Exploring the Synthetic and Antioxidant Potential of 1,2-Disubstituted Benzimidazoles using [Et3 NH][HSO4 ] Ionic Liquid Catalyst.

An [Et3 NH][HSO4 ] ionic-liquid catalyzed, intermolecular C-N bond formation for 1,2-disubstituted benzimidazole synthesis was achieved by the reaction of OPD and substituted aldehydes at ambient reaction conditions. Operational simplicity, use of easily available substrate and reagents, good yields (74-95 %) in short reaction time (4-18 min), simple work-up, and column chromatographic free synthesis are the remarkable features of this new protocol. The applicability of [Et3 NH][HSO4 ] ionic-liquid as a green and inexpensive catalyst with good recyclability and compatibility with a broad range of functional group having heteroatom, electron-withdrawing, and electron-releasing groups manifested the sustainability, eco-friendliness, and efficiency of the present methodology. Moreover, the antioxidant studies of the synthesized compounds using DPPH and ABTS assays were appealing and several synthesized compounds showed significant antioxidant activity.

Advances in the synthetic strategies of benzoxazoles using 2-aminophenol as a precursor: an up-to-date review.

Benzoxazole is a resourceful and important member of the heteroarenes that connects synthetic organic chemistry to medicinal, pharmaceutical, and industrial areas. It is a bicyclic planar molecule and is the most favorable moiety for researchers because it has been extensively used as a starting material for different mechanistic approaches in drug discovery. The motif exhibits a high possibility of broad substrate scope and functionalization to offer several biological activities like anti-microbial, anti-fungal, anti-cancer, anti-oxidant, anti-inflammatory effects, and so on. There has been a large upsurge in the synthesis of benzoxazole via different pathways. The present article presents recent advances in synthetic strategies for benzoxazole derivatives since 2018. A variety of well-organized synthetic methodologies for benzoxazole using 2-aminophenol with aldehydes, ketones, acids, alcohols, isothiocyanates, ortho-esters, and alkynones under different reaction conditions and catalysts, viz. nanocatalysts, metal catalysts, and ionic liquid catalysts, with other miscellaneous techniques has been summarized.

Exploring the synthetic potential of a g-C3N4·SO3H ionic liquid catalyst for one-pot synthesis of 1,1-dihomoarylmethane scaffolds via Knoevenagel-Michael reaction.

A highly promising approach for the synthesis of functionalized 1,1-dihomoarylmethane scaffolds (bis-dimedones, bis-cyclohexanediones, bis-pyrazoles, and bis-coumarins) using g-C3N4·SO3H ionic liquid via Knoevenagel-Michael reaction has been developed and the synthesized derivatives were well characterized using spectral studies. The method involved the reaction of C-H activated acids with a range of aromatic aldehydes, in a 2 : 1 ratio catalyzed by a g-C3N4·SO3H ionic liquid catalyst. The use of g-C3N4·SO3H as a catalyst has several benefits, such as low cost, easy preparation, and high stability. It was synthesized from urea powder and chloro-sulfonic acid and was thoroughly characterized using FT-IR, XRD, SEM, and HRTEM. The present work unveils a promising and environmentally friendly method for synthesizing 1,1-dihomoarylmethane scaffolds with high yield, selectivity, and efficiency, using mild reaction conditions, no need for chromatographic separation, and short reaction times. The approach adheres to green chemistry principles and offers a viable alternative to the previously reported methods.

Glycerol based carbon sulfonic acid catalyzed synthesis, in silico studies and in vitro biological evaluation of isonicotinohydrazide derivatives as potent antimicrobial and anti-tubercular agents.

