对甲基苯甲醛的合成研究

Study on synthesis of 4\|methyl\|benzaldehyde

以对二甲苯为原料，经光溴化，水解，氧化得到对甲基苯甲醛。对三个步骤作了详细研究，得到合成对甲基苯甲醛的最佳反应条件，对二甲苯在光照回流下用液溴直接溴化，溴化产品用Ｎａ２ＣＯ３ 溶液在ｐＨ＝ ９ 时水解，然后用Ｈ２Ｏ２ ＋ ＨＢｒ 氧化得到目的产品。本方法原料易得，操作简单，收率较高。

The method of Photobromination to prepare p\|methyl\|benzaldehyde using the 1,4\|dimethyl benzene as starting materials consisted of three steps:bromination,hydrolysis and oxidation.The three steps of photobromination methods in preparing 4\|methyl\|benzaldehyde have all been studied in this articale. The optimum reaction condition to prepare 4\|methyl\|benzaldehyde was established.The 1,4\|dimethyl benzene is brominated under the condition of refluxing with liquid bromine without solvent.The brominated product is alkaline hydrolysised with Na\-2CO\-3 solution at pH=9,then oxidated by H\-2O\-2+HBr.This method has the advantage of avilable starting meterial,easy procedure and higher yield.