反应详情

Pyridine (25 ml) was added to a mixture of 3,4-dihydro-2H-1,4-benzoxazine (17.8 g) in DCM (200 ml). The mixture was cooled on an ice bath and poured out into a mixture of m-chloro-cinnamoyl chloride (33 g) in DCM (100 ml). The mixture was stirred at room temperature overnight. Water was added and the mixture was decanted. The organic layer was dried, filtered and the solvent was evaporated till dryness, to give a residue which was purified by column chromatography over silica gel (eluent: cyclohexane/ethyl acetate 80/20) and recrystallisation from ACN/diethyl ether, yielding 26 g (65.8%) of 4-[3-(3-chlorophenyl)-1-oxo-2-propen-1-yl]-2,3-dihydro-4H-1,4-benzoxazine (interm. 51).

1. temperatureThe mixture was cooled on an ice bath
2. customthe mixture was decanted
3. customThe organic layer was dried
4. filtrationfiltered
5. customthe solvent was evaporated till dryness
6. customto give a residue which
7. customwas purified by column chromatography over silica gel (eluent: cyclohexane/ethyl acetate 80/20) and recrystallisation from ACN/diethyl ether