Design,Synthesis And Properties Of Quinoline Compounds

Heterocyclic compounds containing nitrogen atom have been the main stream of development of new pesticides because of the diversity of their structures and unique mechanism.Quinoline compounds are the research hotspots in heterocyclic compounds due to their broad biological activity,efficient sterilization and insecticidal activities,and environmentally friendly and have evident prospects for development.Using the high-effect fungicide Tebufloquin and high-effect insecticide Flometoquin as a lead compound based on some defects of its physical properties and biological activity,the report designed some novel potential bioactive compounds by adopting pesticide molecular design techniques including pro-drug theory,bioisosterism,analogue synthesis and sub-structure theory.In this paper,thirty two unreported quinoline derivatives were designed and synthesized.The structures of all the title compounds were confirmed using 1H NMR spectroscopy,LC-MS and so on.The general formula of the target compounds is shown below:Thirty-two novel quinoline compounds were designed and synthesized from p-nitrochlorobenzene and phenol via metal catalyzed reduction,acid-catalyzed cyclization,and condensation reactions.The biological activities of the title compounds were tested according to the standard operation procedures of pesticides bioassay(SOP)established by the National Engineering Research Center for Agrochemicals.The insecticidal activity bioassay results showed that compounds I 2、I 5、I 6、I 11 and I 32 exhibited 100%mortality against Aphis fabae at 500 mg/L;the compounds I2、I8、I9 and I 24 exhibited 100%mortality against Mythimna separata at 500 mg/L.;the compounds I 10、I 11 and I 20 exhibited 100%mortality against Tetranychus urticae at 500 mg/L.The fungicidal activity bioassay results showed that compounds I 5、I 23、I 28 and I 29 exhibited more than 90%A-level fungicidal activity against Blumeria graminis at 500 mg/L;I 8 and I 31 exhibited more than 90%A-level fungicidal activity against Rhizoctonia solani.The title compounds did not show obvious herbicidal activities against Digitaria sanguinalis,Amaranthus spinosus and Chenopodium album at the concentration of 2250 g a.i./ha.The study of structure-activity relationship of the title compounds revealed when R3 is carboxylate cyclopentyl;Rn is 4-trifluoromethoxyl;R1 and R2 are methyl or ethyl,the compound displayed the best insecticidal and fungicidal activities;the research results which were summarized can provide some theoretical guidance for the molecular design and the optimization of quinoline pesticides.