Synonyms: 1H-Pyrazole-4-carboxylicacid, 3-hydrazino-5-methyl-, ethyl ester, monohydrochloride (9CI);Pyrazole-4-carboxylic acid, 3(or 5)-hydrazino-5(or 3)-methyl-, ethyl ester,hydrochloride (6CI); Pyrazole-4-carboxylic acid, 3-hydrazino-5-methyl-, ethylester, monohydrochloride (8CI); Ethyl 5-hydrazino-3-methyl-1H-pyrazole-4-carboxylatehydrochloride