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)(2,5-dichloro-3-trifluoromethyl-4-pyridyl)methanol obtained in Step (b) dissolved in 100 ml of toluene, followed by stirring under reflux with heating for 6 hours. The mixture was cooled and then subjected to filtration, and toluene was distilled off under reduced pressure. The crude product 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 (melting point 106 to 109° C.).

1. temperatureunder reflux
2. temperaturewith 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 was purified by silica gel column chromatography