Regioselective synthesis of 5,6-polymethylene-3-cyanopyridine-2(1H)-thiones and fused heterocycles based on them

Article abstract of DOI:10.1007/BF01169725

Condensation of 2-hydroxymethylenecyclopentan-1-one or -cyclooctan-1-one sodium salts with cyanothioacetamide afforded 5,6-polymethylene-3-cyanopyridine-2(1H)-thiones which were regioselectively alkylated at the sulfur atom by alkyl halides.Derivatives of 3-cyanopyridine-2(1H)-thione and 2-alkylthio-3-cyanopyridine were used for regioselective synthesis of substituted heterocycles: 3-aminothieno<2,3-b>pyridines, pyrido<2,3:2',3'>thieno<4,5-d>pyrimidines, and pyrido<2,3:2',3'>thieno<4,5-d>oxazines. - Key words: fused heterocycles; 5,6-polymethylene-3-cyanopyridine-2(1H)-thiones; 2-alkylthio-3-cyanopyridines; 3-aminothieno<2,3-b>pyridines; pyrido<2,3:2',3'>thieno<4,5-d>pyridines; pyrido<2,3:2',3'>thieno<4,5-d>oxazines; regioselective synthesis.