PEG1000-Based Dicationic Acidic Ionic Liquid Catalyzed One-Pot Synthesis of 4-Aryl-3-Methyl-1-Phenyl-1H-Benzo[h]pyrazolo [3,4-b]quinoline-5,10-Diones via Multicomponent Reactions

Yi-Ming Ren,Hai-Jun Yan,Shuo Jin,Ze Zhang

doi:10.3390/catal5041649

Abstract

A novel and green approach for efficient and rapid synthesis of 4-aryl-3-methyl-1-phenyl-1H-benzo[h]pyrazolo[3,4-b]quinoline-5,10-diones has been accomplished by the one-pot condensation reaction of aromatic aldehydes, 3-methyl-1-phenyl-1H-pyrazol-5-amine and 2-hydroxynaphthalene-1,4-dione using PEG1000-based dicationic acidic ionic liquid (PEG1000-DAIL) as a catalyst was reported. Recycling studies have shown that the PEG1000-DAIL can be readily recovered and reused several times without significant loss of activity. The key advantages are the short reaction time, high yields, simple workup, and recovered catalyst.

Highlights

Green organic chemistry offers enhanced chemical technology procedures economics concomitant with a reduced environmental degradation
The most straightforward synthesis of these compounds involves the three-component condensation of aromatic aldehydes, 5-amino-3-methyl-1-phenylpyrazole and dimedone under thermal [5] or microwave condition [6]
Wu et al [7,8,9] and Khurana et al [10] reported a new route for preparation of 4-aryl-3-methyl-1-phenyl-1H-benzo[h]pyrazolo[3,4-b]quinoline-5,10-diones by the one-pot condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine, 2-hydroxynaphthalene-1,4-dione and aromatic aldehydes under solvent-free conditions [7] or water as solvent [8,9]

Summary

Introduction

Green organic chemistry offers enhanced chemical technology procedures economics concomitant with a reduced environmental degradation. From this viewpoint, it is desirable to achieve multi-bond formation in one operation. Due to the presence of versatile biological activities in pyrazolo[3,4-b]quinolines, several attempts have been made to provide a convenient synthetic route for this fused ring system. Among these reactions, the most straightforward synthesis of these compounds involves the three-component condensation of aromatic aldehydes, 5-amino-3-methyl-1-phenylpyrazole and dimedone under thermal [5] or microwave condition [6]. Wu et al [7,8,9] and Khurana et al [10] reported a new route for preparation of 4-aryl-3-methyl-1-phenyl-1H-benzo[h]pyrazolo[3,4-b]quinoline-5,10-diones by the one-pot condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine, 2-hydroxynaphthalene-1,4-dione and aromatic aldehydes under solvent-free conditions [7] or water as solvent [8,9]

Methods

Results

Conclusion