyl)phenethyiamido]maleoyl-

Leutf [CH(OH)CH₂ ]Val-2S-methylbutyla mide (Formula K-7) Refer to Chart K. By the method of the general coupling procedure, 0.0644 g of the compound of formula K-5 and 0.0836 g of Leutf[CH(O-t-BDMS)CH₂]Val- NHCH₂CH(CH₃)CH₂CH₃ of formula K-4 are converted to 0.1341 g of the compound of formula K-6 (chromatography with 4% methanol-methylene chloride). The material is then stirred with 0.5 ml of 1 M (in tetrahydrofuran) tetra-n-butyl ammonium fluoride and 0.5 ml of tetrahydrofuran overnight. The solvent is removed in vacuo and the residue is chromatographed with 4% methanol-methylene chloride to give 0.0714 g of the title product.

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 602.

HPLC: 40% A, 60% B; k' = 6.3.

Anal. Found: C, 67.25; H, 9.08; N, 6.77.

IC₅₀: 4.3 x 10^-6 molar.

Preparation 2 4-(Phenethylamido)maleic acid (Formula F-3) Refer to Chart F.

To 0.62 g of maleic anhydride in 50 ml of tetrahydrofuran is added 0.7 g of phenethylamine. An initial exotherm is observed. The reaction is stirred for 45 min, concentrated, and the residue is partitioned between methylene chloride and diluted aqueous hydrochloric acid. The organic layers are filtered through sodium sulfate and concentrated to give a white solid. Crystallization from methylene chloride and hexane gives 1.08 g of the title product.

Physical characteristics are as follows:

M.P.: 137-138ºC.

Anal. Found: C, 65.53; H, 6.09; N, 6.36.

Example 3 4-(Phenethylamido)maleoyl-Leuψ[CH(OH)CH₂]Val-Ile-2- (amidomethyl)pyridine (Formula F-5) Refer to Chart F. According to the general coupling method, 0.04406 g of the title product of Preparation 2 and 0.0847 g of LVA-Ile-Amp-2HCl in 10 ml of dimethylformamide and 1 ml of methylene chloride are coupled to give 0.0546 g of the title product after chromatography with 4% methanol- methylene chloride (ammonium hydroxide).

Physical characteristics are as follows:

FAS MS: [m + H] at m/z 636.

HPLC: 40% B-60% A; k' = 6.0.

Anal. Found: C, 67.49; H, 8.55; N, 10.92.

IC₅₀: 1.3 x 10^-7 molar. Preparation 3 4-[(2'-Pyridyl)ethylamido]maleic acid (Formula G-

3) Refer to Chart G.

To 0.76 g of maleic anhydride in 50 ml of tetrahydrofuran is added 0.93 ml of 2-(2-aminoethyl) pyridine (a slight exotherm occurs). After stirring for 45 min, tetrahydrofuran is removed in vacuo and the residue is partitioned between methylene chloride and aqueous ammonium chloride. The organic layers are filtered through sodium sulfate and concentrated. TLC shows a considerable amount of product remaining in the aqueous layer, so the aqueous layer is continuously extracted with methylene chloride (overnight). The product fractions are combined to give 1.37 g of the title product.

Crystallization from methylene chloride and hexane gives 1.22 g of amber crystals.

Physical characteristics are as follows:

M.P.: 136-137ºC.

Anal. Found: C, 59.60; H, 5.60; N, 12.71.

Example 4 4-[(2'-Pyridyl)ethylamido]maleoyl-Leutf[CH(OH)CH₂]Val- Ile-2-(amidomethyl)pyridine (Formula G-5) Refer to Chart G.

Using the general coupling procedure, 0.0445 g of the title product of Preparation 3 and 0.0852 g LVA-Ile-Amp-2HCl are coupled to give 0.0577 g of the title product after chromatography with 6% methanol-methylene chloride (ammonium hydroxide).

Physical characteristics are as follows:

Rf (8% methanol-methylene chloride-ammonium hydroxide): 0.29. FAB MS: [m + H] at m/z 637.

HPLC: 75% A, 25% B, k' = 4.7.

Anal. Found: C, 65.89; H, 8.74; N, 12.37.

IC₅₀: 1-8 x 10^-7 molar.

Preparation 4 Maleic acid, D-Phenylalanine methyl ester amide

(Formula C-4) Refer to Chart C.

