PH26915A

PH26915A - Novel benzopyranylpyrrolinone derivatives and its process of preparation

Info

Publication number: PH26915A
Application number: PH43022A
Authority: PH
Inventors: Gilles Genain; Henri Pinhas
Original assignee: Rech Syntex France S A
Priority date: 1988-12-09
Filing date: 1991-08-29
Publication date: 1992-12-03

Description

x) Ji * NOVEL BENZOPYRANYLPYRROL INONE DERIVATIVES

This is a division of application Serial No. 39644 filed on December 8, 1989. } BACKGROUND OF THE 1HNVENTLON

Field of _the Invention

This invention relates Lo novel benzopyranylpyrrolinone devivatives that are smooth muscle relaxants, and are thus useful as agents in the treatment of essential and pulmonary hypertension, congestive heart failure, angina, smooth muscle gpasm, in particular cerebro vasospasm, cardiac arrhythmia, stroke, dysmenorrhea, venal failure, peripheral vascular ocelugive disease, unstable biadder and urinary retenlLion, nocturnal asthma, and pactrointesl inal digorders, in particular irritable bowel syndrome. Other indications include treatment of haldness.

Related Disclosures

Benzopyran devivatives are disclosed in the patent literature as having blood pressure lowering activity.

For example see U.S. Patent Nos. 4,068,317 and 4,647,670,

European Patent Applications 076,075 and 172,352, and

G.B. 1,548,222. A Lypical example is found in U.S.

Patent 4,446,113, which discloses a broad range of compounds having antihypertensive activity which are of the formula:

So 61S . oy. [7

Ay

R oy) 0 r, wherein:

One of Ry and R, is hydrogen and the other is selected from the class of alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, alkylhydroxymethyl, nitro, cyano, chloro, trifluoromethyl, alkylsulphinyl, alkylsulphonyl,’ alkoxysulphinyl, alkoxysulphonyl, alkoxycarbonylamino, alkylcarbonylamino, or aminosulphinyl, aminosulphonyl or aminocarbonyl, the amino moiety being optionally substituted by one or two alkyl groups, or alkylsulphinylamino, alkylsulphonylamino, alkoxysulphinylamino or alkoxysulphonylamino or ethylenyl terminally substituted by alkylcarbonyl, nitro or cyano, or -C(alkyl)NOH or C(alkyl)NNH, , the alkyl groups or alkyl moieties of alkyl-containing groups having from 1 to 6 carbon atoms; one of Ry and R, is hydrogen or alkyl having from 1 to 4 carbon atoms and the other is alkyl baving from 1 to 4 carbon atoms, or Ry and R, together wikh the carbon atom to which they are attached are spiroalkyl having from 3 to 6 carbon atoms;

Re is hydrogen, alkyl having from 1 to 3 carbon atoms or acyl having from 1 to 8 carbon atoms, and n is 1 or 2, the lactam group being trans to the

OR group.

Sle) . a

Similar compounds hearing a hydroxy group on the pyrrolidin-2-one ring are disclosed in EP 274,871.

In the search for new drugs to treat a specific disease state a desirable goal is to find a class of compounds that effectively treat that disease state at lower dose levels than allowed hy existing therapy, and/or are effective over a longer period of time.

Compounds that are effective at low dose levels generally have a better therapeutic ratio, i.e. separate the desired activity from any undesired side effects, and compounds that are effective over a longer period of time eliminate the need for frequent ¢and inconvenient) administration of the drug.

It has now surprisingly heen found that a structurally distinct class of henzopyran compounds has superior smooth muscle relaxant properties, in particular antihypertensive activity. This class of benzopyran compounds is characterized by the presence of a 3-pyrrolin-2-one ring substituted at the &4-position by an ether group. These compounds have heen found to be more active and/or longer acting than those compounds previously known in the benzopyranpyrrolidin-2-one series.

SUMMARY QF THE INVENTION

One aspect of the invention concerns novel compounds represented by the formula

Vr ee

. | 204) 4. "3

I. (1)

R

1 aN ..OH = I - x 0 ~Rq a) wherein:

Ry is cyano or nitro;

R, and Ry are independently hydrogen or lower alkyl; and

R, is alkyl; alkenyl; phenyl or phenyl-lower-alkyl in which any phenyl group may be optionally substituted with one or two substituents chosen from lower alkyl, lower alkoxy, halo, trifluoromethyl and hydroxy; ~(CH,) OR, or ~(CH,) N(R, ) 5 wherein m is an integer of 1-5 and R, ig as defined above; or a pharmaceutically acceptable ester or acid addition galt thereof.

Other aspects of the invention relate to pharmaceutical compositions containing a compound of fcrmula (I), and to methods pertaining to the use of compounds of formula (I) and the use of compositions containing such a compound. A further aspect of the invention relates to optical isomers of the compounds of formula (I). Yet another aspect relates to the novel processes by which optical isomers or racemic mixtures of compounds of formula (1) are obtained.

Jel

DETALLED DESCRIFITTIOM OF THE INVENTLOM

Definitions "Alkyl" means a branched or unbranched saturated hydrocarbon chain containing 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, tert-butyl, n-hexyl, 2-methylheptyl, n-decyl, n-dodecyl and the like, unless otherwise indicated; "Lower alkyl' means a branched or unbranched saturated hydrocarbon chain containing 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropvl, tert-butyl, n-butyl and the like, unless otherwise indicated. "Alkenyl" means a branched or unbranched hydrocarbon chain containing a double hond and having 2 to 12 carbon atoms, such as vinyl, allyl, but-3-en-1-yl, pent-2-en-1-yl, 4-methylpent-?-en-1-yl, dodec-5-en-1-yl and the like. "Lower alkoxy' means the pioup -0O (lower alkyl), wherein lower alkyl is as herein defined.

Co Cen beg . 20, "Halo' as used herein denotes fluoro, chloro, bromo, ‘ or iodo, unless otherwise indicated. "Phenyl" as used herein encompasses all possible isomeric phenyl radicals optionally monosubstituted or disubstituted with a substituent selected from the group consisting of lower alkyl, lower alkoxy, hydroxy, trifluoromethy! and halc. "“"Phenyl-lower-alkyl' as used herein denotes phenyl as defined herein attached to a lower alkyl group as defined herein, for example henzvl, l-phenylethyl,

Z2-phenylethyl, 3-phenylpropyl, and the like. "Optional" or ''optionally' means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance ocenrs and instances in t af oo bo which it does not. For example, "optionally substituted phenyl" means that the phenyl may or may not be substituted and that the description includes both unsubstituted phenyl and substituted phenyl. "Inert solvent means a solvent in which a reaction may be carried out which will not itself react with the reactants. One of ordinary skill will recognize which solvents are inert for a particular reaction, and may be for example benzene, toluene, xylene, acetonitrile, = 10 dimethylformamide, dimethylsulfoxide, alcohols, esters, . and the like. "Pharmaceutically acceptable ester’ as used herein refers to those non-toxic esters of a compound of formula (I) that are formed by reaction with an appropriate carboxylic acid or carboxylic acid derivative. Typical esters are those derived from formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, pivalic acid, hexanoic acid, optionally substituted benzoic acid, optionally substituted phenylacetic acid, and the like.

The esters are prepared by methods well known in the arf, for example by reacting the compound of formula (I) with the appropriate acid in the presence of an acid catalyst, for example sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, and the like, or alternatively in the presence of a dehydrating agent, for example 1,3-dicyclohexylcarbodiimide. Alternatively the esters may be prepared by reacting the compound of formula (I) with the appropriate acid chloride or anhydride in the presence of a hase at a suitable temperature, typically ranging from about -50 to 50°C, preferably about 07°C to room temperature.

Alternatively, the esters can be prepared by transesterification, according to methods known in the art. It is preferred in preparing the esters via

2s 7 transesterification to go from a lower ester to a higher ester, e.g., from the methyl ester, for example, to the isoamyl ester, for example. However, by using a substantial excess of a lower alcohol, a higher ester can be transesterified to a lower ester; thus, for example, by using a substantial excess of ethanol, the hexyl ester is converted by the transesterification to the ethyl ester. "Pharmaceutically acceptable acid addition salt" refers to those salts which retain the biological effectiveness and properties of the free bases and which are not biologically or olherwise undesirable, formed with inorganic acids such as hydrochloric acid, i hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, and organic acids such as acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid, henzoic acid, cinnamic acid, mandelic acid, menthanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid and the like. It is self-evident that the counterions associated with said pharmaceutically acceptable acid addition salts are the anions derived from said inorganic and organic acids. Furthermore, it js self-evident that said inorganic and organic anions may be mono- or polyvalent depending on the acid from which they are derived.

Typically, the free hase is dissolved in an inert organic solvent such as diethy! ether, ethyl acetate, chloroform, ethanol ov methanol and the like, and the acid added in a similar =olvenl. The temperature is maintained at 0°-50°¢. The reaulting salt precipitates spontaneously or may he bronght out of solution with a less polar solvent. }

NE q [T 8

The salt products are also isolated by conventional means. For example, the reaction mixtures may be evaporated to a dryness, and the salts can be further purified by conventional methods such as those listed above.

The acid addition salts of the compounds of formula (I) may be decomposed to the corresponding free bases by treatment with at least a stoichiometric amount of a suitable base such as sodium or potassium hydroxide, potassium carbonate, sodium bicarbonate, ammonia, and the like.

Salts of the compounds of formula (I), may be interchanged by taking advantage of differential solubilities of the salts, volatilities or activities of the acids, or by treating with the appropriately loaded ion exchange resin. For example, the interchange is effected by the reaction of a salt of the compound of formula (I) with a slight gtoichiometric excess of an acid of a lower pKa than the acid component of the starting salt. This conversion is carried out at a temperature between about 0°C and the boiling point of the solvent being used as the medium for the procedure.

The compounds of this invention possess asymmetric centers and thus can be produced as mixtures of stereoisomers or as individual stereoisomers. The individual stereoisomers may be obtained by resolving A racemic or non-racemic mixture of an intermediate at some appropriate stage of the synthesis, or by resolntion of the compound of formula (I). [It is understood that the individual stereoisomers as well as racemic and non-racemic mixtures of stereoisomers are encompassed within the scope of the present invention.

For the sake of simplicity only one skereoisomer will be depicted by way of illustration in the Reaction nt Jif ) 9 . Schemes. However, it is to be understood that all individual stereoisomers and racemic and non-racemic mixtures of stereoisomers are also encompassed thereby. "Tgomers' are different compounds that have the same molecular formula. "Srereoisomers' are isomers that differ only in the way the atoms are arranged in space. "Enantiomers' are a pair of stereoisomers that are non-superimposable mirror images of each other.

Enantiomers rotate the plane of polarized light in opposite directions. The enantiomer that rotates the plane to the left is called the levo isomer, and is degignated (-). The enantiomer that rotates the plane to the right is called the dextro isomer, and is designated (+). "PDiastereoisomers' are stereoisomers which are not mirror—images of each other. "Racemic mixture" means a mixture containing equal parts of individual enantiomers. "Mon-racemic mixture is a mixture containing unequal parts of individual enantiomers.

The terms "oa and B" indicate the specific stereochemical configuration of a substituent at an asymmetric carbon atom in a chemical structure as drawn.

Thus "«", denoted by a broken line, indicates that the group at the position in question is below the general plane of the molecule as drawn, and "f", dennted hv a bold line, indicates that the group ak the position in question is above the general plane of the molecule as drawn.

The term ''treatment' as used herein covers any treatment of a disease in a mammal, particularly a human, and includes:

; . Ma -10- (i) preventing the disease from occurring in a subject which may be predisposed to the disease but has not yet been diagnosed as having it; (ii) inhibiting the disease, i.e., arresting its development; or (iii) relieving the disease, i.e., causing regression of the disease.

The numbering system used in naming the intermediates and product compounds of the present invention is illustrated below, using a compound of formula (I) as an example.

R,0-4 3 { 1 \ v 0 “Or .OH ‘0 = | I 7 In 2 R 4 8 p R 2

In the final product, the substituents at positions 3 and & on the benzopyran ring are always trans to each other. ’

Following are examples of how representative compounds of formula (I) are named.

A racemic compound of formula (I) wherein Ry is cyano, R, and Ry are both ethyl and R, ig methyl is named : 6-cyano-3,4-dihydro-2,72 diethyl-trans-3-hydroxy-4 (4-methoxy-2-oxo-3-pyrrolin-1-yl)-2l-1-henzopyran.

An optically active isomer of a compound of formula (I) which is levorotatory, wherein R, is cyano, R, and Ry are both methyl and R, is ethyl is named: (=)=6-cyano-3,4-dibydro-2,2-dimethyl-trans-3-hydroxy- 4—(b-ethoxy-2-0x0--3-pyrtolin-1L y1)-2H-1-henzopyran.

