Experimental and quantum chemical study of the reactions of 2-methyloxirane with 5-alkyl-6-(2,6-dihalobenzyl)-2-thioxo1,2-dihydropyrimidine-4(3H)-one derivatives

The reactions of 5-alkyl-6-(2,6-dihalobenzyl)-2-thioxo-1,2-dihydropyrimidin-4(3H)-one with 2-methyloxirane in an alkaline medium afforded uracil and 2-[(2-hydroxyprop-1yl)sulfanyl]pyrimidin-4(3H)-one derivatives. The mechanism proposed for these transformations was studied using the DFT/B3LYP/311+G** quantum chemical method, and the influence of the Nathan—Baker effect on the chemical nature and composition of the reaction products was shown.