2-Chloro-6-methylnicotinic acid

28900-10-9

30529-70-5

General procedure for the synthesis of 2-chloro-6-methylnicotinic acid from 2-chloro-6-methyl-3-pyridinecarbonitrile: First, 2-chloro-3-cyano-6-methylpyridine (3.05 g) was dissolved in 75% sulfuric acid (10 mL). The reaction mixture was stirred at 110 °C for 2 hours. Upon completion of the reaction, the reaction solution was cooled to room temperature and slowly added dropwise to ice water. After stirring the ice-water mixture for 10 minutes, the precipitated crystals were collected by filtration and dried to give 2.91 g of 2-chloro-6-methylnicotinic acid in 85% yield. Next, the resulting 2-chloro-6-methylnicotinic acid (2.91 g) was mixed with 28% aqueous ammonia solution (35 mL) and placed in an autoclave and reacted at 170 °C for 40 hours. At the end of the reaction, the reaction solution was cooled to room temperature and the ammonia was removed by distillation under reduced pressure. The precipitated crystals were collected by filtration, washed with water and air-dried to give 1.91 g of amino-6-methylnicotinic acid in 74% yield. The total yield of the whole synthesis process was 62.9%.