United States Patent
`
`[19]
`
`' 5,217,996
`Ksander
`Jun. 8, 1993
`[45] Date of Patent:
`
`llllllllillllllllIlllllllllIllllllllllllllillllllllllllllIlllllllllllllllll
`U5005217996A
`
`[11] Patent Number:
`
`[54] BIARYL SUBSTITUTED 4-AMINO-BUTYRIC
`ACID AMIDES
`
`[75]
`
`Inventor: Gary Ksander, Milford, NJ.
`
`[73] Assignee: Ciba-Geigy Corporation, Ardsley,
`N.Y.
`
`[21] Appl. No.: 824,132
`
`[22] Filed:
`
`Jan. 22, 1992
`
`Int. Cl.5 ................... C07C 229/34; A61K 31/235
`[51]
`[52] US. Cl. .................................... 514/533; 514/563;
`546/335; 549/452; 558/267; 558/275; 560/41;
`562/450
`[58] Field of Search .................... 560/41, 39; 562/450;
`549/77, 452, 496; 546/335; 558/267, 275;
`514/533, 563
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`514/513
`4,513,009 4/1985 Roques et a1.
`514/464
`4,721,726
`1/1988 Berger ..............
`.
`
`562/444
`4,939,261
`7/1990 Ksander
`514/332
`5,021,430 6/1991 Ksander .......
`
`5,096,925
`3/1991 Ksander .............................. 514/522
`
`FOREIGN PATENT DOCUMENTS
`
`38758 10/1981 European Pat. Off,
`836934
`1/1985 South Africa .
`2207351
`6/1989 United Kingdom .
`
`.
`
`OTHER PUBLICATIONS
`
`C. M. Ksander et a1., J. Med. Chem. 32, 2519 (1989).
`
`Primary Examiner—Jose G. Dees
`Assistant Examiner—-B. Frazier
`Attorney, Agent, or Firm—Norbert Gruenfeld
`
`[57]
`
`ABSTRACT
`
`The invention relates to biaryl substituted 4-amino-
`butyric acid derivatives of formula I
`
`T2
`(1?
`XOC—‘CIZH—Cfll—ffi—NH—C—A-(CHfi1—C0X'
`R1
`CHZ-biaryl
`
`(1)
`
`wherein COX and COX’ independently represent car-
`boxyl or carboxyl derivatized in form of a pharmaceuti-
`cally acceptable ester or amide; R1 represents hydrogen,
`lower alkyl, C3—C7-cycloalky1-lower alkyl, aryl-lower
`alkyl, biaryl-lower alkyl, lower alkoxy, aryl-lower alk-
`oxy, aryloxy, N-lower alkylamino, N,N-di-lower alkyl-
`amino, N-ary1~lower alkylamino, N,N-di-aryl-lower
`alkylamino, N-arylamino, N,N-diarylamino, lower a]-
`kanoylamino, aryl-lower alkanoylamino or aroylamino;
`R2 represents hydrogen, hydroxy, lower alkoxy, lower
`alkyl, aryl-lower alkyl, C3—C7-cycloalkyl-lower alkyl,
`amino-lower alkyl, hydroxy-lower alkyl,
`lower
`a1-
`kylthio-lower alkyl,
`lower alkoxy-lower alkyl, aryl-
`lower alkylthio-lower alkyl or aryl-lower alkoxy-lower
`alkyl; biaryl represents phenyl substituted by carbocy-
`clic or heterocyclic aryl; A represents a direct bond,
`lower alkylene, phenylene or cyclohexylene; m repre-
`sents 1 or zero, provided that m represents 1 when A is
`a direct bond; or pharmaceutically acceptable salts
`thereof; pharmaceutical compositions comprising said
`compounds; methods for the preparation of said com—
`pounds and for the preparation of intermediates; and
`methods of treating disorders in mammals which are
`responsive to the inhibition of neutral endopeptidases
`by administration of said compounds to mammals in
`need of such treatment.
`
`11 Claims, No Drawings
`
`BIOCON PHARMA LTD (IPR2020-01263) EX. 1009, p. 001
`
`BIOCON PHARMA LTD (IPR2020-01263) Ex. 1009, p. 001
`
`

`

`1
`
`5,217,996
`
`BIARYL SUBSTITUTED 4-AMINO-BUTYRIC ACID
`AMIDES
`
`SUMMARY OF THE INVENTION
`
`Endogenous atrial natriuretic peptides (ANP), also
`called atrial natriuretic factors (ANF) have diuretic,
`natriuretic and vasorelaxant functions in mammals. The
`
`natural ANF peptides are metabolically inactivated, in
`particular by a degrading enzyme which has been rec-
`ognized to correspond to the enzyme neutral endopepti-
`dase (NEP) EC 3.4. 24.11, also responsible for e.g. the
`metabolic inactivation of enkephalins.
