CAS No 542-05-2 , 3-oxopentanedioic acid

Title: Acetonedicarboxylic Acid
CAS Registry Number: 542-05-2
CAS Name: 3-Oxopentanedioic acid
Synonyms: 3-oxoglutaric acid; b-ketoglutaric acid
Molecular Formula: C5H6O5
Molecular Weight: 146.10
Percent Composition: C 41.10%, H 4.14%, O 54.75%
Line Formula: CO2HCH2COCH2CO2H
Literature References: Prepd by the action of fuming sulfuric acid on citric acid: Willst?tter, Pfannenstiel, Ann. 422, 5 (1921); Ingold, Nickolls, J. Chem. Soc. 121, 1642 (1922); R. Adams et al., Org. Synth. coll. vol. I, 10 (2nd ed., 1941). By the action of Aspergillus niger on ammonium citrate mixed with some citric acid: Walker et al., J. Chem. Soc. 1927, 3050; also by B. pyocyaneus: Butterworth, Walker, Biochem. J. 23, 931 (1929). Decomposition studies: Wiig, J. Phys. Chem. 32, 961 (1928). Intermediate in synthesis of tropinone: R. Robinson, J. Chem. Soc. 111, 762 (1917); C. Sch?pf, G. Lehmann, Ann. 518, 1 (1921).
Properties: Needles from ethyl acetate, mp 138° (dec). The pure compound may be stored over P2O5 for several months. Crude material dec after a few hours. Decomposed by hot water, acids or alkalies to CO2 and acetone. pK (25°) 3.10. Very sol in water and alcohol; slightly sol in ethyl acetate, ether. Insol in chloroform, ligroin, benzene.
Melting point: mp 138° (dec)
pKa: pK (25°) 3.10
Use: In organic synthesis.