反应详情

To a solution of product from step A (96 mg, 0.20 mmol) in ethanol (4.0 mL) and water (2.0 mL) was added iron powder (57 mg, 1.02 mmol) and ammonium chloride (12 mg, 0.22 mmol). After refluxing for 3 h, the reaction mixture was filtered through a bed of celite and the celite bed washed repeatedly with ethyl acetate. The filtrate was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to give a crude product which was purified by flash column chromatography (SiO2, 3:2 hexanes/ethyl acetate) to give the product tert-butyl 8-(4-aminophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate (76 mg, 87%) as an off-white solid: 1H NMR (CDCl3, 300 MHz) δ 8.22-8.19 (m, 1H), 7.88 (dd, J=8.7, 1.8 Hz, 1H), 7.81-7.75 (m, 2H), 7.67 (d, J=8.4 Hz, 1H), 6.97-6.91 (m, 2H), 4.48 (s, 2H), 3.54-3.52 (m, 2H), 3.23-3.16 (m, 2H), 1.55 (s, 9H).

1. temperatureAfter refluxing for 3 h
2. filtrationthe reaction mixture was filtered through a bed of celite
3. washthe celite bed washed repeatedly with ethyl acetate
4. dry with materialThe filtrate was dried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give a crude product which
8. customwas purified by flash column chromatography (SiO2, 3:2 hexanes/ethyl acetate)