“AT Nv ~11-

Preferred Embodiments

Among the family of compounds of the present invention of formula (I), a preferred group includes compounds wherein Ry is cyano. Within this group a preferred subgroup includes the compounds in which R, and Roy are independently methyl or ethyl, especially where they are both methvl. One preferred class within this subgroup includes compounds in which R, is alkyl, especially lower alkyl, more especially methyl or ethyl.

A second preferred class within this subgroup includes compounds in which R, is alkenyl, especially lower alkenyl of 1-6 carbon atoms, more especially allyl. A third preferred class within this subgroup includes compounds in which R, is phenyl -lower-alkyl, especially benzyl.

A second preferred group includes compounds wherein

R, is nitro. Within this gronp a preferred subgroup includes the compounds in which R, and Ry are independently methyl or ethyl, especially where they are both methyl. One preferred class within this subgroup includes compounds in which R, is alkyl, especially . lower alkyl, more especially methyl or ethyl.

At present the preferred compounds are: 6-cyano-3, 4-dihydro--2,2 dimethyl-trans-3-hyvdroxy-4- (4-methoxy-2-oxo--3-pyrrolin-1-y1)-2H-1-benzopyran; and } 6-cyano-3,h-dihydro-2,2--dimethyl-trans-3-hvdroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-vL) 2H-l-benzopvran.

Methods of Preparation

The compounds of formula (1) may be prepared from the intermediates of formula (72) and (3) as shown in

Reaction Scheme 1 helow.

SGA

~12-

REACTION SCHEME 1

R,0

T\ 0 0 R,0

Ry . : 4 \ Ry __.OH _ — >

Rs Nn SXo 77 Ra 0 R | 0 n 2 H 2 (2) (3? (1 where Ry. R,, Ry and R, are as defined above.

The compound of formula (I) may be prepared by reacting the compound of formula (2) with about 1 molar equivalent of the compound of formula (3) in the presence of about 1 molar equivalent of a strong base such as potassium t-butoxide, lithium diisopropylamide, or an alkali metal hydride, for example potassium hydride, lithium hydride or preferably sodium hydride. The reaction is carried out in an aprotic solvent such as tetrahydrofuran, dimethylformamide, hexamethylphosphoramide, or preferably dimethylsulfoxide, at a temperature of about 0-50°C, preferably about 25°C, for about 2-18 hours, preferably about 5 hours. When the reaction is substantially complete, the compound of formula (I) is isolated by conventional means and purified, preferably by chromatography followed by recrystallizing from a suitable solvent or solvent mixture such as diethylether/pentane.

An alternative preparation of the compound of formula (I) is illustrated in Reaction Scheme 2. 117 ne

. De, ql 5 : 1a

REACTION SCHEME 2

CH;0 R,O

TA TN

N~ NO N J

R i R

CL , 2 on Cr

R . > | R ~ 0 o =~ o o 2 2 (I) cn where R;, R,, R, and R, are as defined above.

The compound of formula (I) where R, is methyl, prepared for example as shown in Reaction Scheme 1 above, is treated with an alcohol or phenol of formula R,OH in the presence of an acid catalyst, giving a compound of formula (I) where R, corresponds to that of the R, OH employed in the reaction. Typically. a mixture of the compound of formula (I) where R, is methyl is mixed with about 1 to 10 molar equivalents, preferably about 4 molar equivalents, of the appropriate alcohol or phenol of formula R,OH and a catalytic amount, for example about 0.1 molar equivalents, of a suitable acid catalyst such as p-toluenesulfonic acid or preferably methanesulfonic acid. The mixture is heated at about 50-150°C, preferably about 80°, at reduced pressure, for example about 20-40 mbar, {or ahont 1-10 hours, preferably about 3 hours. When the reaction is substantially complete, the compound of formula (I) is jignlated by conventional means, for example chromatography.

Alternatively, the reaction may he carried out in the same manner as shown above, buat in the presence of 3A molecular sieves, which eliminates the need for reduced seq re pressure. The mixture is refluxed for about 1-6 hours, preferably about 2 hours. and the product isolated conventionally.

Clearly, compounds where R, is other than methyl, for example ethyl, may be used as a gtarting material.

Tt is necessary, however, that the alcohol displaced is of lower boiling point than the alcohol or phenol used for its displacement.

The reaction is also useful for the preparation of optically active compounds of formula (I); for example starting with an optically active compound of formula (I) where R, is methyl and reacting with a compound of formula R, OH (where R, is not methyl) as shown above leads to an optically active compound of formula (I) where R, is other than methyl.

Optical Isomers of the Compounds of Formula (I)

The optical isomers of the compound of formula (I) may be obtained in various ways. For example, reaction of a racemic mixture of a compound of formula (I) with a chiral isocyanate, for example (R)~(+)-a-methylbenzyl- isocyanate, gives a mixture of diastereoigomeric carbamates (formed at the 3-position by reaction with the 3-hydroxy group), which may be separated by chromatography or crystallization and converted back to the individual enantiomers of the compound of formula (I). This approach is discussed in more detail in

European Patent Application 120,428. A similar method is to react a compound of formula (I) with a chiral acid derivative. for example an acid chloride, which gives a mixture of diasterenisomeric esters, which may be similarly separated and converted back to the individual enantiomers of the compound of formula (I). A tvpical example of a chiral acid chloride is (S)-camphanic acid 110 nae

MN

-15 chloride, the use of which is discussed in more detail in

Circulation Research, Vol. 62, 679 (1988).

Racemic mixtures mav also may be separated by chromatography on a chiral column. For example, on an ay -acid glycoprotein column eluting with a phosphate buffer composition.

Another approach is to first resolve one of the racemic intermediates used in Reaction Schemes 1 and 2 above in the preparation of racemic compounds of formula (I). The optically active isomers of the intermediate thus obtained may then be reacted in the same manner as shown above to give optically active compounds of formula (I). A particularly suitable intermediate is the compound of formula (4), which has a 4-amino group. thus enabling diastereoisomeric salts to be formed with readily available optically active acids, which may then be separated by conventional means, preferably crystallization. The separated pure diastereomeric salts are then cleaved by standard means, such as treatment with a base, to afford the respective enantiomers of the compound of formula (4). For the sake of convenience in the discussion, the two enantiomers of (4) will be referred to as (4A) and (4B).

The latter process is clearly simpler and more convenient to carry out than those detailed above, as formation of a base salt is easier to carry out than the chemical reaction necessary to prepare chiral esters or carbamate of an alcohol, and conversion of the separated diastereoisomeric salts back to the individual isomers fis easier than hydrolysis of esters or carbamates to the free alcohol. In particular, care must be taken in the hydrolysis of chiral esters or carbamates, in that use of a strong base may lead to racemization of the optically active compound.

PP.

LIS

16

In addition, separation of optical isomers at an earlier stage of the synthesis is generally preferred to geparation of optical isomers of the final product, especially in the case where one of the isomers is inactive, as it is more convenient and economical to remove the unwanted isomer before it is reacted with expensive reactants. Yet another consideration is that for compounds of formula (4), the optical isomers of formula (4A) and (4B) can be reacted with various compounds of formula (5) to give a series of optically active compounds of formula (I), thus eliminating the need to resolve a large number of compounds.

Exemplary of optically active acids are the optically active forms of camphor-10-sulfonic acid, 2-bromo-camphor-10-sulfonic acid, camphoric acid, menthoxyacetic acid, tartaric acid, malic acid, mandelic acid, diacetyltartatic acid, pyrrolidine-5-carboxylic acid, abietic acid, aspartic acid, deoxycholic acid, di-p-toluoyltartaric acid, glutamic acid, lactic acid, pyroglutamic acid, and the like. The preferred optically active acid is dibenzoyltartaric acid in the D or L form. Typically the compound of formula (4) is reacted with about 1 molar equivalent of an optically active acid, for example dibenzoyl-L-tartaric acid. The reaction is carried out in a suitable solvent such as methanol, propanol. Z-methoxyethanol, dimethylformamide, acetonitrile and the like, preferably ethanol. at a temperature of about 20°-100C. preferably about 70°C, for re about 10 minutes to 2 hours, preferably about 30 - 30 minutes. The reaction mixture is then allowed to cool to about 0-40°C, preferably about 25°C, for about 1-8 hours, preferably about 3 hours. The precipitated salt thus obtained ig treated with hase conventionally to give one enantiomer of formula (AA) ot (4B). 11s eq ~17

The opposite enantiomer may be obtained in a similar manner as shown above, starting with the optically active acid used above but of opposite rotation, for example dibenzoyl-D~tartaric acid. Alternatively, the salt remaining dissolved in the filtrate (from which the precipitated salt of the first isomer is filtered) may be converted to the free amine as shown above and treated with the optically active acid of opposite rotation, for example dibenzoyl-D-tartaric acid, giving the other diastereomeric salt from which the opposite enantiomer is obtained.

The individual optical isomers of formula (4A) and (4B) are then converted to the optically active compounds of formula (I) by reaction with a compound of formula (5) where X and R are as defined helow, to give either an intermediate of formula (6), which is cyclized to (I) as shown in pathway A of Reaction Scheme 3, or a compound of formula (I) directly, as shown in pathway B of Reaction

Scheme 3.

ug [S -18-

REACTION SCHEME 3

H

R y 2 R,0 1 _.-OH + — —R4 X OR 0 R 0 2 : (4A) or (4B) A (5)

B an “Lu ( yn © N

Ry Je): Ry OH

R > R 3 3 0 R Or R 2 2 (6) (I) where Ry, Ro, Ra and R, are as defined above, X is chloro, bromo or iodo and R is lower alkyl, preferably methyl where R, is methyl, or otherwise ethyl.

The compound of formula (I) is prepared via pathway

A by first reacting the chiral compound of formula (4A) or (4B) with about 1-1.5 molar equivalents, preferably about 1.3 molar equivalents, of the compound of formula (5) where % and R are as defined above, in the presence of about 1-5 molar equivalents, preferably ahout 2 molar equivalents, of a base such as a tertiary amine, for example pyridine, N,M-dimethylaniline, diisopropylethylamine or preferably triethylamine, or an inorganic base such as sodium carbonate, calcium

] 26h ~19. carbonate, sodium hydroxide and the like, preferably potassium carbonate, and about 0.5-1.5 molar equivalents, . preferably about 1 molar equivalent, of an alkaline metal iodide, preferably potassium iodide. The reaction is carried out in a protic sclvent such as methanol, ethanol, 2-methoxyethanol and the like, preferably isopropanol, at a temperature of about 50°-100°C, preferably at reflux temperature, for about 30 minutes to 8 hours, preferably about 3 hours. when the reaction is substantially complete, the compound of formula (6) is isolated by conventional means and purified, preferably by chromatography. The compound of formula (6) is then cyclized, preferably by heating in an inert solvent, preferably xylene, at a temperature of about 80°-140°C, preferably at reflux temperature, for about 10-48 hours, preferably about 15 hours. When the reaction is gubstantiallv complete, the optically active compound of formula (1) is isolated by conventional means and purified, preferably by chromatography.

Alternatively, the compound of formula (I) is prepared via pathway B by reaching the chiral compound of formula (4A) or (4B) with about 1-1.5 molar equivalents, preferably about 1.3 molar equivalents, of the compound of formula (5) where X and R are as defined above, in the presence of about 1-5 molar equivalents, preferably about 2 molar equivalents, or a base such as a tertiary amine. for example pyridine, N,N-dimethylaniline, diisopropylethylamine ox preferably triethylamine. The reaction is carried out in an aprotic solvent, such as benzene, xylene and the like, preferably toluene, at a temperature of about 50°-1720°C, preferably at reflux temperature, for about 30 minutes to 24 hours, preferably about 18 hours. When the reaction is substantially complete, the optically active compound of formula (I) fis 41, e-

~20- isolated by conventional means and purified, preferably by chromatography.

The processes detailed in Reaction Scheme 3 can also of course conveniently be used for the preparation of _ 5 racemic mixtures of the compound of formula (I), starting with the appropriate racemic compound of formula (4) and proceeding either through a racemic intermediate of formula (6) or directly to a compound of formula (I).

Preparation of Starting Materials

The compounds of formula (2) are well known in the art. See for example United States Patent No. 4,062,870. For example, the compound of formula (2) wherein Ry is cyano and R, and R, are both methyl is prepared by reacting 4-cyanophenol with 3-methyl-3-chlorobutyne, cyclizing the product to 6-cyanochromene, forming the trans-3,4-bromohydrin by reaction with N-bromosuccinimide and treating this bromohydrin with base to give the desired epoxide of formula (2). This reaction scheme is set forth in more detail in European Patent Application No. 093,535.

The compounds of formula (3) are known in the art.

For example, the compound of formula (3) where R, is methyl is disclosed in J.A.C.S., 85, 1430 (1963), where

R, is methyl or ethyl in European Patent Application

No. 216,324, and where R, is benzyl in European Patent

Application No. 252,363.

