Chemical Behaviour and Herbicidal Activity of Cyclohexanedione Oxime Herbicides

摘要: Benzoximate (I; Fig. 1) is an acaricide developed by Nippon Soda in 1971 (Iwataki, 1992). However, scientifics of the company observed that some benzohydroxamates showed weak herbicidal activity. After much synthetic developments, a new lead compound, ethoxyimino dehydroacetic acid derivative (II; 1), strong pre-emergence activity against annual grass weed without any effects towards broadleaf plants. Further developmental research was performed on cyclohexanedione skeleton to develop post-emergence herbicide. It ethoximine group between two keto groups essential for (III; 1). Besides, when hetero atoms were introduced ring, compounds high preemergence When ring formed carbons, so-called cyclohexane derivatives, preand activities. Therefore, focused substituents cyclohexanodione skeleton. The higher side chain R1 and R2 (Fig. alkyl groups. As substituents, mono i-Pr germinal dimethyl at R3 position ciano methoxycarbonyl R4 provided maximum This way, alloxydim–sodium discovered market 1978.