反应详情

A mixture of 3-(4-methoxy-2,5-dimethyl-phenyl)-1-methyl-5-trifluoromethyl-1H-pyrazole (described in Reference Preparation example 85) 3 g, 47% hydrobromic acid 29 ml and acetic acid 29 ml was stirred with heating under reflux for twenty one hours. The solvent was distilled off and to the resulting residues was added ice water 90 ml. The precipitates were filtered and were washed with ice water 90 ml and hexane 100 ml, and then were concentrated under reduced pressure to give 2,5-dimethyl-4-(1-methyl-5-trifluoromethyl-1H-pyrazol-3-yl)-phenol 2.9 g.

1. temperaturewith heating
2. temperatureunder reflux for twenty one hours
3. distillationThe solvent was distilled off and to the resulting residues
4. additionwas added ice water 90 ml
5. filtrationThe precipitates were filtered
6. washwere washed with ice water 90 ml and hexane 100 ml
7. concentrationwere concentrated under reduced pressure