`The aim of the present invention is to provide novel
`biaryl substituted 4-amino-butyric acid amide deriva-
`tives described below which are useful as neutral endo-
`peptidase (NEP) inhibitors, e.g. as inhibitors of the
`ANF-degrading enzyme in mammals, so as to prolong
`and potentiate the diuretic, natriuretic and vasodilator
`properties of ANF in mammals, by inhibiting the degra-
`dation thereof to less active metabolites. The com-
`pounds of the invention are thus particularly useful for
`the treatment of conditions and disorders responsive to
`the inhibition of neutral endopeptidase EC 3.4. 24.11,
`particularly cardiovascular disorders, such as hyperten-
`sion, renal insufficiency including edema and salt reten-
`tion, pulmonary edema and congestive heart failure. By
`virtue of their inhibition of neutral endopeptidase, the
`compounds of the invention may also be useful for the
`treatment of pain, depression and certain psychotic
`conditions. Other potential indications include the treat-
`ment of angina, premenstrual syndrome, Meniere’s dis~
`ease, hyperaldosteronism, hypercalciuria, ascites, glau-
`coma, asthma, inflammations and gastrointestinal disor-
`ders such as diarrhea,
`irritable bowel syndrome and
`gastric hyperacidity.
`The present
`invention relates to biaryl substituted
`4-amino-butyric acid derivatives of formula I
`
`0
`1:2
`ll
`XOC—(fH’CHz—CH—NH—C—A—(CH)m—‘COX'.
`R1
`CH2-biaryl
`
`(I)
`
`wherein COX and COX’ independently represent car-
`boxyl or carboxyl derivatized in form of a pharmaceuti-
`cally acceptable ester or amide; R1 represents hydrogen,
`lower alkyl, C3—C7-cycloalkyl-lower alkyl, aryl-lower
`alkyl, biaryl-lower alkyl, lower alkoxy, aryl-lower alk-
`oxy, aryloxy, N-lower alkylamino, N,N-di-lower alkyl-
`amino, N-aryl-lower alkylamino, N,N-di—aryl-lower
`alkylamino, N-arylamino, N,N-diarylamino, lower al-
`kanoylamino, aryl-lower alkanoylamino or aroylamino;
`R2 represents hydrogen, hydroxy, lower alkoxy, lower
`alkyl, aryl-lower alkyl, C3-C7-cycloa1kyl-lower alkyl,
`amino-lower alkyl, hydroxy-lower alkyl,
`lower al-
`kylthio-lower alkyl,
`lower alkoxy-lower alkyl, aryl-
`lower alkylthio-lower alkyl or aryl-lower alkoxy-lower
`alkyl; biaryl represents phenyl substituted by carbocy-
`clic or heterocyclic aryl; A represents a direct bond,
`lower alkylene, phenylene or cyclohexylene; m repre-
`sents l or zero, provided that m represents 1 when A is
`a direct bond; or a pharmaceutically acceptable salt
`thereof.
`Pharmaceutically acceptable ester and amide deriva-
`tives are preferably prodrug derivatives, such being
`convertible by solvolysis or under physiological condi-
`
`2
`tions to the free carboxylic acids of formula I wherein
`COX and/or COX’ represent carboxyl.
`Compounds of formula I and derivatives thereof,
`depending on the nature of substituents, possess one or
`more asymmetric carbon atoms. The resulting diastere-
`oisomers and optical antipodes are encompassed by the
`instant invention.
`
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`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The definitions used herein, unless denoted other-
`wise, have the following meanings within the scope of
`the present invention.
`,
`The term biaryl represents phenyl substituted by
`carbocyclic aryl or heterocyclic aryl as defined herein,
`ortho, meta or para to the point of attachment of the
`phenyl ring, advantageously para; biaryl is also repre-
`sented as the ~C5H4—R3 substituent
`in formulae
`herein.
`
`Carbocyclic aryl preferably represents preferably
`monocyclic carbocyclic aryl or optionally substituted
`naphthyl.
`Monocyclic carbocyclic aryl represents optionally
`substituted phenyl, being preferably phenyl or phenyl
`substituted by one to three substituents, such being
`advantageously lower alkyl, hydroxy, lower alkoxy,
`lower alkanoyloxy, halogen, cyano,
`trifluoromethyl,
`lower alkanoylamino or lower alkoxycarbonyl. Mono-
`cyclic carbocyclic aryl particularly preferably repre-
`sents phenyl or phenyl substituted by lower alkyl, lower
`alkoxy, hydroxy, halogen, cyano or trifluoromethyl.
`Optionally substituted naphthyl represents 1- or 2-
`naphthyl or 1- or 2-naphthyl preferably substituted by
`lower alkyl, lower alkoxy or halogen.
`Heterocyclic aryl represents preferably monocyclic
`heterocyclic aryl such as optionally substituted thienyl,
`indolyl,
`imidazolyl, furanyl, pyridyl, pyrrolyl or N-
`lower alkylpyrrolyl.
`Optionally substituted furanyl represents 2- or 3-fura—
`nyl or 2- or 3-furanyl preferably substituted by lower
`alkyl.
`Optionally substituted pyridyl represents 2-, 3- or
`4-pyridyl or 2-, 3— or 4-pyridyl preferably substituted by
`lower alkyl, halogen or cyano,
`Optionally substituted thienyl represents 2- or 3-thie-
`nyl or 2- or 3-thienyl preferably substituted by lower
`alkyl.
`Optionally substituted indolyl represents preferably
`2- or 3—indoly1 or 2- or 3-indolyl preferably substituted
`by lower alkyl, lower alkoxy or halogen.
