2,4,5,6(1H,3H)-Pyrimidinetetrone, 5-oxime 5-Hydroxyiminobarbituric acid 5-Isonitrosobarbituric acid 87-39-8 Alloxan 5-oxime Alloxan, 5-oxime EINECS 201-741-4 NSC 56338 Violuric acid