反应详情

A solution of hydrazine monohydrate (1.0 mL, 21 mmol) in MeOH (3 mL) was added dropwise to a refluxing suspension of methyl 7-nitro-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (889 mg, 3.7 mmol) and palladium on carbon (10%, 220 mg) in MeOH (25 mL) under N2. After refluxing overnight, the resulting mixture was cooled to room temperature, filtered through celite and the filter cake was washed with MeOH. The combined filtrates were concentrated under reduced pressure and the residue was purified by column chromatography on silica gel eluting with 30% ethyl acetate in hexane to yield methyl 7-amino-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (390 mg, 50%). 1H NMR (CDCl3, 600 MHz) δ 7.19 (s, 1H), 6.17 (s, 1H), 4.24-4.22 (m, 2H), 4.17-4.15 (m, 2H), 3.82 (s, 3H); MS (ES+) m/z 210.1 (M+H)+

1. temperatureAfter refluxing overnight
2. filtrationfiltered through celite
3. washthe filter cake was washed with MeOH
4. concentrationThe combined filtrates were concentrated under reduced pressure
5. customthe residue was purified by column chromatography on silica gel eluting with 30% ethyl acetate in hexane