`Optionally substituted imidazolyl is preferably 1- or
`2-imidazoly1 or 1- or 2-imidazolyl preferably substituted
`by lower alkyl.
`Aryl as in aryl-lower alkyl, aryl-lower alkoxy, aryl-
`oxy, N-arylamino, N,N—diarylamino, aryl-lower alkoxyé
`carbonyl or aryl-lower alkanoylamino is preferably
`phenyl or phenyl substituted by one or two of lower
`alkyl, lower alkoxy, hydroxy, lower alkanoyloxy, halo-
`gen, trifluoromcthyl, cyano, lower alkanoylamino or
`lower alkoxycarbonyl.
`.
`The term “lower” referred to herein in connection
`with organic radicals or compounds respectively de-
`fines such with up to and including 7, preferably up and
`including 4 and advantageously. one or two carbon
`atoms. Such may be straight chain or branched.
`A lower alkyl group preferably contains 1—4 carbon
`atoms and represents e.g. ethyl, n- or iso-propyl, n-, iso-,
`sec.- or tert.-butyl or advantageously methyl.
`
`BIOCON PHARMA LTD (IPR2020-01263) EX. 1009, p. 002
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`BIOCON PHARMA LTD (IPR2020-01263) Ex. 1009, p. 002
`
`

`

`5,217,996
`
`10
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`25
`
`3O
`
`35
`
`3
`A lower alkoxy group preferably contains 1-4 carbon
`atoms and represents for example methoxy, n-propoxy,
`isopropoxy, n-, iso-, sec.- or tert.-butoxy or advanta-
`geously ethoxy.
`Aryl-lower alkyl is advantageously benzyl or phen-
`ethyl optionally substituted by one or two of lower
`alkyl, lOWer alkoxy, hydroxy, lower alkanoyloxy, halo-
`gen or trifluoromethyl.
`Aryl-lower alkoxy represents advantageously e.g.
`benzyloxy, benzyloxy substituted by lower alkyl, lower
`alkoxy, lower alkanoyl'oxy, halogen or trifluoromethyl,
`or pyridylmethoxy.
`Aryloxy preferably represents phenoxy or phenoxy
`substituted by lower alkyl,
`lower alkoxy,
`lower al-
`kanoyloxy, halogen or trifluoromethyl.
`N-arylamino and N,N-diarylamino represent advan-
`tageously N-phenylamino or N,N-diphenylamino op-
`tionally substituted in the phenyl moiety or phenyl moi-
`eties by lower alkyl, lower alkoxy, hydroxy,
`lower
`alkanoyloxy, halogen or trifluoromethyl.
`The term C3-C7-cycloalkyl represents a saturated
`cyclic hydrocarbon radical which contains 3 to 7 and
`preferably 5 to 7 ring carbon and is, most preferably,
`cyclopenty] or cyclohexyl.
`The term cycloalkyl-lower alkyl represents prefera-
`bly l- or 2-(cyclopentyl or cyclohexyl)ethyl, l-, 2- or
`3-(cyclopentyl or cyclohexyl)propyl, or l-, 2-, 3- or
`4-(cyclopentyl or cyclohexyl)-butyl.
`Amino-lower alkyl
`represents preferably amino-
`(ethyl, propyl or butyl), particularly omega-amino-
`(ethyl, propyl or butyl).
`A N-lower alkylamino group preferably contains 1—4
`carbon atoms in the lower alkyl portion and represents,
`for example, N-n-propyl-amino, N-iso-propylamino,
`N-n~butylamino, N-tert.-butylamino
`and
`advanta-
`geously N-methylamino or N-ethylamino.
`A N,N-di-lower alkylamino group preferably con-
`tains 1—4 carbon atoms in each lower alkyl portion and
`represents, for example, N,N-dimethylamino, N-meth-
`yl-N-ethylamino
`and
`advantageously
`N,N-die-
`thylamino.
`Hydroxy-lower alkyl is for example 2-hydroxyethyl
`and preferably hydroxymethyl.
`Lower alkylthio as in lower alkylthio-lower alkyl I
`45
`represents advantageously C1-C4-alkylthio and prefera-
`bly methylthio or ethylthio.
`Lower alkylene represents branched or straight chain
`alkylene of 1 to 7 carbon atoms, advantageously straight
`chain (or linear) alkylene, such as methylene, ethylene,
`propylene, butylene, pentylene or hexylene and most
`preferably straight chain C1-C4-alkylene.
`Phenylene represents preferably 1,3 or 1,4—phenylene,
`advantageously 1,4-phenylene.
`Cyclohexylene represents preferably 1,4-cyclohexy-
`lene.
`
`4
`ben—
`Aroylamino is preferably benzoylamino or
`zoylamino substituted on the benzene ring by lower
`alkyl, lower alkoxy, halogen or trifluoromethyl.
`Carboxyl esterified in form of a pharmaceutically
`acceptable ester, represents advantageously a prodrug
`ester that may be convertible by solvolysis or under
`physiological conditions to the free carboxylic acid,
`such being preferably C1-Czo«alkoxycarbonyl, advanta-
`geously lower alkoxycarbonyl;
`(amino, acylamino,
`mono-or di-lower alkylamino)-lower alkoxycarbonyl;
`carboxy-lower alkoxycarbonyl,
`e.g.
