Ultrasound-promoted an efficient method for one-pot synthesis of 2-amino-4,6-diphenylnicotinonitriles in water: a rapid procedure without catalyst

Synthesis, Cytotoxicity, and Photophysical Investigations of 2-Amino-4,6-diphenylnicotinonitriles: An Experimental and Theoretical Study

In this study, we present a comprehensive investigation of 2-amino-4,6-diphenylnicotinonitriles (APNs, 1-6), including their synthesis, cytotoxicity against breast cancer cell lines, and photophysical properties. Compound 3 demonstrates exceptional cytotoxicity, surpassing the potency of Doxorubicin. The fluorescence spectra of the synthesized 1-6 in different solvents reveal solvent-dependent shifts in the emission maximum values, highlighting the influence of the solvent environment on their fluorescence properties. A quantum chemical TD-DFT analysis provides insights into the electronic structure and fluorescence behavior of 1-6, elucidating HOMO-LUMO energy gaps, electronegativity values, and dipole moments, contributing to a deeper understanding of their electronic properties and potential reactivity. These findings provide valuable knowledge for the development of APNs (1-6) as fluorescent sensors and potential anticancer agents.

A eutectogels-catalyzed one-pot multi-component reaction: access to pyridine and chromene derivatives

The demand for a wide array of functional chemicals and materials has experienced a significant surge in tandem with the advancement of civilization. Regrettably, a number of perilous solvents are employed in chemical laboratories and industrial settings, posing significant risks to the well-being of researchers and contributing to environmental degradation through pollution. Eutectogels, which are based on the eutectic concept, may be synthesized by self-assembling or self-polymerization of various components when put under UV irradiation (254 nm). A novel copolymeric deep eutectic solvent (DES) was successfully synthesized, comprising choline chloride (HBA) as the hydrogen bond acceptor, acetamide (HBD) as the hydrogen bond donor, tetraethyl orthosilicate (TEOS), and formic acid. In this study, we present the preparation of four-component ETGs for synthesizing pyridine and chromene derivatives as a reusable catalyst through a multi-component pathway without solvents. The procedure of synthesizing these heterocyclic compounds is free of using toxic solvents and it could be categorized as a green method.

Magnetically recoverable Fe3O4 nanocatalyst for the synthesis of biodynamically significant 1H-pyrazolo[1,2-b]phthalazine-5,10-diones derivatives and its DFT study

An environmentally sustainable and proficient method is reported for the synthesis of medicinally important pyrazolo[1,2-b] phthalazine dione derivatives by aqueous micellar medium catalysed by Fe3O4 NPs. Dialkyl acetylenedicarboxylate with isocyanides in the presence of phthalhydrazide is used as starting material. The main advantages of this protocol are the availability of starting materials, short reaction times, green solvents and practical simplicity.

Chalcone-inspired rA1 /A2A adenosine receptor ligands: Ring closure as an alternative to a reactive substructure

Over the past few years, great progress has been made in the development of high-affinity adenosine A₁ and/or A_2A receptor antagonists-promising agents for the potential treatment of Parkinson's disease. Unfortunately, many of these compounds raise structure-related concerns. The present study investigated the effect of ring closures on the rA₁ /A_2A affinity of compounds containing a highly reactive α,β-unsaturated carbonyl system, hence providing insight into the potential of heterocycles to address these concerns. A total of 12 heterocyclic compounds were synthesised and evaluated in silico and in vitro. The test compounds performed well upon qualitative assessment of drug-likeness and were generally found to be free from potentially problematic fragments. Most also showed low/weak cytotoxicity. Results from radioligand binding experiments confirm that heterocycles (particularly 2-substituted 3-cyanopyridines) can replace the promiscuous α,β-unsaturated ketone functional group without compromising A₁ /A_2A affinity. Structure-activity relationships highlighted the importance of hydrogen bonds in binding to the receptors of interest. Compounds 3c (rA₁ K_i  = 16 nM; rA_2A K_i  = 65 nM) and 8a (rA₁ K_i  = 102 nM; rA_2A K_i  = 37 nM), which both act as A₁ antagonists, showed significant dual A₁ /A_2A affinity and may, therefore, inspire further investigation into heterocycles as potentially safe and potent adenosine receptor antagonists.

