SIMPLE SYNTHESIS OF FURFURYL SULFIDES VIA EXTRUSION OF COS FROM THE XANTHATES AND ITS MECHANISTIC ASPECTS

Heating of O-furfuryl S-alkyl dithiocarbonates (xanthates) gave furfur yl alkyl sulfides together with S-furfuryl S-alkyl dithiocarbonates. T he crossover reaction using differently substituted furfuryl xanthates in polar solvents indicates that the reaction proceeds intermolecular ly, whereas the reaction in non-polar solvents showed intramolecular r eaction behaviour. The reaction is first-order and the rates are consi derably affected by a change in the solvent polarity, The activation e nthalpy and entropy for the extrusion of O-furfuryl S-methyl xanthate in xylene are 28.0 +/- 1.3 kcal mol(-1)dagger and -2 +/- 4 cal K-1 mol (-1), respectively. Based on these findings together with the MO calcu lation data, the mechanism for the conversion reaction of furfuryl xan thates to furfuryl alkyl sulfides is discussed.