New Heterocyclic Compounds, Molecular Design, Synthesis And Biological Activity Study

Most of heterocyclic compounds containing nitrogen possess diverse biological activities.They are widely used in plant protection.Researches in novel compounds containing N-heterocycles have become one of the significant fields of researches in new agrochemicals.Meanwhile,thiazole derivatives,pyridine-based compounds, pyrazole oximes and 1H-1,2,4-triazole derivatives are several important sorts of heterocyclic compounds containing nitrogen.They are widely investigated by many agricultural and medicinal chemists.In order to search for novel lead compounds with good bioactivities,we analyzed the chemical structure and structure-activity relationships of thiazoles, pyridine derivatives,pyrazole oximes and 1H-1,2,4-triazole derivatives,designed and synthesized ten series of one hundred and thirty-three new compounds containing N-heterocycles by following the principle of combination of bioactive sub-structures.Their structures were confirmed by ~1H NMR,elemental analysis,and some compounds were also determined by MS and X-ray diffraction analysis.Three series of fourty-six new compounds containing 2-cyanoimino-1,3-thiazolidine and thiazole rings were synthesized by the reaction of 2-cyanoimino-3-(2-aminothiazol-4-ylmethyi) thiazolidine with various substituted benzaldehydes,benzoyl chlorides,and benzoyl isothiocyanates.Preliminary bioassay showed that some of the target compounds exhibited fungicidal and plant growth regulatory activities to some extent.Six series of pyrazole oxime derivatives containing important 2-chloro-5-methyl-thiazole or 2-chloro-5-methyl-pyridine ring were synthesized by the methods of union of active groups and bioisosterism.We had tried various reaction conditions for the synthesis of title compounds,and the target compounds were obtained in good yields.Some of the target compounds exhibited good insecticidal and certain plant growth regulatory activities.According to the experience in high transformation of 1,1,1,3,3,3- hexafluoropropan-2-one and other carbonyl compounds to their hydrates,twelve novel gem-diols containing pyridyl and triazolyl groups were designed and synthesized.We investigated various reaction conditions for the synthesis of gem-diols.Finally,the title Compounds were obtained in satisfactory yields by using ethyl acetate as the solvent without addition of any catalyst.The gem-diols obtained above can be acted as the vital materials for the synthesis of the metal-organic compounds.Preliminary bioassay indicated that some of the target compounds displayed good plant growth regulatory activities.