Ultrasound for Drug Synthesis: A Green Approach

This last century, the development of new medicinal molecules represents a real breakthrough in terms of humans and animal life expectancy and quality of life. However, this success is tainted by negative environmental consequences. Indeed, the synthesis of drug candidates requires the use of many chemicals, solvents, and processes that are very hazardous, toxic, energy consuming, expensive, and generates a large amount of waste. Many large pharmaceutical companies have thus moved to using green chemistry practices for drug discovery, development, and manufacturing. One of them is the use of energy-efficient activation techniques, such as ultrasound. This review summarizes the latest most representative works published on the use of ultrasound for sustainable bioactive molecules synthesis.

Ultrasound-assisted facile one-pot sequential synthesis of novel sulfonamide-isoxazoles using cerium (IV) ammonium nitrate (CAN) as an efficient oxidant in aqueous medium

A series of novel 3,5-disubstituted isoxazoles have been synthesized, using a new, green, and versatile "one-pot three-steps" methodology. The key step is an oxidative 1,3-dipolar cycloaddition under ultrasonic irradiation, occurring in aqueous media, and mediated by cerium (IV) ammonium nitrate (CAN). CAN is a one-electron oxidant, highly soluble in water, slightly toxic and inexpensive, that allows the in situ conversion of the intermediate aldoximes into nitrile oxide. The syntheses are highly regioselective, as illustrated by the structures of the final compounds, which have been fully assessed by spectral analyses (¹H and ¹³C NMR, MS). This study illustrates the potency of the ultrasound activation to synthesize a set of highly functionalized heterocycles, with potential applications in biology, in short reaction times and following an eco-friendly process.

Metal- and catalyst-free, one-pot, three-component synthesis of propargylamines in magnetized water: experimental aspects and molecular dynamics simulation

Multi-component reactions of aldehydes, amines, and alkynes in magnetized water as a green-promoting medium.

Computer-aided design of multi-target ligands at A1R, A2AR and PDE10A, key proteins in neurodegenerative diseases

Compounds designed to display polypharmacology may have utility in treating complex diseases, where activity at multiple targets is required to produce a clinical effect. In particular, suitable compounds may be useful in treating neurodegenerative diseases by promoting neuronal survival in a synergistic manner via their multi-target activity at the adenosine A1 and A2A receptors (A1R and A2AR) and phosphodiesterase 10A (PDE10A), which modulate intracellular cAMP levels. Hence, in this work we describe a computational method for the design of synthetically feasible ligands that bind to A1 and A2A receptors and inhibit phosphodiesterase 10A (PDE10A), involving a retrosynthetic approach employing in silico target prediction and docking, which may be generally applicable to multi-target compound design at several target classes. This approach has identified 2-aminopyridine-3-carbonitriles as the first multi-target ligands at A1R, A2AR and PDE10A, by showing agreement between the ligand and structure based predictions at these targets. The series were synthesized via an efficient one-pot scheme and validated pharmacologically as A1R/A2AR-PDE10A ligands, with IC50 values of 2.4-10.0 μM at PDE10A and Ki values of 34-294 nM at A1R and/or A2AR. Furthermore, selectivity profiling of the synthesized 2-amino-pyridin-3-carbonitriles against other subtypes of both protein families showed that the multi-target ligand 8 exhibited a minimum of twofold selectivity over all tested off-targets. In addition, both compounds 8 and 16 exhibited the desired multi-target profile, which could be considered for further functional efficacy assessment, analog modification for the improvement of selectivity towards A1R, A2AR and PDE10A collectively, and evaluation of their potential synergy in modulating cAMP levels.

