1-Phthalazinecarboxylic acid, 4-hydrazino-, hydrazide 23196-04-5 4-Hydrazino-1-phthalazinecarboxylic acid, hydrazide Hydrazide of 1-hydrazino-4-phthalazinic acid Phthalazine-1-carboxylic acid, 4-hydrazino-, hydrazide