对二甲氨基苯甲酸异辛酯的合成工艺

Synthesis of 2-ethylhexyl p-dimethylamiobenzoate

对合成对二甲氨基苯甲酸异辛酯的原始工艺进行了改进,获得了收率高、成本低、毒性小、污染少的合成工艺优化方法;可实现大规模工业生产。即以N,N-二甲基对氨基苯甲酸和异辛醇为原料,无需溶剂脱水,用对甲苯磺酸作为酯化催化剂,采用高负压的方法除去反应过程中生成的水,从而使正反应能够最大限度地进行,反应温度控制在110～120℃。重点讨论了无溶剂参与的酯化反应条件:反应温度110～120℃,真空度-0.095 MPa,反应时间6 h,对二甲氨基苯甲酸与异辛醇的摩尔比为1∶3.5,以对二甲氨基苯甲酸计,产品收率为90%。

2-Ethylhexyl p-dimethylamiobenzoate was synthesized with higher yield,lower cost and nontoxicity,which is easier realized for large-scale industrial production.Dimethylamino benzoic acid and isooctanol were used as starting materials without any solvent by using p-toluenesulfonic acid as a esterification catalyst.The reaction proceeded as much as possible to remove the produced water under highly reduced pressure,and the reaction temperature was controlled in a range between 110℃and 120 ℃.The reaction conditions of the esterification without solvent should be emphasized that the temperature was between 110 and 120 ℃ at a negative pressure of 0.095 MPa for 6h.The molar ratio of dimethyl-aminobenzoic acid with isooctanol was 1∶3.5.2-Ethylhexyl p-dimethylamiobenzoate yield was higher than 90% based ondimethyl-aminobenzoic acid.