反应详情

A mixture of 5-chloro-3-(4-methoxy-3-methyl-phenyl)-1,4-dimethyl-1H-pyrazole (described in Reference Preparation example 92) 0.4 g, 47% hydrobromic acid 3 ml and acetic acid 3 ml was stirred with heating under reflux for fifteen hours. The solvent was distilled off and to the resulting residues was added ethyl acetate 20 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 4-(5-chloro-1,4-dimethyl-1H-pyrazol-3-yl)-2-methyl-phenol 0.3 g.

1. temperaturewith heating
2. temperatureunder reflux for fifteen hours
3. distillationThe solvent was distilled off and to the resulting residues
4. additionwas added ethyl acetate 20 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