GB577418A - Process for the preparation of amides of aromatic carboxylic acids - Google Patents

Abstract

Amide derivatives of aromatic carboxylic acids are obtained by condensing a hydroxy phenyl-mono-carboxylic acid with free or substituted hydroxyl groups, or a reactive derivative thereof, with an amino derivative of a compound containing a mono nuclear uncondensed five-membered heterocyclic ring. Specified substituents in the hydroxyl group of the acid are: acyl, alkyl, aralkyl or aryl radicals; and the acid may contain further substituents in its nucleus. Specified amino derivatives are: pyrroles, furanes, thiophenes, imidazoles, pyrazoles, oxazoles, thiazoles, triazoles and tetrazoles. In examples there is condensed 2-amino-thiazole with: (1) o-acetoxybenzoyl chloride in ethereal solution to form o-acetoxybenzoyl - 2 - aminothiazole and 2 - o - hydroxy - benzoylaminothiazole as a by-product; (2) o-hydroxybenzoyl chloride in benzene to form o-hydroxybenzoyl-2-aminothiazole. Samples of products of the invention have been filed, under Sect. 2 (5) of the Acts, obtained by the condensation of: (1) b -(4-imidazolyl)-ethylamine with o-hydroxy-benzoyl chloride in chloroform solution to form N-(b -4-imidazolyl-ethyl) - o - hydroxy - benzamide; (2) 4 - amino - 1 - phenyl -2.3 - dimethyl - 5 - pyrazolone with o-acetoxybenzoyl chloride in aqueous sodium hydroxide solution to form 4-o-hydroxybenzoylamino - (1 - phenyl - 2.3 - dimethylpyrazolone); (3) 2-amino-4-methylthiazole dissolved in chloroform with o-acetoxybenzoyl-chloride dissolved in pyridine to form 2-o-hydroxy benzoylamino-4 - methyl - thiazole; (4) 2 - amino - 4 - methyl - thiazole with o-acetoxybenzoyl chloride in dioxane solution to form 2-di-(o-hydroxybenzoyl) - amino - 4 - methyl - thiazole; (5) 2 - (o - hydroxybenzoyl)-aminothiazole with o-acetoxybenzoyl chloride in aqueous sodium hydroxide solution to form 2-di-(o-hydroxybenzoyl)-aminothiazole; (6) 2-aminothiazole, dissolved in a mixture of dioxane and ether, with p-carbethoxyoxy-benzoyl chloride dissolved in di-ethyl-ether to form 2-p-carbethoxy-oxy-benzoylamino-thiazole which is saponified by treatment with a mixture of ethanol and aqueous sodium hydroxide to form 2-p-hydroxybenzoylamino thiazole; (7) 2 - amino - thiazole with veratroyl chloride in acetone solution to form 2-veratroylaminothiazole; (8) 2-aminothiazole dissolved in a mixture of dioxane and di-ethyl-ether with anisoyl chloride dissolved in ether to form 2-anisoyl-amino-thiazole. Specification 414,336 is referred to.