Synthesis, dehydration and oxidation of 3-cyano-4,6-diaryl-5-ethoxycarbonyl-6-hydroxypiperidine-2-thiones

6-Hydroxypiperidine-2-thiones 2 and 1,4-dihydropyridine-2(3H)-thiones (3) u nder bar were obtained by an unsymmetrical condensation of ethyl 4-nitroben zoylacetate, an aromatic aldehyde and cyanothioacetamide in the presence of piperidine with subsequent acidification. Oxidation of piperidine-2-thione s (2) under bar with iodine yielded 2,2'-bis(1,4,5,6-tetrahydropyridyl)disu lfides (4) under bar. 2,2'-Bis(1,4-dihydropyridyl)disulfides (5) under bar were obtained by treatment of (1) under bar or (4) under bar with hydrochlo ric acid, or by oxidation of 1,4-dihydropyridine-2(3H)thiones (3) under bar with iodine.