2.22 g (10 mmol) of ethyl 3-(4-methoxyphenyl)-3-oxopropanoate, 50 ml of ethanol, 5 ml of pyridine and 0.5 ml of triethylamine are added respectively to 2.33 g (10 mmol) of 2-cyano-3-(2-nitrophenyl)prop-2-enethioamide. The reaction mixture is stirred at reflux for 5 hours. After returning to room temperature, the solvent is evaporated and the reaction mixture is poured over crushed ice. Acetic acid is added until an acidic pH (2 to 3) is obtained. The precipitate formed is filtered, rinsed with water and diethyl ether, and then dried under vacuum to yield 4.35 g (92%) of ethyl 5-cyano-2-(4-methoxyphenyl)-4-(2-nitrophenyl)-6-thioxo-1,6-dihydropyridine-3-carboxylate in the form of a yellow powder.
