反应详情

423 g of 3-chloro-5-trifluoromethyl-2-pyridinecarboxylic acid ethyl ester (Example P2) is placed in a mixture of 800 ml of water and 160 ml of ethanol. 800 ml of a 2N sodium hydroxide solution are added dropwise at below 35° C. After 3 hours, the mixture is washed twice with dichloromethane and then rendered acidic with excess concentrated hydrochloric acid while cooling with an ice-bath. The resulting slurry is filtered, washed with water and dried in vacuo. 318 g of the desired product are obtained in the form of a white solid having a melting point of 135° C. (decomposition).

1. washthe mixture is washed twice with dichloromethane
2. temperaturewhile cooling with an ice-bath
3. filtrationThe resulting slurry is filtered
4. washwashed with water
5. customdried in vacuo