Reaction #3782

Reaction equation

potassium tert-butoxide

triphenylphosphine ethyl bromide

2,6-dimethoxy-4-hydroxybenzaldehyde

→

3,5-dimethoxy-4-propylphenol

Yield 55.7%

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   workup.STIRRINGfor stirring at room temperature for 30 minutes
2. 2
   workup.STIRRINGfor stirring at room temperature for 2 hours
3. 3
   OtherAfter the termination of the reaction
4. 4
   Otherthe resulting solution was partitioned with ethyl acetate and dilute hydrochloric acid
5. 5
   Washthe resulting ethyl acetate phase was washed in water and subsequently in a saturated sodium chloride solution
6. 6
   Dryingdried over anhydrous magnesium sulfate
7. 7
   workup.DISTILLATIONto distill off the solvents under reduced pressure
8. 8
   OtherThe residue was purified by silica gel column chromatography (developing solvent: hexane:ethyl acetate=2:1)
9. 9
   workup.ADDITIONfollowed by addition of a catalytic amount of platinum dioxide for hydrogenation

Procedure

Anhydrous tetrahydrofuran (36 ml) was added to triphenylphosphine ethyl bromide (12.3 g) prior to stirring at room temperature for 20 minutes. To the resulting mixture was added potassium tert-butoxide (4.5 g), for stirring at room temperature for 30 minutes. Then, 2,6-dimethoxy-4-hydroxybenzaldehyde (3.0 g) was added to the resulting mixture for stirring at room temperature for 2 hours. After the termination of the reaction, the resulting solution was partitioned with ethyl acetate and dilute hydrochloric acid, and the resulting ethyl acetate phase was washed in water and subsequently in a saturated sodium chloride solution and dried over anhydrous magnesium sulfate, to distill off the solvents under reduced pressure. The residue was purified by silica gel column chromatography (developing solvent: hexane:ethyl acetate=2:1), followed by addition of a catalytic amount of platinum dioxide for hydrogenation, to recover 3,5-dimethoxy-4-propylphenol (1.8 g; yield of 55%). By 1H-NMR (90 MHz, CDCl3), the compound has the peaks shown below.

Source