Reaktion #801837

ord-ecaa32ef87e74fe78cc38da2bae338ca

Reaktionsgleichung

O=S([O-])S(=O)[O-].[Na+].[Na+]
sodium dithionite
[Na+].[O-][Br+2]([O-])[O-]
sodium bromate
CCOC(=O)Cc1ccccc1C(F)(F)F
ethyl 2-(trifluoromethyl)phenylacetate
[Na+].[O-][Br+2]([O-])[O-]
sodium bromate
O=S([O-])O.[Na+]
sodium bisulfite
O=S([O-])O.[Na+]
sodium bisulfite
CCOC(=O)Cc1ccccc1C(F)(F)F
ethyl 2-(trifluoromethyl)phenylacetate
CCOC(=O)C(Br)c1ccccc1C(F)(F)F
title compound
Ausbeute 31.0%
CCOC(=O)C(Br)c1ccccc1C(F)(F)F
Ethyl bromo[2-(trifluoromethyl)phenyl]acetate
Ausbeute 31.0%

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.ADDITIONwere added at RT
  2. 2
    ExtraktionThe mixture was extracted with 15 ml of ethyl acetate
  3. 3
    Waschenthe organic phase was washed in each case once with 5 ml of 10% strength sodium dithionite solution and 5 ml of saturated sodium chloride solution
  4. 4
    TrocknenThe organic phase was dried over sodium sulfate
  5. 5
    Filtrationfiltered
  6. 6
    Einengenconcentrated under reduced pressure
  7. 7
    SonstigeThe crude product was purified by chromatography on silica gel (mobile phase
  8. 8
    SonstigeWork-up gave

Vorschrift

585 mg (3.89 mmol) of sodium bromate were initially charged in 2 ml of water, and 300 mg (1.29 mmol) of ethyl 2-(trifluoromethyl)phenylacetate, dissolved in 2.5 ml of ethyl acetate, were added at RT. A solution of 403 mg (3.89 mmol) of sodium bisulfite in 3.8 ml of water was then added slowly. The mixture was stirred at RT for 18 h. 5 ml of 10% strength aqueous sodium dithionite solution were then added. The mixture was extracted with 15 ml of ethyl acetate, and the organic phase was washed in each case once with 5 ml of 10% strength sodium dithionite solution and 5 ml of saturated sodium chloride solution. The organic phase was dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 20:1, then 10:1). This gave 186 mg of a mixture consisting of the title compound and the starting material ethyl 2-(trifluoromethyl)phenylacetate (ratio 16:84 according to GC/MS [Method 20]). This mixture was once more reacted with 362 mg (2.40 mmol) of sodium bromate and 250 mg (2.40 mmol) of sodium bisulfite according to the procedure described above. Work-up gave a mixture of 31% title compound and 69% ethyl 2-(trifluoromethyl)phenylacetate, which was reacted further without any further purification.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US09187466B2uspto-grants-2015_11