A solution of 0.74 g of D-Phe-OCH₃ and 0.425 g of maleic anhydride in 30 ml of tetrahydrofuran is stirred for 2 hrs, after which it is partitioned between ethyl ether and dilute hydrochloric acid brine. The organic layers are dried over magnesium sulfate and concentrated to give 1.25 g of the title produce as a gum.

Physical characteristics are as follows :

1H-NMR (δ. CDCI₃): 3.20, 3.79, 4.91, 6.29, 6.37, 7.07-7.31. Example 5 4-[(1'R-Methoxycarbonyl)phenethylamidojmaleoyl- Leuψ[CH(H0)CH₂]Val-Ile-2-(amidomethyl)pyridine (Formula C-6) Refer to Chart C.

To 0.1347 g of LVA-Ile-Amp-2HCl in 5 ml of dimethylformamide and 5 ml of methylene chloride is added 0.0743 ml of triethylamine. To this is then added 0.0886 g of the title product of Preparation 4, followed by 0.0360 g of 1-hydroxybenzotriazole and 0.0824 g of dicyclohexylcarbodiimide in 5 ml of methylene chloride. The reaction is stirred overnight, after which the solvents are removed in vacuo. Ethyl acetate and methylene chloride are added to the residue and dicyclohexylurea is filtered off. The filtrate is partitioned two times between methylene and aqueous sodium bicarbonate and the organic layers are filtered through sodium sulfate, concentrated, and chromatographed using 4% methanol-methylene chloride (ammonium hydroxide) to give 0.1183 g of the title product.

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 694.

HPLC: 60% A, 40% B; k' = 7.4.

Anal. Found: C, 65.51; H, 7.71; N, 9.90.

IC₅₀: 2.6 x 10^-8 molar.

Preparation 5 4- (N^ιn-formyltryptamido)maleic acid (Formula J-4)

Refer to Chart J.

A mixture of 0.1624 g of Nⁱⁿ-formyltryptamine hydrogen chloride, 0.0780 g of maleic anhydride, 0.101 ml of triethylamine, and 50 ml of tetrahydrofuran is stirred for 45 minutes. The reaction mixture is then concentrated and the residue is partitioned between chloroform and 0.1 N hydrochloric acid and brine. The organic layers are separated, concentrated, and the residue is crystallized from methanol to give 0.1491 g of the title product.

Physical characteristics are as follows:

M.P.: 163-165°C.

Anal. Found (two runs): C, 57.17, 59.48; H, 4.49, 4.79; N, 8.80, 9.09.

Example 6 4- (Nⁱⁿ-formyltryptamido)maleoyl-Leuψ[CH(OH)CH₂]Val- Ile-2-(amidomethyl)pyridine (Formula J-6) Refer to

Chart J.

Using the standard coupling procedure, 0.0701 g of the title product of Preparation 5 is coupled with 0.1032 g of LVA-Ile-Amp-2HCl to give, after chromatography with 5% methanol-methylene chloride (ammonium hydroxide), 0.066l g of the title product.

Physical characteristics are as follows:

TLC: 8% methanol-methylene chloride (ammonium hydroxide): 0.5. FAB MS: [m + H] at m/z 703.

Anal. Found: C, 66.46; H, 7.55; N, 11.21.

IC₅₀: 2.3 x 10^-7 molar.

Preparation 6 N-(tert-Butoxycarbonyl)phenethylamine (Formula I-

2) Refer to Chart I.

To 5.13 g of phenethylamine, 5.85 g of potassium carbonate and 100 ml tetrahydrofuran is added 9.70 g of di-tert-butyldicarbonate in several ml of tetrahydrofuran over 5-10 minutes (an ice bath is added at this point to cool the exotherm). After the addition is complete, about 1 ml of water is added. After 45 min, potassium carbonate is filtered off and the filtrate is partitioned between ethyl ether and IN hydrochloric acid and brine. The organic layers are filtered through sodium sulfate and taken to dryness. The crude product is chromatographed with 5% ethyl acetate-hexane to give 9.24 g of the title product.

Physical characteristics are as follows:

M.P.: 56-57.5ºC.

¹H-NMR (δ, CDCl₃): 2.43, 2.80, 3.37, 4.53, 7.18-7.34.

