Synthesis And Biological Activity Of The N-nitro-2,4,6-Trisubstituted Phenyl Derivative Inhibitors

N-nitro trisubstituted aniline is a kind of double-function chemical compound which have herbicidal activity and plant growth regulating activity. Through years of effort, we successfully designed and synthesized a variety of N-nitrourea compounds, and results showed that N-nitrourea compounds and sulfonylurea compounds have the same target, namely acetolactate synthase. In order to search for novel and high activity compounds, this research designed and synthesized 44 kinds of N-nitro-N-2,4,6- tribromide(fluoro) phenyl substituted phenylacetate compounds by reasonable designing and structure optimization. Then we test the biological activity of synthetic compound.Part I: Synthesis and characterization of target compoundsN-nitro-2,4,6-trisubstituted aniline was prepared using HNO3-Ac2 O to deal with 2,4,6-trisubstituted aniline. On the basis of that acetonitrile and K2CO3 are used as solvent and the acid agents respectively, N-nitro-2,4,6-trisubstituted aniline react with the substituted ethyl benzoate to obtain 44 target compounds. We analyzed the physical and chemical properties identified by IR、1H NMR.Part II: Bioactivity assay of target compoundsWe extracted ALS enzyme from maize and measured the enzyme activities for the target compounds. The results showed that IC50 of class A of compounds were between 50-100 mg/L, while IC50 of class B of compounds were between 15-70 mg/L. It is found that the class of compounds B have a higher inhibitory activity against ALS than the class of compound A. The results showed that the target compounds had certain inhibition effect on ALS, it is worthy of further study.Part III: The “Petri dish test for herbicidal bioactivity(NY/T 1155.1-2006)” was adopted to test herbicidal activities of 44 target compounds. The results indicated that most of target compounds exhibited moderate herbicidal activity against weed, and there is a better inhibition against Barnyardgrass than Sorghum sudanenses by the target compounds, such as the EC50 of compound A-19 were 6.29 mg/L for barnyardgrass. On the whole, the results showed that high concentration of target compounds inhibit the growth of the crop and low concentration promote the growth of the crop, and there is a better promoting rate to rice than rape by the target compounds. The class of compounds B have a better biological activity than the class of compounds A due to the introduction of the fluorine atom. This study would provide a preliminary guidance in exploring new herbicide.