`alpha-carboxy-
`lower alkoxycarbonyl;
`lower alkoxycarbonyl-lower
`alkoxycarbonyl, e.g. alpha-lower alkoxycarbonyl-lower
`alkoxycarbonyl; a-(di-lower alkylamino, amino, mono-
`lower alkylamino, morpholino, piperidino, pyrrolidino,
`l—lower
`alkylpiperazino)-carbonyl-lower
`alkoxycar-
`bonyl; aryl-lower alkoxycarbonyl, preferably option-
`ally (halo,
`lower alkyl or lower alkoxy)-substituted
`benzyloxycarbonyl, or pyridylmethoxycarbonyl; l-(hy-
`droxy, lower alkanoyloxy or lower alkoxy)-lower alk-
`oxycarbonyl, e.g. pivaloyloxymethoxycarbonyl;
`(hy-
`droxy, lower alkanoyloxy or lower alkoxy)-lower al-
`koxymethoxycarbonyl;
`bicycloalkoxycarbonyl-lower
`alkoxycarbonyl, e.g. bicyclo[2,2,l]-heptyloxycarbonyl-
`lower alkoxycarbonyl, especially bicyclo-[Z,2,l]-hep-
`tyloxycarbonylmethoxycarbonyl such as bornyloxycar-
`bonylmethoxycarbony];
`l-(lower alkoxycarbonyloxy)-
`lower
`alkoxycarbonyl;
`5-indanyloxycarbonyl;
`3-
`phthalidoxycarbonyl and (lower alkyl, lower alkoxy or
`halo)-substituted 3-phthalidoxycarbonyl; polyhydroxy-
`lower alkoxycarbonyl or protected polyhydroxy-lower
`alkoxycarbonyl
`in which polyhydroxy-lower alkoxy
`and protected polyhydroxy-lower alkoxy represent
`preferably dihydroxypropyloxy or trihydroxybutyloxy
`wherein hydroxy groups are free or one or more, as
`appropriate, are protected in form of esters, e.g. a lower
`alkanoyl or a benzoyl ester, in form of ethers, e.g. a
`lower alkyl or benzyl ether, or,
`in case two vicinal
`hydroxy groups are involved, in the form of acetals or
`ketals, e.g. a lower alkylidene, a benzylidene or a 5- or
`6—membered cycloalkylidene derivative.
`Protected polyhydroxy-lower alkoxycarbonyl ad-
`vantageously represents (2,2-dimethyl-l,3~dioxolan-4-
`yl)-methoxycarbonyl.
`Acyl as in acyloxy or acylamino represents prefera-
`bly lower alkanoyl, carbocyclic aryl-lower alkanoyl,
`aroyl, lower alkoxycarbonyl or aryl-lower alkoxycar-
`bonyl, advantageously lower alkanoyl. Lower alkoxy-
`carbonyl for acyl is preferably t-butoxycarbonyl (abbre-
`viated t-BOC). Aryl-lower alkoxycarbonyl for acyl is
`preferably benzyloxyearbonyl (abbreviated CBZ).
`Carboxy-lower alkoxycarbonyl represents advanta-
`geously e.g. l-carboxyethoxycarbonyl.
`Lower alkoxycarbonyl-lower alkoxycarbonyl repre-
`sents advantageously e.g. l-(ethoxycarbonyl)ethoxycar-
`bony].
`al-
`alkoxycarbonyl, mono-lower
`Amino-lower
`kylamino—lower alkoxycarbonyl, di-(lower)alkylamino-
`lower alkoxycarbonyl advantageously represent e.g.
`aminoethoxycarbonyl, ethylaminoethoxycarbonyl, die-
`thylaminoethoxycarbonyl.
`Lower alkylidene is preferably isopropylidene.
`Cycloalkylidene is preferably cyclohexylidene.
`Carboxyl esterified in form of a pharmaceutically
`acceptable prodrug ester
`represents most advanta-
`geously C1-C4-a1koxycarbonyl, phenyloxycarbonyl,
`benzyloxycarbonyl optionally substituted on phenyl by
`lower alkyl,
`lower alkoxy, halo or trifluoromethyl,
`
`50
`
`55
`
`fluoro or
`
`Halogen (halo) preferably represents
`chloro, but may also be bromo or iodo.
`Lower alkanoyloxy advantageously contains 2 to 5
`carbon atoms and is preferably acetoxy, pivaloyloxy or
`propionyloxy.
`Lower alkanoylamino advantageously contains 2 to 5
`carbon atoms and is preferably acetylamino or pro-
`pionylamino.
`A lower alkoxycarbonyl group preferably contains 1
`to 4 carbon atoms in the alkoxy portion and represents,
`for example, methoxycarbonyl, n-propoxycarbonyl,
`iso-propoxycarbonyl or advantageously ethoxycarbo-
`nyl.
`
`65
`
`BIOCON PHARMA LTD (IPR2020-01263) EX. 1009, p. 003
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`BIOCON PHARMA LTD (IPR2020-01263) Ex. 1009, p. 003
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`

`

`5,217,996
`
`6
`
`R2
`0
`H
`I?
