Gullapalli. B. Dharma Rao

A fast and enormously efficient new-flanged symmetric 1,4-dihydropyridine analogs were synthesized by the one-pot four-component condensation reaction of substituted arylaldehyde, tert-butyl β-ketoester, (NH4)2CO3, and benzyl alcohol with p-substitution via transesterification followed by Hantzsch ester synthesis using robust and recyclable CaFe2O4 NPs as heterogeneous catalyst under ultrasonic irradiation. The synthesized compounds were well characterized, and the desired derivatives were studied for the quantum chemical computations using density functional theory (DFT) with Spartan software. On the other hand, the molecular docking experience of all compounds was performed to examine their efficacy against digestive enzymes α-amylase, pepsin, and trypsin and observed that the 1,4-dihydropyridine derivatives could be used as effective digestive enzyme inhibitors. Resumen. Se sintetizaron de forma rápida y altamente eficiente nuevos análogos simétricos de 1,4-dihidropiridina mediante una reacción de condensación en un solo recipiente y en cuatro componentes, utilizando arilaldehídos sustituidos, β-cetoéster tert-butilo, (NH₄)₂CO₃ y alcohol bencílico con sustitución en posición para a través de una transesterificación, seguida de una síntesis tipo éster de Hantzsch, empleando nanopartículas de CaFe₂O₄ robustas y reciclables como catalizador heterogéneo bajo irradiación ultrasónica. Los compuestos sintetizados fueron debidamente caracterizados, y los derivados obtenidos se estudiaron mediante cálculos químicos cuánticos usando la teoría del funcional de la densidad (DFT) con el software Spartan. Por otro lado, se realizó un estudio de acoplamiento molecular (docking) de todos los compuestos para evaluar su eficacia contra enzimas digestivas como α-amilasa, pepsina y tripsina, observándose que los derivados de 1,4-dihidropiridina podrían emplearse como inhibidores eficaces de enzimas digestivas.

Organic dyes and heavy metals are renowned environmental contaminants due to their hazardous, long life time in the environment, and capability to accumulate into the human body. Most heavy metals are accumulated naturally, however only some are derived from anthropogenic sources. In the recent decades, metal organic framework (MOF) and their most fashionable derivatives are extensively examined to eradicate heavy metals and organic dye substances from polluted water as powerful adsorbent materials. MOFs have forever exposed attractive applications in adsorption technologies and membrane separation, among which water-stable MOFs are predominantly important in wastewater treatment (WWT) relevance. MOFs like metal-organic polymers, hybrid organic–inorganic materials, organic zeolite materials and coordination polymers have increased awareness and many of the MOFs have been synthesized to eradicate heavy metals and organic dyes from waste water, because of their outstanding characteristics like large surface area, stability, greater porosity which make the MOF a strong and powerful adsorbent. In this paper, we discussed about the removal of hazardous heavy metals and organic dyes using MOF materials and their analogues as strong adsorbents for contaminated waste water.

A rapid and enormously professional new-flanged 3,5-disubstituted triazole derivatives were synthesized by the one-pot five-component condensation reaction in the course of transesterification followed by the Biginelli/Click reaction in aqueous medium using magnetic CuFe₂O₄ NPs as heterogeneous catalyst beneath ultrasonic acceleration in aqueous medium. The synthesized 3,5-disubstituted triazole derivatives were finely characterized and the characterized desired target molecules were employed for the quantum chemical calculations for each reactant and product have been well thought-out using density functional theory. Furthermore, the molecular docking and ADMET revision of all the derivatives have been achieved as digestive enzyme and Cathepsin-B inhibitors and their connections with BSA to treat different diseases.

