2-BUTENOIC ACID, 4-OXO-4-((1,3,4-THIADIAZOL-2-YL)AMINO)-, METHYL ESTER 4-Oxo-4-((1,3,4-thiadiazol-2-yl)amino)-2-butenoic acid methyl ester 90278-94-7 BRN 5540236