反応 #792176

反応方程式

sodium hydroxide

Water

ethyl 1-(3-chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazole-5-carboxylate

water

→

title compound

1-(3-Chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazole-5-carboxylic acid

溶媒

methanol

反応条件

後処理

1. 1
   抽出the reaction mixture was extracted with ethyl ether, which
2. 2
   抽出extracted with ethyl acetate (50 mL)
3. 3
   抽出The ethyl acetate extract
4. 4
   洗浄which was washed with water (20 mL) and brine (20 mL)
5. 5
   乾燥dried over magnesium sulfate
6. 6
   濃縮concentrated

実験手順

To a stirred solution of ethyl 1-(3-chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazole-5-carboxylate (i.e. product of Step B) (0.92 g, 2.8 mmol) in methanol (15 mL) was added water (5 mL), which caused the reaction mixture to become cloudy. An aqueous solution of sodium hydroxide (50%, 1.5 g, 19.2 mmol) was added dropwise, and the reaction mixture was stirred at room temperature for 30 minutes, during which time the reaction mixture became again clear. Water (20 mL) was added and the reaction mixture was extracted with ethyl ether, which was discarded. The aqueous phase was acidified to pH 2 using concentrated hydrochloric acid and then extracted with ethyl acetate (50 mL). The ethyl acetate extract, which was washed with water (20 mL) and brine (20 mL), dried over magnesium sulfate and concentrated to give the title compound, isolated as a white solid (0.8 g).

出典