m-Chloroperbenzoic acid → 2,3,4-Trimethoxyphenol

Temperature

50 °C

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 an aqueous 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 an aqueous 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.

1. temperatureto heat
2. distillationAfter distilling off the solvents under reduced pressure
3. dissolutionthe residue was dissolved in ethyl acetate (100 ml)
4. washwashed in an aqueous saturated sodium hydrogen carbonate solution, in water and in an aqueous saturated sodium chloride solution
5. dry with materialdried over anhydrous magnesium sulfate
6. distillationThen, the solvents were distilled off under reduced pressure
7. additionTo the residue were added dioxane (15 ml)
8. stirringa 3N sodium hydroxide solution (15 ml), prior to stirring at room temperature for 30 minutes
9. extractionadjustment to acidity with dilute hydrochloric acid, followed by ethyl acetate extraction three times
10. washThe organic phase was washed in water and in an aqueous saturated sodium chloride solution
11. dry with materialdried over anhydrous magnesium sulfate
12. distillationfollowed by distillation of the solvents under reduced pressure
13. customThe residue was purified by silica gel column chromatography (developing solvent:hexane:ethyl acetate=3:1)

ORD record

ord-ee7ed8e1aaa940c080f4b096dc9ed833

Source dataset

uspto-grants-2002_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06495592B1