Bromide ion → 6-Methoxychromone

HRID 974787Notes

Reaction equation

HRID 974787 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][CH:7]=[CH:6][C:5]2=[O:12].[CH3:13]OS(OC)(=O)=O.[Br-].C([O-])(O)=O.[Na+]>O.C(Cl)Cl>[CH3:13][O:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][CH:7]=[CH:6][C:5]2=[O:12]

Participants

7

Reactant 4

HCID 259Bromide ionHCID 6497Dimethyl SulfateHCID 516892Sodium BicarbonateHCID 107970646-Hydroxy-4H-1-benzopyran-4-one

Product 1

HCID 6888806-MethoxychromoneYield 83%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

A mixture of 6-hydroxychromone (4.5 g; 27.7 mmol), CH2Cl2 (150 ml), water (150 ml), dimethylsulphate (4 ml; 41.5 mmol), benzyltributylammmonium bromide (2 g; 5.5 mmol) and NaHCO3 (1.67 g; 41.5 mmol) was stirred for 24 hours at ambient temperature. The organic phase was decanted, washed with water, a dilute solution of ammonium hydroxide and with 1N HCl, it was dried over MgSO4 and evaporated. It was purified by chromatography, eluting with ethyl acetate/petroleum ether (50/50) to give 6-methoxychromone (4 g; 83%) as a brown solid.

Workup

  1. customThe organic phase was decanted
  2. washwashed with water
  3. dry with materiala dilute solution of ammonium hydroxide and with 1N HCl, it was dried over MgSO4
  4. customevaporated
  5. customIt was purified by chromatography
  6. washeluting with ethyl acetate/petroleum ether (50/50)

Sources & evidence

ORD record
ord-0628306ae36d4ee0b995254fdb6584c1
Source dataset
uspto-grants-1997_03
Patent number
US05607928

Reaction notes

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