Preparation and characterization of a dual acidic Ionic Liquid functionalized Graphene Oxide nanosheets as a Heterogeneous Catalyst for the Synthesis of pyrimido[4,5-b] quinolines in water

Abstract

Pyrimido[4,5-b]quinolones play a significant role in medicinal chemistry owing to their various biological properties, including antihistaminic, antimalarial, antifungal, anticancer, antioxidant, antiviral, anti-microbial, and anti-inflammatory activities. A dual acidic ionic liquid anchored on graphene oxide nanosheets (GO-Si-Pr-Lysin-SO₃H) was provided and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). The six-step process was utilized to create this catalyst, beginning with graphite powder. This catalyst was capable to develop the one-pot and three components (6-amino-1,3-dimethyluracil, dimedone, and different aromatic aldehydes) synthesis of pyrimido[4,5-b]quinolone derivatives at moderate temperature in water as a green medium (12 derivatives). The results obtained indicated that this method could be an effective approach for synthesizing pyrimido[4,5-b]quinolones with high yields ranging from 86% to 98% in a short reaction time of 15 to 40 minutes. In addition, the pointed catalyst shows reusability and recoverability without remarkable loss of catalytic activity.   Highlights

• GO-Si-Pr-Lysin-H-SO₃H as an efficient heterogeneous catalyst and supported ionic liquid was provided.
• 12 types of pyrimido[4,5-b]quinolone derivatives using GO-Si-Pr-Lysin-SO₃H were prepared.
• GO-Si-Pr-Lysin-H-SO₃H show good catalytic activity for both electron-withdrawing and electron-donating substituents.
• GO-Si-Pr-Lysin-H-SO₃H was characterized and identified using microscopic and spectroscopic techniques.
• GO-Si-Pr-Lysin-H-SO₃H was reused for six catalytic cycle.