1-Methylimidazole-4,5-dicarboxylic acid bis(isopropylidenehydrazide) 21601-15-0 5-25-05-00349 (Beilstein Handbook Reference) BRN 1589993 Imidazole di-isopropylcarboxylhydrazide Imidazole-4,5-dicarboxylic acid, 1-methyl-, bis(isopropylidenehydrazide)