Synthesis And Biological Activity Of Multi-perfluoroalkyl-substituted And Diphenyl-substituted Oxadiazole Derivatives

Fluorinated functional compounds have gained to chemist's attentions since it was found that the introduction of fluorine atoms or fluorous alkyl into organic molecules could lead to significant changes in biological activities. And 1,3, 4-oxadiazole-2-thiones with a broad spectrum of biological activity such as anti-HIV-virus, anti-bacteria and to prevent low blood sugar coma.There a few papers reported the reactivity of the hydrogen of NH group in heterocycle, for example, Mannich base reaction. However, the same hydrogen substituted by perfluoroalkyl is not reported in the literature. A series of N-perfluoroalkylethyl-substituted 1,3, 4-oxadiazole-2-thiones were synthesized in the second chapter this paper and their structures were confirmed by 1H-NMR, 19F-NMR, IR, mass spectra and elemental analysis, And select the part of the herbicidal activity of compounds tested.Containing biphenyl derivatives in recent years because of its high efficiency step-down activity chemists caused great concern at home and abroad. They are generally part of the nitrogen-containing heterocyclic ring and the biphenyl components, the former is much more varied, while the latter is relatively stable. If the introduction of biphenyl ring containing 1,3,4-oxadiazole-2-thione molecule is expected to achieve its biological activity and broaden the antibacterial spectrum superposition. In view of this, the paper design and synthesis of several new heterocyclic compounds biphenyl, and their structures were confirmed by 1H-NMR, IR, mass spectra and elemental analysis.A highly efficient 2-step synthesis of the Sartanbiphenyl was developed by Losartan experiment, 68% of total yield. The most important features are the following: (1) using MnCl2 as a catalyst for cross-coupling reaction, have avoid the use of the palladium catalyst and reduced the cost greatly; (2) in the presence of MnCl2, Grignardreagents can easy react with aryl chlorides which has an electron withdrawing activating group(CN,CH=NR,oxazoline),and can effectively protect CN group; (3) The possible origins of by-product were discussed, and the reaction condition were optimized; (4) the purified process of the products has been improved, and we describe a step-by-step crystallization of the purification process. This process to avoid expensive chromatographic purification and vacuum distillation.