反应详情

Potassium hydroxide (0.5 g, 85%, 2.28 mmol) in water (1 mL) was added to ethyl 1-(3-chloro-2-pyridinyl)-3-(trifluoromethyl)-1H-pyrazole-5-carboxylate (i.e. the product of Step D) (0.66 g, 2.07 mmol) in ethanol (3 mL). After about 30 minutes, the solvent was removed under reduced pressure, and the mixture was dissolved in water (40 mL). The solution was washed with ethyl acetate (20 mL). The aqueous layer was acidified with concentrated hydrochloric acid and was extracted with ethyl acetate (3×20 mL). The combined extracts were dried and evaporated to give the product, as a solid (0.53 g, 93% yield), m.p. 178-179° C. (after crystallization from hexane-ethyl acetate).

1. customthe solvent was removed under reduced pressure
2. dissolutionthe mixture was dissolved in water (40 mL)
3. washThe solution was washed with ethyl acetate (20 mL)
4. extractionwas extracted with ethyl acetate (3×20 mL)
5. customThe combined extracts were dried
6. customevaporated
7. customto give the product