Chlorophenyl)-1-phenylprop-2-en-1-one reacted with 3-amino-N-phenyl-3-thioxopropanamide under basic conditions in ethanol to give a mixture of 3-(4-chlorophenyl)-2-cyano-5-oxo-N,5-diphenyl- pentanamide and 3-(4-chlorophenyl)-1,5-diphenylpentane-1,5-dione. The structure of the former was deter- mined by X-ray analysis. The reaction of the same compounds in DMSO in the presence of sodium hydroxide produced 4-(4-chlorophenyl)-N,6-diphenyl-2-thioxo-1,2,3,4-tetrahydropyridine-3-carboxamide. We previously reported on the synthesis of N-phenyl-2-thioxo-1,2,3,4-tetrahydropyridine-3-car- boxamides from chalcones and 3-amino-N-phenyl-3- thioxopropanamide (II) (1). In the present communi- cation we describe the reaction of 3-(4-chlorophenyl)- 1-phenylprop-2-en-1-one (I) with compound II. The reaction in ethanol in the presence of sodium hydrox- ide did not produce the expected product, 4-(4-chloro- phenyl)-N,6-diphenyl-2-thioxo-1,2,3,4-tetrahydropyri- dine-3-carboxamide (III) (1), but afforded 3-(4-chloro- phenyl)-2-cyano-5-oxo-N,5-diphenyl-pentanamide (IV) (presumably as a result of elimination of hydro- gen sulfide from hypothetical primary Michael adduct A) and 3-(4-chlorophenyl)-1,5-diphenylpentane-1,5-di- one (V) (Scheme 1). The latter is likely to be formed via exchange of methylene components, which is known for analogous reactions (see also (2)). In the reaction of chalcone I with amide II in DMSO in the presence of sodium hydroxide at room temperature we isolated only expected 4-(4-chloro- phenyl)-N,6-diphenyl-2-thioxo-1,2,3,4-tetrahydropyr- idine-3-carboxamide (III). Addition of methyl iodide to the reaction mixture, other conditions being equal, resulted in the formation of substituted pyridine VI. In the 1 H NMR spectrum of IV all proton signals were doubled. No appreciable change of the spectral pattern was observed on heating to 70°C (DMSO-d6); only the amide proton signal was displaced upfield by 0.3 ppm. These findings indicated free rotation of the amide fragment. The structure of IV was determined by X-ray analysis (see figure). The phenacyl group on C 1 occupies +sc-position