Letters in Organic Chemistry - Volume 21, Issue 5, 2024

A mild and eco-friendly one-pot, two-step procedure has been developed for the synthesis of 2-hydroxy-N-arylacetamides from 2-chloro-N-arylacetamides. The procedure overcomes the cleavage of the amide linkage in 2-chloroacetamides, which is usually observed under reflux conditions with the hydroxide when the nucleophilic substitution of the halide is attempted. The reactions were performed by refluxing 2-chloro-N-arylacetamides with Cu(OAc)2 and DIPEA in the ethanol medium to facilitate an acetate exchange with the halogen. Subsequently, by the addition of ethanolic KOH solution to the same reaction flask, the ester linkage was selectively cleaved in the presence of the amide, taking advantage of the difference in electrophilicity. The procedure afforded good yields of the desired products, which are valuable intermediates for several biologically active molecules, in a short reaction time with ease of isolation. The experimental conditions employed are simple and offer the possibility of scaling up to higher quantities.

1,3,4-Thiadiazole has garnered considerable attention in the scientific community due to its captivating molecular structure and ability to serve as a foundation for creating novel pharmaceutical compounds. Numerous medications feature the 1,3,4-thiadiazole ring in their chemical structure, highlighting its relevance and efficacy in pharmaceutical research and development. The key objective of this comprehensive review is to provide an understandable overview of the chemistry and diverse pharmacological activities associated with 1,3,4-thiadiazole compounds. The manuscript was compiled by conducting a thorough literature review, which included an in-depth analysis of globally esteemed scientific research databases. The remarkable chemical characteristics and diverse pharmacological impacts of 1,3,4-Thiadiazole highlight its significant potential as a structural scaffold for the development of novel therapeutic substances. Based on the information available on synthetic molecules that incorporate the 1,3,4-thiadiazole framework and their wide range of uses, it is reasonable to expect significant advancements in the near future and the possibility of employing these compounds in different domains.

To identify potential drug candidates for the treatment of COVID-19 using a computational method. The recent pandemic of COVID-19 is observed as not less than a natural calamity of humankind and raised serious concerns for its immediate management. The continued spread of coronavirus disease across the globe poses a significant threat to human health. Out of this, the application of Dexamethasone has been correlated with reduced mortality in COVID-19 cases. This study sheds new light on the pharmacological potential of Dexamethasone and similar compounds in mitigating SARSCoV2 infection. In this study, we explored Dexamethasone-similar compounds, which can modulate the binding of SARS-CoV-2 spike protein to the host and TH17 programming in the host using a computer-aided drug repurposing method. The docking studies indicate that Desoximetasone can bind to the spike proteins of SARS-CoV-2, which are crucial for viral attachment and entry into host cells. By competing with these spike proteins, Desoximetasone may interfere with the virus's ability to attach to and enter host cells, potentially inhibiting viral replication and spread. The results from molecular dynamic simulation analysis further support this notion by demonstrating that Desoximetasone has a strong interaction with the binding sites of the spike protein. Experimental validation through in vitro studies and clinical trials is needed to evaluate its potential as a treatment option for COVID-19. Together, these findings revealed the underlying mechanism of how Desoximetasone can influence the fate of the virus in the host and advocated its anti-viral potential.

The preparation and characterization of SBA-15 supported Ni catalysts with varying metal loading (1, 2, and 3% by weight) was carried out using the impregnation technique, followed by a rigorous characterization using advanced analytical techniques. The catalytic performance of the synthesized catalysts was evaluated for the Wittig-type olefination reaction, and it was found that the SBA- 15-3Ni catalyst exhibited superior activity for this reaction under mild reaction conditions (70°C and 1 hour). The corresponding stilbenes were obtained in good yield, although with low to average diastereoselectivity. An important feature of this protocol is that the proposed methodology is especially efficient for the synthesis of stilbenes since no additives are required to serve as a hydrogen acceptor. Moreover, the new catalytic system was successfully employed for the synthesis of polymethoxylated and polyhydroxylated stilbenes, including resveratrol and DMU-212, with high yield and easy product isolation. A key advantage of this protocol is that the catalysts can be reused for up to 5 runs without significant loss in catalytic activity, which makes this approach highly sustainable and cost-effective. Additionally, the ligand-free approach proposed in this study is an added advantage, which makes it more attractive for large-scale synthesis of biologically active compounds.

The synthesized ZnO nanoparticles were characterized using UV-Vis spectroscopy, SEM, XRD, FTIR, and TEM analysis. The catalytic activity of the prepared green catalyst ZnO nanoparticles was also investigated in the dye methylene blue (MB) decomposition. The catalytic decomposition reaction completed within 20 minutes, demonstrating the excellent catalytic properties of ZnO nanoparticles in reducing MB. This research describes the green synthesis of ZnO nanoparticles using an extract of the middle part of a walnut shell (Juglans regia). The antioxidant activities (radical capture capacity) of the synthesized ZnO nanoparticles were evaluated by the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assay at different ZnO nanoparticle concentrations, and the radical capture activity was achieved at IC50 = 146.32 μg / mL. The radical capture activity was achieved at IC50 = 146.32 μg / mL. The biosynthesis of ZnO nanoparticles was caused by hydroxide precipitation at room temperature after calcination at 450°C.

Indole–acrylonitrile hybrids were synthesized via a catalyst-free reaction of aromatic aldehydes and 3-(cyanoacetyl)indole in aqueous media. Also, indole-coumarin hybrids were synthesized via a domino reaction of salicylaldehyde derivatives and 3-(cyanoacetyl)indole in the presence of ammonium acetate in aqueous media. The advantages of the present protocol are high yields, short reaction times, mild reaction conditions, operational simplicity, and environmentally benign, and also there is no need to purification of products.

An efficient approach for the tosyloxyl group transfer in several N-arylbenzamides has been achieved using HTIB (Koser’s reagent) under mild reaction conditions. Its simplicity, efficiency, and reduced reliance on hazardous reagents make it an attractive choice for chemists seeking sustainable alternatives. The proposed methodology offered single-step para-selective tosyloxylation, ensuring the prevention of the synthesis of mixtures of ortho and meta-isomers. The corresponding products were obtained with moderate to excellent efficiency. The current approach eliminated the need for harsh, acidic, and toxic metals, ensuring safer handling and minimizing environmental impact. A plausible mechanism for tosyloxylation of N-arylbenzamides involving iodonium ylide has been proposed.

Adhatoda vasica (L.) (Acanthaceae) has essential therapeutic roles and is widely used in the indigenous medicine system or Ayurvedic system of medicine. The important goals of the present study are to report the in-silico anti-corona (COVID-19) activity of different phytochemicals present in A. vasica. This study will help to find specific bioactive compounds, and their use as anti- COVID-19 action for human welfare. A. vasica has chemical phytoconstituents with diverse pharmacological activities. These phytoconstituents have been found active against many diseases such as antibacterial, antitubercular, antivirus, antitussive, hepatoprotective, antiinflammatory, antiulcer, antiurolithiatic, abortifacient, radio modulator, cardio-protection, antidiabetic, antioxidant, anticancer, thrombolytic, antimutagenic, etc. Researchers have been lured to the use of natural and sustainable products with substantial therapeutic potential in the current climate of environmental preservation and safe use. These materials permit biological activity, safety, and compatibility with the environment. Using the SARS-CoV-2 spike receptor (6M0J), we evaluated Adhatoda vasica biomolecules for the Covid-19 variant (RBD- COV-2-S). This study is very encouraging and indicates that herbs should be studied more extensively for their therapeutic benefits.