`I
`n
`V
`a
`XOC—C"CH2—C—NH—C—A"(CH)m—COX'
`
`(1')
`
`Cl-Iz-biaryl
`
`AR
`
`1
`
`wherein COX, COX', R1, R2, A, biaryl and m have the
`meanings as defined herein above for compounds of
`formula I. The compounds of formulae Ia, Ib, Ic, Id, 1e
`and If given below are present as well, preferably in the
`enantiomeric form depicted in formula I'.
`Illustrative thereof, in the above compounds of for-
`mula I wherein R1 is lower alkyl, the carbon atom car-
`rying said substituent is assigned the (R)-configuration;
`and the carbon atom carrying the biarylmethyl substitu-
`ent is assigned the (S)—configuration.
`More particularly, the present invention is concerned
`with and has for its object the compounds of formula Ia
`
`(Ia)
`R2
`0
`ROOC—CH—CHz—CH—NH—g—‘A—(CIIHM—COOR'
`l.
`
`CH2
`
`R3
`
`wherein COOR and COOR’ independently represent
`carboxyl or carboxyl derivatized in form of a pharma-
`ceutically acceptable ester; R1 represents hydrogen,
`lower alkyl, lower alkoxy, N-lower alkylamino, lower
`alkanoylamino, aryl-lower alkyl, aryl-lower alkoxy, .
`aryloxy, N-arylamino or aroylamino wherein aryl in
`each case represents phenyl optionally substituted by
`lower alkyl, lower alkoxy, halogen, hydroxy, cyano,
`acyloxy or trifluoromethyl, or aryl represents thienyl or
`furanyl optionally substituted by lower alkyl; R2 repre-
`sents hydrogen, hydroxy,
`lower alkyl or aryl-lower
`alkyl wherein aryl independently has the meaning given
`above under R]; R3 represents phenyl, or phenyl substi-
`tuted by lower alkyl, lower alkoxy, halogen, cyano,
`acyloxy or trifluoromethyl; or R3 represents thienyl or
`furanyl optionally substituted by lower alkyl; A repre-
`sents a direct bond, lower alkylene, 1,4-phenylene or
`1,4-cyclohexylene; m represents 1 or zero provided that
`111 represents 1 when A is a direct bond; or a pharmaceu-
`tically acceptable salt thereof.
`Advantageously, R3 is located in the para position.
`Particularly preferred embodiments of the invention
`as described above relate to:
`
`a) compounds wherein R3 is phenyl or phenyl substi-
`_
`tuted by lower alkyl, lower alkoxy, halogen, cy-
`ano, acyloxy or trifluoromethyl;
`b) compounds wherein A is lower alkylene, m repre-
`sents l or zero, and R2 represents hydrogen, lower
`alkyl, hydroxy or lower alkoxy.
`c) compounds wherein R1 represents hydrogen,
`lower alkyl,
`lower alkoxy or aryl-lower alkyl
`wherein aryl represents phenyl optionally substi-
`tuted by one or two of lower alkyl, lower alkoxy,
`halogen, hydroxy, cyano, acyloxy or trifluoro-
`methyl; most preferably compounds wherein R1
`represents lower alkoxy or lower alkyl.
`A particular embodiment of the invention relates to
`compounds of formula Ib
`
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`5
`l-(Cz-C4-alkanoyloxy)-
`pivaloyloxymethoxycarbony],
`ethoxycarbonyl,
`(2,2-dimethyl-l,3-dioxolan-4-yl)-
`methoxycarbonyl, 5-indanyloxycarbonyl, 3-phthalidox—
`ycarbonyl,
`bornyloxycarbonylmethoxycarbonyl,
`1-
`(C1—C4—alkoxycarbonyloxy)-ethoxycarbonyl
`or
`3-
`pyridylmethoxycarbonyl.
`Carboxyl derivatized in the form of a pharmaceuti-
`cally acceptable amide represents preferably carbamoyl
`or N-substituted carbamoyl, advantageously [lower
`alkylamino, arylamino, di-lower alkylamino, morpho-
`lino, N—lower alkylpiperazino, pyrrolidino, piperidino,
`perhydroazepino, (amino or acylamino)-lower alkyl-
`amino or aryl-lower alkylamino]-carbonyl.
`Pharmaceutically acceptable salts are either pharma-
`ceutically acceptable acid addition salts for any basic
`compounds of the invention or salts derived from phar-
`maceutically acceptable bases for any acidic com-
`pounds of the invention.
`Pharmaceutically acceptable salts of basic com-
`pounds of the invention are acid addition salts, which
`are preferably such of therapeutically acceptable inor-
`ganic or organic acids, such as strong mineral acids, for
`example hydrohalic, e.g. hydrochloric or hydro-bromic
`acid, sulfuric, phosphoric or nitric acid; aliphatic or
`aromatic carboxylic or sulfonic acids, e.g.
`formic,
`acetic, propionic, succinic, glycollic, lactic, malic, tar-
`taric, gluconic, citric, maleic, fumaric, pyruvic, phenyl-
`acetic, benzoic, 4-aminobenzoic, anthranilic, 4-hydrox-
`ybenzoic, salicylic, 4-aminosalicylic, pamoic, nicotinic,
`methanesulfonic,
`ethanesulfonic,
`hydroxyethanesul-
`fonic, 1,2-ethanedisulfonic acid, benzenesulfonic, p-tol-
`uenesulfonic, naphthalenesulfonic, sulfanilic, cyclohex-
`ylsulfamic acid, or ascorbic acid.
