反应详情

5.35 ml (55 mmoles) of 2-chloropropionyl chloride are added dropwise, at a temperature of 20° to 25° C. and while stirring, to a suspension of 7.5 g (50 mmoles) of 2,3-dihydro-3-methyl-1,4-benzoxazine and 5.8 g (55 mmoles) of sodium carbonate in 120 ml of benzene. The reaction mixture is then stirred at the same temperature for 30 minutes and is then taken up in a mixture of water and ethyl acetate. The organic phase is washed with saturated sodium chloride solution, dried over sodium sulfate and evaporated. Crystallising the residue from diisopropyl ether gives 19.8 g of 4-(2-chloropropionyl)-2,3-dihydro-3-methyl-1,4-benzoxazine, melting point 88°-90° C.

1. washThe organic phase is washed with saturated sodium chloride solution
2. dry with materialdried over sodium sulfate
3. customevaporated
4. customCrystallising the residue from diisopropyl ether