The compounds of formula (3) can also be prepared Aas shown in Reaction Scheme 4. 11m.

FuqI© - -21-

REACTION SCHEME 4 = R,O

H

(3) (3)

The compound of formula (3) where R, is methyl, upon treatment with an alcohol or phenol of formula

R, OH in the presence of an acid catalyst, gives a compound of formula (3) where R, is other than methyl.

Typically, a mixture of the compound of formula (3) where

R, is methyl is mixed with about | to 10 molar equivalents, preferably about 2 molar equivalents, of the appropriate alcohol or phenol of formula R, OH and a catalytic amount, for example about 0.1 molar equivalents, of a suitable acid catalyst such as

P-toluenesulfonic acid or preferably methanesulfonic acid. The mixture is heated at about 50°-150°C, preferably about 100°C, at reduced pressure, for example about 40 mbar, for about 1-10 hours, preferably about 3 hours. When the reaction is substantially complete, the compound of formula (3) is isolated by conventional means.

Alternatively, the reaction may be carried out in the same manner as shown above, but in the presence of 3A molecular sieves, which eliminates the need for reduced pressure. The mixture is refluxed for about 1-6 hours, preferably about 2 hours, and the product isolated conventionally.

Clearly, compounds other than the compound of formula (3) where R, is mokhv! may he used an a starting material. It is necessary, however, that the 11A7M oo MIN

To 27 alcohol displaced is of lower boiling point than the alcohol or phenol used for its displacement.

The compound of formula (4) is known in the art.

See, for example, United States Patent No. 4,251,537, or

European Patent Application No. 093,535.

The compounds of formula (5) are known in the art.

See for example European Patent Application Mo. 216,324.

In summary, the compounds of the present invention — are made by the procedures outlined below:

A 10 1. A process for preparing a compound, as a single stereoisomer or as a mixture of stereoisomers, represented by the formula ‘ R,0 4 T\ nu” No (I)

R

IN on

NN er, 2 0 R, wherein: .

Ry is cyano or nitro;

R, and Ray are independently hydrogen or lower alkyl; and

R, is alkyl; alkenyl; phenyl or phenyl-lower-alkyl in which any phenyl group may be optionally substituted with one or two substituents chosen from lower alkyl, lower alkoxy, haln, trifluoromethyl and hydroxy: 0 (c -( : : 3 (CH,) OR, or —(CH,) N(R,),, wherein m is an integer of 1-5 and R, is as defined above: or a pharmaceutically acceptable ester or acid addition salt thereof, which process comprises:

~273~ (a) reacting a compound of the formula

R.0Q

J

; he 0

R . 1 .OH 7 -°

Xn Ry e R 2 as a single stereoisomer 2r as Aa mixture of stereoisomers, wherein:

Ry, R, and R, are as defined above and Re is methyl or ethyl; with a compound of the formula R,OH, where R, is } as defined ahove but not methyl or ethyl; (b) reacting a compound of the formula 0

Ry . ; (2)

Rs : 07 gr 2 as a single stereoisomer or Aas a mixture of stereoisomers, wherein Ry. Ro and Ry ave as defined above, with a compound of Lhe formula

R, O - (3) —0

MN

H

- QELS -24h- wherein R, is as. defined above; or (c) cyclizing a compound of the formula

R, 0 ="

NH © (6)

R

1 .-OH

Lo | 3 . = R3 0 R 2 as a single stereoisomer or as a mixture of steroisomers, wherein Ry. Ro, Ry and R, are as 15 . . i i defined above and R is lower alkyl; or (d) reacting a compound of the formula n

R 2

INS ,.--OH (6)

NP

R

2 as a single stereoisomer or as a mixture of stereoisomers, wherein Ry. Ry, and Rq are as defined above, with a compound of the formula

R,0O

I~ OR a's a

X 4]

2uql5 ~25- wherein R, is as defined above and R is lower alkyl and

X is chloro, bromo or iodo; or (e) converting a compound of the formula (I) to a pharmaceutically acceptable ester or acid addition salt thereof; or (£) converting an ester or an acid addition salt of a compound of the formula (I) to the free compound of formula (I); or (g) converting one ester or acid addition salt of a compound of the formula (I) to a second pharmaceutically acceptable ester or acid addition salt of the compound of formula (I).

Utility and_administration

The compounds of the present invention exhibit smooth muscle relaxant biological activities, and are thus used in the treatment of mammals where the use of : smooth muscle relaxants is indicated. The compounds of formula (I) are particularly useful as antihypertensive agents to reduce blood pressure in mammals, including man.

Other physiological uses of the novel compounds of ] formula (I) include, for example, treatment of congestive heart failure, angina, smooth muscle spasm, in particular cerebro-vasospasm, cardiac arrhythmia, stroke, dysmenorrhea, renal failure, peripheral vascular occlusive disease, unstable bladder and urinary retention, nocturnal asthma. and gastrointestinal disorders, in particular irritable bowel syndrome. Other indications include treatment of baldness.

In applving the compounds of this invention to treatment of the above conditions, any pharmaceutically i. SLC)S 2 6— acceptable mode of administration can he used, either alone ov in combination with other pharmaceutically acceptable excipients, including solid, semi-solid liquid or aerosol dosage forms, such as, for example, tablets, pills, capsules, powders, liguids, suspensions, aerosols or the like, preferably in unit dosage forms suitable for single administration of precise dosages, or in sustained or controlled release dosage forms for the prolonged ! ) administration of the compound at a predetermined rate. !

The compositions will typically include a conventional pharmaceutical carrier or excipient and an active compound of formula (I) or the pharmaceutically acceptable salts thereof and, in addition, may include other medicinal apents, pharmaceutical agents, carriers, adjuvants, etc. / 3 For Example, the present invention envisages pharmaceutical compositions comprising a combination of an active compound of the formula (I) or the pharmaceutically acceptable esters or acid addition } galta thoreof and other antlhypartensive agents, including, but not limited to bata-blockers, such as atenolol and propranolol, ace-inhibitors, such ag captopril, thiazidic diuretic agents and chlorthalidona analgos, alpha subscript 1-blockers such as prazosin, and calelum entry blockers, such as nifadiptine,

Alitilazem and verapamil. The noval pharmaceutical combination dascrlbed haralnabove may be combined in a aingla composition or may be used sagquantially in the treatment of hypertension and, in addition, may Include other carriers, adjuvants, etc. for formulation into pharmaceutical compositions.

o SC\9 “27 =

Among the pharmaceuticaly compositions described above, a prafarred group Includes combinations of 6~cyano-3,4-dihydro-2, 2~dimethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-L-yl)~-2H-1-banzopyran or the pharmaceutically acceptable estars or acid addition salts theraof, as a racemic mixture or as an individual anantiomer, in combination with the other . antihypertensive agents. . The amount of active compound administered will, of course, be dependent on the subject and disease state being treated, the severity of the affliction, the manner of administration and the judgment of the prescribing physician. However, an effective dosage is in the range of 0.001 mg to about 10 mg/kg of body weight, preferably about 0.01 mg to 1 mg/kg. For an average 70 kg human, this would amount to 0.07-700 mg per day, or preferably 0.7-70 mg/day.

For solid compositions, conventional non-toxic solid carriers include, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like may be used. Liquid pharmaceutically adminiskerable compositions can, for example, be prepared by dissolving, dispersing, etc. an active compound as defined above and optional pharmaceutical adjuvants in a carrier, such as, for example, water, saline, aqueous dextrose, glycerol,

. Luis : 20 ethanol, and the like, to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered may also contain minor amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like, for example, sodium acetate, sorbitan monolaurate, triethanolamine sodium acetate, sorbitan monolaurate, triethanolamine oleate, etc. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art: for example, see Remington's

Pharmaceutical Sciences, Mack Publishing Company, Easton,

Pennsylvania, 16th Edition, 1980. The composition or formulation to be administered will, in any event, contain a quantity of the active compound(s) in an amount effective to alleviate the symptoms of the subject being treated.

Dosage forms or compositions containing active ingredient (compounds of fouvmula (I)) in the range of 0.1 to 95% with the balance made up from non-toxic carrier may be prepared.

For oral administration, a pharmaceutically acceptable non-toxic composition is formed by the incorporation of any of the normally employed excipients, guch as, for example pharmaceutical grades of mannitol, lactose. starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose. sucrose, magnesium, carbonate, and the like. Such compositions take the form of solutions, suspensions. tablets, pills, capsules, powders. sustained release formulations and the like.

Such compositions may contain 0.01%-95% active ingredient, preferably 0.1-50%.

Particularly preferred oral formulations of the compounds of formula (I) are formulations in which the compound is dissolved in a propylene glycol diester of a 110A

. 79 ~ short-chain fatty acid or in a cyclic carbonate diester, such as propylene carbonate. For a solid dosage form, the solution, e.g. in propvlene carbonate, is preferably encapsulated in a soft-shelled gelatine capsule. Such diester solutions, and the preparation and encapsulation thereof, are disclosed in U.S. Patents Mos. 4,328.245; 4,409,239: and 4,410,545. For a liquid dosage form. the solution, e.g. in propylene carbonate, may be diluted with a sufficient quantity of a pharmaceutically-acceptable liquid carrier, e.g. water, to be easily measured for administration.

Other useful formulations include those set forth in

U.S. Patents Mos. Re. 28.819 and 4,358,603.

The formulation can be administered in a single unit dosage form for continuous treatment or in a single unit dosage form ad libitum when relief of symptoms is specifically required.

Parenteral administration is generally characterized by injection, either subcutaneously, intramuscularly or intravenously. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, galine, dextrose, glycerol, ethanol or the like. In addition, if desired, the pharmaceutical compositions to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulgifying agents, pH buffering agents and the like, such as for example, sodium acetate, sorbitan monolaurate, triethanolamine oleate, etc.

A more recently devised approach for parenteral administration employs the implantation of a slow-release or sustained-release system. such that a constant level :

. Ce 1 19 ’ ~30) of dosage is maintained. See, e.g., U.S. Patent No. 3,710,795.

The percentage of active compound contained in such parental compositions is highly dependent on the specific nature thereof, as well as the activity of the compound and the needs of the subject. However, percentages of active ingredient of 0.01% to 10% in solution are employable, and will be higher if the composition iz a solid which will be subsequently diluted to the above percentages. Preferably the composition will comprise 0.2-2% of the active agent in solution.

The following preparations and examples illustrate the invention, but are not intended to limit its scope.

PREFARATION _1

Preparation of 6-cyano-3,4-dihydro=2.2-dimethyl-3 4- epoxy-2H-1-benzopyran and Related Compounds. of Formula (2)

A. 4-Cyanophenol (201.3 g), sodium hydroxide (101.4 g). 40% benzyltrimethylammonium hydroxide in methanol (353 g) and 3-methyl-3-chlorobutyne (260 g) were stirred in a mixture of water (1500 ml) and dichloromethane (1500 ml) for 5 days at room temperature. After separation the organic layer was washed with 10% sodium hydroxide solution (400 ml) and dried over sodium sulphate. The solvent was removed under reduced pressure, leaving a viscous liquid. This liquid (225.6 g) was heated in o_dichlorobenzene (450 ml) at reflux temperature for 3 hours under nitrogen. The solvent was removed under reduced pressure (70°C at 3 mm of Hg), leaving a brown oil (225 g) identified as 6-cyanochromene.

To a solution of the 6-cyanochromene (225 g) in dimethyl sulphoxide (2 1) containing water (22 ml) was

Ltd =371-- added N-bromosuccinimide (433.6 g) with vigorous stirring and cooling to 10°C. After 1 hour at room temperature the mixture was diluted with water and extracted with ethyl acetate to give a mixture which was refluxed in acetone (4 1) and water (1.3 1) for 5 hours to hydrolyze the small amount of 3,4-dibromide present. The acetone was removed under reduced pressure, leaving a precipitate in water. After filtration, the precipitate was dissolved in diethylether and precipitated with pentane, to give 145 g of trans-3-bromo-4-hydroxy-6-cyano-3,4- dihydro-2,2-dimethyl-2B-Jl-benzopyran as white crystals, m.p. 230°C.

Removal of the solvent from the filtrate and chromatography of the residue on silica gel, eluting with methylene chloride, gave an additional 68.5 g of the bromohydrin, m.p. 230°C. ' The bromohvdrin (213.5 g) was stirred with sodium hydroxide (45.4 g) in a mixture of water (2.2 1) and dioxane (1.76 1) for 2 hours at room temperature. The dioxane was removed under reduced pressure and the resulting precipitate filtered off. The precipitate was then dissolved in methylene chloride, dried over sodium sulfate and chromatographed on silica gel, eluting with methylene chloride, to give 6-cyano-3,4-dihydro-2,2- dimethyl-3,4-epoxy-2H-l-benzopyran as white crystals, m.p. 108°C.

