By fusion of 1mol. of p-acetaminobenzene sulfochloride with 2mol. each of 2-aminopyridine-5-carboxylic ester, 2-aminothiazole-4-carboxylic ester, 2-aminothiazole-5-carboxylic ester and 2-aminopyrimidine, the corresponding p-acetaminobenzenesulfonamide compounds are obtaind. Hydrolyses of these comounds give corresponding sulfanilamides.