反应详情

EDC (14.0 g, 73.0 mmol) and DMAP (4.0 g) are added to a solution of 3,5-dibromobenzoic acid (10.0 g, 36.0 mmol) and tert-butanol (3.4 g, 46.8 mmol) in absolute CH2Cl2 (100 ml) and absolute pyridine (30 ml), and the mixture is stirred at RT for 1 h and then at 50° C. for 2 h. The reaction solution is diluted with CH2Cl2 (100 ml) and extracted with a semisaturated aqueous NH4Cl solution (200 ml) (2×), dried over MgSO4, filtered off and concentrated under reduced pressure. Further purification by chromatography [toluene/acetone (95:5)] on a silica gel column gives the title compound (7.7 g) as slightly yellow crystals. TLC, silica gel, glass plates, [toluene/acetone (7.5:2.5)], Rf=0.78.

1. waitat 50° C. for 2 h
2. extractionextracted with a semisaturated aqueous NH4Cl solution (200 ml) (2×)
3. dry with materialdried over MgSO4
4. filtrationfiltered off
5. concentrationconcentrated under reduced pressure
6. customFurther purification by chromatography [toluene/acetone (95:5)] on a silica gel column