ES401162A1 - Benzofuran and benzothiophene derivatives - Google Patents

Abstract

A procedure for the preparation of tricyclic compounds of the general formula **(See formula)** in which R1 and R2 independently represent hydrogen, halogen, lower alkyl, lower alkoxy, lower alkylthio, trifluoromethyl, cyano, carbamoyl, carboxyl, lower alkoxycarbonyl, nitro, amino, mono-lower alkylamino, di-lower alkylamino, acyl, acylamido, sulfamollo, di-lower alkyl-sulfamoyl or difluoromethylsulfonyl; represents hydrogen, lower alkyl, amino-lower alkyl, mono-lower alkylamino-lower alkyl or di-lower alkylamino-lower alkyl; n is 1 or 2; and X represents oxygen or sulfur, and its salts, characterized by cyclizing a compound of the general formula **(See formula)** in which R1, R2, X and n have the same meaning as before, at least one carbon atom of the phenyl ring in ortho position with respect to the carbon atom linked to the X atom until it is unsubstituted and R'3 represents lower alkyl, or, when a compound of the formula I in which X represents oxygen, or a salt thereof is desired, a compound of the general formula is reacted **(See formula)** in which R3 and n have the same meaning as before, while R'1 and R'2 independently represent hydrogen or an electron-withdrawing group chosen from nitro, trifluoromethyl, lower alkoxy-carbonyl, cyano or acyl, provided that at least one of the symbols R'1 and R'2 is other than hydrogen, with an acid catalyst and, when an optically active isomer of a compound of the general formula I above is desired, a racemate of the general formula I obtained is resolved into its optically active isomers and the desired isomer isolated; and, when a salt of a compound of the general formula I above is desired, reacted with a base or an acid, respectively, an acidic or basic compound of the general formula I obtained; and, when a carboxylic acid compound of the formula I is desired, a carboxylic acid ester of the formula I obtained is saponified; and, if desired, converting a sol of a compound of formula I in which R3 is hydrogen to a compound of formula I in which R3 is amino-lower alkyl, mono-lower alkylamino-lower alkyl or di-alkylamino. lower-lower alkyl; and, if desired, converting a nitro group present in a compound of formula I to an amine group; and, if desired, converting an amine group to a diazonium salt and replacing the obtained diazonium group with halogen, cyano, hydroxyl, lower alkoxy or hydrogen. (Machine-translation by Google Translate, not legally binding)