Synthesis And Herbicidal Activity Of 2-(4-aryloxyphenoxy) Propionic Acid Based On Benzofuranol

Based on the principle of agrochemicals molecular design, the benzofuran were introduced into agrochemicals pharmacophore to design novel 2-(4-aryloxyphenoxy) propionic acid herbicide, which has great importance.2-(4-aryloxyphenoxy) propionic acid has been identified as one of the most important herbicides, which inhibited acetyl-CoA carboxylase(ACCase) to restrict fatty acid. As a kind of high efficiency, low toxicity and high selective herbicide, they were used in graminaceous weed. In recent years,2-(4-aryloxyphenoxy) propionic acid have developed resistance in varying degrees among weeds. Therefore, researching novel 2-(4-aryloxyphenoxy) propionic acid herbicide is of great importance. The researches are as follows:(1) Based on modern novel agrochemicals design method, As B9 was the leading compound with keeping the aryloxyphenyl, the (R)-2-(4-aryloxyphenoxy) propionic acid-2-(2,2-dimethyl-2,3-dibenzofuran-7-oxyl)ethyl/propyl ester (7a-7i) were synthesized from the intermediate 6.(2) Based on the combination of active groups and substructure connection principle. By replacing the 7th group to 5th on the position of benzofuranol, C9 was the leading compound with keeping the aryloxyphenyl, the (R)-N-[2/3-(2,2-dimethyl-2,3-dibenzofuran-7-oxyl)ethyl/propyl]-2-[4-(aryloxyphenox yl)]propionamide were synthesized by multistep procedures starting from (R)-2-(4-aryloxyphenoxy) propionic acid and benzofuranol. The target compounds were characterized by 1H NMR?13C NMR?LC/MS?IR and optical rotation. And the synthetic route of intermediate (8) was investigated.(3) At the dosage of 1500 g/hm2, the majority of two series compounds exhibited higher herbicidal efficiency against monocotyledonous herbs(Echinochloa crus-galli and Digitaria sanguinalis). Compounds 7a-7h showed the 100%herbicidal activity against monocotyledonous herbs under the post-emergence treatments/pre-emergence treatments, which was at the same level of Metamifop and Codinafop-propargyl.7e showed the 74.0% inhibition towards the Amaranthus retroflexus. The structure-activity relationship of compounds 7 and 9 were also discussed.Compounds 9c,9e,9g,9h were found to possess A level of herbicidal activity against monocotyledonous herbs(Echinochloa crus-galli and Digitaria sanguinalis). Further herbicidal activity indicated that compounds 7e?7h?9e?9h showed the 96% against the Echinochloa crus-galli at 375 g/hm2.The binding mode between compounds 7a,9a and active site of ACCase were simulated. The results proved the reasonability of the original design.