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The present works describe a highly efficient synthesis of pyrimidine derivatives through a Knoevenagel condensation followed by Michael addition and subsequent cyclization using novel designer Low Transition Temperature Mixture (LTTM) in Glycolic acid: Urea (1:1). The mixture afforded as a green solvent which plays a dual role as a reusable catalyst and solvent, simple to prepare and nontoxic. The thermal stability and working temperature range of low‐temperature mixture were identified by Thermogravimetric analysis and Differential Scanning Calorimetry. The pyrimidine derivatives synthesized via a one‐pot three‐component reaction of two moles of Barbituric/Thiobarbituric acid and one mole of aryl aldehydes reacted through Knoevenagel condensation followed by Michael addition and subsequent cyclization. The Knoevenagel intermediate formed at room temperate while at 80°C Knoevenagel intermediate further reacted with another mole of barbituric acid/Thiobarbituric acid and formed the cyclic compounds. The use of LTTM to yield vital pyrimidine molecules renders this protocol to cope with the current need for an efficient, cost‐effective, and eco‐friendly methodology. [ABSTRACT FROM AUTHOR]

One pot three component reaction of 4‐hydroxy‐6‐methylpyran‐2‐one, 3‐methoxy benzaldehyde, and malononitrile in water using protic ionic liquid as a catalyst at room temperature afforded pyrano[4,3‐b]pyran derivatives. Protic ionic liquid has been proved to be an efficient and mild catalyst for the synthesis of pyrano[4,3‐b]pyran scaffolds due to their highly polar nature. The notable aspects of protic ionic liquid are easy availability, improved reaction rates, high product yields, simple workup procedure, recyclability, and reusability. Molecules docking studies have been performed on enzyme enoyl‐ACP‐reductase from Mycobacterium tuberculosis. The molecular docking simulation indicated plausible π‐alkyl and alkyl‐alkyl interactions between the amino acids and scaffolds. The synthesized derivatives have been evaluated for their in vitro antituberculotic activity against M. tuberculosis H37RV strain using Microplate Alamar Blue Assay method. Together, biological activity data and docking data showed that the tested scaffolds exhibited excellent antituberculotic activity. [ABSTRACT FROM AUTHOR]

A highly competent synthesis of novel 7‐aryl‐10‐thioxo‐7, 10, 11, 12‐tertahydro‐9H‐benzo [H] pyrimido [4, 5‐b] quinoline‐8‐one derivatives has been reported through a Knoevenagel condensation followed by Michael addition and subsequent cyclization using ethanol:acetic acid (8:2 v/v). The mentioned protocol has advantages like high yields, cleaner reactions, operational simplicity, and environment friendliness. Moreover, these compounds were further screened against the plant pathogenic fungi like Colletotrichum truncatum, Ustilago maydis, Trichosporon, Trichothecium sp., Aspergillus oryze, Aspergillus terreus, and Aspergillus niger by agar well method bioassay. The results were elaborated for minimum inhibitory concentration determination using agar dilution method against fungal strains C. truncatum and U. maydis as well as broth dilution method for bacteria species Gram‐positive Bacillus megaterium and Gram‐negative Proteus vulgaris. Most of the tested compounds showed promising results towards the antimicrobial activity. [ABSTRACT FROM AUTHOR]

A series of novel 7-(3-chloro-phenyl)-10-thioxo-7,9,10,11-tetrahedro-6 H-pyrimido-[5′4′:5,6] pyrano[3,2-c]quinoline-6,8(5 H)-dione derivatives have been synthesized through the multi-component condensation of aromatic aldehydes, barbituric acid, and 2,4-dihydroxy quinoline, using heterogeneous sulfamic acid catalyst in water-ethanol (4:1) solvent system under reflux condition. The present protocol is endowed with charming description such as green synthetic procedure, short reaction time, easy work-up procedure, and excellent yield and high atom economy of pyranoquinoline derivatives. In this study, sulfamic acid is used as a heterogeneous catalyst that is easily recoverable and recyclable. The proposed multi-component reaction has been studied with detail mechanism and spectroscopic data. This is one of the potential greener synthetic approaches to build up the series of pyranoquinoline heterocycles. [ABSTRACT FROM AUTHOR]