1,3-Dibromobenzene → 2-Bromo-1-(2,4-dibromophenyl)-1-propanone

HRID 399622Notes

Reaction equation

HRID 399622 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[Br:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([Br:12])[CH:7]=1.[Br:13][CH:14]([CH3:18])[C:15](Br)=[O:16]>C(=S)=S>[Br:13][CH:14]([CH3:18])[C:15]([C:9]1[CH:10]=[CH:11][C:6]([Br:5])=[CH:7][C:8]=1[Br:12])=[O:16]

Participants

5

Reactant 3

HCID 79271,3-DibromobenzeneHCID 79047Propanoyl bromide, 2-bromo-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 189677542-Bromo-1-(2,4-dibromophenyl)-1-propanoneYield 76%

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

15 g of aluminium chloride are added with caution, at 0° C., to 25 g of 1,3-dibromobenzene in 250 ml of carbon disulphide, and 22.86 g of 2-bromopropionyl bromide are then run in slowly. The mixture is maintained at reflux for 8 hours, then the carbon disulphide is evaporated off under vacuum and the reaction medium is poured onto crushed ice. The product is extracted twice with heptane, dried, evaporated to dryness and then is purified on a column of silica, using a mixture of cyclohexane and ethyl acetate (10:1 v/v) as eluent, to give the expected product.

Workup

  1. temperatureThe mixture is maintained
  2. temperatureat reflux for 8 hours
  3. customthe carbon disulphide is evaporated off under vacuum
  4. additionthe reaction medium is poured
  5. customonto crushed ice
  6. extractionThe product is extracted twice with heptane
  7. customdried
  8. customevaporated to dryness
  9. customis purified on a column of silica
  10. additiona mixture of cyclohexane and ethyl acetate (10:1 v/v) as eluent

Sources & evidence

ORD record
ord-acee76ca33654733933892fa063250da
Source dataset
uspto-grants-1998_10
Patent number
US05821255

Reaction notes

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