&lt;strong&gt;Ionic Liquid&lt;/strong&gt;&lt;strong&gt; Mediated Synthesis Of Novel &lt;/strong&gt;&lt;strong&gt;Chromone-Pyrimidine Coupled Derivatives.&lt;/strong&gt;

Anna Pratima Nikalje,Julio Seijas Vázquez,Shailee Tiwari,M Pilar Vazquez-Tato

doi:10.3390/ecsoc-21-04826

Abstract

The work reports synthesis of twelve novel ethyl 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 4(a-f) and 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2- thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carbohydrazide derivatives 6(a-f). The novel chromone-pyrimidine coupled derivatives were synthesized under solvent-free condition using Triethyl ammonium sulphate [Et3NH][HSO4] as an efficient, eco-friendly and reusable catalyst. Compared to other methods, this new method consistently has advantages, including excellent yields, a short reaction time, mild reaction conditions and catalyst reusability. The heterocyclic compound Chromone, is associated with diverse biological activities of immense importance. The nitrogen containing heterocycle such as pyrimidine has attracted continuing interest because of its varied biological activities and its occurrence in natural medicinal plants. Pyrimidine and its derivatives are used as antifungal agents, antibacterial agents, anticancer agents, etc. Considering the importance of the two pharmacophores, promoted us to club both the pharmacophores in a single molecule using green protocol. The structures of the synthesized compounds were confirmed by spectral characterization such as IR, 1H NMR, 13CNMR and Mass spectral studies.

Highlights

Coumarins, an elite class of naturally occurring compounds with promising therapeutic perspectives [1, 2]
An elite class of naturally occurring compounds with promising therapeutic perspectives [1, 2]. This compound have become indispensable structural units that are useful in medicinal chemistry displaying profiles such as anticancer [3], antioxidant [4], antiplasmodial [5], antimalarial [6], antirhinovirus [7], antifungal [8] and antibacterial [9]. 4-Oxo-4H-chromen3-carbaldehyde (3-formylchromone) a useful precursor for the synthesis of several biological active compounds owing to the presence of an unsaturated keto function, a conjugated second carbonyl group at C-3, and an electrophilic centre at C-2
Much research has been focused on the inhibition of bacterial growth by naturally occurring coumarins and on the antifungal activity of umbelliferone, scopoletin, and coumarin itself [10]

Summary

Introduction

An elite class of naturally occurring compounds with promising therapeutic perspectives [1, 2]. 15 mol % of the [Et3NH][HSO4] ionic liquid as catalyst and solvent was considered to ensure the best yield (95 %) in short reaction time (60 min) at 100 °C (Entry 3 of Table 1) These observations make the process under study more expeditious and economic, safe and eco-friendly. 5 mol % of the [Et3NH][HSO4] ionic liquid as catalyst and solvent was considered to ensure the best yield (88 %) in short reaction time (30 min) at 90 °C (Entry 3 of Table 4).

Materials and Methods

Findings

Conclusion