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In this paper, a series of bis(2,3-dihydroquinazolin-4(1H)-one) derivatives (4a-i, 10a-k) were synthesized by the one-pot pseudo-five-component reaction of isatoic anhydride with aromatic aldehydes and aromatic amines under reflux in glacial acetic acid. The synthesized compounds were screened for their antioxidant properties using the DPPH radical scavenging method. Compounds 4i and 10h showed potent radical scavenging activities at 20 [Formula: see text] compared to BHA and ascorbic acid. The anticancer activity of compound 4f was evaluated against human breast cancer cell line (MCF 7), and the observed [Formula: see text] was found to be 11.4 [Formula: see text]. The redox behaviour of some analogues was evaluated by cyclic voltammetric methods, and it is found that compound 7d possesses the maximum redox potential.

One pot cyclocondensation reaction of barbituric/thiobarbituric acid with aromatic aldehydes and p-phenylenediamine/2,6-diaminopyridine by refluxing in glacial acetic acid afforded novel bis(pyrimido[5,4-c]quinoline-2,4(1H,3H)-diones)/pyrido bis(pyrimido[5,4-c]quinoline-2,4(1H,3H)-diones. All the synthesized compounds were screened for their antioxidant activities using FRAP and DPPH methods. Compounds with chloro substituents showed relatively good antioxidant properties., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

In this communication, for the first time we have constructed a series of novel azo group fused 2 H -chromene-3-carboxylate and 3-acetyl-2 H -chromene derivatives via the Knoevenagel condensation reaction of active methylene compounds with aromatic 5-arylazosalicylaldehydes followed by a nucleophilic addition of the phenolic hydroxyl group to the carbonyl group of one of the ester groups. Shorter reaction times, high yields, simple work-up procedure and mild reaction conditions are the advantages of the present method. In addition, we have also studied the antioxidant activities using DPPH, hydroxyl, and ABTS radical scavenging methods. [ABSTRACT FROM AUTHOR]

The title chromenes are efficiently prepared by Knoevenagel condensation of active methylene compounds with aromatic azosalicylaldehydes using piperidine as catalyst followed by nucleophilic addition of the phenolic hydroxyl group to the carbonyl group of one of the ester groups. [ABSTRACT FROM AUTHOR]

The title compounds (IV),(VI) are obtained in an one-pot cyclocondensation reaction of barbituric/thiobarbituric acid with aromatic aldehydes and p-phenylenediamine/2,6-diaminopyridine. [ABSTRACT FROM AUTHOR]