反应详情

To a mixture of 2-chloro-4-methyl-3-pyridinecarboxylic acid (24.7 g, 157 mmol) and 75 mL of toluene at 70° C. was added 75 mL of SOCl2 (22.6 g, 190 mmol) within a period of 1 hour. The reaction mixture was refluxed for 4 hours and the resulting solution was cooled to room temperature. Dry NH3 gas was introduced at such a rate so as to maintain the internal temperature below 30° C. After removing toluene, the solid residue was washed successively with cold water and methanol, and dried to yield 22.72 g of the title compound (91%, m.p. 168°-170° C.).

1. temperatureThe reaction mixture was refluxed for 4 hours
2. temperatureto maintain the internal temperature below 30° C
3. customAfter removing toluene
4. washthe solid residue was washed successively with cold water and methanol
5. customdried