Patent GB-1385404-A (GB)
Title: Disubstituted xanthone carboxylic acid compounds
IPC: C07D311/86
Filed: 1972-07-12
Abstract: 1385404 Disubstituted xanthene carboxylic acid compounds SYNTEX CORP 12 July 1972 [12 Jan 1972] 32535/72 Heading C2C The invention comprises compounds of the formula wherein each R<SP>1</SP> is C 1-5  alkylthio or C 3-5  cycloalkylthio, one R<SP>2</SP> is as R<SP>1</SP> and the other is C 1-5  alkyl or C 3-5  cycloalkyl and one R<SP>3</SP> is as R<SP>1</SP> and the other is C 1-5  alkoxy or C 3-5  cycloalkoxy; and esters, amides and salts thereof. They may be obtained by: (1) condensing a o,p-di(alkylthio or cycloalkylthio)-phenol with a 1,3-dicarboalkoxy (or dicarbocycloalkoxy)-4-halobenzene in the presence of cuprous oxide to give the corresponding 1,3 - dicarboalhoxy (or dicarbocycloalkozy) - 4 - (o,p - dialkylthiophenyloxy or -dicycloalkylthiophenyloxy)- benzene, base hydrolysing the latter to give the corresponding 1,3 - dicarboxy - 4 - (o,p - dialkylthiophenyloxy or -dicycloalkylthiophenyloxy) - benzene, and cyclizing the latter to give the corresponding 5,7- di(alkylthio or cycloalkylthio)-xanthone-2-carboxylic acid; or (2) condensing o,p-dimethoxyphenol with a 1,3-dicarboalkoxy (or -dicarbocycloalkoxy)-4-halobenzene in the presence of cuprous oxide to give the corresponding 1,3, dicarboalkoxy (or dicarbocycloalkoxy - 4 - (o,pdimethoxyphenyloxy)-benzene, base hydrolysing the latter to give the corresponding 1,3-dicarboxy - 4 - (o,p - dimethoxyphenyloxy) - benzene, and cyclizing the latter to give the corresponding 5,7 - dimethoxyxanthone - 2 - carboxylic acid or condensing o,p-dimethoxyphenol with a 1,3- dimethyl - 4 - halobenzene to give the corresponding 1,3 - dimethyl - 4 - (o,p - dimethoxyphenyloxy) - benzene, oxidizing the latter to give the corresponding 1,3-dicarboxy-4-(o,pdimethoxyphenyloxy)-benzene, and cyclizing the latter to give the corresponding 5,7-dimethoxyxanthone-2-carboxylic acid; and subjecting said 5,7-dimethoxyxanthone-2-carboxylic acid to the steps comprising hydrolysing to the corresponding 5,7-dihydroxy acid, esterifying the latter to its lower alkyl ester, treating the latter with a dialkylthiocarbamoyl chloride in the presence of base, rearranging the product thereof, base hydrolysing the rearranged product thereof, treating the latter with alkyl or cycloalkyl halide in the presence of base, optionally followed by hydrolysis, to give the corresponding 5,7- di(alkylthio or cycloalkylthio)-xanthone-2-carboxylic acids or the alkyl esters thereof; or (3) condensing a o-alkyl-,-cycloalkyl-alkoxy or -cycloalkoxy - p - (alkylthio or cycloalkylthio)- phenol with a 1,3-dicarboalkoxy (or dicarbocycloalkoxy - 4 - halobenzene in the presence of cuprous oxide to give the corresponding 1,3- dicarboalkoxy (or dicarbocycloalkoxy) - 4 - (oalkyl-, -cycloalkyl alkoxy, or -cycloalkoxy - palkylthiophenyloxy or -cycloalkylthiophenyloxy)- benzene, base hydrolysing the latter to give the corresponding 1,3-dicarboxy-4-(o-alkyl-, -cycloalkyl-alkoxy or -cycloalkoxy-p-alkylthiophenyloxy or -cycloalkylthiophenyloxy)-benzene, and cyclizing the latter to give the corresponding 5- alkyl-, - cycloalkyl - alkoxy or -cycloalkoxy - 7- (alkylthio or cycloalkylthio) - xanthone - 2- carboxylic acids; or (4) condensing a o-alkylthio or -cycloalkylthio - p - alkyl-, -cycloalkylalkoxy or cycloalkoxy - phenol with a 1,3- dicarboalkoxy (or dicarbocycloalkoxy) - 4- halobenzene in the presence of cuprous oxide to give the corresponding 1,3-dicarboalkoxy (or dicarbocycloalkoxy) - 4 - (o - alkylthio or cycloalkylthio - 7 - alkyl-, -cycloalkyl - alkoxy or -cycloalkoxy - phenyloxy) - benzene, base hydrolysing the latter to give the corresponding 1,3 - dicarboxy - 4 - (o - alkylthio or -cycloalkylthio - 7 - alkyl - cycloalkyl - alkoxy or -cycloalkoxy - phenyloxy) - benzene, and cyclizing the latter to give the corresponding 5-alkylthio or cycloalkylthio-7-alkyl-cycloalkyl-alkoxy or -cycloalkoxy - xanthone - 2 - carboxylic acids; and (5) optionally converting a product of step (1), (2), (3), or (4) to its corresponding non- toxic ester, amide or salt. Examples are given for the production of these compounds. The above compounds are useful for inhibiting the effects of allergic reactions, also as smooth muscle relaxants or vasodilators. They may be administered orally, topically, parenterally, or by inhalation and in the form of either solid, liquid or gaseous doses including tablets, suspensions and aerosols, optionally in conjunction with other pharmaceutical agents, e.g. antibiotics and hormonal agents.