In the pharmaceutical practice directly related to the search of biological active substances and their introduction into medicine or veterinary it is generally recognized that a successful choice of the research object is a prerequisite for a positive final outcome to create original effective and low-toxic drugs. At present, derivatives of 1,2,4-triazoles containing pyridine deserve special attention. That is why the synthesis and study of physicochemical properties of new compounds, which contain 1,2,4-triazole and pyridine rings, are important tasks of modern synthetic and pharmaceutical chemistry. Aim. To study the reactions associated with formation and transformation of 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines and their recovery, study physicochemical properties of new compounds synthesized. Materials and methods. 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heter-yl)methanimines were obtained by the mixture from 6-(5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-amine and aldehydes. The synthesis was carried out in the acetic acid medium. The mixture was kept at room temperature for 6 h. 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines were reduced in the 1,4-dioxane medium. As a reducing agent sodium borohydride was used. Results and discussion. As a result of synthetic transformations 17 new compounds have been obtained, the structure of the compounds synthesized has been confirmed by modern complex of physicochemical methods of analysis (IR-spectrophotometry, elemental analysis), and their individuality has been proven on an Agilent 1260 Infinity HPLC high-performance liquid chromatograph equipped with an Agilent 6120 mass spectrometer. Conclusions. The preparative method for the synthesis of 6-((5-phenethyl-4-R-1,2,4-triazole-3-ylthio)pyridine-3-yl)-(alkyl-, heteryl)methanimines and 6-(5-phenethyl-4-R-1,2,4-triazole-3-ylthio)-N-(alkyl-, heteryl)pyridine-3-amines has been developed.

Objective: The aim of this research was to synthesize and evaluate physical-chemical properties of 5-pheneyhyl-4-R-3-thio-1,2,4-triazole and to establish identity and structure of the synthesized compounds, namely alkil-2-((5-phenethyl-4-R-1,2,4-triazole-3-yl)thio)acet(propan,benz)imidates. Methods: As starting materials for synthesis of alkil-2-((5-phenethyl-4-R-1,2,4-triazole-3-yl)thio)acet(propan,benz)imidates, the corresponding 2-((5-phenethyl-4-R-1,2,4-triazole-3-yl)thio)aceto(propane,benzo)nitrile have been used. Synthesis has been set in the absolute alcohol medium (propanol or butanol alcohol) with chloroform, using the saturation with dry hydrogen chloride. Results: In this study, we have developed nine new compounds have been received as a result of synthetic transformations, the structure of synthesized compounds has been confirmed by modern complex of physical-chemical methods of analysis (1H NMR-spectroscopy, elemental analysis), and their individuality has been conducted on gas-liquid chromatograph Agilent 1260 Infinity HPLC equipped with a mass spectrometer Agilent 6120. Conclusion: As a result of the work, it was synthesized the new compounds of the series of alkil-2-((5-phenethyl-4-R-1,2,4-triazole-3-yl)thio) acet(propan,benz)imidates and was characterized by elemental analysis and proton nuclear magnetic resonance spectroscopic analysis.

An important step in the development of a new drug is the prediction of its toxicity by computer screening using the program GUSAR-online. The purpose of this work is an online prediction of acute toxicity among new derivatives of 5-phenethyl-4-R-3-thio(amino) 1,2,4-triazoles. Computer prediction of acute toxicity of 5-phenethyl-4-R-3-thio(amino)- 1,2,4-triazole derivatives was performed according to the structural formulas of the compounds in the online version of the GUSAR-online program.GUSAR-online prediction for 5-phenethyl-4-R-3-thio(amino)-1,2,4- triazole derivatives was performed during the research. It was found that the average lethal dose of LD50 is from 56.1 to 2396.0 mg / kg. Based on this, all compounds are low-toxic and virtually non-toxic substances.