反应详情

温度

80 °C

To a solution of 2-(3,5-dichloro-pyrid-2-yl)-malonic acid diethyl ester (118.5 g) (prepared as described in WO 07/101859) in methanol (1 ml) was added aqueous sodium hydroxide (47 g dissolved in 300 ml water). The reaction mixture was heated to 80° C. for 1 hour. The methanol was evaporated and the pH of the aqueous phase adjusted to pH 4 by addition of glacial acetic acid and then extracted with ethyl acetate. The combined organic phases were dried over magnesium sulfate and concentrated to give (3,5-dichloro-pyrid-2-yl)-acetic acid as an off-white solid (50 g). 1H-NMR (400 MHz, CDCl3): 4.04 (s, 2H), 7.81 (d, 1H), 8.45 (d, 1H) ppm.

1. customThe methanol was evaporated
2. additionthe pH of the aqueous phase adjusted to pH 4 by addition of glacial acetic acid
3. extractionextracted with ethyl acetate
4. dry with materialThe combined organic phases were dried over magnesium sulfate
5. concentrationconcentrated