Preparation 7 N-Benzyl-N-phenethylamine (Formula 1-5) Refer to

Chart I.

To 0.100 g of N-Boc-phenethylamine of Preparation 6 and 0.036 g of sodium hydride in 5 ml of dimethylformamide are added 0.107 ml of benzyl bromide. After stirring for 2 hrs, a few drops of aqueous sodium bicarbonate are cautiously added. Dimethylformamide is removed in vacuo and the residue is partitioned between ethyl acetate and brine. The organic layers are dried over magnesium sulfate and the crude product is chromatographed with 5% ethyl acetate-hexane to give 0.129 g of the compound of formula 1-4, with physical characteristics as follows: MS: m/z at 311.

To 0.160 g of N-Boc-N-benzyl-N-phenethylamine is added 10 ml of a 1:1 (v/v) solution of trifluoroacetic acid and methylene chloride.

After 15 min, methylene chloride and trifluoroacetic acid are removed in vacuo. The residue is partitioned two times between methylene chloride and aqueous sodium bicarbonate and the organic layers are filtered through sodium sulfate and concentrated to give 0.1032 g of the title product.

Physical characteristics are as follows:

1H-NMR (δ , CDCl₃): 1.52, 2.87, 3.81, 7.21-7.31.

Preparation 8 4-(N-Benzyl-N-phenethylamido)maleic acid (Formula

1-7) Refer to Chart I.

A solution of 0.1032 g of N-benzyl-N-phenethylamine of Preparation 7 and 0.0527 g of maleic anhydride in 5 ml of tetrahydrofuran is stirred overnight. The solvent is then removed and the residue is partitioned between methylene chloride and 0.1 N hydrochloric acid. The organic layers are filtered through sodium sulfate and concentrated. The crude product is crystallized from methylene-hexane to give 0.143 g of the title product.

Physical characteristics are as follows:

M.P.: 124-125ºC.

¹H-NMR (δ, CDCI₃): 2.92, 3.69, 4.58, 6.23, 6.48, 7.10-7.35. Anal. Found: C, 73.84; H, 6.17; N, 5.48.

Example 7 4-(N-Benzyl-N-phenethylamido)maleoyl-Leuψ[CH(OH)CH₂]- Val-Ile-2-(amidomethyl)pyridine (Formula 1-9) Refer to Chart I.

Using standard coupling conditions, 0.0533 g of the title product of Preparation 8 and 0.0792 g of LVA-Ile-Amp-2HCl are coupled to give 0.0942 g of the title product after chromatography with 2% methanol-methylene chloride (ammonium hydroxide).

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 726.

HPLC: 30% A, 70% B, k' = 8.4.

Anal. Found: C, 70.56; H, 8.47; N, 9.25.

IC₅₀: 1.0 x 10^-7 molar.

Preparation 9 Maleic acid, benzyl amide (Formula H-3) Refer to

Chart H.

To 0.2877 g of benzylamine in 10 ml of tetrahydrofuran is added 0.2764 g of maleic anhydride (exotherm occurs). After 20 min, tetrahydrofuran is removed to give a white solid. The solid is crystallized from methanol-methylene chloride-hexane to give 0.517 g of the title product.

Physical characteristics are as follows:

M.P.: 127-132°C. ¹H-NMR (δ , CDCI₃): 4.55, 6.32, 7.33-7.35, 7.55.

Anal. Found: C, 63.56; H, 5.54; N, 6.80.

Example 8 4-(Benzylamido)maleoyl-Leutf[CH(OH)CH₂]Val-Ile-2- (amidomethyl)pyridine (Formula H-5) Refer to Chart H. Using standard coupling conditions, 0.0404 g of the title product of Preparation 9 and 0.0829 g of LVA-Ile-Amp-2HCl are coupled to give 0.0139 g of the title product with chromatography with 5% methanol-methylene chloride-ammonium hydroxide.

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 622.

¹H-mm. (δ, CDCI₃): 0.78-0.92, 1.08-2.28, 3.60, 4.95, 4.20, 4.48, 6.10, 6.19, 6.98-7.88, 8.47.

IC₅₀: 1.7 x 10^-7 molar.

Preparation 10 Maleic acid, D-Phenylalamine ethyl ester amide

(Formula B-4) Refer to Chart B.

