反应详情

0.047 g (0.25 mmol) of ferrocene was weighed and placed in a two-neck flask and the atmosphere in the flask was replaced with argon. The following materials were added thereinto: 0.07 ml (0.88 mmol) of 4-methylpyrazole, 1.7 ml of dimethyl sulfoxide, 1.7 ml of a 1 N dimethyl sulfoxide solution of sulfuric acid, 0.7 ml of a 3.0 mol/l dimethyl sulfoxide solution of trifluoromethyl iodide and 0.15 ml of a 30% hydrogen peroxide aqueous solution, and the mixture was stirred for 20 minutes. During the stirring, the temperature of the reaction system rose up in the range of from 40° C. to 50° C. Thereafter the resulting solution was cooled to room temperature. Formation of 4-methyl-3-trifluoromethylpyrazole (19F-NMR yield: 45%) was confirmed by 19F-NMR with 2,2,2-trifluoroethanol as an internal standard. The subsequent procedure was conducted in the same manner as in Example 1 and 4-methyl-3-trifluoromethylpyrazole was obtained as a colorless oil (0.054 g, yield: 36%).

1. customplaced in a two-neck flask
2. additionThe following materials were added
3. customrose up in the range of from 40° C. to 50° C