Facile synthetic approaches for new series of pyrazole-4-carbonitrile derivatives

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

The review presents data on the synthesis as well as studies of biological activity of new derivatives of pyrimido[1,2-a]benzimidazoles published over the last decade. The bibliography of the review includes 136 sources.

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

Aromatic α-aminoazaheterocycles are the focus of significant investigations and exploration by researchers owing to their key role in diverse biological and physiological processes. The existence of their derivatives in numerous drugs and alkaloids is due to their heterocyclic nitrogenous nature. Therefore, the synthesis of a structurally diverse range of their derivatives through simple and convenient methods represents a vital field of synthetic organic chemistry. Multicomponent reactions (MCRs) provide a platform to introduce desirable structure diversity and complexity into a molecule in a single operation with a significant reduction in the use of harmful organic waste, and hence have attracted particular attention as an excellent tool to access these derivatives. This review covers the advances made from 2010 to the beginning of 2020 in terms of the utilization of α-aminoazaheterocycles as synthetic precursors in MCRs.

Synthesis, Antimicrobial and Antitumor Evaluations of a New Class of Thiazoles Substituted on the Chromene Scaffold

BACKGROUND & OBJECTIVE

A new series of thiazoles substituted on the chromene scaffold were prepared by facial approaches starting from (E)-1-(2,3-Dihydrochromen-4-ylidene)thiosemicarbazide derivatives (2a,b). The thiosemicarbazides (2a,b) were reacted with a series of α-halo carbonyl compounds to give the corresponding rhodanine analogues and reacted also with C-acetyl-or Cethoxy- N-hydrazonoyl chlorides to afford the corresponding tri- and tetra-substituted hybrid hydrazinyl thiazole substituted chromenes.

METHODS

The newly synthesized compounds were screened for their in vitro antimicrobial and antitumor activities by agar diffusion method and MTT assay, respectively.

RESULTS

The results of the antimicrobial activity revealed that some of the new compounds exhibited excellent activity against pathogenic microorganism; Candida albicans compared with Ciprofloxacin and nystatin, as the reference drugs. All of the tested compounds exhibited significant cytotoxic activities comparable to that of the reference drug; Doxorubicin® (on HCT116 (colorectal carcinoma human cell line).

Aminoazole-Based Diversity-Oriented Synthesis of Heterocycles

The comprehensive review contains the analysis of literature data concerning reactions of heterocyclization of aminoazoles and demonstrates the application of these types of transformations in diversity-oriented synthesis. The review is oriented to wide range of chemists working in the field of organic synthesis and both experimental and theoretical studies of nitrogen-containing heterocycles.