To a mixture of 0.5418 g of HCl.D-Phe-OEt, 0.2103 g of maleic anhydride, and 40 ml of tetrahydrofuran is added 0.33 ml of triethylamine. After 30 min, about 1 ml of ethanol is added to put HCl.D- Phe-OEt in solution. After stirring an additional 15 min, the solvents are removed and the residue is partitioned between methylene chloride and 0.5 N hydrochloric acid. The organic layers are filtered through sodium sulfate and taken to dryness to give 0.51 g of the title product as a gum.

Example 9 4-[(1'R-Ethoxycarbonyl)phenethylamido]maleoyl-Leuψ- [CH(OH)CH₂]VaI-Ile-2-(amidomethyl)pyridine (Formula B-

6) Refer to Chart B.

Using standard coupling conditions, 0.0688 g of the title product of Preparation 10 and 0.1085 g of LVA-Ile-A mp 2HCl are coupled to give, after chromatography with 3% methanoi-methylene chloride (ammonium hydroxide). 0.0733 g of the title product.

Physical characteristics are as follows:

FAB MS: fm + H] at m/z 708.

HPLC: 40% A, 60% B, k' = 7.3, 8.4 (ratio of 78 to 22).

Anal. Found: C, 65.99; H, 8.16; N, 10.12.

IC₅₀: 8.6 x 10^-9 molar.

Example 10 4-[(1'R-Carboxy)phenethylamido]maleoyl-Leuψ[CH(OH)- CH₂jVal-Ile-2-(amidomethyl)pyridine (Formula D-2) Refer to Chart D. To 0.0524 g of the title product of Example 5 in 2 ml of methanol is added dropwise 0.163 ml of 1 N potassium hydroxide. After stirring for 2-1/2 hrs, the solvent is removed in vacuo and the residue is partitioned between ethyl acetate and 0.087 ml of 2 N hydrochloric acid with 0.5 ml of water added. (After several extractions, solid is still visible floating in the aqueous layer). The organic layers are dried over magnesium sulfate and taken to dryness to give 0.020 g of the title product.

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 680.

Anal. Found: C, 64.17; H, 8.37; N, 9.50.

IC₅₀: 5.2 x 10^-7 molar.

Preparation 11 Maleic acid, L-Phenylalanine tert-butyl ester amide (Formula E-3) Refer to Chart E.

To 0.1526 g of HCl-L-Phe-O-t-Bu, 0.0614 g of maleic anhydride, and 10 ml of tetrahydrofuran is added 0.087 g of triethylamine. After stirring for 45 min, the reaction mixture is partitioned between ethyl ether and acidified brine. The organic layers are filtered through sodium sulfate and taken to dryness to give 0.20 g of the title product as a solid.

Physical characteristics are as follows:

¹H-NMR (δ, CDCl₃): 2.45, 3.18, 4.78, 6.26, 6.38, 7.03, 7.12- 7.33.

Example 11 4-[(1'S-(tert-Butoxycarbonyl)phenethylamido]maleoyl- Leuψ[CH(OH)CH₂]Val-Ile-2-(amidomethyl)pyridine

(Formula E-5) Refer to Chart E.

Using standard coupling procedures, 0.0463 g of the title product of Preparation 11 and 0.0666 g of LVA-Ile-Amp-2HCl are coupled to give (chromatography with 4% methanol-methylene chloride- ammonium hydroxide) 0.0371 g of the title product.

Physical characteristics are as follows:

FAB MS: [m + H] at m/z 736.

¹H-NMR (5, CDCI₃): 0.86-0.92, 1.40, 1.75, 1.1-2.3, 3.12, 3.58, 3.93, 4.04, 4.42, 4.55, 4.72, 6.03, 6.13, 6.65, 7.17-7.25, 7.37, 7.63, 8.01, 8.47, 3.51.

HPLC: 40% A, 60% B, k' = 14.9, 16.1 (8:92 by area %) .

IC₅₀: 2.9 x 10^{- 8} molar.