Highly efficient four-component synthesis of 2-amino-3-cyanopyridines using doped nano-sized copper(I) oxide (Cu2O) on melamine–formaldehyde resin

A convenient and facile four-component synthesis is described of 2-amino-3-cyanopyridine derivatives from readily available starting materials catalysed by doped nano-sized Cu2O on melamine–formaldehyde resin (nano-Cu2O–MFR). In this method, treatment of different aldehydes, ketones, malononitrile, and ammonium acetate in refluxing H2O/EtOH (1:1) in the presence of doped nano-Cu2O–MFR as a highly efficient heterogeneous catalyst affords the corresponding 2-amino-3-cyanopyridines in good to excellent yields. The nano-Cu2O–MFR is a cheap and stable nano-catalyst that could be easily recovered and reused for many consecutive reaction runs without considerable decrease in its activity.

Experimental and theoretical studies of the nanostructured {Fe3O4@SiO2@(CH2)3Im}C(CN)3 catalyst for 2-amino-3-cyanopyridine preparation via an anomeric based oxidation

2-Amino-4,6-diphenylnicotinonitriles were prepared by using Fe₃O₄@SiO₂@(CH₂)₃Im}C(CN)₃ as a catalyst. Experimental and theoretical studies confirmed that the final step of the synthetic pathway is proceeded via an anomeric based oxidation mechanism.

Covalently anchored 2-amino ethyl-3-propyl imidazolium bromideon SBA-15 as a green, efficient and reusable Brønsted basic ionic liquid nanocatalyst for one-pot solvent-free synthesis of benzopyranopyrimidines under ultrasonic irradiation

Preparation of benzopyranopyrimidine derivatives under ultrasonic irradiation, catalyzed by SBA-IM-NH₂.

Ultrasound assisted the green synthesis of 2-amino-4H-chromene derivatives catalyzed by Fe3O4-functionalized nanoparticles with chitosan as a novel and reusable magnetic catalyst

Fe3O4 nanoparticles were prepared by chemical coprecipitation method. Subsequently immobilization of chitosan on Fe3O4 nanoparticles was accomplished and afforded magnetic Fe3O4-chitosan nanoparticles. Synthesized nanoparticles was found to be a magnetic and heterogeneous catalyst for a one-pot and efficient synthesis of 2-amino-4H-chromenes by condensation of aldehydes with malononitrile and resorcinol under ultrasound irradiation as an ecofriendly method. This convenient procedure allowed us to achieve products under ultrasound irradiation in short time and excellent yield without using of harmful catalyst. The present method will permit a further increase of the diversity within the 2-amino-4H-chromene family.

Ultrasound mediation for one-pot multi-component synthesis of amidoalkyl naphthols using new magnetic nanoparticles modified by ionic liquids

The ionic liquid 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium acetate was immobilized on the Fe3O4 nanoparticles (MNPs-IL-OAc) and used as an efficient new heterogeneous nanocatalyst for the one-pot multi-component synthesis of 1-amidoalkyl-2-naphthols under ultrasound irradiation. The advantages of present combined method are the use of a low scale catalyst, easier work-up procedure, waste-free, green and efficient synthetic entry to excellent yield of products in a high reusability and a short reaction time.

Novel, fast and efficient one-pot sonochemical synthesis of 2-aryl-1,3,4-oxadiazoles

Ultrasound promoted synthesis of 2-aryl-1,3,4-oxadiazoles at ambient temperature is reported. The remarkable features of the new procedure are shorter reaction time, excellent yields, cleaner reaction profile and simple experimental and workup procedure.

A highly efficient magnetic solid acid catalyst for synthesis of 2,4,5-trisubstituted imidazoles under ultrasound irradiation

Fe(3)O(4) nanoparticles were prepared by chemical coprecipitation method and subsequently coated with 3-aminopropyltriethoxysilane (APTES) via silanization reaction. Grafting of chlorosulfuric acid on the amino-functionalized Fe(3)O(4) nanoparticles afforded sulfamic acid-functionalized magnetic nanoparticles (SA-MNPs). SA-MNPs was found to be a mild and effective solid acid catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles under ultrasound irradiation. This protocol afforded corresponding imidazoles in shorter reaction durations, and in high yields. This green procedure has many obvious advantages compared to those reported in the previous literatures, including avoiding the use of harmful catalysts, easy and quick isolation of the products, excellent yields, short routine, and simplicity of the methodology.