反应详情

To the flask charged with 2-chloro-3-(hydroxymethyl)phenol from Step A and a stir bar was added NBS (10.8 g, 60.5 mmol) and TFA (50 mL). The reaction was allowed to stir for 16 hours at RT. TLC showed complete reaction at that point. The solvent was removed under vacuum. The residue was re-dissolved in EtOAc, washed with water, and purified by silica gel flash chromatography. A pair of regio-isomers was collected from the separation. The less polar spot was the desired 4-bromo-2-chloro-3-(hydroxymethyl)phenol according to noe NMR analysis. 1H-NMR (500 MHz, CDCl3) δ ppm 7.42 (d, J=8.5 Hz, 1H), 6.92 (d, J=8.5 Hz, 1H), 4.96 (s, 2H).

1. customreaction at that point
2. customThe solvent was removed under vacuum
3. dissolutionThe residue was re-dissolved in EtOAc
4. washwashed with water
5. custompurified by silica gel flash chromatography
6. customA pair of regio-isomers was collected from the separation