反应详情

Bromine, Br2 (63.9 g) in 50 ml of dichloromethane was added dropwise to a solution of 4-chloro-6-nitrophenol (34.7 g) in 300 ml of dichloromethane. After the addition was completed, the mixture was stirred at room temperature for 30 min. Pyridine (19.0 g, 240 mmol) in 50 ml of dichloromethane was added. This mixture was stirred at room temperature for 2 hours and a white precipitate was formed. The reaction mixture was quenched with 200 ml of water and the white precipitate was dissolved. The organic layer was then washed with water (2×150 ml), 150 ml of brine and dried over MgSO4. The solvent was evaporated under vacuum to give the crude product which was recrystallized from ethyl acetate to afford 41.5 g (82%) yellow crystalline 2-nitro-4-chloro-6-bromophenol. 1H NMR (300 MHz, CDCl3) δ8.11 (d, J=2.5 Hz, 1 H), 7.87 (d, J=2.5 Hz, 1H).

1. additionAfter the addition
2. stirringThis mixture was stirred at room temperature for 2 hours
3. customa white precipitate was formed
4. customThe reaction mixture was quenched with 200 ml of water
5. dissolutionthe white precipitate was dissolved
6. washThe organic layer was then washed with water (2×150 ml), 150 ml of brine
7. dry with materialdried over MgSO4
8. customThe solvent was evaporated under vacuum
9. customto give the crude product which
10. customwas recrystallized from ethyl acetate