Facile DES-mediated synthesis and antioxidant potency of benzimidazoquinazolinone motifs

Dihydroazolopyrimidines: Past, Present and Perspectives in Synthesis, Green Chemistry and Drug Discovery

Dihydroazolopyrimidines are an important class of heterocycles that are isosteric to natural purines and are therefore of great interest primarily as drug-like molecules. In contrast to the heteroaromatic analogs, synthetic approaches to these compounds were developed much later, and their chemical properties and biological activity have not been studied in detail until recently. In the review, different ways to build dihydroazolopyrimidine systems from different building blocks are described - via the initial formation of a partially hydrogenated pyrimidine ring or an azole ring, as well as a one-pot assembly of azole and azine fragments. Special attention is given to modern approaches: multicomponent reactions, green chemistry, and the use of non-classical activation methods. Information on the chemical properties of dihydroazolopyrimidines and the prospects for their use in the design of drugs of various profiles are also summarized in this review.

Ultrafast fabrication of deep eutectic solvent flexible ionic gel with high-transmittance, freeze-resistant and conductivity by frontal polymerization

As a common flexible sensing device, gels are widely used in electronic skin, personalized health monitoring, and smart manufacturing. However, gel suffers from temperature sensitivity, long polymerization times or thickness limitations. Deep eutectic solvents (DESs) have abundant hydrogen bond networks and low saturated vapor pressure, which can accelerate the frontal polymerization of ionic gels, and overcome the temperature sensitivity problem. Here, we showed how choline chloride (ChCl)-glycerol (Gly) DES can be used to create ionic gels with different properties and functions by combining them with different monomers (acrylamide (AM), acrylic acid (AA) and itaconic acid (IA)). Subsequently, we revealed the rapid gelation mechanism of PAM-ChCl-Gly ionic gel from multiple perspectives by density functional theory and molecular dynamics simulation, which was then applied to flexible sensing. The experimental results showed that the PAM-ChCl-Gly ionic gel had excellent tensile properties, high transparency, self-adhesion and stability. In addition, its gelation time was only 90 s without heating. ChCl-Gly DES offered a plentiful and stable hydrogen bonding network. PAM-ChCl-Gly ionic gels can detect tiny pressure and strain changes, making them suitable for flexible sensing. This greatly enriched the theoretical research foundation of DES-based ionic gels and broadened their application areas.

Facile synthesis of triazolo/benzazolo[2,1-b]quinazolinone derivatives catalyzed by a new deep eutectic mixture based on glucose, pregabalin and urea

In this study, a novel natural deep eutectic solvent was prepared from glucose, pregabalin, and urea. The prepared solvent was identified using a variety of techniques, including Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and refractive index measurements (RI). The prepared deep eutectic solvent was then utilized for the one-pot synthesis of quinazolinone derivatives. The yields of the product obtained with and without the catalyst were determined, providing insights into the catalytic efficiency of the system. This protocol offers several advantages, including mild reaction conditions, easy reagent preparation, a green process, short reaction times (2-60 min), high yields (80-99%), and a straightforward procedure with the possibility of catalyst reusability.

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.

Solvent-mediated Highly Efficient Synthesis of [1,2,4]triazolo/benzimidazoloquinazolinone Derivatives

OBJECTIVE

An efficient and catalyst-free procedure for the synthesis of [1,2,4]triazolo/benzimidazolo quinazolinones has been developed in 2,2,2-trifluoroethanol or deep eutectic solvent(DESs) as a clean reaction media.

METHODS

All of the obtained products are known compounds and identified by IR, 1HNMR,13CNMR, and melting points.

RESULT

Various products were obtained in good to excellent yields under reaction conditions.

CONCLUSION

We have efficiently developed a practical and catalyst-free approach for the synthesis of [1,2,4]triazolo/benzimidazolo quinazolinones employing TFE as a clean and reusable media.