Reaction #2467933

Reaction equation

3,5-dibromobenzaldehyde

potassium t-butoxide

ammonium chloride

→

3,5-dibromostyrene

Yield 79.3%

Solvents

Tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   Temperaturecooling
2. 2
   TemperatureThe resultant slurry was cooled to −78° C.
3. 3
   workup.ADDITIONwas added dropwise
4. 4
   Temperatureto warm to room temperature
5. 5
   workup.STIRRINGstirred for 1 hr
6. 6
   ExtractionThe product was extracted with ethyl acetate
7. 7
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure
8. 8
   Otherthe residue was purified with silica-gel column chromatography

Procedure

Tetrahydrofuran (20 mL) was added to methyltriphenylphosphonium bromide (3.150 g, 8.8 mmol). Then potassium t-butoxide (0.989 g, 8.8 mmol) was added herein small portions with ice-cooling, and the mixture was stirred at room temperature for 1 hr. The resultant slurry was cooled to −78° C. and a tetrahydrofuran (20 mL) solution containing 3,5-dibromobenzaldehyde (1.519 g, 5.8 mmol) was added dropwise. The reaction solution was allowed to warm to room temperature and stirred for 1 hr, and then a saturated ammonium chloride aqueous solution was added to the reaction solution. The product was extracted with ethyl acetate, the solvent was distilled off under reduced pressure, and the residue was purified with silica-gel column chromatography to obtain 3,5-dibromostyrene (1.2 g, 4.6 mmol).

Source