反应详情

10 g of manganese dioxide was added to a toluene (80 ml) solution of 2.3 g (5 mmol) of (2,3,4-trimethoxy-6-methylphenyl)(2,6-dichloro-5-(1-hydroxyethyl)-4-trifluoromethyl-3-pyridyl)methanol obtained in step (a), followed by stirring under reflux by heating for 1 hour. The reaction solution was cooled to room temperature 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 1.5 g (yield 66%) of 5-(2,3,4-trimethoxy-6-methylbenzoyl)-3-acetyl-2,6-dichloro-4-trifluoromethylpyridine (compound No. 62; m.p. 109-112° C.).

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