Synthesis and transformations of pyrimidine derivatives

A methoxyl group in the 4 and 6 positions has a passivating effect on the ability of the methyl group in monomethoxymethylpyrimidine derivatives to enter into azo coupling; at the same time, a methoxyl group in the 2 position does not have an appreciable effect on the activity of the methyl group because the conjugation effect of the methoxyl group in this position is less than in the 4 and 6 positions.See [1] for Communication XVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1573–1574, November, 1970.