1,2-Dibromoethane → 5-(2-Bromoethoxy)benzofurazan

HRID 1781381Notes

Reaction equation

HRID 1781381 reaction equation
[OH-].[Na+].[OH:3][C:4]1[CH:5]=[CH:6][C:7]2[C:8]([CH:12]=1)=[N:9][O:10][N:11]=2.[Br:13][CH2:14][CH2:15]Br>C(O)C>[Br:13][CH2:14][CH2:15][O:3][C:4]1[CH:5]=[CH:6][C:7]2[C:8]([CH:12]=1)=[N:9][O:10][N:11]=2

Participants

5

Reactant 3

HCID 78391,2-DibromoethaneHCID 14798Sodium HydroxideHCID 1354568365-Hydroxybenzofurazan

Product 1

HCID 190453515-(2-Bromoethoxy)benzofurazanYield 41%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Sodium hydroxide (40 mg, 1 mmol) was added to a solution of 5-hydroxybenzofurazan (136 mg, 1 mmol) in ethanol (2 ml) and the mixture was stirred at room temperature for 30 min. 1,2-dibromoethane (0.26 ml, 0.56 g, 3 mmol) was added and the mixture was heated under reflux for 20 hr., cooled and the solvent was evaporated under reduced pressure. Aqueous sodium bicarbonate (saturated, 10 ml) was added and the mixture was extracted with dichloromethane (3×10 ml). The combined organic fractions were dried (Na2SO4) and evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with hexane/10% EtOAc to give the benzofurazan as a pale yellow oil (99 mg, 41%).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 20 hr
  3. temperature, cooled
  4. customthe solvent was evaporated under reduced pressure
  5. additionAqueous sodium bicarbonate (saturated, 10 ml) was added
  6. extractionthe mixture was extracted with dichloromethane (3×10 ml)
  7. dry with materialThe combined organic fractions were dried (Na2SO4)
  8. customevaporated under reduced pressure
  9. customThe residue was purified by flash column chromatography on silica gel
  10. washeluting with hexane/10% EtOAc

Sources & evidence

ORD record
ord-3a716ce8682049ba850c6a9e0138388f
Source dataset
uspto-grants-1997_05
Patent number
US05633247

Reaction notes

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