反应详情

U.S. Pat. No. 3,855,306 discloses methylation of 5-hydroxyvanillin (initially prepared from vanillin by bromination and subsequent hydrolysis) with dimethyl sulfate in the presence of an alkali carbonate in an organic medium such as acetone. 3,4,5,-Trimethoxybenzaldehyde in yields of about 94% are obtained in this method, but the reaction is slow and operating with organic solvents presents disadvantages of operation and cost.