Microwave-assisted, solvent-free, parallel syntheses and elucidation of reaction mechanism for the formation of some novel tetraaryl imidazoles of biological interest

Structure-Activity Relationship of Benzofuran Derivatives with Potential Anticancer Activity

Simple Summary

Cancer is the leading cause of death worldwide and responsible for killing approximately 10 million people per year. Fused heterocyclic ring systems such as benzofuran have emerged as important scaffolds with many biological properties. Furthermore, derivatives of benzofurans demonstrate a wide range of biological and pharmacological activities, including anticancer properties. The main aim of this review is to highlight and discuss the contribution of benzofuran derivatives as anticancer agents by considering and discussing the chemical structure of 20 different compounds. Evaluating the chemical structure of these compounds will guide future medicinal chemists in designing new drugs for cancer therapy that might give excellent results in in vivo/in vitro applications.

Abstract

Benzofuran is a heterocyclic compound found naturally in plants and it can also be obtained through synthetic reactions. Multiple physicochemical characteristics and versatile features distinguish benzofuran, and its chemical structure is composed of fused benzene and furan rings. Benzofuran derivatives are essential compounds that hold vital biological activities to design novel therapies with enhanced efficacy compared to conventional treatments. Therefore, medicinal chemists used its core to synthesize new derivatives that can be applied to a variety of disorders. Benzofuran exhibited potential effectiveness in chronic diseases such as hypertension, neurodegenerative and oxidative conditions, and dyslipidemia. In acute infections, benzofuran revealed anti-infective properties against microorganisms like viruses, bacteria, and parasites. In recent years, the complex nature and the number of acquired or resistant cancer cases have been largely increasing. Benzofuran derivatives revealed potential anticancer activity with lower incidence or severity of adverse events normally encountered during chemotherapeutic treatments. This review discusses the structure–activity relationship (SAR) of several benzofuran derivatives in order to elucidate the possible substitution alternatives and structural requirements for a highly potent and selective anticancer activity.

The regioselective catalyst-free synthesis of bis-quinoxalines and bis-pyrido[2,3-b]pyrazines by double condensation of 1,4-phenylene-bis-glyoxal with 1,2-diamines

The oxidation of 1,4-diacetylbenzene using several oxidizing agents gave 1,4-phenylene-bis-glyoxal in 61–85% yields. A convenient and efficient synthesis of bis-quinoxaline and bis-pyrido[2,3-b]pyrazine derivatives involves the double condensation of 1,2-diamines with 1,4-phenylene-bis-glyoxal in ethanol under reflux conditions. The structures of the new products were defined by proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), Fourier-transform infrared spectroscopy (FT-IR) and mass spectrometry (MS).

Synthesis of dimethyl aryl acylsulfonium bromides from aryl methyl ketones in a DMSO-HBr system

A new, simplified method for the synthesis of dimethyl aryl acylsulfonium salts has been developed. A series of dimethyl aryl acylsulfonium bromides were prepared by the reaction of aryl methyl ketones with hydrobromic acid and dimethylsulfoxide (DMSO). This sulfonium salt confirms that bromine production and the bromination reaction take place in the DMSO-HBr oxidation system. What’s more, it is also a key intermediate for the synthesis of arylglyoxals.

Microwave-assisted, solvent-free and parallel synthesis of some novel substituted imidazoles of biological interest

Solvent free microwave assisted synthesis of some novel substituted imidazoles of biological interest is reported. First, primary aromatic or heteryl amine was condensed with aryl or heteryl aldehydes to afford corresponding Schiff's base. The Schiff's base further on treatment with ammonium acetate (NH(4)OAC) and isatin using silica gel as the solid support, yielded the corresponding aryl imidazoles. In this paper a comparative study between the developed microwave method and conventional method is described. The synthesized compounds were analyzed by physical and analytical data. The synthesized compounds were evaluated for their antibacterial, anthelmintic, short-term anticancer and antitubercular activity. All the synthesized substituted imidazoles have shown good antibacterial activity against gram negative bacterial strains Klebsiella pneumoniae and Escherichia coli and moderate to good anthelmintic activity. The synthesized imidazole derivative possessed significant cytotoxic activity against Ehrlich's ascites carcinoma (EAC) cell lines. None of the compounds exhibited prominent antitubercular activity.