B. Similarly, optionally replacing é4-cyanophenol with 4-nitrophenol, and optionally replacing 3-methyl-3-chlorobutyne with a propyne substituted in the 3-position with the appropriate definitions of R, and

Ra, the following compounds of formula (2) are prepared: 6-cyann-3.4-dihydro-?-methyl-3,4-epoxy-2H-1- benzopyran: 6-cyano-3, d—dibydro-?2-ethyl-3, 4-epoxy-2H-1-benzopyran;

Qeq15 . _32- 6-cyano-3,4-dihydro-2-n-butyl-3, 4-epoxy-2H-1- bhenzopyran: 6-cyano-3,4—dihydro-2-methyl-2-ethyl-3, 4-epoxy-2H-1- benzopyran; 6-cyano-3.4—dihydro-2.2-diethyl-3, 4-epoxy-2H-1- benzopyran; 6-cyano-3,4-dihydro-2.2-di-n-butyl-3, 4-epoxy-2H-1- benzopyran; 6-nitro-3,4-dihydro-2,2-dimethyl-3,4-epoxy-2H-1- benzopyran; 6-nitro-3,4-dihydro-2-methyl-3, 4-epoxy-2H-1- benzopyran; 6-nitro-3,4-dibydro-2-ethyl-3,4-epoxy-2H-1- benzopyran; 6-nitro-3,4-dihydro-2-n-butyl-3,4-epoxy-2H-1- benzopyran; 6-nitro-3,4—~dihydro-2-methyl-2-ethyl-3,4-epoxy-2H-1- benzopyran,; 6-nitro-3,4—-dihydro-2.2-diethyl-3,4-epoxy-2H-1- penzopyran; and 6-nitro-3,4-dihydro-2,2-di-n-butyl-3, 4-epoxy-2H-1- benzopyran. .

PREPARATION 2

Preparation of 4-methoxv-3-pyrrolin-2-one and Related rm Compounds _of Formula (3) ol A. A mixture of methyl é4-chloroacetoacetate (96.5 g) and trimethyl orthoformate (340.2 g) was stirred under argon with 96.5 g of Amberlyst-15 ion exchange resin.

The temperature was raised to 40°C and stirring continued for 5 hours. The resin was filtered off and the filtrate distilled under vacuum (13 mm). The distillate was mixed

- - RGIS : ~33- with 3.2 g of p-toluenesulfonic acid and heated at 150°C until no more methanol distilled off. Distillation of the residue under vacuum gave &4-chloro-3-methoxy-2-E- butenoic acid, methyl ester, b.p. 75°C (3 mm Hg).

The 4-chloro-3-methoxy-2-E-butenoic acid, methyl ester thus obtained (84.42 g) was stirred with 210 ml of 287% aqueous ammonia solution under a reflux condenser at 80°C for 2 hours. The mixture was then cooled to room temperature and extracted with methylene chloride. The extract was dried over sodium sulfate, filtered and solvent removed from the filtrate under reduced pressure. The residue was triturated with diethyl ether. giving 40,6 g of 4-methoxy-3-pyrrnlin-2-one, m.p. 132°C.

B. Similarly, replacing trimethyl orthoformate with triethyl orthoformate, 4-ethoxy-3-pyrrolin-Z-one was prepared, m.p. 148°C.

PREPARATION 3 preparation of &4-octyloxv-3-pvrrolin-=2-one_and Related

Compounds_of Formula (3)

A. A mixture of 4-methoxy-3-pyrrolin-2-one (3g), l-octanol (7.4 ml) and methanesulfonic acid (0.2 g) were heated at 100°C for 2 hours under reduced pressure (40 mbars). The product was chromatographed on silica gel, eluting with 27 methanol in methylene chloride, to give #-octyloxy-3-pyrrolin-2-one.

B. Similarly. replacing l-octanol with the appropriate alcohol of the formula R,OH. the following compounds of

Formula (3) were prepared: h-benzyloxy-3-pyrrolin-2-one; and 4-(3-bromopropoxy) -3-pvrrolin-2.-one.

Re) 143 - 134 -

Alternative Procedure

C. A mixture of 4-methoxy-l-pytrrolin-2-one (3g). 1-propanol (3.5 ml) and methanesul fonic acid (0.2 g) was refluxed for 2 hours in the presence of 3A molecular gieves. Solvent was removed from the mixture, and the residue chromatographed on silica gel, eluting with 2% methanol). in methylene chloride, to give 4-n-propoxyv-3-pyrrolin-2-one.

D. Similarly, replacing l-propanol with the appropriate alcohol of the formula R,OH. the following compounds of formula (3) were prepared: 4--ethoxy-3-pyrrolin-2--one; 4-n-butoxy-3-pyrrolin-2--one; 4-igso-butoxy-3-pyrrolin-2-one; and 4-allyloxy-3-pyrrolin-2-one.

E. Similarly, replacing l-octanol with the appropriate alcohol or phenol of the formula R,OH, the following compounds of formula (3) are prepared: : 4-iso-propoxy-3-pyrrolin-2-one; 4-t-butoxy-3-pyrrolin-Z-one; 4-n-pentyloxy-3-pyrrolin-2-one; f-n-hexyloxy-3-pyrrolin-2-one; 4—(5-methylhexyloxy)-3-pyrrolin-2-one; 4-dodecyloxy-3-pyrrolin-2-one; 4-(but-3-en-1l-yloxy)-3-pvrrolin-2-one; 4-phenoxy-3-pyrrolin-2-one; 4-(2-methylphenoxy)-3-pyrrolin-2-one; and 4-(1l-phenylethoxy)-3-pytrolin-2-one.

. | | R6q\9 - =~ 3%

PREPARATION 4

Resolution of trans-4-amino-6-cyano-3,4-dihydro- 3-hydroxy-2.,2-dimethyl-2Hi-1-benzopyran and Related

Compounds._of Formula. (4)

A. A mixture of racemic 6-cyano-3-4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-amino-2H-1l-benzopyran (14 g) and dibenzoyl-L-tartaric acid (24 g) was heated at 70°C in ethanol (50 ml) with stirring for 30 minutes, then stood for 3 hours at room temperature without stirring.

The precipitate was filtered off and dried to give

LS 15.88 g of salt. This crude salt was triturated in hot ethanol (100 ml) to give 12.67 g of the dibenzoyl-L-tartaric acid salt of f-cyano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-amino-2H-1l-benzopyran, : mp 230°C, [o)2%= —4.06 (c = 0.49, DME).

The salt (7.5 g) was treated with a mixture of water (100 wml) and 10N sodium hydroxide (5 ml), and the mixture extracted with diethyl ether (200 ml), giving 2.7 g of the (+) isomer form of 6-cyano-3,4-dihydro-2,2-dimethyl- trans-3-hydroxy-4-amino-2H-1-benzopyran as an amorphous solid, [«]23= +71.97 (c = 1.0 Ethanol).

The mother liquor obtained during the first precipitation of the crude salt was treated with a mixture of water (300 ml) and 10N sodium hydroxide (15 ml), and extracted with diethyl ether (2 X 300 ml). giving 6-cvano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 39 4-amino-2H-l-benzopyran (7.83g) enriched in the (-) isomer form. This product was stirred at 70°C with dibenzoyl-D-tartaric acid (12g) in ethanol (50 ml) for 30 minutes Fhen stood for 21 hours at room temperature without stirring. The precipitate thus formed was

: QQ 6 filtered and dried giving l4.28g of the dibenzoyl-D-tartaric acid salt of 6-cyano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-amino-2H-1l-benzopyran, mp 230°C, [a)}’= +3.86 (c = 0.47. DHE). 3 After treating the salt (7.5g) with sodium hydroxide as described above, 2.7 g of the (-) isomer form of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4-aminn- 2H-l-benzopyran was obtained as an amorphous solid, 25 [a] = -72.32 (¢ = 1.13 Ethanol).

D

B. Similarly, replacing 6-cvano-3-4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-amino-2H-1-benzopyran with the appropriate compound of formula (4), the (+) and (-) optical isomers of the following compounds of formula (4) are separated: 6-cyano-3,4-dihydro-2-methyl-trans-3-hydroxy-4- amino-2H-1l-benzopyran; 6-cvano-3,4-dihydro-2-ethyl-trans-3-hydroxy-4- amino-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-n-butyl-trans-3-hydroxy-4- amino-2H-1l-benzopyran; ’ 6-cyano-3,4-dihydro-2-methyl-2-ethyl-trans-3-hydroxy- 4—amino~2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- amino-ZH-~1-benzopyran; 6-cvano-3,4-dihydro-2.2-di-n-butyl-trans-3-hydroxy-4- amino-2H-1-benzopyran; 6-nitro-3.4-dihydro-2-methvl-trans-3-hydroxy-4- amino-2H-1l-benzopyran; p-nitro-3.4-dihydro-2-ethyl-trans-3-hydroxy-4- amino-2H-1-benzopyran;

’ of vq | 4 37 6-nitro-3,4-dihydro-2 n-bntyl-trans-3-hydroxy-4- amino-2H-l-benzopyran; 6-nitro-3,4-dihydro-2-methyl-2-ethyl-trans-3-hydroxy- 4-—amino-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- amino-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- amino-2H-1-benzopyran; and : 6-nitro-3,4-dihydro-2.2-di-n-butyl-trans-3-hydroxy-4- amino-2H-1-benzopyran.

PREPARATION 5

Preparation of 6-cyano-3,4-dihydro-2,2-dimethyl- trans—3-hydroxy-4-(2-methoxy-3-carbonylmethoxy-2-E- propen-l-yl)amino-2H-l-henzopvran and Related

Compounds of Formula (6)

A. A mixture of 6-cyano-3,4-dihydro-2,2-dimethyl- trans-3-hydroxy-4-amino-2H-l-benzopyran 4.7 gy, 4-chloro-3-methoxy-2-E-butencic acid, methyl ester (3.55 g), potassium carbonate (5.95 g) and sodium iodide (3.2 g) was refluxed for 3 hours in isopropanol. After cooling the mixture was filtered and solvent removed from the filtrate under reduced pressure. to give 1.1 g of 6-cyano-3.4~dihydro-2,2-dimetbyvl-trans-3-hydroxy-4- (2-methoxv-3-carbonylmethoxy-2-FE-propen-l-ylj)amino-2H-1- benzopyran. a compound of formula (6). The compound was used in the next reaction (Example 3) with no further purification.

B. Similarly, replacing s-chloro-3-methoxy-2-E-butenoic acid, methyl ester with t-chloro-3-ethoxy-2-E-butenoic acid, ethyl ester, the following racemic compound of formula (6) was prepared:

= Dug . ~38- 6—-cvano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran.

C. Similarly, replacing 6-cyano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-&4-amino-2H-1-benzopyran with its (-) or (+) optically active isomer and replacing 4—chloro-3-methoxy-2-E-butenoic acid, methyl ester with oT 4-chloro-3-ethoxy-2-E-butenoic acid, ethyl ester, the following optically active compounds of formula (6) were prepared, respectively: (-)-6-cvano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethoxy-2-F-propen-l-yl)amino-2H-1- benzopyran; and (+)-6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-(2-ethoxy—3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran.

