Synthesis of new antibacterial agents encompassing tosyl, piperidine, propanamide and 1,3,4-oxadiazole functionalities

• 发表在: Pakistan Journal of Pharmaceutical Sciences
• 主要作者: 2-s2.0-85090136596
• 格式: 文件
• 语言: English
• 出版: Pakistan Journal of Pharmaceutical Sciences 2020
• 在线阅读: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090136596&doi=10.36721%2fPJPS.2020.33.4.REG.1697-1705.1&partnerID=40&md5=d64476865c582b5c8917e9a83801eb7b

A series of propanamide compounds 6a-l was derived by N-substitution reactions, encompassing tosyl, piperidine and 1,3,4-oxadiazole moieties. The intended array of compounds 6a-l was afforded by a series of five steps reaction scheme. 1-Tosylpiperidin-4-carboxylate (1) was synthesized by the reaction of tosyl chloride (a) with ethyl isonipecotate (b) under mild basic conditions. Compound 1 was subjected to nucleophillic substitution by hydrazine to synthesize 1-tosylpiperidin-4-carbohydrazide (2). The compound, 5-(1-tosylpiperidin-4-yl)-1,3,4-oxadiazole-2-thiol (3) was synthesized by intermolecular cyclization of compound 2 by CS2 under strong basic conditions. The target compounds, 6a-l, were finally synthesized from 3 by reacting with different electrophiles, 5a-l, in an aprotic polar solvent with sodium hydride as an activator. The different propanamoyl electrophiles, 5a-l, were synthesized by the reaction of different aromatic and aliphatic amines, 4a-l, with 3-bromopropionyl chloride under mild basic conditions. The structural elucidation was carried out using modern spectroscopic techniques including IR, 1H-NMR and EI-MS. The antibacterial potential of synthesized compounds was assessed against five bacterial strains. Compounds 6a, 6c, 6d, 6e and 6f were found to be potent antibacterial agents. © 2020 Pakistan Journal of Pharmaceutical Sciences. All rights reserved.