Methylation of the cyclic homolog of xanthine

Alkylation of the cyclic homolog of xanthine in the methyl iodide-sodium hydride system as a function of the reagent-alkylating system ratio yields different products: for a 13 ratio of reagents, a homolog of caffeine is formed, while for a 12 ratio, a homolog of theobromine is formed. In contrast to xanthine, methylation of its cyclic homolog initially takes place at the imidazole ring and occurs in the sequence N₍₁₎, N₍₄₎, N₍₇₎.A. V. Bogatskii National Academy of Sciences of Ukraine, Odessa 270080. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 701–703, May, 1998.