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

HRID 636842Notes

Reaction equation

HRID 636842 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 are boiled under reflux 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 for 3 hours. The solvent is distilled off in vacuo and the reaction mixture is poured onto 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 in vacuo. 7.27 g (89.2% of theory) of crude benzofuran-3-one O-methyl oxime are obtained. For analysis, it is distilled under 2 torr at 70° C. in a bulb tube. An oil is obtained which, both according to the NMR analysis and according to the HPLC analysis, comprises two stereoisomers (79% of isomer B and 21% of isomer A).

Workup

  1. distillationThe solvent is distilled off in vacuo
  2. additionthe reaction mixture is poured onto water
  3. extractionextracted with ethyl acetate
  4. washThe organic phase is washed with saturated aqueous sodium carbonate solution
  5. dry with materialThe organic phase is dried over sodium sulphate
  6. distillationthe solvent is distilled off in vacuo

Sources & evidence

ORD record
ord-1333f01ab593474ab51f9c7f1b5e7522
Source dataset
uspto-grants-2001_02
Patent number
US06194590B1

Reaction notes

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