Title: Violuric Acid
CAS Registry Number: 87-39-8
CAS Name: 2,4,5,6(1H,3H)-Pyrimidinetetrone 5-oxime
Additional Names: alloxan 5-oxime; 5-isonitrosobarbituric acid; 5-(hydroxyimino)barbituric acid
Molecular Formula: C4H3N3O4
Molecular Weight: 157.08
Percent Composition: C 30.58%, H 1.93%, N 26.75%, O 40.74%
Literature References: Known to exist as a mixture of keto-enol tautomers. Prepd from alloxan and hydroxylamine: Cresole, Ber. 16, 1133 (1883); Guinchard, Ber. 32, 1723 (1899).
Properties: Orthorhombic crystals, dec 240-241°. pK 4.7. Sparingly sol in water to a violet-colored soln; sol in alcohol. With FeCl3 produces blue color.
pKa: pK 4.7
Use: Analytical reagent for chromatographic separation of cations. Forms chelates: Leermakers, Hoffman, J. Am. Chem. Soc. 80, 5663 (1958). |