PROCESS FOR THE PREPARATION OF PHENYL PYRUVIC ACID

摘要

The invention provides an improvement in the method for the preparation of phenyl pyruvic acid by the reaction of benzyl chloride and carbon monoxide in a liquid reaction medium in the presence of a cobalt carbonyl as the catalyst. In the inventive method, the reaction is performed in the presence of calcium hydroxide and the reaction medium is a binary system composed of water and an organic solvent capable of dissolving the catalyst and not freely miscible with water. The reaction can proceed even under normal pressure and the desired product can be readily recovered in the form of precipitates of the calcium salt while the catalyst dissolved in the organic phase after completion of the reaction can be recycled and re-used as such in the next run so that the costs for the catalyst regeneration in the prior art can be entirely saved.