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 solution of 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