反应详情

To a solution of 6-fluoro-2H-1,4-benzoxazin-3(4H)-one (1.5 g) in tetrahydrofuran (30 ml), lithium aluminum hydride (683 mg) was added under ice cooling and heated under reflux for 3.5 hours. The reaction mixture was cooled to room temperature, diluted with 28% aqueous ammonia under ice cooling, and then filtered to remove insoluble materials. The filtrate was evaporated under reduced pressure to remove the solvent. The resulting residue was purified by silica gel column chromatography (eluting solvent: n-hexane:ethyl acetate=20:1 to 5:1) to give the titled compound, i.e., 6-fluoro-3,4-dihydro-2H-1,4-benzoxazine (1.35 g) as a red oil.

1. temperatureheated
2. temperatureunder reflux for 3.5 hours
3. filtrationfiltered
4. customto remove insoluble materials
5. customThe filtrate was evaporated under reduced pressure
6. customto remove the solvent
7. customThe resulting residue was purified by silica gel column chromatography (eluting solvent: n-hexane:ethyl acetate=20:1 to 5:1)