反应详情

In 10 ml of N,N-dimethylformamide was dissolved 2.66 g of 3,4-dihydro-2,2-dimethyl-6-nitro-2H-1,4-benzoxazine followed by addition of 1.02 g of sodium hydride (60% in oil) and the mixture was stirred at room temperature for 30 minutes. Then, 2.77 g of 2-bromopyridine N-oxide hydrochloride was added with ice-cooling and, after the evolution of heat had subsided, the mixture was stirred at room temperature for 2 hours. The reaction mixture was then poured in water and extracted with ethyl acetate. The organic layer was separated and dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure and the residue was chromatographed on a silica gel column using chloroform as the eluent to give crude 2-(3,4-dihydro-2,2-dimethyl-6-nitro-2H-1,4-benzoxazin-4-yl)pyridine N-oxide.

1. temperaturecooling
2. temperatureafter the evolution of heat
3. stirringthe mixture was stirred at room temperature for 2 hours
4. extractionextracted with ethyl acetate
5. customThe organic layer was separated
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure
9. customthe residue was chromatographed on a silica gel column