SYNTHESIS AND PROPERTIES OF 3-CYANO-4-(4-CYANOPHENYL)-1,4-DIHYDROPYRIDINE-2(3H)-THIONES
DOI:
https://doi.org/10.1007/239Keywords:
pyridines, thienopyridines, alkylation, intramolecular cyclizationAbstract
Piperidinium 3-cyano-4-(4-cyanophenyl)-1,4-dihydropyridine-2(3H)-thiolates were obtained by the condensation of 1,3-dicarbonyl compounds, 4-cyanobenzaldehyde, and cyanothioacetamide in the presence of an equimolar amount of piperidine. The acidification of these thiolates gave the corresponding 1,4-dihydropyridine-2(3H)-thiones and pyridine-2(1H)-thione. Alkylation of 1,4-dihydropyridine-2-thiolates or the reaction mixture of the three-carbon condensation using iodacetamide gave 2‑carbamoylmethylthio-1,4,5,6-tetrahydro- or 1,4-dihydropyridines, which were characterized by their conversion to 4,7-dihydrothieno[2,3-b]pyridines.
Authors: A. Krauze and G. Duburs.
English Translation in Chemistry of Heterocyclic Compounds, 2000, 36 (6), pp 693-697