Diethyl Carbonate → Ethyl 4-bromo-2,5-difluoro-β-oxobenzenepropanoate

HRID 1461376

Reaction equation

HRID 1461376 reaction equation
[CH3:1][C:2]([C:4]1[C:9]([F:10])=[CH:8][C:7]([Br:11])=[C:6]([F:12])[CH:5]=1)=[O:3].[C:13](=O)([O:17]CC)[O:14][CH2:15][CH3:16].[H-].[Na+]>>[Br:11][C:7]1[C:6]([F:12])=[CH:5][C:4]([C:2]([CH2:1][C:13]([O:14][CH2:15][CH3:16])=[O:17])=[O:3])=[C:9]([F:10])[CH:8]=1

Participants

4

Reactant 3

HCID 7766Diethyl CarbonateHCID 24758Sodium hydrideHCID 99916531-(4-Bromo-2,5-difluorophenyl)ethan-1-one

Product 1

HCID 10018069Ethyl 4-bromo-2,5-difluoro-β-oxobenzenepropanoate

Conditions

Temperature
80 °C

Procedure

To a stirred mixture of 18 g 4-bromo-2,5-difluoroacetophenone and 233 ml diethyl carbonate cooled in an ice-bath was slowly added 6.4 g sodium hydride (60% in oil). The reaction mixture was heated at 80° C. for 90 min. and then added to 700 ml ice containing 25 ml acetic acid. The aqueous mixture was extracted with ether, and the ether extracts were washed with sodium chloride solution, dried (magnesium sulfate) and concentrated. The residue was distilled, collecting the material (15.33 g) boiling at 85°-135° C. (0.05 mm). The latter material was chromatographed on 185 g silica gel (Kieselgel 60) using 20% ether in hexane as eluant to give 6.69 g ethyl 4-bromo-2,5-difluorobenzoylacetate as the first product to be eluted.

Workup

  1. temperaturecooled in an ice-bath
  2. extractionThe aqueous mixture was extracted with ether
  3. washthe ether extracts were washed with sodium chloride solution
  4. dry with materialdried (magnesium sulfate)
  5. concentrationconcentrated
  6. distillationThe residue was distilled
  7. customcollecting the material (15.33 g) boiling at 85°-135° C. (0.05 mm)
  8. customThe latter material was chromatographed on 185 g silica gel (Kieselgel 60)

Sources & evidence

ORD record
ord-682d2dec772a4cda9c651257759b7e3b
Source dataset
uspto-grants-1991_12
Patent number
US05075319

Linked notes

Loading…