Alkylation of Thio- and Dithio-carboxylates

Synthesis of Thiono- and Dithio-esters.—Alkylation of Thio- and Dithio-carb-oxylates. Alkylation of thiocarboxylates takes place at the sulphur atom, and thiolesters are the reaction products in almost all cases. The reaction of thio-benzoic acid with diazomethane yields, however, some methyl thionobenzoate, along with a ten-fold amount of the thiolobenzoate, from which it may be cleanly separated by chromatography, On the other hand, silylation of monothio- or monoseleno-carboxylates affords the 0-silyl esters, in contrast to germylation or stannylation, which occur at the sulphur atom. 

Mitani, and M. Mizuta, Internat. J. Sulfur Ghent., 1973, 8, 359. 

A great number of dithioesters have been prepared by alkylation of dithio-carboxylates/ The carboxymethyl dithiocarboxylates 

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