Patent GB-1425501-A (GB)
Title: Substituted benzodioxoles
IPC: C07D317/72
Filed: 1973-02-06
Abstract: 1425501 1,3-Benzodioxoles ISTITUTO LUSO FARMACO D'ITALIA 6 Feb 1973 [9 Feb 1972 4 Dec 1972] 5899/73 Heading C2C Novel 1,3-benzodioxoles of the general formula and pharmaceutically acceptable salts and stereoisomers thereof, wherein R is a hydrogen atom or a C 1-4  alkyl, C 1-4  haloalkyl, C 1-4  hydroxyalkyl, aryl or aralkyl group (optionally substituted in the aromatic ring by a halogen atom or an alkyl, hydroxyl or alkoxy group; Alk is a straight or branched C 1-4  alkylene or C 2-4  alkenylene or C 3  cycloalkylene group; or R and Alk may be joined together, in which case R is a C 1-4  alkylene, C 1-4  haloalkylene or C 1-4  hydroxy-alkylene group and Alk is as defined above, but is trivalent; R<SP>1</SP> is a hydrogen or halogen atom or a C 1-4  alkyl, C 1-4  haloalkyl, hydroxyl, alkoxy, nitro, amino (optionally substituted), sulphamoyl or diethylsulphamoyl group or R<SP>1</SP> is a benzene ring condensed with the benzodioxide ring; and R<SP>2</SP> is (a) -OR<SP>3</SP>, in which R<SP>3</SP> is a hydrogen atom or a straight or branched alkyl, hydroxyalkyl, arylalkyl, aminoalkyl or aminoalkoxyalkyl group, the amino group optionally being substituted by one or two C 1-4  alkyl group(s) or forming part of a heterocyclic ring, or (b) -NR<SP>4</SP>R<SP>5</SP>, in which each of R<SP>4</SP> and R<SP>5</SP> is a hydrogen atom or a straight, branched or cyclic C 1-4  alkyl, hydroxyalkyl, aralkyl, aminoalkyl (the amino group optionally being substituted by one or two alkyl group(s) or forming part of a heterocyclic ring), hydroxyl, acyloxy or aryl group (optionally substituted by a halogen atom or alkyl group), or -NR<SP>4</SP>R<SP>5</SP> is a heterocyclic amine residue; provided that when R is CH 3  and R<SP>1</SP> is H or 5-CH 3 , -Alk-COR<SP>2</SP> is not a carboxymethyl, 2-carboxyethyl, 1- methyl - 2 - carboxyethyl or 2 - carboxypropyl group or an ethyl ester thereof; when R is CH 3  and R<SP>1</SP> is 5-NO 2 , -Alk-COR<SP>2</SP> is not a carboxymethyl group or an ethyl ester thereof; when R is phenyl and R<SP>1</SP> is H, -Alk-COR<SP>2</SP> is not a carboxymethyl or carbomethoxymethyl group; and when R is H and R<SP>1</SP> is H, -Alk-COR<SP>2</SP> is not -CH 2 CONH 2 , are prepared by reacting a pyrocatechol of the general formula  or a compound having one of the following general formulµ with (a) a compound of the general formula RCOAlkCOR<SP>2</SP> or RCOAlkCN in the presence of a dehydrating agent or acid catalyst or (b) a compound of the general formula in the presence of a basic catalyst, followed by acidic or basic hydrolysis when a nitrile is used, and optionally converting the residue R<SP>2</SP> into another residue R<SP>2</SP> by a method known per se. 2 - Carboethoxy - 3 - phenyl - 1,4 - benzodioxane is obtained as a by-product in the production of ethyl (2 - phenyl - 1,3 - benzodioxol - 2 - yl)- acetate from pyrocatechol, ethyl. 2,3-dibromocinnamate or #-bromocinnamate, and sodium methoxide. (2 - Phenyl - 1,3 - benzodioxol - 2 - yl) acetonitrile is prepared by treating the corresponding acetamide with catechol phosphotrichloride or P 2 O 5 . 2 - Phenyl - 2 - bromomethyl - 1,3 - benzodioxole is prepared by reacting bromoacetophenone with pyrocatechol in the presence of P 2 O 5 . Ethyl (2 - methyl - 5 - chlorosulphonyl - 1,3- benzodioxol-2-yl) acetate is prepared by treating ethyl (2 - methyl - 1,3 - benzodioxol - 2 - yl)- acetate with chlorosulphonic acid. Pharmaceutical compositions having antiinflammatory, analgesic, antipyretic, antitussive, CNS depressant, local anaesthetic, antiarrhythmic, antihistaminic and/or hypolipidic activity comprise, as active ingredient, at least one 1,3-benzodioxole of the first general formula above or pharmaceutically acceptable salt or stereoisomer thereof, together with a compatible pharmaceutically acceptable carrier.