反应详情

To a suspension of 2-amino-5-nitrophenol (3.00 g) in N,N-dimethylformamide (30 mL) was added potassium fluoride (3.40 g), and the mixture was stirred at room temperature for 15 minutes, and thereto was added 2-bromo-2-methylpropiophenone (4.42 g). The mixture was stirred at room temperature for 0.5 hour, at 60° C. for 20 hours and at 80° C. for 3 days. After cooling, to the reaction mixture was added cold water, and the mixture was extracted with ethyl acetate. The organic layer was washed successively with water and brine, dried over sodium sulfate and concentrated in vacuo. The resultant residue was purified by column chromatography on silica gel (solvent; n-hexane/ethyl acetate=10/1) to give 2,2-dimethyl-7-nitro-3-phenyl-2H-1,4-benzoxazine (3.65 g) as a pale yellow powder.

1. stirringThe mixture was stirred at room temperature for 0.5 hour, at 60° C. for 20 hours and at 80° C. for 3 days
2. temperatureAfter cooling, to the reaction mixture
3. extractionthe mixture was extracted with ethyl acetate
4. washThe organic layer was washed successively with water and brine
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated in vacuo
7. customThe resultant residue was purified by column chromatography on silica gel (solvent; n-hexane/ethyl acetate=10/1)