D. Similarly, optionally replacing 6-cyano-3, 4— dihydro-2,2-dimethyl-trans-3-hydroxy-4~amino-2H-1- benzopyran with the appropriate optically active or racemic compound of formula (4), and optionally replacing 4-chloro-3-methoxy-2-E-butenoic acid, methyl ester with the appropriate compound of formula (5), the following compounds cf formula (6) are prepared as the (-) or (+) optical isomer or as a racemic mixture: 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (2-methoxy-3-carbonylmethoxy-2-F-propen-l-yl)amino-2H-1- benzopyran; : 6—cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4 (2-benzyloxy-3-carbonylethoxy-2-F-propen-l-ylyamino-2H-1- benzopyran: 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4-- (2-isobutoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran;

Qeqy : LQ 6-cvano-3.4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-octyloxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran: 6-cvano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-n-propoxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-i-propoxv-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran;

6-cvano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-n-butoxy-3—carbonylethoxv-2-F-propen-l-vi)amino-2H-1.- benzopyran,;

6-cvano-3.4-dihydro-2.2-dimethvl-trans-3-hydroxy-4- (2-t—butoxy-3-carbonylethoxy-2-F-propen-l-yl)amino-2H-1-- benzopyran; 6—cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-n-hexyloxy-3-carbonylethoxv-7-F-propen-l-yl)amino-21-1- henzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4-

(2-dodecyloxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H. 1 -

benzopyran; 6-cyano-3.4-dihydro-2-methyl-trans-3-hydroxy-4- ! (2-ethoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran;

6-cyano-3,4-dihydro-2~ethyl-trans-3-hydroxy-4- (2-ethoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran:

6—cyano-3.4-dihydro-7-n-butvi-trans-3-hydroxy-4- (2-ethoxv-3-carhbonylethoxy-2-E-propen-i-yl)amino-2H-1- penzopyran; p-cvano-3,4-dihydro-? -methvl-2-ethyl-trans-3-hydroxy h-(2-ethoxy-3-carbonylethoxv-2-F-propen-1-vijamino-2H-1- benzopyran:

-A40 - 6-cyano-3.4-dihydro-2.2-diethyl-trans-3-hydroxy- 4—(2-ethoxv-3-carbonylethoxy-Z-FE-propen-l-yl)amino-2H-1- benzopyran; 6-cyano-3.4-dihydro-2,2-diethyl-trans-3-hydroxy- 4—(2-methoxy-3-carbonylmethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran; 6-cyano-3,4-dihydro~2,2-diethyl-trans-3-hydroxy- 4-(2-n-hexyloxv-3-carbonylethoxy-2-E-propen-1-yl)amino-2H- l-benzopyran:

6-cyano-3.4-dihydro-2,2-di-n-butyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethoxy-2-E-propen-1l-yl)amino-2H- l-benzopyran;

6-cyano-3.4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-(2-allyloxy-3-carbonylethexy-2-E-propen-1-yl)amino-2H-

1-benzopyran;

6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-[2-(but-3-en-l-yl)oxy-3-carbonylethoxy-2-E-propen-1-v1}- amino-2B-1l-benzopyran;

6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-

4-(phenoxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- henzopyran;

6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4— (1-phenylethoxy)-3-carbonylethoxy-2-E~propen-1-y1]- amino-2H-l-benzopyran;

6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-(2-ethoxv-3-carbonylethoxv-2-F-propen-1-vl)amino-2H-1- benzopyran:

6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-methoxy-3-carbonylethoxy-i-E-propen-1l-yl)amino-2H-1 - henzopyran: 6-nitro-3.4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-benzyloxy-3-carbonylethoxy-2-E-propen-l-ylyamino-2H-1- benzopyran:

Aa] 6-nitro-3,4—-dihydro-2.72-dimethyl-trans-3-hydroxy-4- (2-isobutoxy-3-carbonylethoxy-2-E~propen-l-yl)amino-2H-1- : benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-octyloxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran, 6-nitro-3,4-dihydro-2.2 -dimethyl-trans-3-hydroxy-4- (2-n-propoxy-3-carbonylethoxy-2-FE-propen-l-yl)amino-2H-1- benzopyran:

6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-i-propoxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran:

6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-n-butoxy-3-carbonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran; and 6-_nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (2-t-butoxy-3-carhonylethoxy-2-E-propen-l-yl)amino-2H-1- benzopyran. 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4-

(2-n-hexyloxy-3-carbonylethoxy-7-E-propen-l-yljamino-2H-1~ benzopyran; 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (2-dodecyloxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran,

§_nitro-3,4-dihydro-2-methyl-trans-3-hydroxy-4- (2-ethoxy-3-carbonylethoxy-2-F-propen-l-yl)amino-2H-1- benzopyran,

6-nitro=3,4-dihydro-2-athvi.trans-3-hydroxy-4- (2-ethoxy-3-carbonylethoxv-2-F-propen-l-yl)amino-2H-1- penzopyran; 6-nikro=3,4-dihydro-2-n-bntvl-trans-3-hydroxy-4- (7-ethoxy-3—carbonylethosy-2-F.propen-l-ylyamino-2H-1- benzopyran;

AD

6-nitro-3,4-dihydro-2-methvl-2-ethyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran; 6-nitro-3,4-dihydro-2.2-diethyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopyran; 6-nitro-3,4-dihydro-2,2-diethyl-trans-3-hydroxy- 4-(2-methoxy-3-carbonylmethoxy-2-E-propen-1-yl)amino-2H-1- bhenzopyran: , 6-nitro-3,4-dihydro-2,2-diethyl-trans-3-hydroxy- 4—(2-n-hexyloxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H- l-benzopyran, : 6-nitro-3,4-dihydro-2,2-di-n-butyl-trans-3-hydroxy- 4-(2-ethoxy-3-carbonylethexy-2-F-propen-1l-yl)amino-2H- 1-benzopyran; 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4—(2-allyloxy-3-carbonylethoxy-2-E-propen-1l-yljamino-2H- l1-benzopyran; 6-nitro-3,4-dihydro~2.2-dimethyl-trans-3-hydroxy- 4-[2~(but-3-en-l-yl)oxy-3-carhonylethoxy-2-E-propen-1-yl]}- amino-2H-1-benzopyran; 6_nitro-3,4-dihydro-2.2-diméthyl-trans-3-hydroxy- 4-(2-phenoxy-3-carbonylethoxy-2-E-propen-1-yl)amino-2H-1- benzopytran: and 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-[ (1-phenylethoxy)-3-carhonylethoxy-2-E-propen-1-y1J- amino-2H-1l-benzopyran.

LO.

EXAUPLE

Preparation of 6-cyano-3.4-dihvdro-2,2-dimethyl-trans-3- hvdroxy-4-(4-methoxy-2-0x0-3-pyrrolin-l-yl)- 2H-1-benzopvran and Related Compounds of Formula (L)

A. A solution of 6-cyano-23,~-dihydro-2,2-dimethyl- 3,4-epoxy-2H-1l-benzopyran (15 g) and 4-methoxy-3- pyrrolin-2-cne (8.5 g) in dimethyvlsulfoxide (40 ml) was stirred and sodium hydride (80% dispersion in oil, 2.2 g) was added. The mixture was stirred at rcom temperature for 5 hours. Water (50 ml) was slowly added, and the resulting solution extracted with ethyl acetate (2x50 ml). After drying the organic layer with sodium sulfate the solvent was removed undet reduced pressure and the residual oil chromatographed on silica gel (4% methanol in methylene chloride). The product obtained was dissolved in diethylether and precipitated with pentane to afford tg of 6-cyano-3.4-dihvdre-2,2-dimethyl- trans-3-hydroxy-4-(4-methoxy-2-oxc-3-pyrrolin-1-yl)-2H- l-benzopyran, m.p. 256°C.

B. Similarly, replacing “-methoxy-3-pyrrolin-2Z-one with the appropriate compound of formula (3), the following compounds of formula (I) were prepared: 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-ethoxy-i-oxo-3-pyrrolin-1l-v1)-2H-l-benzopyran, m.p. 225°C: 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxy-2-0x0-3-pyrrolin-l-yl)-2H-1-benzopyran, m.p. 248°C; 6-cyano-2,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4—iso-butoxy-2-0xo-3-pyrrolin-1-vl)-2H-1-benzopyran, m.p. 235°C; and

Ju] 1 hf 6-cyano-3,A-dihydro-2.2 -dimethyl-trans-3-hydroxy-4- (4-0ctyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran, m.p. 158°C.

C. Similarly, optionally replacing 6-cyano-3,4-dihydro- 2,2-dimethyl-3,4-epoxy-2H-]l-benzopyran with the appropriate compound of formula (2), and optionally replacing &4-methoxy-3-pyrrclin-2-one with the appropriate compound cof formula (3), the following compounds of formula (I) are prepared: 6—cyano-3,4—-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-propoxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cvano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-butoxy-2-oxo-3-pyrrolin-1l-y1)-2H-1-benzopyran; 6-cyano-3,4—dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-t-butoxv-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6—cvano-3,4—dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-cyano-3,4—-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran: 6—cyano-3,4-dihydro-2-methyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-v1)-2H-1l-benzopyran; 6-cyano-3,4~dihydro-2-ethyl-trans-3-hvdroxy-4- (4-ethoxy-2-0%x0o-3-pyrrolin-1-v1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-n-butyl-trans-2-hydroxy-4- (4—ethoxy-2-0ox0-3-pyrrolin-t-v1)-2H-1-benzopyran; 6—cyano-3.4-dihydro-2-methyl-2-ethyl-trans-3~hydroxy- 4-(4-ethoxy-2-0x0o-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cyano-3.4—-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-methoxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; p-cyann-3,4-dibydro-Z.2-diethvl-trans-3-hydroxy-4- (4—ethoxy-z-oxo-3-pyrrolin-l-vl)-20-Ll-benzopyran;

20h ah 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-i-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-di-n-butyl-trans-3-hydroxy-4- (4—ethoxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-vinyloxv-2-oxo-3-pyrrolin-l-yl)-2H-l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-oxo-3~pyrrolin-1-v1)-2H-]1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- : "10 [4-(but-3-en-l-yl)oxy-2-oxo-3-pyrrolin-1-v1]-2H-1- , benzopyran; |, 6-cyano-3,4-dihydro-2.2-dimethyl-trans—-3-hydroxy-4- (4-phenoxy-2-oxo-3-pyrrolin-l-yl)-2H-l-benzopyran; : 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- [4-(l-phenylethoxy)-2-oxo-3-pyrrolin-l-y1]-2H-1- benzopyran: 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxv-2-oxo-3-pyrrolin-l-y1)-2H-l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- : 20 (4-methoxy-2-oxo-3-pyrrolin-1-v1)-2R-1l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-y1)-~2i-1-benzopyran, mp 240°C; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-propoxv-2-oxo-3-pyrrolin-1-y1)-2H-1l-benzopyran; f-nitro-3.4-dihydro-2.2-dimethyvl.-trans-3-hydroxy-4- (4-iso~propoxy-2-oxo-3-pyrrolin-1-v1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.72-dimethvl-trans-3-hydroxy-4- (4-n-butoxy-2-0x0o-3-pyrrolin-1-v1)-21l-1-benzopyran; - 30 6-nitro-3.4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-t-butoxy-2-oxo-3-pyrrolin-1-vI)-2H-l-benzopyran; f-nitro-3,4-dihydro-72.2 dimethyl -trans-3-hyvdroxy-4- (f-n—-hexyloxy-2-oxo-3-pyrrolin-i-v1)-7H-1-benzopyran;

BAD ORIGINAL

. HG : 6-nitro-1,h-dilydro-2,2-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-oxo-3-pyrrolin-1l-yl)-2H-1-benzopyran; 6-nitro-3,4-dibydro-2-methyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2-ethyl-trans-3-hydroxy-4- (4—ethoxy-2-0%x0-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2-n-butyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4—-dihydro-2-methyvl-2-ethyl-trans-3-hydroxy- 4~(4-ethoxy-2-oxo-3-pyrrolin-1l-y1)-2H-1-benzopyran; 6-nitro-3,4—dihydro-2,2-diethyl-trans-3-hydroxy-4- (4-methoxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-diethvl-trans-3-hydroxy-4- (4-ethoxy-2-0x0-3~pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-diethyl-trans-3-hydroxy-4- } (4-n-hexyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-di-n-butyl-trans-3-hydroxy-4- (4-ethoxy-2-ox0-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-nitro-3,4—dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-vinyloxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6_nitro-3,4—dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; and 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- [4~(but-3—en-1-yl)oxy-2-oxo-3-pyrrolin-1-y1]-2H-1- benzopyran.

EXAMPLE 2

Preparation of 6-cyano=3,4-dihydro=2.2-dimethyl-trans- 3- hydroxy-4-(4-benzyloxy-2-0xo=3-pyrrol inz1-yl)= 2H-1-benzopvran and Related Compounds of Formula (I)

A. A mixture of 6-cyano-3,4-dihydro-2,2-dimethyl- trans-3-hydroxy—4-(4-methoxy-2-oxo-3-pyrrolin-l-yl)-zt-1- benzopyran (0.7 g), benzyl alcohol (0.92 ml) and oo J ! "BAD ORIGINAL qs ya. methanesulfonic acid (0.0L g) was heated at 80°C for 3 hours under reduced pressure (40 mbars). After cooling the residue was stirred with diethylether, and the insoluble product filtered off and washed twice with diethylether, to give 6-cvano-3,4-dihydro-2,2-dimethyl- trans-3-hydroxy-4-(4-benzyloxy-2-oxo-3-pyrrolin-1-yl)-2H- l-benzopyran., m.p. 248°C.

B. Alternatively, a mixture of 6-cyano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-(4-methoxy-2-oxo-3-pyrrolin-1- yl1)-2H-l-benzopyran (0.7 g). benzyl alcohol (0.92 ml) and methanesulfonic acid (0.01 g) was refluxed for 2 hours in ' the presence of 3A molecular sieves. After cooling the molecular sieves were filtered off, the filtrate stirred with diethvlether, the inscluble product filtered off and washed twic=z with diethylether, to give 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-benzyloxv-2-0oxo-3-pyrrolin-1-v1l)-2H-1l-benzopyran, m.p. 248°C.