`Pharmaceutically acceptable salts of the acidic com-
`pounds of the invention, e.g. those having a free car-
`boxyl group are salts formed with ‘pharmaceutically
`acceptable bases, e.g. alkali metal salts (e.g. sodium,
`potassium salts), alkaline earth metal salts (e. g. magne-
`sium, calcium salts), ammonium salts, mono-, di- or
`tri-lower (alkyl or hydroxyalkyl)-ammonium salts (e.g.
`ethanolammonium, diethanolammonium, triethanolam-
`monium, tromethamine salts).
`The compounds of the invention, of formula I and
`derivatives thereof may contain several asymmetric
`carbon atoms, depending on the nature of the substitu-
`ents. Thus the compounds of the invention exist in the
`form of geometric isomers, racemates, diastereoisomers,
`pure enantiomers or mixtures thereof, all of which are
`within the scope of the invention.
`For example, the compounds of formula I exist in
`isomeric forms, e.g. wherein the asymmetric carbon
`atom on the butyryl chain bearing the R1 and/or biaryl-
`methyl groups may either exist in the S or R configura-
`tion. The compounds of the invention, e.g.
`those of
`formula I having said two asymmetric centers exist as
`two different racemic diastereoisomeric forms which
`may be called erythro and threo depending on the rela-
`tive orientation of the R1 and biarylmethyl substituents
`of the chain. Each of the two racemates consists of the
`
`optically active enantiomers (or antipodes) having
`(S,S), (R,R), (R,S) or (S,R) configurations, respectively.
`Preferred is the threo racemic form and particularly
`the enantiomeric form depicted in formula I'
`
`BIOCON PHARMA LTD (IPR2020-01263) EX. 1009, p. 004
`
`BIOCON PHARMA LTD (IPR2020-01263) Ex. 1009, p. 004
`
`

`

`7
`
`5,217,996
`
`O
`H
`4
`2
`HOOC—CH—CHz-CH—NH—C-(CHZ),,—COOH
`
`' 00
`
`CH2
`
`R1
`
`(M)
`
`wherein R1 is lower alkyl; n is an integer 1 through 4; or
`a pharmaceutically acceptable mono- or di-ester deriva-
`tive thereof in which one or two of the acidic hydroxy
`groups of the carboxyl functional groups are esterified
`in form of a mono- or di-pharmaceutically acceptable
`ester; or a pharmaceutically acceptable salt thereof; or
`an optical antipode thereof.
`Preferred are said compounds of formula Id wherein
`R1 is methyl and n is 2; and mono- or di-esters thereof.
`As discussed before, the butyric acid compounds of
`e.g. formula Id exist
`in two distinct diastereomeric
`forms which may be called erythro and threo. Preferred
`are e.g. the compounds of formula Id as the threo diaste-
`reomer (racemate), more particularly as the enantio-
`meric form having the R-configuration at C-atom 2 and
`the S-configuration at C-atom 4 and wherein the buty-
`ryl portion is as depicted in formula Id'
`
`H
`
`a
`
`0
`II
`V
`HOOC—C—CH;—C*NH—C- (CH2)n"COOH
`
`(Id')
`
`6H2 O 0
`
`AR
`
`1
`
`wherein R1 and n are as defined under formula Id; or a
`pharmaceutical acceptable mono-or diester derivative
`thereof; or a pharmaceutical acceptable salt thereof.
`Particularly preferred are compounds of formula Ie
`
`t
`.
`2
`ROOC—CH-CHZ— CH— NH—C—(CH2)2—COOR'
`CH3
`
`' oo
`
`CH2
`
`as
`
`wherein COOR and COOR’ independently represent
`carboxyl or carboxyl esterified in form of a pharmaceu-
`tical acceptable prodrug ester; or a pharmaceutically
`acceptable salt thereof.
`Particularly preferred embodiments of the invention
`as. described above relate to:
`(a) compounds of the above formula Ie wherein R
`and R' independently represent hydrogen, C1—C4-
`alkyl, benzyl optionally substituted on phenyl by
`lower alkyl, lower alkoxy, halo or trifluoromethyl,
`pivaloyloxymethyl,
`l-(C2—C4-alkanoyloxy)-ethyl,
`(2,2-dimethyl-l,3-dioxolan-4—yl)-methyl, S-indanyl,
`3-phthalidyl, bornyloxycarbonylmethyl, l-(Cy—C4—
`alkoxycarbonyloxy)-ethyl or 3-pyridylmethyl; or a
`pharmaceutically acceptable salt thereof;
`(b) compounds of the above formula Ie wherein
`COOR'
`is carboxyl; and COOR represents car-
`boxyl or carboxyl derivatized in form of a pharma-
`
`0
`R2
`(1b)
`ROOC—CH-CHr—CH—NH—g—A-(éH)M—COOR'
`l,
`R,
`
`O 0 R4
`
`wherein COOR and COOR’ independently represent
`carboxyl or carboxy] derivatized in form of a pharma-
`ceutically acceptable ester; R1 is hydrogen, lower alkyl,
`lower alkoxy or aryl-lower alkyl wherein aryl repre-
`sents ‘phenyl optionally substituted by lower alkyl,
`lower alkoxy, halogen, hydroxy, cyano, acyloxy or
`trifluoromethyl; R2 represents hydrogen, hydroxy or
`lower alkoxy; R4 and R5 independently represent hy-
`drogen, lower alkyl, hydroxy, lower alkoxy, halogen,
`cyano or trifluoromethyl; A represents lower alkylene;
`m represents 1 or zero; or a pharmaceutical acceptable
`salt thereof.
