Abstract
S-Alkyl pyrimidine derivatives 2-5 were obtained by the reactions of ethyl 4-sulfanyl-6-methyl-2-phenylpyrimidine-5-carboxylate (1) with allyl bromide, propargyl bromide, epichlorohydrin and vinyl acetate (Scheme 1). On reaction of sulfanylpyrimidine 1 with iodine, hydrogen peroxide under different conditions afforded bisdisulphide, desulphrization, and 4-hydroxypyrimidines 6-8. Treatment of the sulfanylpyrimidine 1 with ethylbromoacetate followed by oxidation, and hydrazonlysis gave the thienopyrimidine dioxide derivative 10 and pyrazolopyrimidine 11, respectively (Scheme 2). Reaction of 1 with benzalidene derivatives in ethanol/TEA yielded pyridopyrimidine derivatives 12a,b and 13. On reaction with ethyl acrylate afforded thienopyrimidine 14 under the same condition. Furthermore, reaction of 1 with dimethyl amine/sulfur in absolute ethanol and with 4-chlorobenzaldhyde afforded the dihydrothienopyrimidine, and 6-styrylpyrimidinthione 15 and 16, respectively (Scheme 3). N-alkylated pyrazolopyrimidine 18 and pyridazinopyrimidine 19 were obtained by the reaction of 4-chloropyrimidine 17 with acetophenonehydrazone and hydrazones derivative of malononitrile in the presence of TEA (Scheme 4). All of the newly synthesized compounds were characterized by IR, H-1, C-13 NMR and microanalysis.