2233-18-3

74-88-4

39250-90-3

The reaction was carried out by dissolving 3,5-dimethyl-4-hydroxybenzaldehyde (1.54 g, 10.3 mmol), iodomethane (0.77 mL, 12.4 mmol), and potassium carbonate (K2CO3, 1.71 g, 12.4 mmol) in N,N-dimethylformamide (DMF, 10.0 mL) and stirring the reaction for 18 hours at room temperature. After completion of the reaction, the reaction mixture was extracted with ethyl acetate (EtOAc, 100 mL) and washed sequentially with water (2 x 25 mL) and saturated saline (25 mL). The organic phase was dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. Purification by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 9:1, v/v) afforded 3,5-dimethyl-4-methoxybenzaldehyde as a white solid (1.60 g, 95% yield). The structure of the product was confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H-NMR, 500 MHz, CDCl3) and carbon spectroscopy (13C-NMR, 125 MHz, CDCl3): 1H-NMR δ 9.88 (s, 1H), 7.56 (s, 2H), 3.78 (s, 3H), 2.35 (s, 6H); 13C-NMR δ 191.69,. 162.41, 132.25, 131.94, 130.73, 59.71, 16.19. Gas chromatography-mass spectrometry (GC-MS) showed the molecular ion peak m/z 163 [M+H]+, which is consistent with the theoretical value of molecular formula C10H12O2. Reversed-phase high performance liquid chromatography (RP-HPLC) analysis showed that the purity of the product was greater than 99%.