| abstract |
A cyanophenoxy-phenoxypentenoic acid derivative which is excellent in selective herbicide function to kill weeds of Gramineae family and harmless to cereal plants. The cyanophenoxy-phenoxypentenoic acid derivative is represented by the general formula of:n wherein R 1 is hydrogen, chlorine or bromine atom, X isn oxygen or sulfur atom, and R 2 is hydrogen atom, cation, alkyl, fluoroalkyl, benzyl or -N= C ( di a lk yl) group. The cyanophenoxy-phenoxypentenoic acid is prepared by reacting, in the presence of a base, a cyanophenoxy-phenol derivative represented by the general formula of:n wherein R, is the same as set forth above; with a 4-halocarboxylic acid derivative represented by the general formula of:n wherein A isn or -CH=CH-, Hal is a halogen atom and X and R 2 is the same as set forth above. |