Cascade engineered synthesis of the drug butamben (n-butyl-p-aminobenzoate), a local anaesthetic, which is used for the treatment of chronic pain, is presented here. A new multifunctional heterogeneous catalyst was synthesized, characterized and used for the direct synthesis of n-butyl-p-aminobenzoate by hydrogenation and esterification. A mixture of p-nitrobenzoic acid, n-butanol, hydrogen, acetonitrile as solvent and catalyst was used and hydrogenated in which hydrogenation precedes esterification. A series of aluminum exchanged dodecatungstophosphoric acids (DTP) (Al_x-DTP; x = 0.33–1) (5–20% w/w) supported on mesocellular foam silica (MCF) were prepared. 2% Fe loaded on 15% Al_0.66DTP/MCF showed the best activity for one-pot synthesis because the metal and acid sites had proper strength and distribution on MCF. Reaction mechanism and kinetic model were developed. The catalyst 2%Fe-15% Al_0.66DTP/MCF was found reusable for four catalytic cycles. This work presents an interesting case of reaction engineering using multi-functional catalyst useful in synthesis of a pharmaceutical drug butamben and has potential applications in other areas.

本文介绍了用于局部治疗的局部麻醉药butamben（对氨基苯甲酸正丁酯）的级联工程合成。合成，表征了一种新型多功能非均相催化剂，并将其用于加氢和酯化反应直接合成对氨基苯甲酸正丁酯。使用对硝基苯甲酸，正丁醇，氢气，乙腈作为溶剂和催化剂的混合物，并进行氢化，其中氢化先于酯化。一系列铝交换的十二碳杂磷酸（DTP）（Al _x-DTP; x = 0.33-1）（5-20​​％w / w）负载在介孔泡沫二氧化硅（MCF）上。负载在15％Al _0.66 DTP / MCF上的2％Fe对一锅法合成显示出最佳活性，因为金属和酸性部位在MCF上具有适当的强度和分布。建立了反应机理和动力学模型。发现催化剂2％Fe-15％Al _0.66 DTP / MCF可重复使用四个催化循环。这项工作提出了使用多功能催化剂进行工程反应的有趣案例，该多功能催化剂可用于合成药物丁苯本，并在其他领域具有潜在的应用。