4-Ethoxy-3-methoxybenzaldehyde was prepared as follows: 1 kg of vanillin, 6.6 liters of ethanol (the concentration of vanillin is 1 mol/L), 0.3 kg of Catalyst B and 0.15 kg of Catalyst F were added to a reactor and charged with 1.5 MPa of hydrogen, and the reaction was heated to 30 for 24 h. The complete reaction of vanillin was detected, and the heating was stopped, the catalyst was filtered when the reactor was cooled down. The catalyst was dried directly and reused. The filtrate was rotary evaporated to get out the excess ethanol, and the vanillin ether (4-ethoxy-3-methoxybenzaldehyde) was obtained as 1.36 kg, the yield was 98%, the purity was >98%.
