反应详情

To a solution of methyl 2-[(2-bromoethyl)oxy]-5-nitro-3-[(phenylcarbonyl)oxy]benzoate (30 g, 70.7 mmol) in methanol (200 mL) was added potassium carbonate (9.8 g, 70.7 mmol). The reaction mixture was allowed to stir at room temperature for 30 min., at which time it was concentrated in vacuo. The residue was taken up in N,N-dimethylformamide (150 mL) and the resulting suspension was heated to 65° C. and stirred for 12 h. The reaction mixture was then cooled to room temperature and concentrated. The residue was dissolved in water (300 mL) and extracted with ethyl acetate (2×300 mL). The combined organic layers were washed with brine, dried over anhydrous magnesium sulfate and concentrated. The residue was triturated with 10% diethyl ether/hexanes to give 5.6 g (33%) of methyl 7-nitro-2,3-dihydro-1,4-benzodioxine-5-carboxylate as an off-white powder: 1H NMR (400 MHz, CDCl3): 8.34 (d, J=2.8 Hz, 1H), 7.90 (d, J=2.8 Hz, 1H), 4.48-4.46 (m, 2H), 4.37-4.35 (m, 2H), 3.93 (s, 3H).

1. concentrationwas concentrated in vacuo
2. temperaturethe resulting suspension was heated to 65° C.
3. stirringstirred for 12 h
4. temperatureThe reaction mixture was then cooled to room temperature
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in water (300 mL)
7. extractionextracted with ethyl acetate (2×300 mL)
8. washThe combined organic layers were washed with brine
9. dry with materialdried over anhydrous magnesium sulfate
10. concentrationconcentrated
11. customThe residue was triturated with 10% diethyl ether/hexanes