Claims

1. A renin inhibitory peptide having a non-cleavable transition state insert corresponding to the 10,11-position of a renin substrate (angiotensinogen) and having a moiety of the formula I

R₂₀N(R₃₀)-(O)CCH=CHC(O)- I

at the N-terminus;

wherein R₂₀ is

(a) -C(R₂₁)(R₂₂)-C(O)-OR₂₃, or

(b) -(CH₂)_n-R₂₄;

wherein R₂₁ is

(a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₂₂ is

(a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₂₃ is

(a) hydrogen, or

(b) C₁-C₁₀alkyl;

wherein R₂₄ is

(a) -(CH₂)p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₃₀ is

(a) hydrogen,

(b) C₁-C₅alkyl,

(c) -(CH₂)_p-aryl, or

(d) -(CH₂)_p-Het;

wherein n is 1 to 5 , inclusive;

wherein p is 0 to 5, inclusive.

2. In a renin inhibitory peptide having a non-cleavable transition state insert corresponding to the 10, 11-position of a renin substrate (angiotensinogen) and having a moiety of the formula I

R₂₀N(R₃₀)-(O)CCH=CHC(O)- I

at the N-terminus;

wherein R₂₀ is

(a) -C(R₂₁)(R₂₂)-C(O)-OR₂₃, or

(b) -(CH₂)_n-R₂₄;

wherein R₂₁ is (a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₂₂ is

(a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₂₃ is

(a) hydrogen, or

(b) C₁-C₁₀alkyl;

wherein R₂₄ is

(a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₃₀ is

(a) hydrogen,

(b) C₁-C₅alkyl,

(c) -(CH₂)_p-aryl, or

(d) -(CH₂)_p-Het;

wherein n is 1 to 5, inclusive;

wherein p is 0 to 5, inclusive.

3. The renin inhibitory peptide of claim 1 of the formula II

II

wherein Ag is a monovalent moiety of the formula I;

R₂₀N(R₃₀)-(O)CCH=CHC(O)- I wherein X₁ is

(a) -CH(OH)-CH(OH)-CH₂-P₁, or

(b) -L₁₀-C(R₁)(R₄)-C(O)-F₁-Z₁;

wherein P₁ is

(a) -N₃,

(b) -CN,

(c) C₁-C₆alkyl,

(d) C₁-C₆cycloaikyl,

(e) aryl, or

(f) Het;

wherein L₁₀ is a divalent moiety of the formula

(a) -CH(OH)-,

(b) -CH(NH₂)-, (c) -C(O)-,

(d) -CH(OH)-C(K₁)(K₂)-,

(e) -C(O)-C(K₁)(K₂)-,

(f) -CH(OH)-CH(OH)-,

(g) -CH(OH)-CH₂-,

(h) -CH(NH₂)-CH₂-,

(i) -C(O)-CH₂-,

(j) -CH₂-NH-,

(k) -CH₂-O-, or

(1) -P₁(O)(G₁)-I₁-;

wherein F₁ is absent or a divalent moiety of the formula L₄; L₄

wherein G₁ is

(a) -OH, or

(b) -NH₂;

wherein I₁ is

(a) -O-,

(b) -NH-, or

(c) -CH₂;

wherein K₁ and K₂ are the same or different and are

(a) H,

(b) F, or

(c) Cl;

wherein Y₁ is

(a) hydrogen,

(b) alkali metals,

(c) alkali earth metals, or

(d) pharmaceutically acceptable base addition salts thereof; wherein Z₁ is

(a) -O-R₅, or

(b) -N(R₁)R₅;

wherein R₁ is

(a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₂ is (a) hydrogen,

(b) C₁-C₅alkyl,

(c) C₃-C₇cycloalkyl,

(d) aryl,

(e) Het,

(f) -(CH₂)_p-OH, or

(g) -(CH₂)_p-NH₂;

wherein R₃ is

(a) C₁-C₅alkyl,

(b) C₃-C₇cycloalkyl,

(c) aryl , or

(d) Het;

wherein R₄ is

(a) hydrogen,

(b) C₁-C₈alkyl,

(c) -(CH₂)_p-aryl,

(d) -(CH₂)_p-Het,

(e) -(CH₂)_p-CO₂H,

(f) -(CH₂)_p-NH₂,

(g) -(CH₂)_p-CH(NH₂)(C0₂H),

(h) C₃-C₇cycloalkyl, or

(i) 1- or 2-adamantyl;

wherein R₅ is

(a) hydrogen,

(b) C₁-C₁₀alkyl,

(c) aryl,

(d) Het,

(e) - (CH₂)_p- (C₃-C₇cycloalkyl),

(f) -(CH₂)_p-CH(NH₂)(CO₂H), or

(g) -(CH₂)_n-Rg;

