Catalyst-Free One-Pot Three-Component Synthesis of Diversely Substituted 5-Aryl-2-oxo-/thioxo-2,3-dihydro-1H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11(5H)-triones Under Ambient Conditions

A potential DES catalyst for the fast and green synthesis of benzochromenopyrimidines and pyranopyrimidines

A gentisic acid based-Deep Eutectic Solvent (MTPPBr/GA-DES) was synthesized by mixing one mole of methyl triphenylphosphonium bromide (MTPPBr) and one mole of gentisic acid (GA: 2,5-dihydroxy-benzoic acid) based on the eutectic point phase diagram. Then, it was characterized by FT-IR, NMR, densitometer, and TGA/DTA techniques and used as a potent and novel catalyst for the fast and green synthesis of: (i) Five new 2(a-e) and five known 2(f-j) benzo[6,7]chromeno[2,3-d]pyrimidines and (ii) One new (3a) and eleven known 3(b-l) pyrano[2,3-d]pyrimidines, in solvent-free conditions, short reaction times, and high yields. It is important to mention that for the synthesis of 2(a-j), there is only one reference which states that the reaction times are extremely long (720-2400 min), while these times are reduced to approximately 35-50 min in our proposed strategy, indicatinging that the rate of reactions will be 20-48 times faster, which is the clear and most obvious advantage of our approach.

Copper Immobilized on Modified LDHs as a Novel Efficient Catalytic System for Three-Component Synthesis of Pyrano[2,3-d]pyrimidine and pyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine Derivatives

A novel catalyst based on layered double hydroxides coated with copper nitrate [LDH@(3-chloropropyl)trimethoxysilane@N1,N4-bis(4,6-diamino-1,3,5-triazin-2-yl)benzene-1,4-disulfonamide@Cu] was successfully synthesized. The structure of the new synthesized catalyst was investigated and confirmed using different analytical techniques, such as Fourier-transform infrared spectroscopy (FTIR), energy-scattered X-ray spectroscopy (EDX) mapping, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and heat gravity/heat derivatization (TGA/DSC). The skilled catalyst proved its efficiency for one-pot three-component synthesis of pyrano[2,3-d]pyrimidine and new dihydropyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine-dione derivatives. Using this efficient catalyst, products were synthesized with a high yield, in a short time, and under soft and solvent-free conditions. The catalyst can be recovered and reused four times without a significant loss of efficiency.

Synthesis, physico-chemical characterization, and environmental applications of meso porous crosslinked poly (azomethine-sulfone)s

To develop innovative mesoporous crosslinked poly(azomethine- sulfone)s with environmental applications, a simple Schiff base condensation technique based on barbituric acid BA or condensed terephthaldehyde barbituric acid TBA in their structures as monomeric units are applied. Different analysis methodologies and viscosity measurements identify them as having stronger heat stability and an amorphous structure. The photophysical features of the multi stimuli response MSR phenomenon are observable, with white light emission at higher concentrations and blue light emission at lower concentrations. Their emission characteristics make them an excellent metal ions sensor through diverse charge transfer methods. They can have a better inhibition efficiency and be employed as both mixed-type and active corrosion inhibitors according to their fluorescence emission with metals, demonstrating their capacity to bind with diverse metals. The adsorption of two distinct dye molecules, Methylene blue MB cationic and sunset yellow SY anionic, on the mesoporous structures of the polymers is investigated, revealing their selectivity for MB dye adsorption. Quantum studies support these amazing discoveries, demonstrating a crab-like monomeric unit structure for the one that is heavily crosslinked.

Dicarbonyl compounds in the synthesis of heterocycles under green conditions

Carbon–carbon and carbon-heteroatom bond forming reactions are strategically employed for the generation of a variety of heterocyclic systems. This class of compounds represents the most general structural unit, present in many natural compounds. They are recognized for their valuable biologically properties and wide range of applications in medicinal, pharmaceutical, and other related fields of chemistry. This is an updated review on the use of dicarbonyl compounds under environmentally friendly conditions to access a series of heterocyclic structures, e.g., quinoxaline, quinazolinones, benzochalcogenazoles, indoles, among others. Synthetic protocols involving copper-catalyzed, multicomponent and cascade reactions, decarboxylative cyclization, recycling of CO2, and electrochemical approaches are presented and discussed.

Recent Advances in the Application of Barbituric Acid Derivatives in Multicomponent Reactions

Abstract:

Barbituric acid is a pyrimidine heterocyclic organic compound, which is pharmacologically active. It is important to build structures containing various medicinal activities. This compound attracts the scientific research community in organic synthesis. It can be used in the synthesis of polyheterocyclic, natural, medicinal compounds, and organic sensors. Herein, the utilization of barbituric or thiobarbituric acid in multicomponent reactions is reported from 2016-2021 in this manuscript.

Screening of Synthetic Heterocyclic Compounds as Antiplatelet Drugs

BACKGROUND

Antiplatelet drugs represent the keystone in the treatment and prevention of diseases of ischemic origin, including coronary artery disease. The current palette of drugs represents efficient modalities in most cases, but their effect can be limited in certain situations or associated with specific side effects. In this study, representatives of compounds selected from series having scaffolds with known or potential antiplatelet activity were tested. These compounds were previously synthetized by us, but their biological effects have not yet been reported.

OBJECTIVE

The aim of this study was to examine the antiplatelet and anticoagulation properties of selected compounds and determine their mechanism of action.

METHODS

Antiplatelet activity of compounds and their mechanisms of action were evaluated using human blood by impedance aggregometry and various aggregation inducers and inhibitors and compared to appropriate standards. Cytotoxicity was tested using breast adenocarcinoma cell cultures and potential anticoagulation activity was also determined.

RESULTS

In total, four of 34 compounds tested were equally or more active than the standard antiplatelet drug acetylsalicylic acid (ASA). In contrast to ASA, all 4 active compounds decreased platelet aggregation triggered not only by collagen, but also partly by ADP. The major mechanism of action is based on antagonism at thromboxane receptors. In higher concentrations, inhibition of thromboxane synthase was also noted. In contrast to ASA, the tested compounds did not block cyclooxygenase-1.

CONCLUSION

The most active compound, 2-amino-4-(1H-indol-3-yl)-6-nitro-4H-chromene-3-carbonitrile (2-N), which is 4-5x times more potent than ASA, is a promising compound for the development of novel antiplatelet drugs.

Series of Functionalized 5-(2-Arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones: A Water-Mediated Three-Component Catalyst-Free Protocol Revisited

A water-mediated and catalyst-free practical method for the synthesis of a new series of pharmaceutically interesting functionalized 5-(2-arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones has been accomplished based on a one-pot multicomponent reaction between arylglyoxal monohydrates, 2-aminopyridines/2-aminopyrimidine, and barbituric/N,N-dimethylbarbituric acids under reflux conditions. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of water as reaction medium, clean reaction profiles, operational simplicity, ease of product isolation/purification without the aid of tedious column chromatography, good to excellent yields, and high atom-economy and low E-factor.