Monem Arezo, Habibi Davood, Goudarzi Hadis
Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 6517838683, Iran.
Sci Rep. 2023 Oct 21;13(1):18009. doi: 10.1038/s41598-023-45352-4.
Deep eutectic solvents have countless advantages over normal solvents, and in addition to complying with the principles of green chemistry, depending on their nature, they can also act as catalysts. The use of deep eutectic solvents as acid catalysts has several advantages such as non-toxicity, a catalytic effect similar to or higher than the acid itself, and the possibility of recovery and reuse without significant loss of activity. In this project, A novel deep eutectic solvent (MTPPBr-PCAT-DES) was prepared from a one-to-one mole ratio of methyltriphenyl-phosphonium bromide (MTPPBr) and 3,4-dihydroxybenzoic acid (PCAT = protocatechuic acid) and characterized by various techniques such as FT-IR, TGA/DTA, densitometer, eutectic point, H NMR, C NMR and P NMR. Then, it was used as a novel and capable catalyst for the synthesis of pyranopyrimidines from the multicomponent condensation reaction of barbituric acid, 4-hydroxycoumarin, and aromatic aldehydes in mild conditions, short reaction times, and high yields.
深共熔溶剂相较于普通溶剂具有无数优势，除了符合绿色化学原则外，根据其性质，它们还可充当催化剂。将深共熔溶剂用作酸催化剂具有诸多优点，如无毒、催化效果与酸本身相似或更高，且有可能回收再利用而活性无显著损失。在本项目中，由等摩尔比的甲基三苯基溴化鏻（MTPPBr）和3,4 - 二羟基苯甲酸（PCAT = 原儿茶酸）制备了一种新型深共熔溶剂（MTPPBr - PCAT - DES），并通过傅里叶变换红外光谱（FT - IR）、热重/差示热分析（TGA/DTA）、密度计、低共熔点、氢核磁共振（¹H NMR）、碳核磁共振（¹³C NMR）和磷核磁共振（³¹P NMR）等多种技术对其进行了表征。然后，它被用作一种新型且高效的催化剂，用于在温和条件、短反应时间和高收率下，通过巴比妥酸、4 - 羟基香豆素与芳香醛的多组分缩合反应合成吡喃并嘧啶。
