Cobalt bis(2-pyridinecarbooxylate)-tetrahydrate (Co(Pyca) 2·4H 2O) has been prepared with the reaction of 2-pyridinecarboxylic acid and CoCO 3 Elementary analysis, ICP-AES, IR were used to characterize the structure of the compound It is found that this complex can catalyze carbonylation of benzyl chloride to phenylacetic acid under 333～358K and over 1MPa CO The yield of phenylacetic acid is 17 5%, and the catalyst is also unsensitive to oxygen and water The addition of base and benzyl chloride has critical effect on this reaction One molecule of Co(Pyca) 2·4H 2O can combine with two CO molecules under 323K and 0 1MPa
The complex cobalt pyridine2carboxylate Co(Pyca) 2·4H 2O catalyst is found to have a good activity and selectivity for double carbonylation of benzyl chloride to a substituted phenylpyruvic acid, βbenzyl αphenylpyruvic acid, in CaO/CH 3OH/H 2O reaction system. After stirring 10 h in 3.0 MPa and 333 K with the PhCH 2Cl to CaO ratio 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, MS and microanalyses. The strong IR bands at 3 453—3 554 cm -1 are assigned to the —COOH , and the sharp bands at 1 706 and 1 729 cm -1 are assigned to the two C=O groups stretch, respectively. In the 13 C NMR spectra, two characteristic strong peaks at δ 1932 and 1592 are assigned to C=O and COOH. The MS spectra 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.
