2,4,6-三甲基苯甲醛的合成

Synthesis of 2,4,6-Trimethylbenzaldehyde

采用Gattermann-Koch反应合成了2,4,6-三甲基苯甲醛,并优化了合成的工艺条件。探讨了反应温度、CO压力、浓盐酸用量及助催化剂的影响。最佳工艺条件为：当均三甲苯用量为200.0 g时,均三甲苯与无水AlCl3摩尔比为3.08,反应温度26～28℃,CO压力1.06～1.48 MPa,AlCl3与浓盐酸质量比为550,AlCl3与TiCl4的质量比为45,反应20 h,收率86.86%。添加助催化剂TiCl4可以提高收率,溶剂乙醚的加入能大幅度地减少反应时间。

2,4,6-trimethylbenzaldehyde was synthesized through Gattermann-Koch reaction, and the reaction condition was optimized. The effects of reaction temperature, pressure of carbon monoxide, the amount of hydrochloric acid, and the promoter were discussed. The reaction can be promoted by titanium（Ⅳ ） chloride （TiCl4） and ethyl ether. The optimized condition is： the molar ratio of 2, 4, 6-trimethylbenzaldehyde to anhydros aluminum chloride （ AlCl3 ） is 3.08, molar ratio of AlCl3 to concentrated aqueous hydrochloride is 550, weight ratio of anhydros AlCl3 to TiCl4 is 45, pressure of carbon monoxide is 1.06-1.48 MPa, at 26- 28 ℃, for 20 h, yield of 86.86%.