反应详情

A solution of (3-benzyloxy-5-bromo-phenyl)-thiourea (2.0 g, 5.93 mmol) in CHCl3 (80.0 mL) was cooled to −60° C. followed by drop wise addition of a solution of bromine (0.30 mL, 5.93 mmol) in CHCl3 (20.0 mL). The resulting reaction mixture was stirred at room temperature for 15 minutes followed by refluxing at 70° C. for 1 h. The reaction mass was then cooled and basified with 25% aqueous ammonia solution to pH 8-9 and then extracted with EtOAc (3×150.0 mL). The combined organics was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude residue was purified over silica gel (60-120 M, 40% EtOAc-Hexane) to get the desired compound (1.35 g, 68%).

1. customThe resulting reaction mixture
2. temperatureby refluxing at 70° C. for 1 h
3. temperatureThe reaction mass was then cooled
4. extractionextracted with EtOAc (3×150.0 mL)
5. dry with materialThe combined organics was dried over anhydrous Na2SO4
6. concentrationconcentrated under reduced pressure
7. customThe crude residue was purified over silica gel (60-120 M, 40% EtOAc-Hexane)