`Particularly preferred are compounds of formula Ic
`
`10
`
`15
`
`20
`
`0
`II
`ROOC—CH—CHZ—CH—NH—C—(CH2)n—COOR'
`I
`R1
`
`
`
`CH2
`
`00114
`
`25
`
`(1C)
`
`3O
`
`35
`
`wherein COOR and COOR’ independently represent
`carboxy] or carboxyl derivatized in form of a pharma-
`ceutically acceptable ester; R1 is lower alkyl or lower
`alkoxy; R4 represents hydrogen,
`lower alkyl,
`lower
`alkoxy, halogen, or trifluoromethyl; n represents an
`integer 1 through 6; or a pharmaceutical acceptable salt
`thereof.
`
`Preferred are compounds of formula Ic wherein
`COOR and COOR’ independently represent carboxyl,
`C1—Czo-alkoxycarbonyl, (carbocyclic or heterocyclic
`aryl)-lower alkoxycarbonyl, (di-lower alkylamino, N-'
`lower alkylpiperazino, morpholino, pyrrolidino, piperi-
`dino or perhydrazepino)-C2 to C4-alkoxycarbonyl,
`dihydroxypropyloxycarbonyl protected in form of a
`ketal, 5-indanyloxycarbonyl, 3-phthalidoxycarbonyl,
`bicycloalkoxycarbonyl-lower
`alkoxycarbonyl,
`a-
`(lower alkoxycarbonyl or di-lower alkylaminocar-
`bonyl)-lower
`alkoxycarbonyl,
`l-(lower
`alkoxycar-
`bonyloxy)-lower
`alkoxycarbony]
`or
`l-(lower
`al-
`kanoyloxy)-lower alkoxycarbonyl; or a pharmaceuti-
`cally acceptable salt thereof.
`Particularly preferred are said compounds of formula
`Ic wherein COOR and COOR’ independently represent
`carboxyl, C1—C4-alkoxycarbonyl,
`3-pyridylmethox-
`ycarbonyl, benzyloxycarbonyl optionally substituted on
`phenyl by lower alkyl, lower alkoxy, halo or trifluoro-
`methyl, 5-indanyloxycarbonyl, 1-(C2-C5-a1kanoyloxy)-
`ethoxycarbony], 3-phthalidoxycarbonyl, (2,2'-dimethyl-
`l,3-dioxolan>4~yl)-methoxycarbonyl,
`bornyloxycar-
`bonylmethoxycarbonyl,
`l-(C1-—C4-alkoxycarbonyloxy)-
`ethoxycarbonyl; or a pharmaceutically acceptable salt
`thereof.
`
`45
`
`50
`
`55
`
`65
`
`A preferred embodiment of the invention relates to
`compounds of formula Id
`
`BIOCON PHARMA LTD (IPR2020-01263) EX. 1009, p. 005
`
`BIOCON PHARMA LTD (IPR2020-01263) Ex. 1009, p. 005
`
`

`

`9
`ceutically acceptable ester; or a pharmaceutically
`acceptable salt thereof;
`(c) compounds of the above formula 16 having the
`R-configuration at C-atom 2 and the S-configura—
`tion at C-atom 4;
`(d) the compound according to the above formula Ie
`wherein COOR is ethoxycarbonyl and COOR’ is
`carboxyl, namely being 4-[N-(3-carboxy-1-oxo-
`propyl)amino]-4-(p-phenylphenylmethyl)-2-
`methylbutanoic acid ethyl ester,
`the (2R,4S)an-
`tipode thereof or a pharmaceutical acceptable salt
`thereof.
`The novel compounds of the invention are pharmaco-
`logically potent neutral endopeptidase enzyme inhibi-
`tors which inhibit e.g. the degradation of atrial natri-
`uretic factors (ANF) in mammals. They thus potentiate
`the diuretic and natriuretic effect of exogenous or en-
`dogenous ANF in mammals.
`The compounds of the invention are thus particularly
`useful in mammals as diuretic, natriuretic (saluretic) and
`antihypertensive agents for the treatment of e. g. hyper-
`tension, congestive heart failure and edema.
`As neutral endopeptidase inhibitors, the compounds
`are also e.g. enkephalinase inhibitors so as to inhibit the
`degradation of endogenous enkephalins and may thus
`also be useful for the treatment of pain in mammals.
`The above-cited properties are demonstrable in vitro
`and in vivo tests, using advantageously mammals, e.g.
