反应详情

A mixture of 2.28 g (10 mmol) of 1-phenyl-3-trifluoromethyl-5-hydroxypyrazole and 1.6 g (12 mmol) of N-chlorosuccinimide in 8 ml of 20% TFA/acetic acid and 32 mL of acetic acid was stirred at room temperature for 16 hours and diluted with ice/water with cooling. The white precipitate was filtered and purified by column chromatography (silica gel; 20-33% ethyl acetate/hexane) to afford 550 mg (21%) of 1-phenyl-3-trifluoromethyl-4-chloropyrazole as a solid.

1. temperaturewith cooling
2. filtrationThe white precipitate was filtered
3. custompurified by column chromatography (silica gel; 20-33% ethyl acetate/hexane)