Hydrogen Bromide → Benzene, 1-bromo-3,5-dimethyl-

HRID 2090823Notes

Reaction equation

HRID 2090823 reaction equation
N([O-])=O.[Na+].[BrH:5].[CH3:6][C:7]1[CH:8]=[C:9]([CH:11]=[C:12]([CH3:14])[CH:13]=1)N.CCCCCC>O.[Cu]Br>[Br:5][C:9]1[CH:8]=[C:7]([CH3:6])[CH:13]=[C:12]([CH3:14])[CH:11]=1

Participants

7

Reactant 4

HCID 260Hydrogen Bromide2×HCID 79493,5-DimethylanilineHCID 8058HexaneHCID 23668193Sodium Nitrite

Product 1

HCID 136357Benzene, 1-bromo-3,5-dimethyl-Yield 60%

Reagents, catalysts & solvents 2

HCID 24593copper(I) bromideCatalystHCID 962WaterSolvent2×

Procedure

A solution of 42 g of sodium nitrite in 150 ml of water is added to a mixture, cooled to −5° C., of 200 ml of 48% HBr and 50 g of 3,5-dimethylaniline. The reaction mixture is stirred for 1 hour at from −5° C. to 0° C. Finally, this reaction mixture is slowly added to a mixture, heated to 80° C., of 88.3 g of copper(I) bromide and 150 ml of 48% HBr. The reaction mixture is stirred for 2 hours at 80° C. and observed by TLC monitoring (silica; hexane). When the reaction is complete, the product is obtained by water-vapour distillation and is purified by column chromatography (silica; hexane). In this manner, 1-bromo-3,5-dimethylbenzene was obtained in a yield of 60% (30 g).

Workup

  1. additionFinally, this reaction mixture is slowly added to a mixture
  2. stirringThe reaction mixture is stirred for 2 hours at 80° C.
  3. customis purified by column chromatography (silica; hexane)

Sources & evidence

ORD record
ord-6534bcccbe2843b9a373db19d8deb857
Source dataset
uspto-grants-2013_05
Patent number
US08435978B2

Reaction notes

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