一种合成2，5—二甲氧基苯甲醛的新方法

2，5－二甲氧基苯甲醛是重要、不易合成的药物中间体。以对甲氧基苯酚为原料，经聚乙二醇10000催化的Reiman-Tiemann反应及甲氧基化制备而得。通过比较不同相转移催化剂对Reimer-Tiemann反应产率的影响，选择效果最佳的聚乙二醇－10000（PEG－10000）作为该反应的相转移催化剂。把2－羟基－5－甲氧基苯甲醛的甲氧基化放在缓冲溶液中进行，产物的收率和品质有明显提高。就影响产率的各种因素进行了探讨，并从机理上作了简要解释。通过反应条件改进，总收率达68％。

A New Synthetic Method for 2,5-Dimethoxybenzaldehyde

dimethoxybenzaldehyde, as a valuable intermediate for drugs, is unconveniently synthsized in usual way. Reimer-Tiemann reaction and a methoxylation through dimethyl sulfate are employed for the preparation of 2,5-dimethoxybenzaldehyde from p-methoxyphenol in this paper. Comparing different phase transfer catalysts,it can be demonstrated that the polye thene glycel 10 000(PEG 10 000) is the most favorable catalyst used in Reimer Tiemann reaction. The yield and quality are improved through the methoxylation of 2 hydroxy 5 methoxy benzaldehyde in a buffer solution, The diverse factors influcencing the yield are examined. Some explanations are given from theoretical viewpoint. The proper experimental conditions are found and the overall-yield reached 68%.