反应详情

温度

0 °C

To a solution of methyl 4-(4-chloro-2-fluorophenyl)nicotinate (15 g, 56.5 mmol) (as prepared in Ex 1, Part B) in a solvent mixture of methanol (150 mL) and water (150 mL) cooled to 0° C. was added sodium hydroxide (9.03 g, 226 mmol) and the mixture was warmed to room temperature and stirred for 1 h. The reaction mixture was concentrated under reduced pressure and pH of the resultant aqueous solution was adjusted to pH=4 using 1.5 N Hydrochloric acid during which time the product crashed out as a solid. Filtration of the mixture provided 4-(4-chloro-2-fluorophenyl)nicotinic acid (9 g, 35.8 mmol, 63% yield) as an off white solid. LC/MS (ESI) m/e 252.0 [(M+H)+, calcd for C12H8ClFNO2 252.1]; LC/MS retention time (method A): tR=0.97 min.

1. temperaturethe mixture was warmed to room temperature
2. concentrationThe reaction mixture was concentrated under reduced pressure and pH of the resultant aqueous solution
3. filtrationFiltration of the mixture