Selective monomethylation reactions of methylene-active compounds with dimethylcarbonate. An example of clean synthesis

Abstract

Dimethylcarbonate (DMC), an environmentally friendly substitute for dimethyl-sulfate and methyl halides in methylation reactions, is also a very selective reagent. Under batch conditions, with potassium carbonate as the catalyst, the reactions of DMC, used as the solvent of the reactions, with methylene-active compounds (arylacetonitriles and arylace-toesters, aroxyacetonitriles and methyl aroxyacetates, benzylaryl- and alkylaryl-sulfones) produce monomethylated derivatives, with a selectivity not previously observed (i. e., >99%). These are examples of "green chemistry".