Synthesis of 6-methyl-3-cyano-5-ethylpyridine-2(IH)thione and condensed heterocycles based on this compound

Summary It has been established that the direction of formylation of methyl propyl ketone depends on the reaction conditions. By condensation of the synthesized salts of 3-hydroxymethylene-2 pentanone with cyanothioacetamide, we have synthesized 6-methyl-3-cyano-5-ethylpyridine-2(1H)-thione and 6 propyl-3cyancpyridine-2(IH)-thione, respectively, which are alkylated regioselectively by halides ClCH₂Z (Z = Alk, COOAlk, COPh, CONH₂, CN) at the sulfur atom. These thiones and the derived 2-SCH₂Z-3-cyanopyridines have been used in the regioselective synthesis of substituted annelated heterocycles: 3-aminothieno(2, 3b]pyridines and 4-aminopyridol2,3:2,3]thieno4,5-d]pyrimidines. 3:2, 3]thieno4, 5-d]pyrimidines.N. D. Zelinski Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 851–857, June, 1995. Original article submitted May 22, 1995.