Reaction #2028903

Reaction equation

THF

4-ethoxy-2,2′,3,3′-tetrafluorobiphenyl-4-carboaldehyde

THF

methoxymethyltriphenylphosphonium chloride

Potassium t-butoxide

→

4-ethoxy-2,2′,3,3′-tetrafluoro-4′-(2-methoxyvinyl)biphenyl

Yield 94.5%

Solvents

water

Conditions

Workup

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   workup.WAITthe stirring was continued for 1 hour
3. 3
   TemperatureThe reaction mixture was warmed to room temperature
4. 4
   Otherto give two layers
5. 5
   ExtractionThe water layer was extracted with toluene (100 ml) three times
6. 6
   Washthe combined organic layer was washed with water
7. 7
   Dryingdried over anhydrous magnesium sulfate
8. 8
   workup.DISTILLATIONThe solvent was distilled off under reduced pressure
9. 9
   OtherThe residue was purified by silica gel chromatography (silica gel: 20 g, eluent: toluene)

Procedure

THF (150 ml) was added to methoxymethyltriphenylphosphonium chloride (26.8 g) in a reaction vessel under an atmosphere of nitrogen and the solution was cooled to −20° C. Potassium t-butoxide (10.1 g) was added, and the stirring was continued for 1 hour. A THF (100 ml) solution of 4-ethoxy-2,2′,3,3′-tetrafluorobiphenyl-4-carboaldehyde (7) (17.9 g) prepared in the fifth step was added dropwise, and the stirring was continued for 1 hour. The reaction mixture was warmed to room temperature and water (200 ml) was added to give two layers. The water layer was extracted with toluene (100 ml) three times, and the combined organic layer was washed with water and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (silica gel: 20 g, eluent: toluene) to give 4-ethoxy-2,2′,3,3′-tetrafluoro-4′-(2-methoxyvinyl)biphenyl (8) (18.5 g) in 94.5% yield.

Source