It is found that the cobalt pyridine-2-carboxylate tetrahydrate [Co (Pyca)2(H2O)2]·2H2O has a very good catalytic activity and selectivity for the double carbonylation of benzyl chloride to phenyl pyruvic acid in CaO/dioxane/H2O reaction system. The catalyst is also unsensitive to H2O and O2 in the system, which is very convenient to handle in the reaction. The conversion of benzyl chloride is 74.5% with a selectivity of 99%, and the yield of the phenyl pyruvic acid is above 73.8% after running 10 h in 2.4 mPa and 535K with the PhCH2Cl/CaO ratio of 1.00 and the catalyst of 5.5 mmol in the solvent. The only by-product in the reaction is phenyl acetic acid. It has also been found that the solvents used in the reaction have critical effect on the distribution of products in the reaction. The less polar solvent dioxane is more favourable to the formation of phenyl pyruvic acid than the omre polar solvent CH3OH. The products is characterized by IR, UV and GC-MS.

Key words: KETONE ACID, PHENYL-PYRUVIC ACID, CATALYST, PYRIDINE P, COBALT COMPLEX, CARBONYLATION, CARBOXYLATES