Coumaranone → 3(2H)-Benzofuranone, O-methyloxime

HRID 612809Notes

Reaction equation

HRID 612809 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[C:3](=O)[CH2:2]1.Cl.[CH3:12][O:13][NH2:14].C([O-])(=O)C.[Na+]>CO>[CH3:12][O:13][N:14]=[C:3]1[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[O:1][CH2:2]1

Participants

5

Reactant 3

HCID 23556CoumaranoneHCID 517045Sodium AcetateHCID 521874O-Methylhydroxylamine hydrochloride

Product 1

HCID 542716163(2H)-Benzofuranone, O-methyloximeYield 89.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

6.7 g (0.05 mol) of benzofuran-3-one together with 4.2 g (0.05 mol) of O-methylhydroxylamine hydrochloride and 4.1 g (0.05 mol) of sodium acetate in 50 ml of methanol are heated under reflux for 3 hours. The solvent is distilled off under reduced pressure and the reaction mixture is poured into water and extracted with ethyl acetate. The organic phase is washed with saturated aqueous sodium carbonate solution. The organic phase is dried over sodium sulphate and the solvent is distilled off under reduced pressure. 7.27 g (89.2% of theory) of crude benzofuran-3-one O-methyl-oxime are obtained. For analysis, the crude product is distilled at 2 torr and 70° C. using a Kugelrohr. An oil is obtained which, both according to NMR analysis and according to HPLC analysis, comprises two stereoisomers (79% of isomer B and 21% of isomer A).

Workup

  1. temperatureunder reflux for 3 hours
  2. distillationThe solvent is distilled off under reduced pressure
  3. additionthe reaction mixture is poured into water
  4. extractionextracted with ethyl acetate
  5. washThe organic phase is washed with saturated aqueous sodium carbonate solution
  6. dry with materialThe organic phase is dried over sodium sulphate
  7. distillationthe solvent is distilled off under reduced pressure

Sources & evidence

ORD record
ord-9cbadb58fa8848a8bf638f3b575c76d6
Source dataset
uspto-grants-1999_12
Patent number
US06005104

Reaction notes

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