Abstract

In this study, three different choline chloride-based deep eutectic solvents were synthesized. And it is the first time to synthesize 1,10-phenanthroline through an improved Skraup reaction using deep eutectic solvent as the new catalyst from acrolein and 8-aminoquinoline. The deep eutectic solvents were characterized by Fourier transform infrared (FT-IR), ¹H nuclear magnetic resonance (¹H NMR), pH/mV meter, and thermogravimetric analysis (TGA). The research results show that the deep eutectic solvent formed by sulfanilic acid and choline chloride has the strongest acidity and highest catalytic active among the three deep eutectic solvents. Besides, the impacts of reaction parameters and molar ratio of raw materials on the reaction were also investigated. Under the optimized reaction conditions, the maximum selectivity and yield of 1,10-phenanthroline were achieved as 84.6 and 75.6%, respectively. The synthesis method, meanwhile, also has simple preparation process and low cheaper catalyst raw.

Graphical abstract

中文翻译：

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深度共晶溶剂用作通过改进的Skraup反应合成1,10-菲咯啉的催化剂

摘要

在这项研究中，合成了三种不同的基于氯化胆碱的深共熔溶剂。这是第一次通过改进的Skraup反应，使用深共晶溶剂作为丙烯醛和8-氨基喹啉的新催化剂，通过合成的Skraup反应来合成1,10-菲咯啉。深共晶溶剂的特征在于傅立叶变换红外光谱（FT-IR），¹ H核磁共振（¹1 H NMR），pH / mV计和热重分析（TGA）。研究结果表明，由磺胺酸和氯化胆碱形成的深共晶溶剂在三种深共晶溶剂中具有最强的酸度和最高的催化活性。此外，还研究了反应参数和原料摩尔比对反应的影响。在优化的反应条件下，1,10-菲咯啉的最大选择性和产率分别为84.6和75.6％。同时，该合成方法制备工艺简单，催化剂原料廉价。

图形概要