To a mixture of p-benzoquinone (1 mmol) and n-propanol (4.0 mL) was added Amberlyst-15 (40 mg), and the mixture was reacted at reflux for 4-7 hours at 100 °C until the p-benzoquinone was fully reacted (monitored by TLC). After completion of the reaction, the reaction mixture was filtered and the residue was washed with ethyl acetate (25 mL). The washed solution was combined with the filtrate, water (25 mL) was added to the combined solution, and the aqueous layer was extracted with ethyl acetate (2 x 10 mL). The ethyl acetate extracts were combined and dried with anhydrous Na2SO4. The dried extracts were concentrated under reduced pressure and the resulting crude product was purified by silica gel column chromatography with the eluent being a mixed solvent of ethyl acetate-petroleum ether. The purified product was further crystallized using CH2Cl2-petroleum ether mixed solvent. All the synthesized 4-propoxyphenols were characterized by physical properties, elemental analysis and spectral data.