C. Similarly, replacing benzyl alcohol with the appropriate alcohol of formula R,OH and following the procedures of 2A or 2B above, the following compounds of formula (I) were prepared: : 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-propoxv-2-oxo-3-pyrrolin-1-yl1)-2H-1l-benzopyran, m.p. 210°C: 6-cyano-3,4-dihydro-2.2-dimethvi-trans-3-~hydroxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-1l-vl)-2H-l-benzopyran,. m.p. 246°C: 6-cyano-3,4-dihydro-2.2-dimethyi-trans-3-hydroxy-4- (4-allyloxy-Z-oxo-3-pyrrolin-1-v1)-2H-l-benzopyran, m.p. 208°C; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-butoxy-2-oxo-3-pyrrolin-l-vi)-20-l-benzopyran, m.p. 220°C: and

A ro ZevAL : BAD ORIGINAL

) he 6-cyvano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- [4—(3-N.N-diethylaminopropoxy)-2-oxo-3-pyrrolin-1-y1}-2H- l-benzopyran hydrochloride. m.p. 210°C.

D. Similarly, optionally replacing f-cyano-3,4~dihydro- 2,2-dimethyl-trans-3-hydroxy-4-(4-methoxy-2-oxo~3- pyrrolin-1-yl)-2H-1-benzopvran with the appropriate optically active or racemic compound of formula (I), and optionally replacing benzyl alcohol with the appropriate compound of formula R,OR, the following compounds of formula (I) zre prepared as the (=) or (+) optical isomer or as a racemic mixture: f-cyano-3.A-dibydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-A- (4-n-propoxy-2-oxo-3-pyrrolin-1-yl)-2H-1l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-i-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-butoxy-2-0xo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- {4—(3-N,N-diethylaminopropoxy)-2-0x0-3-pyrrolin-1-y1]-2H- 1-benzopyran;: 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- 7 (4-benzyloxy-2-0x0-3-pyrrolin-l-vi)-2H-1-benzopyran; 6—cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydvoxy-4- (4—iso-butoxy-2-oxo-3-pyreolin-l-yi)-2H-l-benzopyran; 6-cvano-3,4-dihydro-2.72-dimethyl-trans-3-hydroxy-4- (4-octyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran: 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydvoxy-4- (4-n—propoxy-2-oxo-3-pyrrolin-l-vi)-ZH-1-benzopyran; 6—cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-jg0-propoxy-2-oxo-3-pyrralin-il-vl)-2H-1-benzopyran;

BAD ORIGINAL

5Gq9

AY

6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-butoxv-2-oxo-3-pyrrolin-1-y1)-2H-1l-benzopyran: 6-cyano-3,4-dibydro~2.2-dimethyl-trans-3-hydroxy-4- (4—t-butoxy-2-oxo-3-pyrrolin-1-yL)-2H-1-benzopyran; 6-cvano-3.4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-1l-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-0xo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo~3-pyrrolin-l-vl)-2H-1-benzopyran; 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-vinyloxy-2-oxo-3-pyrrolin-l-v1)-ZH-l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- [4-(but-3-en-1-yl)oxy-2-oxo-3-pyrrolin-1-y1]-28-1- benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- : (4-phenoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran;. } 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- [4-(l-phenylethoxy)-2-oxo-3-pvrrolin-1-y1]-2H-1- benzopyran; 6-cvano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- [4-(3-methoxypropoxy)-2-oxo-3--pysrolin-1-y1]-2H8-1- benzopyran: 6-nitro-3.4-dihydro-z.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hvdroxy-4- (4-n-propoxy-2-0xo-3-pyrrolin-l-v1)-2H-1l-benzopyran: 6-nitro-3.,4-dihydro-2.2-dimethyl-trans-3-bvdroxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-l-vl)-2H-1-benzopyran; : 6-nitro-3,4-dihydro-2.2-dimethvl-trans-3-hvdroxy-4- (4-n-butoxy-2-0xo-3-pyrrolin-l-y1)-2H-1-benzopyran: 6-nitrn-3, 4-dihydro-2.2~dimethyl-trans-3-hydroxy-4- (4—t-butoxy-2-0x0-3-pyrrolin-l-v1)-2H-1-benzopyran;

SAD ORIGINAL

: 26g -50 ~ 6-nitro-3.4-dihydro-2.72-dimethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrnlin-t-yl)-2H-1l-benzopyran; 6-nitro-3,4~dihydro-2.7-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-diethvl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-nitro-3,4-dibydro-2,2-dimethyl-trans-3-hydroxy-/- (4-vinyloxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-ox0-3-pyrrolin--1-v1)-2H-1-benzopyran: and 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- [4-(but—-3-en-1-y1)oxy-2-oxc-3-pyrrolin-1-y1]-2H--1- benzopyran.

EXAMPLE 3 .

Preparation of (-)-=6-cyano-3,4-dihydro=2,2-dimethyl- trans-—3-hvdroxy-4-(4-ethoxy-2-oxo=3=pyrrolin-l-yl)~ 2H-1-benzopyran and Related Compounds of Formula (I)

A. A mixture of (+)-6-cyano-3,4-dihydro-2,2-dimethyl- trans—3-hydroxy-4-(2-ethoxy-3-carbonylethoxy-2-E-propen- 1-yl)amino-2H-l-benzopyran (2.05 g) and 40 ml of xylene was refluxed for 15 hours. Xylene was removed under reduced pressure and the residue purified by flash chromatographv on silica gel. eluting with 3% " methanol/methylene chloride. The product was triturated in diethyl ether, to give 0.46 ¢ of the pure (~)-6-cvano-2, fi-dihydro-7.2 dimethyl-trans-3 -hydroxy-4- (4-ethoxy-Z-oxo-3-pyrrolin-l-v1)-ZH-1-benzopyran, mp 210°C. [2]%°= -20.71 (c = 0.25. ethanol).

B. Similarly. replacing (2)-f-cvano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-4-(2-ethoxy-3-carbonylethoxy-2-F-

Co AD ORIGINAL

; 269i 51. propen-1l-yl)amino-2H-l-benzopyran with the (-)-isomer, the following compound of formula (I) was prepared: (+)-6-cyano-3,4-dihydro-2, 2-dimethyl-trans-3-hydroxy- 4—(h4-ethoxy-2-oxo-3-pyrrolin-1-yl)--2H-1-benzopyran, mp 210°C, [2]2°= 420.29 (c¢ = 0.27. ethanol).

C. Similarly, replacing (+)-%-cyano-3,4-dihydro-2,2- dimethyl-trans-3-hydroxy-4—(2-ethoxy-3-carbonylethoxy-2-F- propen-l-vl)amino-2H-1-benzopyran with the appropriate racemic compound of formula (5) the following racemic compounds of formula (I) were prepared: : 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-methoxy-Z-oxo-3-pyrrolin-Ll-yl1)-2H-1-benzopyran, m.p.

A 256°C; and 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-ethoxy-2-0oxo-3-pyrrolin-1l-v1)-2H~1-benzopyran, m.p. 225°C.

D. Similarly, replacing (+)-5-cvano-3.4-dihydro-2,7- dimethyl-trans-3-hydroxy-4-(Z-ethoxy-3-carbonylethoxy-2-F- propen~l-yl)amino-2H-1l-benzopyran with the appropriate optically active or racemic compound of formula (6) the following compounds of formula (1) are prepared as the (-) or (+) optical isomer or as ‘a racemic mixture: (-=)-6~cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy- 4—(4-methoxv-2-o0xo-3-pyrrolin-1-v1)-2H-1-benzopyran, mp 189°C, [432° = -31.97° (c=1.0. ethanol): 6-cy2no-3.4-dibydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzvloxy-2-oxo-3-pyrrolin-l-v1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-iso-butoxy-2-o0xo-3-pyrrolin-1-vl)-2H-1-benzopyran; (+)=6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy- 4-(4-methoxyv—-2-0xo-3-pyrrolin-l-v1)-2H-1-benzopyran, mp 190°C. (212° = 434.187 (c=1.0. ethanol):

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RD. [6-cyano-3.4-dihydre-2.72-dimethyl-trans-3-hydroxy-4-] (4-octyloxy-2-0xo-3-pyrrolin-l-yl)-2H-1-benzopyran: 6-cyano-3,4-dihydro-2.7-dimethyl-trans-3-hydroxy-4- (4-n-propoxy-2-0xo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-iso-propoxy-2-0xo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-butoxy-2-oxo-3-pyrrolin-1-v1)-2H-l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-t-butoxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6-cyano-3,4~dihydro-2.2-dimethyl-trans-3-hydroxy-4- : (4-n-hexyloxv-2-0x0-3-pyrrolin-1l-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-0xo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cvano-3,4-dihydro-2-methyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-vi)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-ethyl-trans-3-hydroxy-4- (4—ethoxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6—cyano-3,4~dihydro-2-n-butyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-Ll-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-methyl-2-ethyl-trans-3-hydroxy- 4-(4-ethoxy-2-oxo-3-pyrrolin-1l-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-diethyl-trans-3-hydroxy-4- (4-methoxy-2-oxo-3-pyrrolin. t-y1)-ZH-1-benzopyran; 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4—ethoxy-2-0xo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-n—-hexyloxy~2-oxo-3-pyrrolin-L-v1)-2H-1-benzopyran: 6-cyano-3,4-dihydro-2.2-di-u-butyl-trans-3-hydroxy-4- (4—ethoxy-2-0x0-3-pyrroliv-1-v1)-ZH-Ll-benzopyran; (+)-6-cyano-3,4-dihydro~2.2-dimethyl-trans-3-hydroxy- 4-(4-allyloxy-2-oxo-3-pyrrelin-1l-v1)-2H-1-benzopyran. mp 176°C, [«]3% = +20.767 (¢ = 1.0. ethanol):

Ce BAD ORIGINAL

Qu } La. 6-cvano-3,4~-dihydro-2.Z2-dimethyl-trans-3-hydroxy-4- [{4-(but--3-en-1l-yl)oxy-2-oxo-3-vyvrrolin-1-v1]-2H-1- benzopyran, (-)-6-cyano-3,4-dihydro-2, 2-dimethyl-trans-3-hydroxy- 4-(4-allyloxy-2-oxy-3-pyrrolin-l-yl)-2H-1-benzopyran, mp 180°C, [2)2% = -20.85" (c = 1.0, ethanol); 6-cyano-3,4-dihydro-2,2-dim=thyl-trans-3-hyvdroxy-4- (4-phenoxy-2-oxo0-3-pyrrolin-l-v1}-2H~1-benzopyran; 6—cyano-3,4-dihydro-2.2-4imethyl-trans-3-hydroxy-4-- f4-(l-phenvlethoxy)-2-oxo-2-pyrrolin-Ll-v1]-2H~-1-~ bénzopyran; 6-nitro-3,4-dihydro-2,2-dimethvl-trans-3-hydroxy-4- (4-benzyloxy-2-oxo-3-pyrrelin-l-y1l)-2H-1-benzopyran; 6p-nitro-3,4-dihydro-2.2-dimethvl-trans-3-hyvdroxy-4- (4-methoxy-2-oxo-3-pyrrolin-1-v1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl--trans-3-hydroxy-4- (4-ethoxy~2-ox0-3-pyrrolin-l-yl)-ZH-1-benzopyran; 6-nitro-3,4-dihydro-72.2-dimathvi-trans-3-hydroxy-4 - (4-n-propoxy-2-oxo-3-pyrrolin-1-vl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-1-v1)-2H-1l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimgthyl-trans-3-hydroxy-4- (4-n-butoxy-2-oxo-3-pyrrolio-L-vi)-2H-1l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-t-butoxv-2-0xo-3-pyrrolin-l-vi)-2H-l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- . (4-n-hexyloxy-2-oxo-3-pyrrclin-l-vl)-2H-1-benzopyran; f-nitro-3,4-dihydro-2.2-dim=hyvi-trans-3-hydroxy-4- (4-dodecyloxy-2-o0oxo-3-pyrrolin-l-yv1)-2H-l-benzopyran; 6-nitro-3,4-dibydro-Z2-methyvi-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-v1l)-2H-1l-benzopyran; 6-nitro-3,4-dibydro-2-ethvi-trans-3-hydroxy--4- (4-ethoxy-2-o0x0-3-pyrrolin-l-vi)-2H-1-benzopyramn:

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20q1% ’ ZA. f-nitro-3,6-dihydro-7-n-hutvl-trans-3-hydroxy-4- (4-ethoxy-2-0x0-3-pyrrolin-J-vl)-2H-1-benzopyran; 6-nitro-3,4—~dihydro-2-methyl-2-ethyl-trans-3-hydroxy- 4—(4—ethoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-diethyvl-trans-3-hydroxy-4- - (4-methoxy-2-0xo-3-pyrrolin-1-v1)-2H-1-benzopyran; ’ 6-nitro-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-diethyl-trans-3-hydroxy-4- (4-n-ethoxy-2-oxo-3~pyrrolin-1-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-di-n-butyl-trans-3-hydroxy-4- (4-ethoxy-2-0xo-3-pyrrolin-1l-y1l)-2H-1-benzopyran, 6-nitro-3,4-dibydro-2.2~dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-oxo-3-pyrrolin-l-y1)-2H~1l-benzopyran; and 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- [4-(but-3—en-l-yl)oxy-2-oxne-3-pyrrolin-1-y1]-2H-1- benzopvran.

