反应详情

A mixture of 1-(4-methoxy-3-methyl-phenyl)-3,4,5-trimethyl-1H-pyrazole (described in Reference Preparation example 33) 7.3 g, 47% hydrobromic acid 50 ml and acetic acid 50 ml was stirred with heating under reflux for thirty hours. The solvent was distilled off and to the resulting residues was added ethyl acetate 400 ml, and the resulting mixture was stirred at room temperature for one hour. The precipitates were filtered and were washed with hexane, and were concentrated under reduced pressure to give 2-methyl-4-(3,4,5-trimethyl-pyrazol-1-yl)-phenol 6.1 g.

1. temperaturewith heating
2. temperatureunder reflux for thirty hours
3. distillationThe solvent was distilled off and to the resulting residues
4. additionwas added ethyl acetate 400 ml
5. stirringthe resulting mixture was stirred at room temperature for one hour
6. filtrationThe precipitates were filtered
7. washwere washed with hexane
8. concentrationwere concentrated under reduced pressure