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The synthesis and chemoselective study of a novel series N-methyl-2-methylthio-tetrahydropyrimidines and or N-methyl-2-methylthiodihydropyrimidines, from the cyclocondensation reaction of b-alkoxyvinyl trihalomethyl ketones (enones) with 1,2-dimethylisothiourea sulfate is described. It was found that the chemoselectivity depends on both the reaction conditions and the steric and electronic effects of the substituents on the enones.

The regiospecific synthesis of a novel series of 4trifluoro[chloro]-2-(5-hydroxy-5-trifluoro[chloro]methyl-4,5-dihydro-1H-pyrazol-1-yl]-pyrimidines from the reactions of 4-alkoxy-1,1,1-trifluoro[chloro]-alk-3-en-2-ones with 6-trifluoro[chloro]methyl-2-hydrazine pyrimidines is presented.

A Convenient Two-Step Synthesis of 6-Methylenesubstituted-4-trichloromethyl-2-methylsulfanyl Pyrimidines. -A simple method for the selective synthesis of side-chain mono-and dibrominated trihalomethyl sulfanyl pyrimidines is described. The reactivity of bromomethyl derivative (IIIa) toward a variety of nucleophiles is tested. -(ZANATTA*, N.; FLORES, D. C.; MADRUGA, C. C.; FLORES, A. F. C.; BONACORSO, H. G.; MARTINS, M. A. P.; Tetrahedron Lett. 47 (2006) 4, 573-576; Nucl. Quim. Heterociclos, Univ. Fed. Santa Maria, 97105 Santa Maria, Brazil; Eng.) -Mais 18-151

This work describes the synthesis of a novel series of 2-methylsulfanyl-tetrahydropyrimidines, from the cyclocondensation reaction of -alkoxyvinyl trihalomethyl ketones with 2-methyl-2-thiopseudourea sulfate, in good yields. A detailed 1 H-and 13 C-NMR study was performed on the 2-methylsulfanyltetrahydropyrimidines obtained and 3D structures were proposed based on AM1 calculations supported by 1 H NMR coupling constants and NOESY experiments.