Boron tribromide → 2-Fluoro-3-hydroxy-4-methoxybenzonitrile

HRID 725361Notes

Reaction equation

HRID 725361 reaction equation
[F:1][C:2]1[C:9]([O:10]C)=[C:8]([O:12][CH3:13])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5].B(Br)(Br)Br>C(Cl)Cl>[F:1][C:2]1[C:9]([OH:10])=[C:8]([O:12][CH3:13])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5]

Participants

4

Reactant 2

HCID 25134Boron tribromide2×HCID 214590582-Fluoro-3,4-dimethoxybenzonitrile

Product 1

HCID 214591072-Fluoro-3-hydroxy-4-methoxybenzonitrile

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2.0 g of 2-fluoro-3,4-dimethoxybenzonitrile are dissolved in 60 ml of methylene chloride, treated with 1.1 ml of boron tribromide, stirred at 23° for 1 hour, subsequently treated with an additional 1.0 ml of boron tribromide and stirred at 23° for an additional 80 minutes. Thereupon, the reaction mixture is poured into 100 ml of ice-cold saturated sodium hydrogen carbonate solution, whereupon the mixture is extracted twice with 300 ml of ether, the combined ether phases are washed twice with sodium chloride solution, dried over sodium sulfate, evaporated and the residue is chromatographed on 50 g of silica gel with methylene chloride and methylene chloride/methanol (97:3). There is obtained 2-fluoro-3-hydroxy-p-anisonitrile of m.p. 198°-200°.

Workup

  1. stirringstirred at 23° for an additional 80 minutes
  2. extractionis extracted twice with 300 ml of ether
  3. washthe combined ether phases are washed twice with sodium chloride solution
  4. dry with materialdried over sodium sulfate
  5. customevaporated
  6. customthe residue is chromatographed on 50 g of silica gel with methylene chloride and methylene chloride/methanol (97:3)

Sources & evidence

ORD record
ord-9fc921f75d1c4bd78d4cd25da1cac334
Source dataset
uspto-grants-1998_01
Patent number
US05705703

Reaction notes

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