| abstract |
PURPOSE: To provide a herbicide effective to whiten and kill the weeds, and containing as an effective component, a 3-pyrazolin-5-one derivative, most of which is novel. n CONSTITUTION: A herbicide containing a compound of formula I [R 1 is H or alkyl; R 2 is alkyl, alkoxycarbonylmethyl, or phenyl; R 3 is alkyl; R 4 is H, alkanoyl, or formula II ( A is CO or CH 2 ; X is alkyl, alkoxy, halogen, or nitro; n is 0, 1 or 2)], e.g. 4-(2-chlorobenzoyl)-1,2,3-trimethyl-3-pyrazolin-5-one, as an effective component. The compound I wherein R 1 and R 2 are alkyl is prepared by reacting a compound III with an alkyl halide, etc. in the presence of a base. n USE: Effective to the perennial weeds such as galingale, arrowhead, etc. n COPYRIGHT: (C)1980,JPO&Japio |