Reaktion #80587

Reaktionsgleichung

HBr

1-(4-chlorophenoxy)-2-chloro-2-propene

N-bromosuccinimide

acetonitrile water

→

1-bromo-3-[(4-chlorophenoxy)phenyl]-2-propanone

Ausbeute 54.0%

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with 5% w/v of sodium thiosulfate
2. 2
   SonstigeThe organic layer was separated
3. 3
   Waschenwashed with saturated sodium bicarbonate and brine
4. 4
   SonstigeAfter drying
5. 5
   Filtration(MgSO4), filtration and concentration in vacuo
6. 6
   Sonstigethe crude liquid (4.8 g) was chromatographed (silica gel, hexane/ethyl acetate, 80/20)

Vorschrift

To a turbid solution of 1-(4-chlorophenoxy)-2-chloro-2-propene from Step 1 (3 g, 15.7 mmol) in acetonitrile/water (4/1, 100 mL), N-bromosuccinimide (4.84 g, 31.4 mmol) was added in one lot. A catalytic amount of 48% HBr (40 μl) was added to the reaction and the yellowish orange mixture was stirred at room temperature. After 24 hours, the reaction mixture was diluted with ether and washed with 5% w/v of sodium thiosulfate. The organic layer was separated and washed with saturated sodium bicarbonate and brine. After drying (MgSO4), filtration and concentration in vacuo, the crude liquid (4.8 g) was chromatographed (silica gel, hexane/ethyl acetate, 80/20) to give crude 1-bromo-3-[(4-chlorophenoxy)phenyl]-2-propanone (2.3 g, 54%) which was used in the next step without further purification.

Quelle