反应详情

A mixture of 5-nitro-1-(2-piperidin-1-yl-ethyl)-1H-indazole (4.3 g, 16 mmol), iron powder (8.8 g, 157 mmol), and ammonium chloride (430 mg, 8 mmol) in a 4:1 ethanol/H2O solution (75 mL) was heated to reflux for 3 hours, cooled to room temperature and concentrated under reduced pressure. The residue was stirred in triethylamine/ethyl acetate (1/4, 50 mL) for 15 minutes, filtered through a plug of silica gel which was rinsed with triethylamine/ethyl acetate (1/4). The filtrate was concentrated under reduced pressure to provide the title compound (3.4 g, 93%). 1H NMR (300 MHz, DMSO-d6) ppm 1.34–1.45 (m, 6H), 2.36 (m, 4H), 2.64 (t, J=6.44, 2H), 4.35 (t, J=6.44, 2H), 4.76 (s, 2H), 6.71 (m, 1H), 6.79 (m, 11H), 7.35 (m, 1H), 7.67 (m, 1H); MS (DCI/NH3) m/z 245 [M+H]+.

1. temperaturewas heated
2. temperatureto reflux for 3 hours
3. concentrationconcentrated under reduced pressure
4. filtrationfiltered through a plug of silica gel which
5. washwas rinsed with triethylamine/ethyl acetate (1/4)
6. concentrationThe filtrate was concentrated under reduced pressure