To a mixture of 4-methyl-2-(3-nitrophenyl)-6-phenyl-3-pyridinecarboxylic acid (1.4 g), methylene chloride (14 ml) and N,N-dimethylformamide (2.8 ml) was added a solution of thionyl chloride (0.33 ml) in methylene chloride (3 ml) at 7° C. under ice cooling. After stirring for 2 hours at the same condition, a solution of 1-methylpiperazine (1.05 g) in methylene chloride (7 ml) was added thereto and the mixture was stirred for 2 hours at the same temperature. After adding water (100 ml) and methylene chloride (50 ml) thereto, the mixture was adjusted to pH 8.5 with 10% aqueous sodium hydroxide. The organic layer was separated, washed successively with water and saturated brine, dried over magnesium sulfate and evaporated in vacuo. The residue was recrystallized from a mixture of ethanol and diethyl ether to give 4-methyl-3-(4-methylpiperazin-1-ylcarbonyl)-2-(3-nitrophenyl)-6-phenylpyridine (0.97 g).