wherein R₆ Is

(a) aryl,

(b) Het,

(c) hydroxy,

(d) amino,

(e) C₁-C₅alkyl substituted by 1 to 3 -OH groups,

(f) -CO₂H,

(s) guanidinyl. (h) -SO₃H, or

(i) -SO₂NH₂;

wherein R₉ is

(a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₁₀ is

(a) hydrogen,

(b) C₁-C₈alkyl,

(c) -(CH₂)_p-aryl,

(d) -(CH₂)_p-Het,

(e) -(CH₂)_p-CO₂H,

(f) -(CH₂)_p-NH₂,

(g) -(CH₂)_p-CH(NH₂)(CO₂H), (h) C₃-C₇cycloalkyl, or (i) 1- or 2-adamantyl;

wherein R₁₁ is

(a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₂₀ is

(a) -C(R₂₁)(R₂₂)-C(O)-OR₂₃, or (b) -(CH₂)_n-R₂₄;

wherein R₂₁ is

(a) hydrogen, or

(b) C₁-C₅alkyl;

wherein R₂₂ is

(a) -(CH₂)_p-aryl, or

(b) -(CH₂)_p-Het;

wherein R₂₃ is

(a) hydrogen, or

(b) C₁-C₁₀alkyl;

wherein R₂₄ is

(a) -(CH₂)_p-aryi, or

(b) -(CH₂)_p-Het;

wherein R₃₀ is

(a) hydrogen,

(b) C₁-C_salkyl,

(c) -(CH₂)p-aryl, or

(d) -(CH₂)_p-Het; wherein n is 1 to 5, inclusive;

wherein p is 0 to 5, inclusive;

wherein q is 1 to 8, inclusive;

wherein aryl is phenyl or naphthyl, optionally substituted by zero to three of the following;

(a) C₁-C₅alkyl,

(b) hydroxy,

(c) hydroxy (C₁-C₅alkyl),

(d) halogen,

(e) amino,

(f) amino (C₁-C₅alkyl),

(g) -CHO,

(h) -CO₂H,

(i) -CO₂-(C₁-C₅alkyl),

(j) -CONH₂,

(k) -CONH- (C₁-C₅alkyl),

(1) nitro,

(m) mercapto,

(n) mercapto (C₁-C₅alkyl),

(o) -SO₃H,

(p) -SO₂NH₂,

(q) -CN, or

(r) -O-C₁-C₅alkyl;

wherein Het is a 5 or 6-membered saturated or unsaturated ring radical containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur; and including any bicyclic group in which any of the above heterocyclic rings is fused to a benzene ring or another heterocycle; and if chemically feasible, the nitrogen and sulfur atoms may be In the oxidized forms; and optionally substituted by zero to three of the following;

(a) C₁-C₅alkyl,

(b) hydroxy,

(c) hydroxy (C₁-C₅alkyl),

(d) halogen,

(e) amino,

(f) amino (C₁-C₅alky!),

(g) -CHO,

(h) -CO₂H, (i) -CO₂ - (C₁-C₅alkyl) ,

(j ) -CONH₂ ,

(k) -CONH- (C₁-C₅alkyl) ,

(l) nitro ,

(m) mercapto ,

(n) mercapto (C₁-C₅alkyl) ,

(o) -SO₃H,

(p) -SO₂NH₂ ,

(q) -CN, or

(r) -O-C₁-C₅alkyl ;

or a carboxy- , amino- or other reactive group protected form thereof ;

or a pharmaceutically acceptable acid or base addition salts thereof .

4. The renin inhibitory peptide of claim 3 wherein Ag is R₂₀N(R₃₀)- (O)CCH-CHC(O)- wherein R₂₀ is -C(R₂₁) (R₂₂) -C(O) -OR₂₃ and R₃₀ is hydrogen, and wherein R₂₁ is hydrogen, R₂₂ is -CH₂-phenyl and R₂₃ is hydrogen, methyl, ethyl or t-butyl.

5. The renin inhibitory peptide of claim 3 wherein Ag is R₂₀N(R₃₀)- (O)CCH=CHC(O)- wherein R₂₀ is -(C_H2)_n-R₂₄ and R₃₀ is hydrogen or -CH₂-phenyl, and wherein n is 1 or 2 and R₂₄ is phenyl, pyridyl or N-formyl-indolyl.

