GB806812A - Heterocyclic sulphonamides - Google Patents

Abstract

The invention comprises a 1 : 2 : 3-thiadiazole compound of the formula <FORM:0806812/IV (b)/1> and amine and alkali metal and alkaline earth metal salts and ortho-carboxy benzoyl and b -carboxy propionyl derivatives thereof, and derivatives of the compound containing in the 5-position a lower alkyl group. The compounds are made by usual methods for the preparation of N1-heterocyclic derivatives of sulphanilamide, for example by reacting a benzenesulphonyl halide bearing a substituent convertible to an amino group (such as an acylamino, alkoxycarbonylamino, carbonamide or nitro group) in the para position, with a 4-aminothiadiazole followed, if necessary, by conversion of the para substituent into an amino group or a salt or acyl derivative thereof. In examples: (1) 4-amino-5-methyl-1 : 2 : 3-thiadiazole is treated with p-acetamidobenzene sulphonyl chloride and the resulting 4-p-acetamidobenzenesulphonamido - 5 - methyl - 1 : 2 : 3 - thiadiazole is hydrolysed to give 4-sulphanilamido - 5 - methyl - 1 : 2 : 3 - thiadiazole; (2) 4-amino-1 : 2 : 3-thiadiazole is treated as in (1) to give 4 - p - acetamidobenzenesulphonamido - 1 : 2 : 3-thiadiazole and 4 - sulphanilamido - 1 : 2 : 3-thiadiazole; and (3)-(6) the product of (2) is converted into its N4-b -carboxypropionyl and N4-o-carboxybenzoyl derivatives and into its potassium and triethylamine salts. 4 - Amino - 5 - methyl - 1 : 2 : 3 - thiadiazole is made by treating ethyl 5-methyl-1 : 2 : 3-thiadiazole-4-carboxylate with hydrazine to give 5 - methyl - 1 : 2 : 3 - thiadiazole - 4 - carboxyhydrazide, treating with nitrous acid to give the 4-carboxyazide and decomposing this by heat and hydrochloric acid to give the amine. Similarly 4-amino-1 : 2 : 3-thiadiazole is prepared from 1 : 2 : 3 - thiadiazole - 4 - carboxylic acid via the acid chloride, the carboxyhydrazide and carboxyazide.