Synthesis, structure and properties of N-R-2-(5-(5-methyl-1H-pyrazole-3-yl)-4-phenyl-4H-1,2,4-triazole-3-ylthio)acetamides

Abstract

Heterocyclic compounds remain the most promising group of compounds, through which the new drugs with characteristic list of properties are successfully created. Examples of this systems are 1,2,4-triazole and pyrazole. The presence in one molecule structure of fragments of two different azaheterocycles is synthetically interesting and allows increasing the probability to obtain biologically active substance with a wide spectrum of action.The aim of the work was to optimize the synthesis conditions and investigate the properties of N-R-2-(5-(5-methyl-1H-pyrazole-3-yl)-4-phenyl-4H-1,2,4-triazole-3-ylthio)acetamides in case of change of chemical process conditions.Methods and results. Ethyl 5-methyl-1H-pyrazole-3-carboxylate, which was obtained by known techniques using acetone, diethyl oxalate, sodium methoxide, followed by hydrazine hydrate in equivalent amount, was used as the key starting reagent. The resulting ethyl 5-methyl-1H-pyrazole-3-carboxylate was used to carry out hydrazinolysis reactions and nucleophilic addition of phenyl isothiocyanate with subsequent alkaline heterocyclicization. The synthesized 5-(5-methyl-1H-pyrazol-3-yl)-4-phenyl-4H-1,2,4-triazole-3-thiole was used in alkylation reactions with promising reagents for the design of pharmacophoric fragments. The products of such reaction are N-R-2-(5-(5-methyl-1H-pyrazole-3-yl)-4-phenyl-4H-1,2,4-triazole-3-ylthio)acetamides. The structure of the resulting compounds was confirmed by elemental analysis, 1H NMR spectroscopy, IR spectrophotometry. The individuality of the substances was determined by thin-layer chromatography and chromatographic mass spectrometry. For synthesized compounds, preliminary screening was performed using the PASS On-line® software and molecular docking.Conclusions. N-R-2-5-(5-methyl-1H-pyrazole-3-yl)-4-phenyl-4H-1,2,4-triazole-3-ylthio)acetamides are obtained with high yields and purity, their properties are investigated.

Keywords

• 1
• 2
• 4-triazole
• pyrazole
• physical-chemical properties
• molecular docking