Design, Synthesis And Biological Evaluation Of Cyanoacrylates Based Herbicide

Inhibitors of photosystem II electron transport system have excellent herbicidal activity and are safe to animal and human. So this kind of compounds is a research focus in herbicide discovery and development.Based on the photosynthesis center D1 protein structure model of high plant Pisum Sativum, we rationally designed and modified the branch chains of cyanoacrylates in order to improve their herbicidal activity. The structure is shown as the following:A total fourteen final compounds and thirty-eight intermediates were designed and synthesized. The final compounds structures were characterised by 1HNMR, elemental analysis and IR as well.Herbicidal activity of the compounds was evaluated both in vitro and in vivo. The results showed that most of them had good biological activities.Structure activity relationship was further discussed. Substituent effects showed that better activity can be expected by changing of substituents. Therefore the important information for the future design was provided.Meanwhile, efficient and effective synthesis of p-fluoroacetophenone, the key strarting material of proprietary herbicide H-0306 (S-(Z)-2-ethoxyethyl 3-(1-(4-fluorophenyl)ethylamino)-2-cyanopent-2-enoate), was established through a key reaction of direct halogen replacement without catalyst using potassium fluoride.