The Synthesis Of Novel 2-Chloro-hexafluoroisopropyl-Containing Benzoylurea Derivatives And Their Bioactivities

The introduction of fluorine-containing group can often improve the bioactivities of target compounds. The fluorine-containing compounds are important in the development of pesticides and pharmaceuticals. The hexafluoroisopropyl group exhibits good lipid solubility and strong electronic electron-withdrawing ability and these 2-chloro-hexafluoroisopropyl-containing compounds have found many applications in pesticides, pharmaceuticals and materials. In the first and second parts of this dissertation, the 2-chloro-hexafluoroisopropyl group was introduced into benzoylurea derivatives and the reaction conditions and insecticidal activities were studied. In the third part of this dissertation, hydrodefluorination of gem-difluoromethylene derivatives with lithium aluminum hydride was described.1. The new fluorine-containing compounds were synthesized by introduction of the 2-chloro-hexafluoroisopropyl group benzoylureas. The eleven new compounds were confirmed by 1H,13C,19F-NMR and HR-MS, and their insecticidal activities were tested. The preliminary results indicated that some target compounds exhibited obviously activities against armyworm. The CJHa01 showed high insecticidal activity and the mortality against armyworm is 70% at 0.1mg/L2. The reaction conditions of the synthesis of new high bioactive benzoylurea compound(CJHa01) was optimized via changing reaction time, reaction temperature, ratio of starting materials, sequence of addition of reactants and workup. The yield of the synthesis of CJHa01 was greatly improved. The yield of last step reaction, chlorination of the synthesis of CJHa01, was increased from 55% to 90%. Furthermore, results from fields trial indicated that the efficacies of 5% EC CJHa01 against Spodoptera litura in capsicum and Spodoptera litura in vegetable are 76.7% and 69.0%, respectively at 60 g of ai/ha in field plot trials. The efficacy of 5% EC CJHa01 is better than that of hexaflumuron and is lower than that of flubendiamide at the same concentration.3. The carbonefluorine bond is the strongest single bond, which carbon can form. The activation and functionalization of organofluorine compounds attract much interest from synthetic organic chemists. But at the same time, hundreds of thousands of tons of fluorine-containing industrial pollutants, especially for these difluoromethylene-containing wastes, have been produced and contaminated our environment. In the third part of this dissertation, hydrodefluorination of gem-difluoromethylene derivatives with lithium aluminum hydride in the presence of a catalytic amount of ZnCl2 in good to high yields was described. A possible mechanism is also suggested.