反应详情

A solution of ethyl 5-bromo-3-(trifluoromethyl)-1H-pyrazole-1-acetate (i.e. the product of Example 11, Step C) (2.84 g, 9.4 mmol) in tetrahydrofuran (10 mL) was treated with a 50 wt. % aqueous sodium hydroxide solution (1.0 mL). The reaction mixture was stirred at room temperature for 2 h. The reaction mixture was treated with concentrated aqueous hydrochloric acid to lower the pH to 1 and then extracted with ethyl acetate. The extract was dried (MgSO4) and concentrated under pressure to give 2.26 g of the title compound as a light brown solid. Recrystallization from 1-chlorobutane (20 mL) gave 0.68 g of the title compound as lustrous light pink plates.

1. extractionextracted with ethyl acetate
2. dry with materialThe extract was dried (MgSO4)
3. concentrationconcentrated under pressure