6. The renin inhibitory peptide of claim 4 wherein R₂ is C₃-C₇- cycloalkyl and X ₁ is -CH(OH)-CH(OH) -CH₂-P₁ wherein P₁ is C₁-C₆alkyl; or

wherein R₂ is C₁-C₅alkyl and X₁ is -L₁₀-C(R₁) (R₄)-C(O)-F₁-Z₁ wherein L₁₀ is -CH(OH)-CH₂-, R₁ is hydrogen, R₄ is C₁-C₈alkyl, F₁ is absent and Z₁ is N(R₁)R₅ wherein R₁ is hydrogen and R₅ is C₁-C₁₀alkyl; or wherein R₂ is C₁-C₅alkyl and X₁ is -L₁₀-C(R₁) (R₄)-C(O) -F₁-Z₁ wherein L₁₀ is -CH(OH)-CH₂-. R₁ is hydrogen, R₄ is C₁-C₈alkyl, F₁ is the moiety of formula L₄ wherein R₉ is hydrogen, R₁₀ is C₁-C₈alkyl, and R₁₁ is C₁-C₅; and Z₁ is N(R₁)R₅ wherein R ₁ is hydrogen and R₅ is -(CH₂)_n-R₆.

7. The renin inhibitory peptide of claim 5 wherein R₂ is C₁-C₅alkyl and X₁ is -L₁₀-C(R₁) (R₄)-C(O)-F₁-Z₁ wherein L₁₀ is -CH(OH) -CH₂-, R₁ is hydrogen, R₄ is C₁-C₈alkyl, F₁ is the moiety of formula L₄ wherein R₉ is hydrogen, R₁₀ is C₁-C₈alkyl and R₁₁ is C₁-C₅alkyl; and Z₁ is N(R₁)R₅ wherein R₁ is hydrogen and R₅ is -(CH_2)n-R₆.

8. The renin inhibitory peptide of claim 6 wherein -NH-CH(CH₂) (R₂)- X₁ of formula II is

2S -amino-1-cyclohexyl-3R,4S-diol-6-methylheptane;

LVA-2S-methylbutylamide; or

LVA-Ile-Amp.

9. The renin inhibitory peptide of claim 7 wherein -NH-CH(CH₂) (R₂) - X₁ of formula II is LVA-Ile-Amp.

10. A compound of claim 8 selected from the group consisting of:

4-[(1'R-tert-Butoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)- C₂]Val-Ile-2-(amidomethyl)pyridine;

4-[(1'R-Ethoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)CH₂]- Val-lie-2-(amidomethyl)pyridine;

4-[(1'R-Methoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)CH₂]-

Val-Ile-2-(amidomethyl)pyridine;

4-[(1'R-Carboxy)phenethylamido]maleoyl-Leuψ[CH(OH)CH₂]Val-Ile-2- (amidomethyl)pyridine;

4-[(1'S-(tert-Butoxycarbonyl)phenethylamido]maleoyl-Leuψ- [CH(OH)CH₂]Val-Ile-2-(amidomethyl)pyridine;

4-[(1'R-tert-Butoxycarbonyl)phenethylamido]maleoyl-Leuψ[CH(OH)- CH₂]Val-2S-methyIbutylamide; and

4-[(1'R-tert-Butoxycarbonyl)phenethylamido]-maleoyl-2S-amino-1- cyclohexyl-3R,4S-diol-6-methylheptane.

11. A compound of claim 9 selected from the group consisting of:

4-(Phenethylamido)maleoyl-Leuψ[CH(OH)CH₂]Val-Ile-2-(amidomethyl)pyridine;

4-[(2'-Pyridyl)ethylamido]maleoyl-Leuv[CH(OH)CH₂]Val-Ile-2- (amidomethyl)pyridine;

4-(Benzylamido)maleoyl-Leuψ [CH(OH)CH₂]Val-Ile-2-(amidomethyl)- pyridine;

4-(N-Benzyl-N-phenethylamido)maleoyl-Leuψ[CH(OH)CH₂]-Val-Ile-2- (amidomethyl) pyridine; and

4- ((Nⁱⁿ-formyltryptamido)maleoyl-Leuψ[CH(OH)CH₂]Val-Ile-2- (amidomethyl)pyridine