反应详情

To a solution of 5-(2-methoxy-5-nitro-phenyl)-1-methyl-1H-pyrazole (7.95 g, 34.1 mmol) in acetic acid (250 mL) was added zinc dust (11.7 g, 179 mmol) in portions under cooling in an ice bath over a period of 10 minutes. After stirring for 30 min at room temperature, solids were filtered of through celite. Filtrate was concentrated and residue was purified by SiO2 column chromatography (Eluent: methylene chloride/methanol 20:1) to give 4-methoxy-3-(2-methyl-2H-pyrazol-3-yl)-phenylamine (4.34 g, 21.4 mmol, 62%) as an oil. LCMS m/z (%)=204 (M+H). 1H NMR (400, CDCl3) δ: 7.51 (d, J=1.8 Hz, 1H), 6.83 (d, J=8.7 Hz, 1H), 6.76 (dd, J=2.8, 8.7 Hz, 1H), 6.62 (d, J=2.8 Hz, 1H), 6.22 (d, J=1.8 Hz, 1H), 3.74 (s, 3H), 3.73 (s, 3H), 3.24-3.55 (broad s, 2H).

1. temperatureunder cooling in an ice bath over a period of 10 minutes
2. filtrationsolids were filtered of through celite
3. concentrationFiltrate was concentrated
4. customresidue was purified by SiO2 column chromatography (Eluent: methylene chloride/methanol 20:1)