EXAMPLE 4

Preparation of 6-nitro-3.4-dihydro=2.2-dimethyl- trans-3-hydroxv-4=(4-ethoxy=2-0%0=3= pvrrolin-1-y1)-2H-l-benzopyran and Related

Compounds _of Formula (1)

A. A mixture of 6-nitro-3.4-dibydro-2,2-dimethyl- trans-3-hydroxy-4-amjno-21-1-benzopyran (2.0g, 8.4 mmol), ethyl a-hromo-3-ethoxy-2-E-hutenoate (2.5g, 10.5 mmol). in toluene (17mL) containing triethylamine (1.8 mL) was heated at 50°C with agitaticn for 3 hours. The temperature was increased tn reflux and the mixture stirred for 18 hours. After cocling to room temperature, water and ethyl acetate were added and the organic phase geparated, dried and evaporated. The residue was

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209) 9 nh chromatographed on silica g=l (57 MeOH/95% CH,CLl,) and the product thus obtainad was triturated with ether and dried to give 1.0g (347 vield) of 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4—ethoxy-2-0xo-3-pyrrolin-1-y1)-2H-1-benzofuran, m.p. 240°C.

B. Similarly, replacing ethyl A-bromo-3-ethoxy-2-

E-butenoate, with ethyl 4_hromo-3-methoxy-2-E-butenoate, the following racemic compound of Formula (I) was prepared: 6-nitro-3.4-dihydro-2.2-dimethyl-trans-3-hydroxy- h-(fh-methoxy-2-0x0o-Y-pyrrolin-l-v1)-2H-1- benzopyran.

C. Similarly, replacing q_nitro-2.a-dihydro-2,2- dimethyl-trans-3-hydroxy-4-amino-2H-1l-benzopyran with its (=) or (+) optically active isomer and replacing ethyl f-bromo-3—-ethoxy-2-E-butencate with ekhyl 4-bromo-3-methoxy-2-E-butencate. Lhe following optically active compounds of formula (1) were prepared, respectively: (-)-6-nitro-3,4-dihydrc-2,2-dimethyl-trans-3-hydroxy - 4—(4-methoxy-2-oxo-3-pyrrolin-l-yI)-2H-1-henzopyran; and (+)-6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy- 4-(h-methoxy-2-0oxo-3-pyrrolin-l-v13-20-1-benzopyran. 7 25 Dp. similarly, optionally replacing fp-nitro-3,4- dihydro-2,2-dimethyl-trans-3-hydroxy-A4-amino-2H-1- benzopyran with the appropriate optically active or racemic compound of formula (4). and optionally replacing : ethyl 4-bromo-3-methoxy-2-E-hutenoate with the appropriate compound of formula (5). the following compounds of formula (I) are prepared as the (-) or (1) : optical isomer or as A racemic mixhture:

BAD ORIGINAL e915 ~5G- 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxy-2-oxo-3-pyrrolin-l-y1)-2H-l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-iso-butoxy-2-oxo-3-pyrrolin-1-v1)-2H-1-benzopyran; (+)-6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy- 4—(4-methoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran, mp 190°C, [«)2> = +34.18° (c=1.0. ethanol) 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-a- (4-octyloxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-propoxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-is0-propoxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran: 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-butoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4i-t~butoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6_cyano-3,4-dihydro-2,2-dimethyl-trans-3-hydroxy-4- (4-dodecyloxy-2-0x0o-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-methyl-trans-3-hydroxy-4- (4-ethoxy—2-ox0-3-pyrrolin-1-vi)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2--ethyl-trans-3-hydroxy-4- (4—ethoxy-2-0x0-3-pyrrolin-l-yi)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-n-hutyl-trans-3-hvdroxy-4- (4-ethoxy—-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2-methyl-2-ethyl-trans-3-hydroxy- 4-(4-ethoxy-2-0x0-3-pyrrolin-L-vl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.7-diethyl-trans-3-hydroxy—4- (4-methoxy-2-0xn-3-pyrroliv-1l-v1)-2H-t-benzopyran: 6-cvano-3,4-dihydro-2.2-disthyl-trans-3-hydroxy—4- (4-ethoxy-2-0x0-3-pyrrolin.-l-yl)-2H-1-benzopyran;

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Lcq1y -57 6-cvano-3,4-dibydro-2.7 ~diethyl-trans-3-hydroxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-1-vl)-2H-1-benzopyran; 6—cyano-3,4-dilydro-2.2-di-n-butyl-trans-3-hydroxy-4- (4-ethoxy-2-0oxo-3-pyrrolin-1-v1)-ZH-l-benzopyran; (+)-6-cyano-3,s-dihydro-2.2-dimethyl-trans-3-hydroxy- 4-(4-allyloxy-2-oxo-3-pyrrolin-1.-y1)-2H-l-benzopyran; mp 176°C. [a]d’ = $20.76" (c = 1.0. =thanol); 6-cvano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- [4-(but-3-en-l-y1)oxy-2-oxo-3-pvrrolin-l-y1]-2H-1-

Co 10 benzopyran: : (~)-6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy- 4—(h-allyloxy-2-oxy-3-pyrrolin-t-v1)-2H-1l-benzopyran, mp 180°C, [+137 = ~20.85° (c = 1.0. ethanol): 6-cyano-3,4-dihydro-2. 2-dimzthyl-trans-3-hydroxy-f4- © 15 (4-phenoxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-f- [4-(l-phenylethoxy)-2-oxo-3-pyrrolin-l-y1]-2H-1- henzopyran: 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-benzyloxy-2-oxo-3-pyrrolin-l-vl)-2H-l-benzopyran; : 6-nitro-3,4-dihydro-2.2--dimethyl-trans-3-hydroxy-4- -(4-methoxy-2-oxo-3-pyrrolin-1-yl)-2H-1-benzopyran; 6—cvano-3,4~dihydro-2, 2-dimethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-i.-v1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-n-propoxy-2-0x0-3-pyrrolin-l-vi)-2H-l-benzopyran; 6-nitro-3,4-dibydro-2.2-dimethyl-trans-3-hydroxy-i- (4-iso-propoxy-2-oxo-3-pyrrolin-l-v1)-2f. 1-benzopyran: 6-nitro-3,4-dihydro-2. 2-dimelhyl-trans-3-hydroxy--4- (4-n-butoxy-2-0xo-3-pyrrolin-l-v]l)-?H-l-benzopyran; 6-nitro-3,4-dihydro-2 72-dimethvl -trans-3-hydroxy-4- (4-t--butoxy-2-oxo-3-pyrrolin-1-yvI -7H-l-benzopyran: fonikro-3,4-dihydro-2. 7 dimethyl. trans-3. hydroxy -4 (4-n-hexyloxy-2-0ox0-3.-py rrotin lowly PH l-benzopyran; 1 {7 ORIGINAL

26 19

HR. 6-nitro-3,4-dihydro-7.7-dimethyl-trans-3-hydroxy-i- (4—dodecyloxy-2-oxo-3-pyrrolin-1-yl)-ZH-1-benzopyran; 6-_nitro-3,4—dihydro—2-methyl-trans-3-hydroxy-4- (4-ethoxy-2-0xn-3-pyrrolin-1l-yl)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2-ethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-y1)-2H-1-benzopyran; 6-nitro-3,4—dihydro—z-n-hutyl-trans-3-hydroxy-4- (4-ethoxy—2-ox0-3-pyrrolin-l-v1)-2H-1-benzopyran; 6-nitro_3,4—-dihydro—2--methyvl-2-ethyl-trans-3-hydroxy- 4—(b-ethoxy-2-0x0-3-pyrrolin-t-y1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2,2-diethyl-trans-3-hydroxy-4- (4-methoxy-2-0x0-3-pyrrolin-l-yl)-2H-1-benzopyran; 6-nitro-3,4—dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-diethyl-trans-3-hydroxy-4- (4-n-ethoxy-2-0x0-3-pyrrolin-1-yl)-2H-1-benzopyran: 6-nitro-3,4-dibydro-2.72-di-o-butyl-trans-3-hydroxy-4- (4-ethoxy-2-ox0-3-pyrrolin-J-yv1)-20-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- (4-allyloxy-2-oxo-3-pyrrolin-l-yl)-zH-1-benzopyran: and 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-hydroxy-4- [4-(but—3-en-1l-yl)oxy-2-oxo-3-pysrolin-1-y1]-2H-1- benzopyran.

EXAMPLE 5

Preparation of 6-cyano-3,4-dihydro=2.2-d imethyl-trans- 3_acetyloxy-4-(4-ethoxy=-2-cxo-3-pyrrolin=1-y1)-2H- 1-benzopvran and Related Tharmaceutically Acce ptable

Esters of the Compounds of Formula (1)

A. To a suspension of p-cvano-3.4-dihydro-2,2-dimethyl- trans—3-hydroxy—4-(4-ethoxy-2-oxo-3-pyrrolin-l-yl)-2H-1- benzopyran (0.5 g) in 25 ml of methylene chloride at 07°C was added pyridine (0.415 g£) and acetic anhydride - | BAL ORIGINAL

LCT) 59. (0.56 g), and the mixture stirzad at room temperature for days. The reaction mixture was then stirred with a mixture of 50 ml of water and 40 ml of methylene chloride. The organic laver was separated, washed with 5 water, dried over anhydrous sodium sulfate and solvent removed under reduced pressure. The residue was triturated with ether followed by pentane to give 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4-(4- ethoxy-2-oxo-3-pyrrolin-1-v1)-2¥-]-henzopyran, m.p. 156°C.

B. Similarly, replacing 6-cyvave-3, 4-dihydro-7,2- dimethyl-trans-3-hydroxy-A-(t-ethoxy-2-oxo-3-pyrrolin- 1-y1)-2H-1-benzopyran with the appropriate compound of formula (I), the following compounds of formula (I) are prepared: 6-cyano-3,4-dihydro-2.2-dimethyl trans-3-acetyloxy-/- (4-methoxy—2-0xo-3-pyrrolin-l-yi)-28-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-a- (4-benzyloxy-2-0xo-3-pyrrolin-l-y1)-2H-1l-benzopyran; 6-cyano-3,4-dihydro-2.z2-dimethyl--trans-3-acetyloxy-4- (4-iso-butoxy-2-oxo-3-pyrrolin-1l-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-octyloxy-2-oxo-3-pyrrolin-1l-yvL)-2H-l-benzopyran; 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-n-propoxy-2-o0xo-3-pyrrolin-1l-yl)-2H-l-benzopyran; 6-cvano-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4- (4-iso-propoxy-2-oxo-3-pyrrolin-1-v1)-ZH-1-benzopyran; 6-cyano-3,4-dihydro-2.7-dimethyl -traps-3-acetyloxy-4- (4-n-butoxv-2-oxo-3-pyrrolin-l-vi)-/H l-heunzopyran, 6-cyano-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy bo - (4-t-butoxy-2-oxo-3-pyrrolin-i-vi -7H-1-henzopyran; b-cyano-3, h-dihydro-2.7- dimethyl trans-3-acetyloxy 4 (4-n-hexyloxy-2-oxn-3-pyrrolin-l-v1)-2H~1-benzopyran; 6-cvano-3,4-dibydro-2.7 -dimeshvi-trans-3-acetyloxy-4- (h—dodecylnxy-2-0x0 3-pyrrolin-l-vi)-20-l-benzopyran; 6—cvano-3,4-dihydro-2-methvl-trans-2-acetyloxy-4- (4-ethoxv-2-0xo-3-pyrrolin-l-vi:-2H-1-henzopyran;

