Efficient synthetic methods for unsaturated 3,4,5-trimethoxybenzyl sulfides and ethers

Abstract

Convenient and efficient procedures were developed for preparation of 3,4,5-trimethoxybenzyl sulfides and ethers containing vinyl, allyl, and propargyl groups proceeding from 3,4,5-trimethoxybenzyl alcohol, elemental sulfur, and thiourea in basic and basic-reductive systems (hydrazine hydrate‒KОН‒DMF, NaBH₄‒EtOH, KОН‒DMSO). The effective method of the synthesis of 1,1'-[disulfandiylbis(methylene)]bis-(3,4,5-trimethoxybenzene) consists in the reduction of the elemental sulfur to disulfide anion with hydrazine hydrate in the presence of KОН followed by the reaction with 3,4,5-trimethoxybenzyl chloride under the conditions of phase-transfer catalysis or in DMF.