Introduction of a novel dicationic Brönsted acidic ionic liquid based on pyrazine and its application in the synthesis of xanthenediones and 3, 4-dihydropyrimidin-2(1H)-ones under solvent-free conditions
作者:Seyyed Erfan Sadati Sorkhi、Mohammad M. Hashemi、Ali Ezabadi
DOI:10.1007/s11164-020-04089-9
日期:2020.4
acidic ionic liquid based on pyrazine has been prepared and characterized by FTIR, 1HNMR, 13C NMR, MS, thermal gravimetric and differential thermal gravimetric analysis and also Hammett acidity function. The prepared dicationic ionic liquid is found to be an efficient and reusable catalyst for the synthesis of xanthenediones and 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions. The merits
制备了一种新型的吡嗪类布朗斯台德酸性离子液体,并通过FTIR,1 H NMR,13 C NMR,MS,热重分析和差示热重分析以及Hammett酸度函数进行了表征。发现所制备的阳离子型离子液体是在无溶剂条件下用于合成黄二酮和3,4-二氢嘧啶-2(1 H)-one的有效且可重复使用的催化剂。所开发方法的优点包括离子液体的新颖性,离子液体的易于制备,易于后处理,催化剂的可重复使用性,高收率,短的反应时间以及不存在有毒的有机溶剂。
Molybdate sulfonic acid: preparation, characterization, and application as an effective and reusable catalyst for octahydroxanthene-1,8-dione synthesis
作者:Bahador Karami、Zahra Zare、Khalil Eskandari
DOI:10.2478/s11696-012-0263-y
日期:2013.1.1
Molybdate sulfonic acid (MSA) as a highly efficient catalyst was synthesized and employed for the synthesis of octahydroxanthene-1,8-dione derivatives. MSA efficiently catalyzed condensation of a wide range of aryl aldehydes and cyclohexane-1,3-diones to obtain octahydroxanthene-1,8-diones. It was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and FT-IR spectroscopy. This catalyst
Silica-supported phosphomolybdic acid was found to be an efficient heterogeneous catalyst for the synthesis of 1,8-dioxooctahydroxanthenes from aldehydes and dimedone and of tetrahydrochromenes fro...
DMSO or aq HBr (10 mol %) is developed as an efficient and cost effective acid catalyst for the simple one-pot synthesis of 9-aryl-1,8-dioxooctahydroxanthene derivatives. Reaction of aromatic aldehyde (1 equiv) and dimedone (2 equiv) in the presence of CaCl2 (20 mol %) in CHCl3 at room temperature gave the open chain analogue of 1,8-dioxooctahydroxanthene. Similarly, aq HBr (10 mol %) in water at reflux
utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensationbetween poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product,