CAS No 3051-09-0 , Purpuric Acid, Ammonium Salt

Title: Murexide
CAS Registry Number: 3051-09-0
CAS Name: 5-[(Hexahydro-2,4,6-trioxo-5-pyrimidinyl)imino]-2,4,6(1H,3H,5H)-pyrimidinetrione monoammonium salt
Synonyms: 5,5￠-nitrilodibarbituric acid monoammonium salt; acid ammonium purpurate; ammonium purpurate
Molecular Formula: C8H8N6O6
Molecular Weight: 284.19
Percent Composition: C 33.81%, H 2.84%, N 29.57%, O 33.78%
Literature References: Prepn from alloxan + NH3: Hartley, J. Chem. Soc. 87, 1791 (1905); Schwartz, Handritschk, DD 17589 (1959), C.A. 55, 3630a (1961); from alloxantin + ammonium acetate: Davidson, J. Am. Chem. Soc. 58, 1821 (1936). Structure: Hartley, J. Chem. Soc. 87, 1796 (1905); Winslow, J. Am. Chem. Soc. 61, 2089 (1939); Schreiber, Mitt. Dtsch. Pharm. Ges. 28, 20 (1958).
Properties: Purple-red crystals with green metallic luster. Absorption max in water: 520 nm. Sparingly sol in cold water, more in hot water; practically insol in alcohol, ether. The H2O soln is deep purple and the aq NaOH soln is deep blue.
Absorption maximum: Absorption max in water: 520 nm
Use: Indicator for complexometric titrations.