Réaction #3779

Équation de réaction

2,3,4-Trimethoxybenzaldehyde

m-chloroperbenzoic acid

→

2,3,4-trimethoxyphenol

Rendement 51.1%

Solvants

methylene chloride

Conditions de réaction

Traitement

1. 1
   Températureto heat
2. 2
   workup.DISTILLATIONAfter distilling off the solvents under reduced pressure
3. 3
   workup.DISSOLUTIONthe residue was dissolved in ethyl acetate (100 ml)
4. 4
   Lavagewashed in an aqueous saturated sodium hydrogen carbonate solution, in water and in a saturated sodium chloride solution
5. 5
   Séchagedried over anhydrous magnesium sulfate
6. 6
   workup.DISTILLATIONThen, the solvents were distilled off under reduced pressure
7. 7
   workup.ADDITIONTo the residue were added dioxane (15 ml)
8. 8
   workup.STIRRINGa 3N sodium hydroxide solution (15 ml), prior to stirring at room temperature for 30 minutes
9. 9
   Extractionadjustment to acidity with dilute hydrochloric acid, followed by ethyl acetate extraction three times
10. 10
    LavageThe organic phase was washed in water and in a saturated sodium chloride solution
11. 11
    Séchagedried over anhydrous magnesium sulfate
12. 12
    workup.DISTILLATIONfollowed by distillation of the solvents under reduced pressure
13. 13
    AutreThe residue was purified by silica gel column chromatography (developing solvent: hexane:ethyl acetate=3:1)

Mode opératoire

2,3,4-Trimethoxybenzaldehyde (5 g) was suspended in anhydrous methylene chloride (50 ml), followed by addition of m-chloroperbenzoic acid (10 g; purity of 70%) to heat and stir the resulting mixture at 50° C. for 3 hours. After distilling off the solvents under reduced pressure, the residue was dissolved in ethyl acetate (100 ml) and washed in an aqueous saturated sodium hydrogen carbonate solution, in water and in a saturated sodium chloride solution, and dried over anhydrous magnesium sulfate. Then, the solvents were distilled off under reduced pressure. To the residue were added dioxane (15 ml) and a 3N sodium hydroxide solution (15 ml), prior to stirring at room temperature for 30 minutes and adjustment to acidity with dilute hydrochloric acid, followed by ethyl acetate extraction three times. The organic phase was washed in water and in a saturated sodium chloride solution and dried over anhydrous magnesium sulfate, followed by distillation of the solvents under reduced pressure. The residue was purified by silica gel column chromatography (developing solvent: hexane:ethyl acetate=3:1), to recover 2,3,4-trimethoxyphenol (2.4 g; yield of 51%). By 1H-NMR (90 MHz, CDCl3), the compound has the peaks shown below.

Source