反应详情

To a solution of [5-(2-chloro-phenyl)-2H-pyrazol-3-yl]-thiourea (2.25 g, 8.9 mmol) in glacial AcOH (900 mL) was added a 1.5 M solution of bromine in AcOH (20 mL) dropwise under vigorous stirring. The resulting heterogeneous mixture was stirred at room temperature for 2 hours then it was concentrated to dryness. Water was added followed by a saturated solution of aqueous sodium bicarbonate to neutralize to pH 7. The resulting precipitate was filtered, washed with water and dried in vacuo. Recrystallization from isopropyl alcohol afforded 1.48 g (66% yield) of 3-(2-chloro-phenyl)-1H-pyrazolo[3,4-d]thiazol-5-ylamine as a tan solid. 1H-NMR (d4-MeOH) δ: 7.64 (broad s, 1H), 7.53 (d, 1H), 7.42 (m, 2H); HPLC/MS m/z: 251 [MH]+.

1. concentrationit was concentrated to dryness
2. additionWater was added
3. filtrationThe resulting precipitate was filtered
4. washwashed with water
5. customdried in vacuo
6. customRecrystallization from isopropyl alcohol