Imidazole → (4-Bromo-3-bromomethyl-phenoxy)-tert-butyl-dimethyl-silane

Participants

Reaction Conditions

Reaction Steps

4-Bromo-3-methylphenol(4.49 g, 24.0 mmol), t-butyldimethylsilyl chloride (5.43 g, 36.0 mmol) and imidazole (4.90 g, 22.0 mmol) in N,N-dimethylformamide (30 ml) were stirred at room temperature for 16 h. Water (100 ml) was added and the products extracted with ethyl acetate. Drying (MGSO4), evaporation to dryness under reduced pressure and purification by flash chromatography using hexane as eluent gave the crude silylated phenol (4.16 g, 57%), to this crude product (4.16 g, 13.77 mmol) was added N-Bromosuccinimide (2.70 g, 15.15 mmol) and carbon tetrachloride (100 ml). The mixture was heated to reflux over a 150 W light bulb for 2 h. Cooling to 5° C., filtration, evaporation of the filtrate to dryness under reduced pressure and purification by flash chromatography using hexane as eluent gave the title compound as a colourless oil: δH (CDCl3) 0.20 [6H, s, Si(CH3)2 ], 0.97 (9H, s, t bu), 4.50 (2H, s, CH2Br), 6.63 (1H, dd, J 2.9 and 8.5 Hz, 4-H), 6.91 (1H, d, J 2.9 Hz, 5-H), 7.37 (1H, d, J 8.5 Hz, 3-H); m/z (E.I.) 382 (M+, 5%), 380 (M+, 10%), 378 (M+, 5%); (Found: M+, 377.9642. C13H20Br2OS; requires M, 377.9652).

Provenance & Evidence