反应详情

17.3 g (0.18 mol) of manganese dioxide was added to a solution having 4.35 g (9.70 mmol) of (2,3,4-trimethoxy-6-methylphenyl)(2-fluoro-4-iodo-5-methyl-3-pyridyl)methanol obtained in Step (b) dissolved in 130 ml of toluene, followed by reflux with heating for 2 hours. After cooling to room temperature, manganese dioxide was removed by filtration on the pad of celite, and toluene was distilled off under reduced pressure, followed by purification by silica gel chromatography to obtain 2.80 g (yield: 65%) of 3-(2,3,4-trimethoxy-6-methylbenzoyl)-2-fluoro-4-iodo-5-methylpyridine (Compound No. 18, melting point 140 to 141° C.).

1. temperatureby reflux
2. temperaturewith heating for 2 hours
3. custommanganese dioxide was removed by filtration on the pad of celite, and toluene
4. distillationwas distilled off under reduced pressure
5. customfollowed by purification by silica gel chromatography