Synthesis And Bioactivities Of Tetrahydrochromeno Derivatives

The development of green chemical pesticides has increasingly gained the attention and support from the Governments. Because of their widespread biological activities, heterocyclic compounds have become the hot spots for green chemical pesticides. And that, most of the pesticides developed in the late1990s were heterocyclic compounds. As a class of oxygen-containing heterocyclic compounds, benzopyran derivatives have been taken much attention in the formulation of new pesticides in recent years, due to their broad physiological and pharmacological activities. Herein, a series of new tetrahydrochromeno derivatives were designed and synthesized in good to excellent yields. Their spectral properties, bioactivities and structure-activity relationships were studied, which would be conducive to further research. This dissertation maybe summarized as follows:Firstly, the development of pesticide, the structure-activity relationship and the synthesis of benzopyran derivatives were reviewed. Secondly, according to the structures of the compounds (2-aryl-4H-chromen-4-ones) separated from the stems, leaves of Murraya paniculata (L.) Jacks with silica gel column chromatography and the design principles of pesticide molecules (e.g., the bioisosterism, the connecting principle of actively biological groups, etc.), twenty2-amide-3-carboxylate-4-aryl-4H-chromene derivatives were designed and synthesized smoothly. The structures of all the target compounds were confirmed by1H NMR, MS and elemental analyses. And, one of them was characterized by X-ray single crystal diffraction technique. Finally, in accordance with the standard operation procedure of pesticide bioassay, the preliminary biological activity studies were carried out. The results were as follows:Insecticidal activity:Compound3c exhibited certain extent of insecticidal activity. For example, at the concentration of500mg/L, it exhibited60.1%mortality ratio (24h) against2nd instar Prodenia litura.Bactericidal activity:Compound3a exhibited different extent of fungicidal efficacy. For example, at the concentration of150mg/L, it exhibited61.6%inhibition ratio to Colletotrichum gloeosporioides Penz and exhibited66.7%inhibition ratio to Colletotrichum musae (Berk. Curt.) Arx.Herbicidal activity:The herbicidal activities of all the target compounds were not ideal. At the dose of500mg/L, the inhibition rates of the monocotyledonous Echinochloa oryzoides (Ard.) Fritsch and the dicotyledonous Eclipta pro strata (L.) L. were both less than50%.In addition, the structure-activity relationships of the target compounds were analyzed in brief. It showed that the changes of2-substituent groups had a positive impact on the insecticidal activity, while the changes of4-substituent groups did not.