2-Bromoethanol → 2,3-Benzofurandione, 2-[O-(2-hydroxyethyl)oxime] 3-(O-methyloxime)

HRID 1018120Notes

Reaction equation

HRID 1018120 reaction equation
[CH3:1][O:2][N:3]=[C:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[O:6][C:5]1=[N:13][OH:14].[H-].[Na+].Br[CH2:18][CH2:19][OH:20].C[O-].[Na+]>CN(C)C=O.O>[CH3:1][O:2][N:3]=[C:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[O:6][C:5]1=[N:13][O:14][CH2:18][CH2:19][OH:20]

Participants

7

Reactant 4

HCID 108982-Bromoethanol3×HCID 24758Sodium hydrideHCID 10942334Sodium Methoxide2×HCID 178502623HCID 178502623, compound

Product 1

HCID 543010792,3-Benzofurandione, 2-[O-(2-hydroxyethyl)oxime] 3-(O-methyloxime)Yield 40.9%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

49 g (0.0234 mol) of benzofuran-2,3-dione3-(O-methyl-oxime)2-oxime (VIII-1) are dissolved in 25 ml of dimethylformamide. 1 g (0.025 mol) of 60% strength sodium hydride is added to this solution which is then stirred at room temperature for one hour. 3.1 g (0.0248 mol) of 2-bromoethanol are added and the mixture is stirred at 25° C. for 12 hours. After the addition of 0.5 g of sodium methoxide and 1.22 g of 2-bromoethanol, the mixture is stirred at room temperature for 2 hours. A further 0.5 g of sodium methoxide and 1.22 g of 2-bromoethanol are added and the mixture is stirred for a further 2 hours at room temperature. The reaction mixture is poured into water and the resulting mixture is extracted with ethyl acetate and the organic phase is washed 3 times with 20 ml of 2 N aqueous sodium hydroxide solution. The solvent is distilled off under reduced pressure and the residue is chromatographed over silica gel using diethyl ether/petroleum ether (1:1). The eluent is distilled off under reduced pressure, affording 2.26 g (39.6% of theory) of benzofuran-2,3-dione2-[O-(2-hydroxy-ethyl)-oxime] 3-(O-methyl-oxime) (II-1) which, according to HPLC, comprises 84.29% of stereoisomer A and 12.58% of stereoisomer B.

Workup

  1. stirringthe mixture is stirred at 25° C. for 12 hours
  2. stirringthe mixture is stirred at room temperature for 2 hours
  3. stirringthe mixture is stirred for a further 2 hours at room temperature
  4. extractionthe resulting mixture is extracted with ethyl acetate
  5. washthe organic phase is washed 3 times with 20 ml of 2 N aqueous sodium hydroxide solution
  6. distillationThe solvent is distilled off under reduced pressure
  7. customthe residue is chromatographed over silica gel
  8. distillationThe eluent is distilled off under reduced pressure

Sources & evidence

ORD record
ord-4d1ca446822e459fad6128ee2b3a6e96
Source dataset
uspto-grants-2002_11
Patent number
US06479675B1

Reaction notes

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