(1R,2R,3R,4R)-1-([1,2,4]Triazolo[3,4-a]phthalazin-3-yl)pentane-1,2,3,4,5-pentaol

(1R,2R,3R,4R)-1-([1,2,4]Triazolo[3,4-a]phthalazin-3-yl)pentane-1,2,3,4,5-pentaol Impurity is used in method development and validation  during commercial production of Hydralazine.