反应详情

4-Nitro-1-(2-pyrrolidin-1-yl-ethyl)-1H-indazole (1.90 g, 7.30 mmol), iron powder (4.10 g, 73.4 mmol), and ammonium chloride (0.200 g, 3.65 mmol) were suspended in a 4:1 solution of ethanol/H2O. The mixture was heated to reflux for 3 hours, cooled to room temperature and concentrated under reduced pressure. The residue was taken up and stirred in triethylamine/ethyl acetate (1/4, 30 mL) for 15 minutes and filtered through a plug of silica gel. The silica gel was rinsing with triethylamine/ethyl acetate (1/4) and combined filtrate concentrated under reduced pressure to provide the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.62 (m, 4H), 2.44 (m, 4H), 2.81 (t, 2H, J=6.78), 4.34 (t, 2H, J=6.78), 5.73 (s, 2H), 6.13 (m, 1H), 6.66 (m, 1H), 7.01 (m, 1H), 8.05 (s, 1H); MS (DCI/NH3) m/z 231 [M+H]+.

1. temperatureThe mixture was heated
2. temperatureto reflux for 3 hours
3. concentrationconcentrated under reduced pressure
4. filtrationfiltered through a plug of silica gel
5. washThe silica gel was rinsing with triethylamine/ethyl acetate (1/4)
6. concentrationconcentrated under reduced pressure