反应详情

To a solution of [5-(2-bromo-phenyl)-2H-pyrazol-3-yl]-thiourea (1.6 g, 5.38 mmol) in glacial AcOH (200 mL) was added a 1.5 M solution of bromine in AcOH (3.59 mL, 5.38 mmol) dropwise under vigorous stirring. The resulting heterogeneous mixture was stirred at room temperature for 2 hours then at 80° C. for 1 hour. The reaction was cooled to room temperature and concentrated to dryness. Water was added followed by 1 N aqueous NaOH to neutralize to pH 7. The resulting precipitate was filtered, washed with water and dried in vacuo. The solid was then refluxed in MeOH for 2 hours, filtered and washed with MeOH to give 588 mg of pure 3-(2-bromo-phenyl)-1H-pyrazolo[3,4-d]thiazol-5-ylamine as an off-white solid. The filtrate was further purified on silica gel with 0-10% MeOH in CH2Cl2 as eluent to provide another 460 mg of 3-(2-bromo-phenyl)-1H-pyrazolo[3,4-d]thiazol-5-ylamine for a total of 1.408 g (88% yield). 1H-NMR (d6-DMSO) δ: 13.1 and 12.6 (2 broad s, 1H, NH+tautomer), 7.73 (d, 1H), 7.61 (broad m, 1H), 7.48 (m, 3H), 7.34 (t, 1H); HPLC/MS m/z: 294.9, 296.9 [MH]+.

1. waitat 80° C. for 1 hour
2. temperatureThe reaction was cooled to room temperature
3. concentrationconcentrated to dryness
4. additionWater was added
5. filtrationThe resulting precipitate was filtered
6. washwashed with water
7. customdried in vacuo
8. temperatureThe solid was then refluxed in MeOH for 2 hours
9. filtrationfiltered
10. washwashed with MeOH