جستجوی مقالات مرتبط با کلیدواژه « Pyrazolone » در نشریات گروه « شیمی »

Hantzsch reaction is a popular procedure for the synthesis of dihydropyridines (DHPs) through the reaction of two equivalents of a β-ketoester with one equivalent of aldehyde in the presence of an ammonia source. The Hantzsch reaction of pyrazolone, aromatic aldehydes and ammonium acetate was studied in the presence of SBA-Pr-SO3H, as the catalyst, to gain tetrahydrodipyrazolopyridines. The high yield of products (80-95%) within a short reaction time (6-15 min) proves the efficiency of this methodology. Finally, molecular docking studies were used to show the binding mode of these compounds in the active site of 3-phosphoinositide-dependent kinase 1 (5OOT). Docking computations show the Gold Score value and the binding mode of resulting complexes. The synthesized compounds can bind to the receptor’s residues by forming hydrogen bonds and π interactions. The detailed analysis of the binding mode of the best-docked molecule exhibited a hydrogen bond between NH substituent and Tyr20. Moreover, π-π and π-cation interactions can be seen with the residues Tyr20 and Lys38, respectively.

The analog of 4-aminoantipyrine (4-amino-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazole-3-one), is interesting in the field of pharmacology and pharmaceutical chemistry and plays an important role as the ingredients for the production of the drugs and medicines. In the current study, a series of Schiff (including two new compounds) bases have been synthesized from 4-aminoantipyrine and substituted benzaldehydes via a simple and easy procedure in a short time with high yields. The structures of products have been characterized by (FTIR, 1HNMR, 13CNMR, and Elemental Analysis).

Recently, infectious diseases have increased enormously, causing a major threat to public health despite the marvelous progress in the medicinal chemistry. Fused pyrazole derivatives are having a wide range of pharmacological activities, playing a vital role as potential therapeutic agents in various pathological conditions. In the present study, novel fused pyrazoles derivatives were synthesized and evaluated for protein kinase inhibition, antioxidant, and antimicrobial activities. 3-Methyl-5-pyrazolone was first prepared by treating ethyl acetoacetate with hydrazine hydrate in absolute ethanol. Then it was treated with different aromatic aldehydes (benzaldehyde, salicylaldehyde, vanillin, 4-diamethylaminobanzaldehyde, and cinnamaldehyde) to form benzylidene derivatives of pyrazoles. These substituted pyrazoles were then treated with hydrazine and phenylhydrazine to produce fused pyrazole ring systems. The synthesized compounds were purified by recrystallization, and then characterized using the spectroscopic techniques. All the compounds exhibited moderate antibacterial activity. Antioxidant potential was determined by three methods and most of the compounds exhibited good antioxidant potential. Two compounds including, 5a and 5e demonstrated protein kinase inhibitory activity. The results indicated that, the fused pyrazoles ring systems possess prominent biological properties.

Hexagonal mesoporous silica (SBA-15) was prepared and then functionalized by(3-mercaptopropyl)trimethoxysilane. The obtained 3-mercaptopropyl functionalized SBA-15 (SBA-Pr-SH) was then oxidized using H2O2 in methanol under an acidic condition to give sulfonic acid functionalized mesoporous silica (SBA-Pr-SO3H). The latter was characterized using different techniques (including TGA, BET, BJH, CHN, SEM, and TEM) and then used as a catalyst in organic synthesis. In the next step, SBA-Pr-SO3H catalyzed the three-component reaction of pyrazolone, salicylaldehydes, and barbituric acid in water under reflux condition. Through this procedure various pyrazolchromeno[2,3-d]pyrimidinone derivatives were obtained. The reaction conditions were completely green due to the use of water as a solvent and the presence of an environmentally benign catalyst.

An efficient and eco-friendly method is introduced for the synthesis of 4,4'-(arylmethylene)-bis-(1H-pyrazol-5-ols) by the condensation reaction of two equivalents of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one with various aromatic aldehydes, catalyzed by the boehmite nanoparticles (BNPs). This heterogeneous catalyst was recycled and used in four runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without any loss of its catalytic activity.

In the present work, DFT calculations are employed to obtain the optimized structures of 4- acyl pyrazolone tautomers (19 tautomers) using B3LYP/6-311++G** calculations. In addition, molecular parameters, IR frequencies and relative energies are extracted for all tautomers. The existence of aromatic ring, keto tautomer (versus enol tautomer), N-H bond (versus C-H bond) and C=N double bond (versus N=N double bond) are stabilizing factors in relative stabilities of tautomers. Calculation of vibrational frequencies showed that, in accordance with reported values, intramolecular hydrogen bond (existed in some tautomers) decreased the value of OH frequency. The solvent effects on relative stabilities of tautomers are calculated. The relative stabilities of all the tautomers in acetone, tetrahydrofurane and chloroform (in all solvents, except water) were relatively the same as those in the gas phase. In addition, a nearly good relationship is found between dipole moments of tautomers and their 7Gsolv in chloroform. This relation shows that by increasing the dipole moment, the absolute amount of 7Gsolv in chloroform increases.