反应详情

To a stirred solution of 3,4-dihydro-2H-benzo[1,4]oxazine (5 g, 37.0 mmol) in DMF (20 mL) was added potassium tert-butoxide (6.22 g, 55.55 mmol) at 0° C. After stirring for 5 min, bromo-cyclopropane (4.44 mL, 55.55 mmol) was added and the reaction mixture was stirred for another 4 h at room temperature. The reaction was quenched by addition of water and extracted with ethyl acetate (50×2 mL). The organic layer was washed with water (20 mL), concentrated and purified by silica gel column chromatography to furnish 4-Cyclopropyl-3,4-dihydro-2H-benzo[1,4]oxazine (4.42 g).

1. stirringthe reaction mixture was stirred for another 4 h at room temperature
2. customThe reaction was quenched by addition of water
3. extractionextracted with ethyl acetate (50×2 mL)
4. washThe organic layer was washed with water (20 mL)
5. concentrationconcentrated
6. custompurified by silica gel column chromatography