2-Thenoylhydrazine 2-Thienylcarboxylic acid hydrazide 2-Thiophenecarbohydrazonic acid 2-Thiophenecarboxylic acid, hydrazide (8CI)(9CI) 2361-27-5 EINECS 219-107-0 NSC 653 Thiophene-2-carbohydrazide Thiophene-2-carboxylic acid hydrazide