Synthesis, Multiparametric Structure Assessment and Biological Evaluation of Some New 1,3,4-Oxadiazoles Containing Piperidine Nucleus
作者:Javed Iqbal、Aziz-Ur -Rehman、Muhammad Athar Abbasi、Sabahat Zahra Siddiqui、Shahid Rasool、Muhammad Rehan、Syed Adnan Ali Shah
DOI:10.14233/ajchem.2017.20564
日期:——
With an aim to introduce more biologically active compounds, S-substituted derivatives of 5-[1-(4-nitrophenylsulfonyl)piperidin-4-yl]-1,3,4-oxadiazole-2-thiol (3) were synthesized through four steps. In the first step, ethyl 1-(4-nitrophenylsulfonyl)piperidine-4-carboxylate (1) was synthesized by reacting 4-nitrobenzenesulfonyl chloride (a) and ethyl isonipacotate (b) in basic medium. In the second step, compound 1 and hydrazine monohydrate were converted to corresponding hydrazide (2). In third step, hydrazide (2), CS2 and KOH were refluxed in the presence of MeOH to acquire 5-(1-(4-nitrophenylsulfonyl)piperidin-4-yl)-1,3,4-oxadiazole-2-thiol (3). In the last step, alkyl/aralkylhalides (4a-o) and 3 were made to react in an aprotic polar solvent to get the final compounds, 2-(substitutedthio)-5-[1-(4-nitrophenylsulfonyl)piperidin-4-yl]-1,3,4-oxadiazole (5a-o). The synthesized compounds were structurally confirmed by spectroscopic techniques including 1H NMR, EIMS and IR. Finally the synthesized compounds were screened for antibacterial activity against five bacterial strains.
为了引入更多的生物活性化合物,通过四个步骤合成了5-[1-(4-硝基苯磺酰基)哌啶-4-基]-1,3,4-恶二唑-2-硫醇(3)的S-取代衍生物步骤。第一步,通过使4-硝基苯磺酰氯(a)和异哌啶甲酸乙酯(b)在碱性介质中反应合成1-(4-硝基苯磺酰基)哌啶-4-甲酸乙酯(1)。第二步,化合物1和一水合肼转化为相应的酰肼(2)。第三步,酰肼(2)、CS2和KOH在MeOH存在下回流,得到5-(1-(4-硝基苯磺酰基)哌啶-4-基)-1,3,4-恶二唑-2-硫醇( 3)。最后一步,使烷基/芳烷基卤化物(4a-o)和3在非质子极性溶剂中反应,得到最终化合物2-(取代硫基)-5-[1-(4-硝基苯磺酰基)哌啶-4-基]-1,3,4-恶二唑(5a-o)。合成的化合物通过1H NMR、EIMS和IR等光谱技术进行了结构确认。最后筛选了合成的化合物对五种细菌菌株的抗菌活性。