反应 #792176

反应方程式

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

溶剂

methanol

反应条件

后处理

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

实验过程

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).

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