反应详情

温度

-78 °C

A mixture of 4-(5-hydroxy-3-trifluoromethyl-pyrazol-1-yl)-benzoic acid ethyl ester (1 g, 3.3 mmol), difluorochloromethane (3 g, 34 mmol) and potassium carbonate (0.5 g, 3.6 mmol) in DMF (9 mL) was stirred in a sealed tube at −78° C. for 3 minutes and then at 100° C. for 12 hours. The mixture was cooled to −78° C. and the precipitate was removed by filtration and washed with DMF (3×1 mL). The filtrate and washings were poured into cold water (200 mL). The resulting suspension was transferred into a centrifuge tube and the contents were centrifuged at room temperature for 10 minutes and filtered to give 4-(5-difluoromethoxy-3-trifluoromethyl-pyrazol-1-yl)-benzoic acid ethyl ester (1.1 g, 94% yield) as a yellow solid.

1. waitat 100° C. for 12 hours
2. temperatureThe mixture was cooled to −78° C.
3. customthe precipitate was removed by filtration
4. washwashed with DMF (3×1 mL)
5. additionThe filtrate and washings were poured into cold water (200 mL)
6. customThe resulting suspension was transferred into a centrifuge tube
7. waitthe contents were centrifuged at room temperature for 10 minutes
8. filtrationfiltered