In this study, we present the highly efficient and rapid synthesis of substituted dihydropyrimidinone derivatives through an ultrasound-accelerated approach. We utilize copper ferrite (CuFe₂O₄) magnetic nanoparticles as heterogeneous catalysts, employing the well-known Biginelli reaction, under solvent-free conditions. The impact of the solvent, catalyst amount, and catalyst type on the reaction performance is thoroughly investigated. Our method offers several notable advantages, including facile catalyst separation, catalyst reusability for up to three cycles with the minimal loss of activity, a straightforward procedure, mild reaction conditions, and impressive yields, ranging from 79% to 95%, within short reaction times of 20 to 40 min. Furthermore, in the context of fighting COVID-19, we explore the potential of substituted dihydropyrimidinone derivatives as inhibitors of three crucial SARS-CoV-2 proteins. These proteins, glycoproteins, and proteases play pivotal roles in the entry, replication, and spread of the virus. Peptides and antiviral drugs targeting these proteins hold great promise in the development of effective treatments. Through theoretical molecular docking studies, we compare the binding properties of the synthesized dihydropyrimidinone derivatives with the widely used hydroxychloroquine molecule as a reference. Our findings reveal that some of the tested molecules exhibit superior binding characteristics compared to hydroxychloroquine, while others demonstrate comparable results. These results highlight the potential of our synthesized derivatives as effective inhibitors in the fight against SARS-CoV-2.

The transesterification process has attained more significant importance in synthesizing a variety of commercial and non‐commercial β‐ketoesters using alcohols and variety of acetoacetates. β‐Ketoesters have been considered essential synthons in synthetic organic chemistry because of electrophilic and nucleophilic reactive sites and are used as key intermediates in synthesizing the diversity of complex drug molecules. This review provides an overview of the synthesis of β‐ketoesters, various reaction mechanisms, substrate scope, and diverse applications in the bio‐diesel industry and the pharmaceutical industry to synthesize novel drug molecules via transesterification transformation.

A rapid and operationally simple approach for synthesising biologically relevant 2-oxazoline derivatives has been developed through highly efficient ultrasound-promoted coupling reactions of thioamides and amino alcohols using calcium ferrite nanoparticles as heterogeneous catalysts. The major advantage of using ultrasound irradiation lies in the drastic reduction of reaction time as compared with conventional stirring. Furthermore, quantum chemical investigations for the synthesised 2-oxazoline derivatives have been carried out at the DFT/B3LYP/6-311 + G (d, p) level of theory to predict the optimized geometry. The molecular properties such as bond lengths, bond orders, Milliken charges, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential map, and thermodynamic parameters of all the compounds have also been reported at the same level of theory.

Methyl 4-(4-fluorophenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate, (I), was found to exhibit solvatomorphism. The compound was prepared using a classic Biginelli reaction under mild conditions, without using catalysts and in a solvent-free environment. Single crystals of two solvatomorphs and one anhydrous form of (I) were obtained through various crystallization methods. The anhydrous form, C₁₃H₁₃FN₂O₃, was found to crystallize in the monoclinic space group C2/c. It showed one molecule in the asymmetric unit. The solvatomorph with included carbon tetrachloride, C₁₃H₁₃FN₂O₃·0.25CCl₄, was found to crystallize in the monoclinic space group P2/n. The asymmetric unit revealed two molecules of (I) and one disordered carbon tetrachloride solvent molecule that lies on a twofold axis. A solvatomorph including ethyl acetate, C₁₃H₁₃FN₂O₃·0.5C₄H₈O₂, was found to crystallize in the triclinic space group P\overline{1} with one molecule of (I) and one solvent molecule on an inversion centre in the asymmetric unit. The solvent molecules in the solvatomorphs were found to be disordered, with a unique case of crystallographically induced disorder in (I) crystallized with ethyl acetate. Hydrogen-bonding interactions, for example, N—H...O=C, C—H...O=C, C—H...F and C—H...π, contribute to the crystal packing with the formation of a characteristic dimer through N—H...O=C interactions in all three forms. The solvatomorphs display additional interactions, such as C—F...N and C—Cl...π, which are responsible for their molecular arrangement. The thermal properties of the forms were analysed through differential scanning calorimetry (DSC), hot stage microscopy (HSM) and thermogravimetric analysis (TGA) experiments.

An expeditious synthesis of new series of symmetrical 1,4‐dihydropyrimidine derivatives has been developed using a four‐component reaction involving the in situ generation of non‐commercial β‐ketoesters via transesterification transformation of tert‐butyl‐β‐ketoester with corresponding alcohol followed by the one‐pot Hantzsch reaction with arylaldehyde and ammonium carbonate in aqueous medium at 70°C under catalyst‐free conditions.