Hydrochloric Acid → 3-(4-methoxy-3-methyl-phenyl)-1-methyl-5-trifluoromethyl-1H-pyrazole

Participants

Reaction Steps

A mixture of 5-(4-methoxy-3-methyl-phenyl)-2-methyl-3-trifluoromethyl-3,4-dihydro-2H-pyrazol-3-ol (described in Reference preparation example 77) 2.3 g, 6N aqueous hydrochloric acid solution 4 ml and tetrahydrofuran 30 ml was stirred with heating under reflux for two hours. The reaction mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium carbonate solution and saturated saline. The organic layer was dried over anhydrous magnesium sulfate, and was then concentrated under reduced pressure. The resulting residue was subjected to a silica gel column chromatography to give 3-(4-methoxy-3-methyl-phenyl)-1-methyl-5-trifluoromethyl-1H-pyrazole 2.2 g.

Provenance & Evidence