Method for preparing dithiocarbamates in particular from polyols of the glycerol type

Abstract

The present invention concerns a method for the synthesis of glycerol dithiocarbamates or bis-dithiocarbamates (GDTCs) in which a reaction medium comprising (1) a carbonate selected from diethyl carbonate, dimethyl carbonate and ethylene or propylene carbonate associated with a glycerol type polyol in the presence of a basic catalyst or (2) a cyclic carbonate comprising five ring members, in a solvent medium, is supplemented with a primary or secondary amine in the presence of carbon disulphide, and the GDTC formed is recovered. In particular, a glycerol type polyol is brought into the presence of diethyl carbonate in the presence of a catalyst, then a primary or secondary amine is added to the reaction medium in the presence of carbon disulphide, and the GDTC formed is recovered. The invention can be used for one-step synthesis of glycerol dithiocarbamates directly from glycerol as the starting material and solvent. This method involves glycerol, diethyl carbonate, carbon disulphide (CS) and a primary or secondary amine to produce glycerol dithiocarbamates; the glycerol/NaOH phase can be recycled 6 times without a noticeable drop in yield; the ethyl acetate is also recycled after each extraction.