反应详情

温度

70 °C

To a suspension of 2,4,4-trimethyl-4H-3,1-benzoxazin-5-ol (Intermediate 202, 500 mg, 2.61 mmol) and 2-chloro-5-nitropyridine (410 mg, 2.58 mmol) in dry DMF (4 mL) potassium carbonate (400 mg, 2.89 mmol) was added and the resulting mixture was heated in a MW apparatus at 70° C. for 40 min. The mixture was diluted with water and ethyl acetate, phases were separated and the aqueous was back-extracted with ethyl acetate (2×20 mL). The combined organic layers were washed with brine (2×20 mL), dried over Na2SO4, filtered and concentrated and the residue was purified by flash chromatography on silica gel using cyclohexane/ethyl acetate from 70:30 to 50:50 as eluents affording the title compound (225 mg) as yellow foam.

1. additionwas added
2. customwere separated
3. extractionthe aqueous was back-extracted with ethyl acetate (2×20 mL)
4. washThe combined organic layers were washed with brine (2×20 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customthe residue was purified by flash chromatography on silica gel