Reaktion #595298

Reaktionsgleichung

2′,4′-difluoroacetophenone

diethyl 2-chlorobenzylphosphonate

sodium hydride

→

1-[1-(2-chlorophenyl)prop-1-en-2-yl]-2,4-difluorobenzene

Ausbeute 26.0%

Lösungsmittel

DMF

water

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenfreshly washed with dry heptane) in dry DMF (20 ml)
2. 2
   workup.STIRRINGThe resulting mixture was stirred at RT for 68 h
3. 3
   Extraktionextracted with diethyl ether
4. 4
   SonstigeThe organic phase was dried
5. 5
   Einengenconcentrated to dryness under reduced pressure
6. 6
   Sonstigethe residue was purified by chromatography on silica gel, which

Vorschrift

At 3° C., a solution of diethyl 2-chlorobenzylphosphonate (2.00 g, 7.61 mmol) in dry DMF (30 ml) was added to a stirred suspension of sodium hydride (60% by weight suspension in mineral oil, 365 mg, 9.13 mmol; freshly washed with dry heptane) in dry DMF (20 ml). After 1 h of stirring at 3° C., a solution of 2′,4′-difluoroacetophenone (1.31 g, 8.37 mmol) in dry DMF (20 ml) was added dropwise. The resulting mixture was stirred at RT for 68 h and then diluted with water and extracted with diethyl ether. The organic phase was dried and concentrated to dryness under reduced pressure, and the residue was purified by chromatography on silica gel, which gave 1-[1-(2-chlorophenyl)prop-1-en-2-yl]-2,4-difluorobenzene as a 93/7 mixture of diastereoisomers [colourless solid, 560 mg, yield 26%; GC/MS: m/z=264 (M+); HPLC/MS: log P(HCOOH)=5.05 (major diastereoisomer), 5.34 (minor diastereoisomer)].

Quelle