反应详情

14 g of manganese dioxide was added to a solution having 3.5 g (8.2 mmol) of (2,3,4-trimethoxy-6-methylphenyl)(2,915 5-dichloro-3-trifluoromethyl-4-pyridyl)methanol obtained in step (b) dissolved in 100 ml of toluene, followed by stirring under reflux by heating for 6 hours. The mixture was cooled and then subjected to filtration, and toluene was distilled off under reduced pressure. The crude product thus obtained was purified by silica gel column chromatography to obtain 3.1 g (yield 89%) of 4-(2,3,4-trimethoxy-6-methylbenzoyl-2,5-dichloro-3-trifluoromethylpyridine (compound No. 90; m.p. 106-109° C.).

1. temperatureunder reflux
2. temperatureby heating for 6 hours
3. temperatureThe mixture was cooled
4. filtrationsubjected to filtration, and toluene
5. distillationwas distilled off under reduced pressure
6. customThe crude product thus obtained
7. customwas purified by silica gel column chromatography