A convenient synthesis of 2-alkylthio-4,5-dihydro-5-methoxythiazoles

Abstract

A series of 2-alkylthio-4,5-dihydro-5-methoxythiazoles 3 were prepared by thermal or diethyl ether-boron trifluoride mediated intramolecular cyclization of the corresponding N-(2,2-dimethoxyethyl)dithiocarbamic acid esters 2. Methyl N-(2,2-dimethoxyethyl)dithiocarbamate (36) and 4,5-dihydro-5-methoxy-2-methylthiothiazole (3b) were converted by a two-step sequence to methyl 2-methyl-3-thioxo-1,2,3,4-tetrahydro-1,2,4-triazine-4-carbodithioate (6).