反应详情

To a solution of ethyl 2,2-dimethylchroman-6-carboxylate (Compound 216, 500 mg, 2.14 mmol) in HOAc (4 mL) was added Br2 (0.11 mL, 2.14 mmol). The reaction mixture was stirred at room temperature overnight and then a stream of air was passed through the reaction mixture to remove the excess Br2. Removal of the solvent under reduced pressure and column chromatography using the residue (EtOAc:hexanes1:9) afforded 741 mg (100%) of the title compound as an oil. 1H NMR δ 8.05 (1H, d, J=2.2 Hz), 7.73 (1H, d, J=2.2 Hz), 4.34 (2H, q, J=7.1 Hz), 2.84 (2H, t, J=6.7 Hz), 1.85 (2H, t, J=6.7 Hz), 1.40 (6H, s), 1.38 (3H, t, J=7.2 Hz). Anal (C14H17BrO3.0.2 H2O) C, H.

1. customto remove the excess Br2
2. customRemoval of the solvent under reduced pressure and column chromatography