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

HRID 1735384Notes

Reaction equation

HRID 1735384 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([OH:8])=[CH:4][C:3]=1[CH3:9].[Si:10](Cl)([C:13]([CH3:16])([CH3:15])[CH3:14])([CH3:12])[CH3:11].N1C=CN=C1.[Br:23]N1C(=O)CCC1=O>CN(C)C=O.C(Cl)(Cl)(Cl)Cl.O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([O:8][Si:10]([C:13]([CH3:16])([CH3:15])[CH3:14])([CH3:12])[CH3:11])=[CH:4][C:3]=1[CH2:9][Br:23]

Participants

8

Reactant 4

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 67184N-bromobutanimideHCID 728574-Bromo-m-cresol

Product 1

HCID 19437125(4-Bromo-3-bromomethyl-phenoxy)-tert-butyl-dimethyl-silane

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 5943Carbon TetrachlorideSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
5 °C

Procedure

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).

Workup

  1. extractionthe products extracted with ethyl acetate
  2. customDrying
  3. custom(MGSO4), evaporation to dryness
  4. customunder reduced pressure and purification by flash chromatography
  5. customgave the crude silylated phenol (4.16 g, 57%)
  6. temperatureThe mixture was heated
  7. temperatureto reflux over a 150 W light bulb for 2 h
  8. filtrationfiltration, evaporation of the filtrate to dryness
  9. customunder reduced pressure and purification by flash chromatography

Sources & evidence

ORD record
ord-9332db5252d94f7fb831880fec0a9f58
Source dataset
uspto-grants-1996_07
Patent number
US05536745

Reaction notes

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