HETEROCYCLIC COMPOUNDS AND HERBICIDAL COMPOSITIONS

The invention concerns novel compounds of the formula I wherein: X is selected from halogen, nitro, cyano, alkyl, substituted alkyl, alkenyl, alkynyl, hydroxy, alkoxy, substituted alkoxy, alkenyloxy, alkynyloxy, alkanoyloxy, alkoxycarbonyl, alkylthio, alkylsulfinyl, alkylsulfonyl, sulfamoyl, substituted sulfamoyl, benzyloxy, substituted benzyloxy, amino, substituted amino, and the groups formyl and alkanoyl and the oxime, imine and Schiff base derivatives thereof; Y and Z are independently selected from methylene, oxygen and sulfur provided that at least one of Y and Z is selected from oxygen and sulfur; R is selected from hydrogen, alkyl , alkenyl, alkynyl, substituted alkyl, acyl, alkylsulfonyl, benzenesulfonyl, substituted benzenesulfonyl, and an inorganic or organic cation; R is selected from alkyl, alkenyl, alkynyl, substituted alkyl, haloalkenyl and haloalkynyl.; R is selected from alkyl, fluoroalkyl, alkenyl, alkynyl and phenyl; R is selected from hydrogen, halogen, cyano, C1 to C6 alkyl and (C1 to C6 alkoxy) carbonyl: n is an integer selected from 1 to 3; and m is zero or an integer selected from 1 to 3. The compounds are cereal selective herbicides and in further embodiments the invention provides processes for the preparation of compounds of formula I, intermediates useful in the preparation of compounds of formula I, intermediates useful in the preparation of compounds of formula I, herbicidal compositions containing as active ingredient a compound of formula I, and processes for severely damaging or killing unwanted plants by applying to the plants or to the growth medium of the plants an effective amount of a compound of formula I.