726207-85-8Relevant academic research and scientific papers
Effect of the structure of 1- and 3-methylpyrimidin-4-ones on the rate of nucleophilic substitution of the 2-methylsylfanyl group
Kheifets,Gindin,Nikolova
, p. 104 - 113 (2004)
Rate constants for substitution of the 2-methylsulfanyl group in 1- and 3-methyl-2-methylsulfanyl-pyrimidin-4-ones and their 5-fluoro analogs were measured in the reaction with butylamine, alkaline hydrolysis, and methanolysis. The rate of substitution in 1-methyl isomers having a zwitterionic structure is greater by a factor of ～2 than the rate of substitution in 3-methyl isomers with conjugated double bonds in the ring. The presence of a fluorine atom in position 5 accelerates nucleophilic substitution in 1-methyl isomers, while 5-fluoro-3-methyl-2-methylsulfanylpyrimidin-4-ones react at a lower rate than their 5-unsubstituted analogs. According to the NMR data, the reactions involve formation of a tetrahedral intermediate. Anchimeric effect of the methyl group on N1 hampers attack by basic reagent on the C6 atom.
