Synthesis Of 1,3-Benzoxazinone Benzimidazole And N-(Arylaminoethyl)-3,1-Benzoxazin-2-One And Their Bactericidal Activity

Pesticides are essential to the development of modern agriculture,and it is increasingly important to create new,safe,pollution-free and highly biologically active pesticides.This thesis designed and synthesized 1,3-benzoxazinonobenzi midazole ?,N-(arylaminoethyl)-3,1-benzoxazine-2-one ?.The structure of the synthesized target compound was characterized by ¹H NMR?¹³C NMR?IR,and the fungicidal activity of the compounds was studied.(1)Under the action of sodium bisulfite,a series of substituted2-benzimidazolylphenol compounds ?-1??-18 were synthesized by the reaction of substituted salicylaldehyde and substituted o-phenylenediamine in 38?78%.(2)Substituted 2-benzimidazolylphenol ? reacted with triphosgene to synthesize a series of 1,3-benzoxazinonobenzimidazole ?-1??-18,and the reaction conditions were explored.As a result,the optimized conditions obtained are:the molarratio of 2-benzimidazole-2-phenol ? and triphosgene is 1:0.65,with triethylamine(200 mol%)as acid binding agent and toluene as solvent,reaction temperature 100?and time 18h,and the yields were 38.2%?83.3%under these optimized conditions.The substituents R² and R³ on the benzene ring being hydrogen gave higher yields greater than methyl group regardless of whether R¹ is an electron-donating or electron-withdrawing group.(3)Under the action of cesium carbonate and tetrabutylammonium iodide,1,2-dichloroethane is used as both a reactant and a solvent,and 3,1-benzoxazin-2-one is reacted at 65?to synthesize N-(2-chloroethyl)-3,1-benzoxazin-2-one ?-1.(4)Under the action of sodium iodide and potassium carbonate,reaction of N-(2-chloroethyl)-3,1-benzoxazinone ?-1 and aromatic amine(the molar ratio is 1:1.1)in acetonitrile at 80?for 26h afforded N-(arylaminoethyl)-3,1-benzoxazin-2-one ?-1??-10 in yields of 41.8%?61.3%.The yields of the compounds with electron-donating group R⁴ on the benzene ring are higher than those with electron-withdrawing group.(5)The fungicidal activity of the 1,3-benzoxazinonobenzimidazoles ?-1??-18,?-1 and N-(arylaminoethyl)-3,1-benzoxazin-2-ones ?-1??-10 were evaluated.The compounds showed moderate to excellent activity,of which compounds ?-1 and ?-8 exhibited an inhibition rate of 100.0%against Phytophthora capsici,and compounds ?-1 and ?-1 had an inhibition rate of 75.1%and 72.7%against S.sclerotiorum,respectively.