Synthesis And Biological Activities Of Chitin Synthesis Inhibitors Containing Pytidazinone

Our country is the large agricultural nation, the foodstuff production is directly influenced by crop pests prevention and control. The traditional pesticides not only kill pests, but also damage the human body and the environment. The chitin synthesis inhibitors interfere the insect larvae growth and development by inhibiting insect larvae skinning over and generation of new corneous layer. The insects finally die because they can't molt normally. So the chitin synthesis inhibitors own good selectivity and environmentally friendly properties.We combined the bioactive units of the N-2,6- difluorobenzoyl(thio)urea moiety and the 3(2H)-pyridazinone core, and other bioactive groups to design novel benzoylphenylthioureas and their derivates in order to find new compounds with higher insecticidal activity. Seventeen novel compounds including benzoylphenylthioureas containing 3(2H)-pyridazinone and imidazole-2-thiones with 3(2H)-pyridazinone were synthesized. All of the new compounds were confirmed by 1H NMR, MS and IR. Their insecticidal activities were also determined.(1)Eight key intermediates of 2-alkyl-4-amino-3(2H)-pyridazinones were synthesized using mucochloric acid from their corresponding 4,5-dichloropyridazinones under microwave-assisted conditions. All of the new compounds were confirmed by melting point and, MS. The microwave method greatly shortened the reaction time, and the yield was improved.(2)Nine novel compounds benzoylphenylthioureas containing 3(2H)-pyridazinone were synthesized using intermediate 2 - alkyl - 4 - amino - 3 ( 2H ) pyridazinone as raw material. One of the compouds contained pyridazinone ring benzoylurea and the other eight compouds contained pyridazinone ring benzoyl thiourea compounds. Novel structure of the target compounds were confirmed by 1HNMR, MS and IR. Their insecticidal activities were also determined. The result showed that the part of the series of compounds exhibited weak inhibition, and LDL2, LDL3 inhibition rates were 38.4% and 44.7%, respectively.(3)Eight imidazole-2-thiones with 3(2H)-pyridazinone were synthesized using the bromination acetophenone and aroyl thiourea as raw materials. The reaction conditions were detected. The results showed that reaction should adopt theω- bromination acetophenone as starting material, dried acetone as solvent, and the molar ratio of triethylamine and staring material was 1:1 . All of the new compounds were confirmed by 1H NMR, MS and IR. Their insecticidal activities were also determined. The results of biological activity experiment showed that this series did not show obvious insecticidal activity.