反应详情

5-Amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-(1,2,4-oxadiazol-3-yl)-4-trifluoromethylsulfinylpyraz ole (500 mg, 1.04 mmol) and N,N-dimethylformamide dimethylacetal (90%) (280 mg, 2.12 mmol) were suspended in 20 ml of dry toluene. The resulting suspension was stirred with heating under reflux for 5 hours. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. The residue was dissolved in 50 ml of toluene and then concentrated again under reduced pressure. The resulting concentrated residue was purified by subjecting to silica gel preparative TLC [developing solvent: mixed solvent of hexane and ethyl acetate (volume ratio=3:1)] to obtain 350 mg (0.65 mmol) of the title compound as a colorless crystal. Yield 62.5%.

1. temperaturewith heating
2. temperatureunder reflux for 5 hours
3. concentrationconcentrated under reduced pressure
4. dissolutionThe residue was dissolved in 50 ml of toluene
5. concentrationconcentrated again under reduced pressure
6. customThe resulting concentrated residue was purified
7. additionby subjecting to silica gel preparative TLC [developing solvent: mixed solvent of hexane and ethyl acetate (volume ratio=3:1)]