`mice, rats, dogs, monkeys or isolated organs, tissues and
`preparations thereof. Said compounds can be applied in
`vitro in the form of solutions, e.g. preferably aqueous
`solutions, and in vivo either enterally, parenterally,
`advantageously intravenously, e.g. as a suspension or in
`aqueous solution. The dosage in vitro may range be-
`tween about 10'“4 molar and 10”9 molar concentra-
`tions. The dosage in vivo may range depending on the
`route of administration, between about 0.01 and 50
`mg/kg, advantageously between about 1.0 and 25
`mg/kg.
`The analgesic activity can be determined by measur-
`ing the potentiation of the analgesic effects of enkepha-
`lin and derivatives thereof, and by classical analgesic
`tests, such as the phenyI-p-benzoquinone induced writ-,
`ing test [J. Pharmacol. Exp. Therap. 125, 237 (1959)]
`and the hot plate test in the mouse [J . Pharmacol. Exp.
`Therap. 107, 385 (1953).
`The antihypertensive activity can be determined in
`the spontaneously hypertensive. rat, Goldblatt rat or
`Goldblatt dog by direct measurement of blood pressure.
`Advantageously, the effect is measured in the DOCA-
`salt hypertensive rat and/or renal hypertensive rat or
`dog model.
`The diuretic (saluretic) activity can be determined in
`standard diuretic screens, e.g. as described in “New
`Antihypertensive Drugs”, Spectrum Publications, 1976,
`pages 307—321, or by measuring the potentiation of
`atrial natriuretic factor-induced natriuresis and diuresis
`in the rat.
`
`The potentiation of ANF can also be determined by
`measuring the increase in ANF plasma level achieved.
`The in vitro inhibition of neutral endopeptidase
`(NEP) 3.4.24.11 can be determined as follows:
`Neutral endopeptidase 3.4.24.1] activity is deter-
`mined by the hydrolysis of the substrate glutaryl-Ala-
`Ala-Phe-2-naphthylamide (GAAP) using a modified
`procedure of Orlowski and Wilk (1981). The incubation
`mixture (total volume 125 1.1.1) contains 4.2 pg of protein
`(rat kidney cortex membranes prepared by method of
`
`10
`
`15
`
`20
`
`25
`
`3O
`
`35
`
`45
`
`50
`
`55
`
`65
`
`5,217,996
`
`.
`10
`Maeda et a1, 1983), 50 mM tris buffer, pH 7.4 at 25° C.,
`500 uM substrate (final concentration), and leucine
`aminopeptidase M (2.5 pg). The mixture is incubated
`for 10 minutes at 25° C. and 100 pl of fast garnet (250 pg
`fast gamet/ml of 10% Tween 20 in 1M sodium acetate,
`pH 4.2) is added. Enzyme activity is measured spectro-
`photometrically at 540 nm. One unit of NEP 24.11 ac-
`tivity is defined as 1 nmol of 2-naphthylamine released
`per minute at 25° 'C. at pH 7.4. IC50 values are deter-
`mined, i.e. the concentration of test compound required
`for 50% inhibition of the release of 2-naphthylamine.
`Neutral endopeptidase activity is also determined
`using ANF as a substrate. A trial natriuretic factor de-
`grading activity is determined by measuring the disap-
`pearance of rat-ANF (r-ANF) using a 3 minute reverse
`phase-HPLC separation. An aliquot of the enzyme in 50
`mM Tris HCl buffer, pH 7.4, is preincubated at 37° C.
`for 2 minutes and the reaction is initiated by the addition
`of 4 nmol of r-ANF in a total volume of 50 ill. The
`reaction is terminated after 4 minutes with the addition
`of 30 ul of 0.27% trifluoroacetic acid (TFA). Forty
`microliters of the mixture is injected into a reverse
`phase-HPLC and analyzed using a C4 cartridge in a 3
`minute, isocratic separation. Twenty-three percent of
`buffer B (0.1% TFA in 80% acetonitrile) is used. Buffer
`A is 0.1% TFA in water. One unit of activity is defined
`as the hydrolysis of 1 nmol of r-ANF per minute at 37°
`C. at pH 7.4. IC50 values are determined, i.e. the concen-
`tration of test compound required for 50% inhibition of
`the hydrolysis of ANF.
`The test compound is dissolved in dimethyl sulfoxide
`or 0.25M sodium bicarbonate solution, and the solution
`is diluted with pH 7.4 buffer to the desired concentra-
`tion.
`
`In vitro testing is most appropriate for the free car-
`boxylic acids of the invention.
`.
`The effect of the compounds of the invention on rat
`plasma ANF concentration can be determined as fol-
`lows:
`'
`
`Male Sprague-Dawley rats (275—390 g) are anesthe-
`tized with ketamine (150 mg/kg)/acepromazine (10%)
`and instrumented with catheters in the femoral artery
`and vein to obtain blood samples and infuse ANF, re-
`spectively. The rats are tethered with a swivel system
`and are allowed to recover for 24 hours before being
`studied in the conscious, unrestrained state.
`In this assay, plasma ANF levels are determined in
`the presence and absence of NEP inhibition. On the day
`of study, all rats are infused continuously with ANF at
`450 ng/kg/min. iv. for the entire 5 hours of the experi-
`ment. Sixty minutes after beginning the infusion, blood
`samples for baseline ANF measurements are obtained
`(time 0) and the rats are then randomly divided into
`groups treated with the test compound or vehicle. Ad-
`ditiona