ES421973A1 - A procedure for the preparation of pharmaceutically acceptable salts of benzopyran-carboxylic acid derivatives. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A process for the preparation of pharmaceutically acceptable salts of derivatives of bensopyran-carboxylic acids of the formula: **(See formula)** where R5 represents hydrogen, hydroxy, or -OR'5 where R'5 is a straight or branched, saturated or ethylenically unsaturated hydrocarbon group, the group of which is optionally substituted by an -OH or by an oxygen-containing heterocyclic ring 5 to 6 membered, R'5 together with any of the substituents therein, contains from 3 to 8 carbon atoms inclusive, R6 represents hydrogen, alkyl containing from 1 to 6 carbon atoms inclusive, alkenyl containing from 2 to 6 carbon atoms inclusive, or phenyl, R7 represents hydrogen or lower alkoxy-lower alkoxy, R8 represents hydrogen, alkyl containing from 1 to 6 carbon atoms inclusive or alkenyl containing from 2 to 6 carbon atoms inclusive, with the provided that i) R8 does not represent propyl when R5 represents hydroxy-propoxy, ii) R8 does not represent ethyl when R5 is but-3-enoxy- iii) two or three of R5, R6, R7 and R8 are other than hydrogen, except that when a) R'5 represents a group po of straight chain alkyl or alkenyl, containing from 5 to 7 carbon atoms or a branched chain alkyl or alkenyl group containing from 6 to 8 carbon atoms, or b) R6 represents phenyl, none, one or two of R6, R7 and R8 are other than hydrogen, iv) R6 and R8 are both ethyl or both are secondary butyl only when R5 is not hydrogen, v) R6 is alkyl containing 4 to 6 carbon atoms, when R7 is lower alkoxy-lower alkoxy, and vi) at least one of R6 and R8 contains two or more carbon atoms, when R5 is hydrogen or hydroxy, which comprises treating a compound of formula Ic, **(See formula)** wherein R5, R6, R7 and R8 and the caveats are as defined above, and E is a carboxylic acid group (or an ester thereof or another salt thereof), a nitrile group, a group acid halide or amide group, with a compound containing an available pharmaceutically acceptable cation and capable of converting group E to a pharmaceutically acceptable salt of a carboxylic acid group. (Machine-translation by Google Translate, not legally binding)