BAD ORIGINAL

Juq1y _ 60 = 6-cyano-3,4-dihydro-2-2thvl-trans-3-acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1l-v!l)-2H-1-benzopyran; 6-cyano-3, 4—-dihydro-2-n-butyl-trans-3--acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-yl)-2B-1-benzopyran; 6-cyano-3,4-dihydro-2-methyl-2-ethyl-trans-3-acetyloxy- 4-(4-ethoxy-2-oxo-3-pyrrolin-1-vl)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-diethyl-trans-3-acetyloxy-4- (4-methoxy-2-oxo-3-pyrrolin-l-v1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-di=thyl-trans-3-acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-vl)-ZH-1l-benzopyran; 6-cyano-3,4-dihydro-2,2-diethyl-trans-3-acetyloxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-l-y1l)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2.2-di-n-butyl-trans-3-acetyloxy- 4-(4-ethoxy-2-ox0o-3-pyrrolin-1l-y1l)-2H-l-benzopyran; 6—cyano-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4- (4-allyloxy-2-oxo-3-pyrrolin-1-y1)-2H-1-benzopyran; 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4- [4-(but-3-en-1l-yl)oxy-2-0xo-3-pyrrolin-l-yl]-2H-1-benzopyran. 6-cyano-3,4—-dihydro~2.2-dimethyl-trans-3-acetyloxy-4- (4-phenoxy-2-o0xo-3-pyrrolin-1-yl)-2H-1-benzopyran: 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4- [4-(l-phenylethoxy)-2-oxo-3-pyrrélin-1-yl]-2H-1-benzopyran; 6-nitro-3,4-~dihydro-2,2-dimethyl-trans-3-acetyloxy-4- (4-benzyloxy-2-oxo-3-pyrrolin-l-yl)-2H-l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-methoxy-2-oxo-3-pyrrolin-1-y1)-ZH-l-benzopyran;: 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-ethoxy-2-0x0-3-pyrrolin-1-v1)-ZH-l-benzopyran; 6-nitro-3,4-dihydro-2.72-dimethvli-ktrans-3-acetyloxyv-4- (4-n-propoxy-2-oxo-3-pyrinlin i-vi)y-ZH-l-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-is0-propoxy-2-oxo-3-pyvriclin-l-viY-ZH-1-benzopyran; 6-nitro-3.4-dihydro-2.2-dimethvl-trans-3-acetyloxy-4- (4-n-butoxy-2-oxo-3-pyrrolin-Il-v11-2H-l-benzopyran; ’ } BAD Dayna

VIZ

AY. 6-nitro-3.4—dihydro-72. 2-dimethyl-trans-3-acetvloxy-1 (4-t—-butoxy-2-oxo-3-pyrrolin-l-vi)-2H-l--henzopyran; 6-nitro—-3.4-dihydro-2.7-dimethvl-trans-3-acetyloxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-benzopyran; ] 5 6-nitro-3,4-dihydro-2,2-dimethyl-trans-3-acetyloxy-4- (4—-dodecyloxy-2-oxo-3-pyrrolin-l-v1l)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2-methyl-trans-3-acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-1-v1)-2H-1-benzopyran; . 6-nitro-3,4—dihydro-2—-ethvl-trans-3-acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-i-y1)-2M-l-benzopyran; 6-nitro-3.4—dihydro-2-n-butyli-trans-3-acetyloxy-4- : (4-ethoxy-2-oxo-3-pyrrolin-1-v1)-2H-l-benzopyran; 6-nitro-3,4-dihydro-2-methvi-2-ethyl-trans-3- acetyloxy-&-(fh-ethoxy-2-oxo-3-pyrralin-l-y1)-2H-1- benzopyran; 6-nitro-3.4—dihydro-2,2-diethvl-trans-3-acetyloxy-4- (4-methoxy-2-oxo-3-pyrrolin-t-vl)-7H-l-henzopyran; 6-nitro-3,4-dihydro-2.7-diethvl trans-3-acetyloxy-4- (4-ethoxy-2-oxo-3-pyrrolin-l-y1)-2l-1-benzopyran; 6-nitro-3,4-dihydro-2.2-diethyl-trans-3-acetyloxy-4- (4-n-hexyloxy-2-oxo-3-pyrrolin-l-yl)-2H-1-henzopyran; 6-nitro-3,4-dihydro-2.2-di-n-butyl-trans-3-acetyloxy- 4-(b-pthoxy-2-oxo-3-pyrrolin-1-vi)-2H-1-benzopyran; 6-nitro-3,4-dihydro-2.2-dimethyl-trans-3-acetyloxy-4- (4-allyloxy-2-oxo-3-pyrrolin-1-v1)-2H-1-benzopyran; and 6-njtro-3.4-dihydro-2,2-dimethvl-trans-3-acetyloxy -4- [4-(but-3—en-l-yl)oxy-2-0z0-3-pyrrolin-l-yl]-2H-1- benzopyran.

In Examples 6 through 10 the active ingredient is b-cyano-3,4-dihydro-2,2-dimethy! trans -3-hydroxy-4- (4-ethoxy-2-ox0-3-pytrolin-1-v1l)-/H-1-benzopyran. Other compounds of formula (T) may he mnhstituted therein. ened er BY of Gq 9 62

EXAMPLE ©

Composition for Oral Administration

The composition contains: 7% owt. /wt.

Active ingredient 20%

Lactose 80%

The two ingredients are milled. mixed and dispensed into capsules containing 100 mg each: one capsule would approximate a total daily dosage.

EXAMPLE 1 : Composition for Oral Administration

The composition contains: % wt. /wt.

Active ingredient 20.0%

Magnesium stearate 0.9%

Starch 8.6%

Lactose 79.6%

PVP (polyvinylpyrrolidine) 0.9%

The above ingredients with the exception of the magnesium stearate are combined and granulated using water as a granulating liquid. The formulation is then dried, mixed with the magnesium stearate and formed into tablets (containing 20 mg of active compound) with an appropriate tableting machine.

EXAIFLE 8

Parenteral Formulation (IV)

The composition contains: % wt. jut.

Active ingredient 0.02 g

Propylene glycol 20. g

Polyethylene glycol 400 20. g

Folysorbate 80 1. g 0.9% Saline solution gs ad 100 ml

To EE

7 «q 19

NO

The active ingredient is dissolved in propylene glycol, polvethylene glycol 400 and polvsorbate B80. A sufficient quantity of 0.9% saline solution is then added with stirring to provide 100 mb. of the I.V. solution which is filtered through a 0.2 micron membrane filter and packaged under sterile conditions.

EXAMPLE 2

Oral Solution Formulation

The composition contains: To owt. fut.

Active ingredient 0.1 g

Propylene glycol 20. ¢

Polvethylene glvcel 400 20. g } Folysorbate 80 1. ¢ water to q.8. 100 ml

The active ingredient iz dissolved in propylene glycol, polyethylene glycol 400 and polysorbate 80. A sufficient quantity of water is then added with stirring to provide 100 ml. of the solution which is filtered and bottled.

EXAMPLE 10

Suppository Formulation

The composition contains: % owt. jut.

Active ingredient 1.0%

Polyethylene glycol 1000 74.5%

Polvethylene glycol A000 26.57

The ingredients are melted together and mixed on a steam bath. and poured into molds containing 2.5 g total weight.

A —

EXAMPLE 11

Determination of Smooth Muscle Relaxant Properties

The smooth muscle relaxant property of the compounds was evaluated in-vitro, using vascular preparations previously contracted with an appropriate spasmogen.

Aortas were quickly removed from either rats or rabbits killed by a blow to the head. The tissue was cleared of connective tissue and cut into helical strips after removing endothelium by gently rubbing with forceps. These strips were then bathed in Krebs physiological solution at 37°C. and saturated with a mixture of 95% oxygen/5% carbon dioxide under 1 g tengion. Sustained contractions were evoked by adding barium chloride (1 mM). Contractile tension of the muscle strips was recorded isometvically. Test compounds were added at cumulatively increasing concentrations (1078 to 1074 M) in water or water with 2-3 drops

Tween or 1% alcohol. The maximum reduction in barium induced-tension was compared for each differing concentration of test compounds used. Results for the compounds of formula (I) in this- assay are set out below

PP in terms of their pICeq values (PICs = Logg oH]

Be compound to cause 50% inhibition of contraction induced by 1mM BaCl,).

2p hh-

Sm nnmTI Sm TT TT oT To - to TT mmr "RARRIT

Rg,R3 Ry Ry, ENAN- RAT AORTA AORTA

TTOMER ESTER plCsq pila

Me ,Me CN Me 6.4 [Ot

Me ,Me CN Et 6.9 7.0

Me ,Me CN Et (-) 7.36

Me ,Me CN Et (+) 5.3

Me ,Me CN n-propyl 5.8 5.7

Me ,Me CN isopropyl 5.5

Me Me CN n-butyl 5.7 5.7

Me ,Me CN isobutyl 5.4

Me ,Me CN n-octyl “<n .5

Me,Me CN allyl 5.2

Me ,Me CN allyl (=) 5.7

Me ,Me CN allyl (+) <h

Me ,Me CN benzyl “<5

Me ,Me CN (Clg) 3-N(Et), “h.5

Me ,Me CN Ft acetyl “8

EXAMPLE 12

Determination _of Antihypertensive Activity

The antihypertensive effects of the compounds of formula (I) were evaluated in spontaneously hypertensive rats (Charles River, aged 18 weeks)). The rats were anesthetized with pentobarbital (50 mg/Kg i.p.), and a , catheter was implanted into the descending aorta via a ‘ carotid artery. The catheter was exteriorized at the , Co 10 back of the neck and sealed with a pin. After surgery - . Co the rats were housed in individual cages. and pulsatile aortic blood pressure was measured directly 2-5 days ‘ later in groups of 4-6 conscious animals, using a Statham : P50 pressure tranducer connected to a Gould $8000 chart recorder. Heart rate was determined by using the pulse pressure to trigger a ratemeter. Rats with mean blood pressure greater than 150 mm Hg wer= considered to he hypertensive.

The test compounds were suspended in 2% Tween 80 vehicle for oral administration. A control group received vehicle (0.5 ml/Kg p.o.) alone. Cardiovascular parameters were recorded at 15,°30 and 45 minutes, and thereafter at hourly intervals for the first 7 hours, then at 24 hours post dosing. Maximum changes in systolic, diastolic and mean hlood pressure were measured, as was change in heart rate. Calculations were made of the percentage changes in bicod pressure and heart rate with respect to the initial values and vehicle-treated time controls. The duration of the antihypertensive effect was calculated as the time durivg which the blood pressure value rtemains significantly lower than the vehicle-treated group. The compounds of formula (I) demonstrated positive antihypertensive activity in this assay as set out in the table helow.

26qI¢ of -

Ry,R3 “Ry Ry, ENAN- DOSE(p.o.)

TTOMER (mg/kg) (n) DBPLax DURATION

Me ,Me CN Me 0.1 (7) -25% 7@

Me ,Me CN Et 0.1 (bh) -=35% 9 @

Me,Me CN Et (-) 0.1 (4) 31.57% 5%@ * p less than 0.05; Student's t-test @ p less than 0.05, DBP significantly different from placebo treated animals at that time.

DBP ax? maximal fall in diastolic blood pressure.

Claims

DAs - 68 - CLAIMS:

1. MN compound represented by the formula: NH Ry _..04 (6)

a . 0 3 "2 wherein: R is lower alkyl; Ry is cyano or nitro; Ra and Ras are independently hydrogen or lower alkyl: and Ra is alkyl of 1 to 12 carbon atoms; alkenyl of 1 to 6 carbon atoms; phenyl or; —(CHa)mORa or ~(CHa)mN(Ra)a: wherein m is an integer of 1 to 5 and Ra is as defined above.

2. The compound of claim 1, wherein R, is cyano.

3. The compound of claim 2, wherein Ra and Rs are both methyl.

4, The compound of claim 3, wherein Ra is lower alkyl.

Lg 15 69 - EXAMPLE 13 Toxicology Rats (males and females, Charles River) were treated once daily orally at dose levels of 5, 10, 15 and 20mg /kg/day for three weeks.

No dose-related mortality was observed and no gross pathological abnormalities were detected.

In addition, no abnormalities were detected during histopathological evaluation up to the dose of 20mg/kg.

At all dose levels, vasodilation, accelerated growth and associated increases in food consumption were seen.

2eq1s — 69

5. The compound of claim 4, wherein Ra is selected from the group consisting of methyl and ethyl.

} 6. ‘The compound of claim 3, wherein Ra is lower alkenyl of 1 to 6 carbon atoms.

7. A process for preparing a compound, as a single sterecisomer or as a mixture of stereoisomers represented by the formula R,O T\, (1) R

1 _.-0H 0 <3 R : 2 wherein: ’ R; is cyano or nitro; Ra and R» are independently hydrogen or lover alkyl; and R4 is alkyl of 1 to 12 carbont atoms; alkenyl of 1 to 6 carbon atoms: phenyl or; —(CHa)mORa or —(CHz)mN(R2)a, wherein m is an integer of 1-5 and Ra is as defined above; or a pharmaceutically acceptable ester or acid addition salt thereof, which process comprises: (a) cyclizing a compound of the formula

2 (q)G < ot “> — 70 — R, 0 =" ’ 5 NH OD 6)

R .-0OH = | - J Ry Ra which comprises heating a compound of the formula (6) in an inert solvent: (b) converting a compound of the formula (I) to a pharmaceutically acceptable ester or acid addition salt thereof; or (c) converting an ester or an acid addition salt of a compound of the formmla (1) to the free compound of formula (1); or (d) converting one ester or acid addition salt of a compound of the formula (1) to a second pharmaceuti- cally acceptable ester or acid addition salt of the compound of formula (1). HENRI PINHAS GILES GENAIN (Inventors)