Boron tribromide → 2-Bromo-1-(3,4-dihydroxy-5-nitro-phenyl)-ethanone

HRID 2254746Notes

Reaction equation

HRID 2254746 reaction equation
[Br:1][CH2:2][C:3]([C:5]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[C:8]([OH:14])=[C:7]([O:15]C)[CH:6]=1)=[O:4].B(Br)(Br)Br>C(Cl)Cl>[Br:1][CH2:2][C:3]([C:5]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[C:8]([OH:14])=[C:7]([OH:15])[CH:6]=1)=[O:4]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 144509832-Bromo-4'-hydroxy-3'-methoxy-5'-nitroacetophenone

Product 1

HCID 218455962-Bromo-1-(3,4-dihydroxy-5-nitro-phenyl)-ethanone

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A suspension of 29.0 g of 2-bromo-4'-hydroxy-3'-methoxy-5'-nitroacetophenone in 700 ml of dry methylene chloride is treated at -20° within 30 minutes with a solution of 125.3 g of boron tribromide in 300 ml of dry methylene chloride. After the addition the mixture is stirred at -20° for a further 1 hour and at room temperature for 16 hours, then evaporated, the residue is treated cautiously with water while cooling with ice and stirred at 50° for 30 minutes. After cooling the mixture is extracted with ether, the ethereal phase is washed with water, dried over sodium sulfate, filtered and evaporated. There is obtained 2-bromo-3',4'-dihydroxy-5'-nitroacetophenone of m.p. 138°-140° (from methylene chloride).

Workup

  1. additionAfter the addition the mixture
  2. customevaporated
  3. additionthe residue is treated cautiously with water
  4. temperaturewhile cooling with ice
  5. stirringstirred at 50° for 30 minutes
  6. temperatureAfter cooling the mixture
  7. extractionis extracted with ether
  8. washthe ethereal phase is washed with water
  9. dry with materialdried over sodium sulfate
  10. filtrationfiltered
  11. customevaporated

Sources & evidence

ORD record
ord-69ec8789bcbd4b9daddf9f4d00536f72
Source dataset
uspto-grants-1993_08
Patent number
US05236952

Reaction notes

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