反应详情

A solution of ethyl 3,5-dichloro-1H-pyrazole-1-acetate (1.29 g, 5.8 mmol) (i.e. the product of Example 12, Step E) in tetrahydrofuran (10 mL) was treated with sodium hydroxide (5 mL, 15% aqueous solution) in water (3 mL), and the reaction mixture was stirred at ambient temperature for 1.5 h. The reaction mixture was then diluted with water (15 mL) and was concentrated under reduced pressure. The aqueous solution was acidified with concentrated hydrochloric acid to pH 1. The reaction mixture was then extracted with ethyl acetate and the extract was dried over MgSO4. The extract was then concentrated and recrystallized from 20% ethyl acetate in hexanes to give 370 mg of the title compound.

1. concentrationwas concentrated under reduced pressure
2. extractionThe reaction mixture was then extracted with ethyl acetate
3. dry with materialthe extract was dried over MgSO4
4. concentrationThe extract was then concentrated
5. customrecrystallized from 20% ethyl acetate in hexanes