Abstract: The complex cobalt pyridine-2-carboxylate Co(Pyca)₂·4H₂Ocatalyst is found to have a good activity and selectivity for double carbonylation of benzyl chloride to a substituted phenylpyruvic acid, β-benzyl-αphenylpyruvic acid, in CaO/CH₃OH/H₂Oreaction system. After stirring 10h in3.0 MPa and 333 Kwith the PhCH₂Cl to CaOratio of 1.33 and catalyst of 5.5 mmol, the yield of the substituted phenylpyruvic acid is 40%, the selectivity is 80%, and the conversion of benzyl chloride is 51%. The substituted phenylpyruvic acid is characterized by IR, NMR, MSand microanalyses. The strong IRbands at 3453-3554 cm^-1are assigned to the -COOH , and the sharp bands at 1706 and 1729 cm^-1are assigned to the two C=Ogroups stretch, respectively. In the ¹³C NMRspectra, two characteristic strong peaks at δ 193.2 and 159.2 are assigned to C=Oand COOH. The MSspectra shows that the main characteristic peaks are m/z=254(M⁺), 236, 209, 181(basic peak), 91 and 77. The melting point of the phenylpyruvic acid is 87-89 ℃. Further study of the double carbonylation reaction over this new catalyst system is being carried out.

Key words: Cobalt bis(2-pyridinecarboxylate)-tetrahydrate, Substituted phenylpyruvic acid, Double carbonylation