Réaction #595298

Équation de réaction

2′,4′-difluoroacetophenone

diethyl 2-chlorobenzylphosphonate

sodium hydride

→

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

Rendement 26.0%

Solvants

DMF

water

DMF

Conditions de réaction

Traitement

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

Mode opératoire

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)].

Source