The present pathway involves synthesis of isonicotinohydrazide derivatives using isoniazid and diversely substituted aldehydes in the presence of EtOH and catalytic amount of glycerol based carbon sulfonic acid catalyst. The developed pathway has so many merits like excellent yields (91-98%), short reaction time (4-10 min), easy reaction set up, no need of column chromatography, large substrate scope, easily recyclable and reusable catalyst. The synthesized compounds were screened for antimicrobial and anti-tubercular activity and it was observed that compounds possessed high biological potency against the Gram positive and Gram negative bacterial and fungal strains. Regarding anti-tubercular activity, compound 3m exhibited high % inhibition against Mycobacterium tuberculosis H37RV strain. Based on the outcome of in vitro studies, all the synthesized compounds were docked against E. coli (1KZN), C. albicans (1IYL), and M. tuberculosis H 37 Rv strain (2NSD). The synthesized derivatives were docked within the binding site of 1KZN, and 1IYL. However, with 2NSD, apart from 3h, all the derivatives displayed interaction within the binding cavity of the protein. All the crucial interactions with Asn46, Asp73, and Arg136 in 1KZN, His227, Leu451 in 1IYL, and Tyr158 in 2NSD were witnessed in the top-scored docked candidates. Molecular docking studies revealed the importance of the substitution at R position on isonicotinohydrazide scaffold. The nitrogen atoms of hydrazide moiety were involved in forming hydrogen bonding with the active site amino acids, and the substitution at the R position occupy the hydrophobic position in the binding pocket. Also, the functional groups present on the substituted R position were involved in forming hydrogen bonding with the crucial active site residues.

Synthetic aspects of 1,4- and 1,5-benzodiazepines using o-phenylenediamine: a study of past quinquennial.

Benzodiazepines, seven-membered heterocyclic compounds having two nitrogen atoms at different positions, are ruling scaffolds in the area of pharmaceutical industry. They act as cardinal moieties in organic synthesis as well as in medicinal chemistry. Among the different benzodiazepines, 1,4- and 1,5-benzodiazepines play a far-reaching role in the field of biological activities such as anticonvulsion, anti-anxiety, sedation, and hypnotics. In the past few decades, researchers have conducted a lot of work on these moieties and developed broad, valuable, and significant approaches for their synthesis. In this review article, we recapitulate the systematic synthetic strategies of 1,4- and 1,5-benzodiazepines using o-phenylenediamine as a precursor over the past five years (2018-2022). This article will be helpful for scientists and researchers to examine and explore novel and efficient methods for the synthesis of these biologically active moieties.

Tandem Protocol of Hexahydroquinoline Synthesis Using [H2-DABCO][HSO4]2 Ionic Liquid as a Green Catalyst at Room Temperature.

Green, eco-benign, and sustainable synthesis is paramount in present chemistry. Here, a facile, efficient, and [H2-DABCO][HSO4]2 ionic-liquid-catalyzed one-pot multicomponent synthesis of hexahydroquinolines was reported under ambient reaction conditions. The reaction of 1,3-dicarbonyls, malononitrile, and ammonium acetate with various aldehydes in the presence of an ionic liquid catalyst and EtOH solvent at room temperature afforded excellent yields (76-100%) of hexahydroquinolines under a short reaction time (5-15 min). Mild reaction conditions, broad substrate scope (28 derivatives), and column-chromatography-free synthesis with excellent catalytic efficiency and good recyclability rendered this protocol superior and practical. The greenness of the present method was assessed through eco-score and E-factor. The significant results in gram-scale synthetic conditions validate its applicability in industries as well as academia in the near future.

An Overview on Immunity Booster Foods in Coronavirus Disease (COVID-19).

The present COVID-19 pandemic is terrible for the respiratory system and is caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). It has affected millions of people globally and over 511.9 million cases and 6.2 million deaths have been reported across the world. Various drugs have been repurposed, however, no specific medicine has been approved by the FDA to combat this disease till date. In this condition, researchers have been attracted to natural and safe products to improve immunity to viral infections through inhibiting viral cell entry, replication, and modulation. Various natural products, probiotics, and nutrients have antimicrobial, antiviral, analgesic, anti-inflammatory, and antiproliferative activities, and some of the compounds are also utilized in traditional medicine in Ayurveda, Siddha, and other cultures. This review provides a clinical perspective on the application of herbs for the prevention of viral infections.

Current advances in the synthetic strategies of 2-arylbenzothiazole.

Benzothiazole is a privileged scaffold in the field of synthetic and medicinal chemistry. Its derivatives and metal complexes possess a gamut of pharmacological properties and high degree of structural diversity that has proven it vital for the investigation for novel therapeutics. The 2nd position of benzothiazole is the most active site that makes 2-arylbenzothiazole as felicitous scaffolds in pharmaceutical chemistry. The extensive significance of benzo-fused heterocyclic moieties formation has led to broad and valuable different approaches for their synthesis. This review deals with the synthetic approaches developed so far for the synthesis of 2-arylbenzothiazoles. Moreover, this article abridges the publications devoted to the synthesis of this moiety over the last 6 years. This study gives a current precis of research on the fabrication of 2-arylbenzothiazoles through different synthetic pathways and shall be helpful for researchers and scientists who are working in this field to make more potent biologically active benzothiazole-based drugs.

