Synthesis of 2,3-dihydro-6-methyl-2-thiopyrimidin-4(1 H)-one (6-methylthiouracil) derivatives and their reactions

The synthesis and characterization of 2,3-dihydro-6-methyl-2- thioxopyrimidin-(1h)-one (i) and some of its derivatives has been performed in our lab. ring-closing cyclization,as a result of the condensation of ethyl-3-oxobutanoate with thiourea in koh in an ethanol medium produced 2,3-dihydro-6-methy -2-thioxopyrimidin-(1h)-one (i). the reaction of compound (i) with 2- chloroacetic acid in an alkaline koh solution produced the carboxylate derivative,2-(2,6-dihydro-4-methyl-6-oxopyrimidin-2-yl-thio) ethanoic acid (ii). the reaction of the resulted derivative of carboxylate (ii) with the salt of copper sulphate,produced a new copper salt (iii). a substitution reaction between synthesized compound (i) and 2-chloroethanol in an aqueous solution of koh,created 2-(2-hydroxyethylthio)-6-methylpyrimidin-4(3h) -one (iv). the reaction of compound (i) with 2-(chloromethyl)oxirane in the presence of an aqueous solution of koh,resulted yielded 2-(3-chloro-2-hydroxy- propylthio)-6-methylpyrimidin-4(3h)-one (v). sodium mercaptide compound (vi),was produced by the reaction of (i) with naoh and then the sodium salt of 2,3-dihydro-6-methyl-2-thioxopyrimidin-(1h)-one (vi) was reacted with 2-(chloromethyl)oxirane to result in 2-((oxiran-2-yl) methyl-thio)-6-methyl- pyrimidin-4(3h)-one (vii). different acylation reagents (acetyl chloride,benzoyl chloride) were reacted with compound (i),in dimethylformamide,acylation happens on sulfur and furnished s-acylified derivatives of (viii-ix). all the synthesized and obtained products were confirmed by ir,1h,and 13c nmr and elemental analysis. © 2013 mohammad barmaki et al.