反应详情

To a solution of the product of step 1 (60 g, 246 mmol) in CCl4 (900 mL) and CHCl3 (900 mL) was added dropwise a solution of Br2 (43.2 g, 270 mmol) in CCl4 (50 mL). After addition was completed, the mixture was concentrated to about 1/3 of its original volume. The mixture was washed with saturated NaHCO3 (500 mL) and Na2S2O8 (2×250 mL). The pale yellow solution was dried over Na2SO4 and concentrated to dryness. The residue was stirred in 10 % EtO2 /hexane for 20 h and filtered to give 59 g of the title compound.

1. additionAfter addition
2. concentrationthe mixture was concentrated to about 1/3 of its original volume
3. washThe mixture was washed with saturated NaHCO3 (500 mL) and Na2S2O8 (2×250 mL)
4. dry with materialThe pale yellow solution was dried over Na2SO4
5. concentrationconcentrated to dryness
6. filtrationfiltered