RECOVERY OF PHENYLACETALDEHYDE

PURPOSE:To produce a phenylacetic acid ester together with the titled compound, and to recover the titled compound in high yield, by properly selecting the condition of the reaction of a benzyl halide with CO, H2 and an aliphatic alcohol in the presence of a cobalt carbonyl catalyst under mild condition. CONSTITUTION:A mixture of a phenylacetic acid ester and phenylacetaldehyde is prepared by reacting a benzyl halide with CO, H2, a basic substance and an aliphatic alcohol in the presence of a cobalt carbonyl catalyst (e.g. alcohol solution of cobalt tetracarbonyl anion), if necessary in the presence of an inert solvent. The unreacted substances, the solvent, and the volatile components are removed from the reaction mixture by distillation, and the resultant concentrated liquid is washed with an aqueous solution of a mineral acid. A bisulfite, etc. is added to the organic phase to obtain the bisulfite of phenylacetaldehyde, which is separated from the organic phase. The phenylacetic acid ester is recovered from the organic phase by distillation, and the distillation residue is added with an acidic substance and distilled again to recover phenylacetaldehyde.