Exploration of Potent Multi-target-directed-ligands as Anti-alzheimer's Disease Agents: A Moiety Based Review.

Dementia is a chronic neurodegenerative disease, and a maximum number of the cases are directly related to Alzheimer's disease. More than 4 million people are living with Alzheimer's disease-related dementia in India, making it a national crisis. Alzheimer's disease deteriorates cognitive functions with the passage of time and consists of multi-faceted factors, such as the decline of acetylcholine level, amyloid ß-aggregation, tau hyperphosphorylation, oxidative stress, etc. The classical drugs used to date, are focused on only one target and are not serving the cause properly. Hence, the community of scientists is rigorously working on multi-target-directed agents that incorporate two or more active scaffolds in one compound or hybrid of active moieties. This article aims to evaluate novel potential compounds and moieties, such as quinolines, chalcones, coumarins, chromenes, piperazine, carbazoles, cinnamic acids, tacrine hybrids, donepezil hybrids, etc., that have been introduced as multi-target-directed agents in the recent five years.

New Insights into the Microstructural Analysis of Graphene Oxide.

AIM AND OBJECTIVE: To explore the impact of synthesis conditions (temperature and time) on the properties of developed Graphene Oxide (GO). BACKGROUND: A highly promising approach has been used for the synthesis of graphene oxide (GO) from graphite flakes using the modified Hummers method. Concentrated sulfuric acid was used as an intercalating agent and the oxidation was done with the help of potassium permanganate and hydrogen peroxide. METHODS: The present method does not need expensive membranes for the filtration of Carbon and metalcontaining residues. The pre-cooling method is used to eradicate the explosive behavior of intermediate steps. The high quality of synthesized graphene oxides was confirmed by a series of characterization techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, energy-dispersive X-ray spectroscopy, and atomic force microscopy. RESULTS: The results indicated the presence of Oxygen-containing functional groups, and a rise in the Oxygen content confirmed the synthesis of high-quality graphene oxide. CONCLUSION: As per obtained experimental findings and subsequent analysis, the synthesized high-quality graphene oxide could be used in the design of membranes for water treatment applications.

Recent Advances in the Synthesis of Perimidines and their Applications.

Perimidines are versatile scaffolds and a fascinating class of N-heterocycles that have evolved significantly in recent years due to their immense applications in life sciences, medical sciences, and industrial chemistry. Their ability of molecular interaction with different proteins, complex formation with metals, and distinct behavior in various ranges of light makes them more appealing and challenging for future scientists. Various novel technologies have been developed for the selective synthesis of perimidines and their conjugated derivatives. These methods extend to the preparation of different bioactive and industrially applicable molecules. This review aims to present the most recent advancements in perimidine synthesis under varied conditions like MW radiation, ultrasound, and grinding using different catalysts such as ionic liquids, acid, metal, and nanocatalyst and also under green environments like catalyst and solvent-free synthesis. The applications of perimidine derivatives in drug discovery, polymer chemistry, photo sensors, dye industries, and catalytic activity in organic synthesis are discussed in this survey. This article is expected to be a systematic, authoritative, and critical review on the chemistry of perimidines that compiles most of the state-of-art innovation in this area.

Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications.

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

Contemporary Progress in the Synthetic Strategies of Imidazole and its Biological Activities.

Heterocyclic compounds are pervasive in many areas of life and one of the heterocycles, imidazole is a unique heterocyclic five-membered aromatic compound having two sp2 hybridized nitrogen atoms. Its integral name is 1, 3 diazole and previously, it was known as glyoxalin. This moiety has achieved a considerable place among scientists in recent years by reason of its divergent synthetic strategies and uncommon biological and pharmacological activities, for example, anti-convulsant, anti-microbial, anti-cancer, anti-inflammatory, anti-tumor, anti-viral, anti-ulcer, analgesic, etc. Due to distinct therapeutic actions, it is still an engrossed area of research. Researchers currently are inventing new greener methods to synthesize its derivatives and to improve its pharmacological activities. The purpose of this review is to study the literature that can help researchers to explore this area, its prevailing program for synthesis in environmentally friendly conditions and biological profile throughout past decades.