反应详情

To a stirring solution of 5-(3-chloro-phenyl)-2H-pyrazol-3-ylamine (1.53 g, 7.9 mmol) in THF (32 mL) was added N-bromosuccinimide (1.55 g, 8.7 mmol). The reaction mixture was stirred for 5 h at room temperature, then absorbed on silica gel. Purification on silica gel with 0-10% MeOH in CH2Cl2 as eluent provided 1.73 g (80%) of 4-bromo-5-(3-chloro-phenyl)-2H-pyrazol-3-ylamine as a brown solid. 1H NMR (d6-DMSO) δ: 12.2 and 12.4 (2 broad s, 1H, NH+tautomer), 7.77 (s, 1H), 7.73 (broad s, 1H), 7.48 (broad s, 1H), 7.43 (broad s, 1H), 5.30 (broad s, 1H, NH), 4.82 (broad s, 1H, NH); HPLC/MS m/z: 272 [MH]+.

1. customabsorbed on silica gel
2. customPurification on silica gel with 0-10% MeOH in CH2Cl2 as eluent