Allyl bromide → 5-Allyl-2-bromo-1,3-dimethylbenzene

HRID 237532Notes

Reaction equation

HRID 237532 reaction equation
[CH:1]([Mg]Cl)([CH3:3])[CH3:2].C([Li])CCC.[Br:11][C:12]1[C:17]([CH3:18])=[CH:16][C:15](Br)=[CH:14][C:13]=1[CH3:20].C([Cu])#N.[Li+].[Cl-].BrCC=C>O1CCCC1.CCCCCC>[CH2:3]([C:15]1[CH:14]=[C:13]([CH3:20])[C:12]([Br:11])=[C:17]([CH3:18])[CH:16]=1)[CH:1]=[CH2:2]

Participants

9

Reactant 6

HCID 7841Allyl bromideHCID 433294Lithium ChlorideHCID 27580472,5-Dibromo-1,3-dimethylbenzeneHCID 178418339ButyllithiumHCID 178418546HCID 178418546, compoundHCID 178418918HCID 178418918, compound

Product 1

HCID 866971955-Allyl-2-bromo-1,3-dimethylbenzene

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent4×HCID 8058HexaneSolvent

Conditions

Temperature
-40 °C

Procedure

To a solution of isopropylmagnesium chloride (6.15 mL of a 2 M solution in tetrahydrofurane) in tetrahydrofurane (75 mL) is added dropwise at 0° C. n-butyllithium (15.4 mL of a 1.6 M solution in n-hexane). The mixture is stirred for 10 minutes, a solution of 2,5-dibromo-1,3-dimethylbenzene (5 g) in tetrahydrofurane (75 mL) is added within 10 minutes. The mixture is stirred for 2 hours, cooled to −40° C. and then CuCN×LiCl (5.5 mL of a 1 M solution in tetrahydrofurane) is added dropwise. After stirring for 5 minutes 3-bromopropene (6.6 mL) is added dropwise, the mixture is stirred for 1 hour, warmed to room temperature and stirred for further 12 hours. Then the reaction is quenched by addition of saturated aqueous NH4Cl solution. The mixture is extracted with diethylether, the organic phase is dried (MgSO4) and concentrated. The residue is chromatographed on silica gel (dichloromethane) to give the title compound. Yield: 3.76 g; LC (method 8): tR=0.83 min; Mass spectrum (ESI+): m/z=225 [M+H]+.

Workup

  1. stirringThe mixture is stirred for 2 hours
  2. additionis added dropwise
  3. stirringthe mixture is stirred for 1 hour
  4. temperaturewarmed to room temperature
  5. stirringstirred for further 12 hours
  6. customThen the reaction is quenched by addition of saturated aqueous NH4Cl solution
  7. extractionThe mixture is extracted with diethylether
  8. dry with materialthe organic phase is dried (MgSO4)
  9. concentrationconcentrated
  10. customThe residue is chromatographed on silica gel (dichloromethane)

Sources & evidence

ORD record
ord-c595b52dfdca4e89a16b78074e810d5e
Source dataset
uspto-grants-2014_02
Patent number
US08642585B2

Reaction notes

Loading…