对二甲氨基苯甲醛合成工艺优化

Optimization of synthesis technology for p-dimethylaminobenzaldehyde

研究了对二甲氨基苯甲醛的合成工艺,考察了物料配比n[N,N-二甲基苯胺(DMA)]∶n[N,N-二甲基甲酰胺(DMF)]∶n[三氯氧磷(POCl3)]、溶剂添加与否、滴加温度、保温反应温度、中和终点pH等对反应收率的影响,优化的工艺条件为在无苯或甲苯作溶剂和冰冷却下,n(DMA)∶n(DMF)∶n(POCl3)=1∶1.1∶1.2时,40℃内滴加DMF和DMA,90℃保温反应,终点pH值为2.5～3.5,对二甲氨基苯甲醛的收率>75%.该方法减少了溶剂和废水处理的难度,降低了能耗.

The synthesis technology of p-dimethylaminobenzaldehyde was studied. The effects of materials male ratio of N,N-dimethyl benzyl amine （DMA）, N,N-dimethyl for mamide （DMF） and phosphorous oxychloride （POCl3）, adding or without solvent, dropwise temperature and pH of neutralization end point on the reaction yield were investigated. The optimal synthesis condition was as follows：without adding solvents such as benzene or toluene, without ice cooling, n（DMA）：n（DMF）：n（POCl3）=1：1.1：1.2, DMF and DMA were dropwised at 40 ℃, reacted at 90 ℃, the end point pH 2.5N3.5. Under the optimal condition, the yield of p-dimethylaminobenzaldehyde was over 75%. This method could decrease the treatment difficulty of solvent and wastewater and reduce the energy consuming.