Synthesis of 6-Alkylthio-5-carbamoyl-3-cyano-4-phenyl-3,4-dihydropyridin-2(1H)-ones

Condensation of ethyl benzylidenecyanoacetate with thiocarbamoylacetamide in the presence of an equimolar amount of piperidine produces piperidinium 5-carbamoyl-3-cyano-2-oxo-4-phenyl-3,4-dihydropyridine-6(1H)-thiolate, which is then used in synthesis of the corresponding 6-alkylthiosubstituted 3,4-dihydropyridin-2(1H)-ones. Dedicated to Professor Henk van der Plas on his 70th birthday. Latvian Institute of Organic Synthesis, Riga LV-1006 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 506–509, April, 1999.