反应详情

At 0° C., to a mixture of 4,4,4-trifluoro-1-(4-methoxy-2,5-dimethyl-phenyl)-butane-1,3-dione (described in Reference Preparation example 83) 6.8 g and ethanol 100 ml was added methyl hydrazine 1.7 g. The resulting mixture was raised to room temperature and was stirred for one hour. The reaction mixture was concentrated under reduced pressure and the resulting residue was subjected to a silica gel column chromatography to give 5-(4-methoxy-2,5-dimethyl-phenyl)-2-methyl-3-trifluoromethyl-3,4-dihydro-2H-pyrazole-3-ol 3.2 g and 5-(4-methoxy-2,5-dimethyl-phenyl)-1-methyl-3-trifluoromethyl-1H-pyrazole 3 g.

1. concentrationThe reaction mixture was concentrated under reduced pressure