Process for the production of phenylmalonic acid mono-esters
Sodium salts of phenylmalonic acid mono-esters are produced by reacting a phenylacetic acid ester with carbon dioxide in the presence of a sodium substituted compound, which is prepared by substituting a sodium atom for a hydrogen atom of an organic compound selected from a group consisting of acetylene, cumene, triphenylmethane, methyl-methylthiomethyl-sulfoxide and dimethyl-sulfoxide, at a temperature in a range of -20° C. to -40° C.