Abstract: Disclosed herein are derivatives of 4-((aryloxy)phenoxy)fluoroalkanoic acid and their use as active herbicides for the pre- and postemergent control of grassy weeds, especially in the presence of broadleaf crops.

Abstract: Dicarboximides of the formulae Ia, Ib and Ic ##STR1## where X is oxygen or sulfur, R.sup.1 is hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, alkylthio, haloalkoxy, haloalkylthio, alkylsulfonyl, haloalkylsulfonyl, phenyl, phenylalkyl, phenoxy or phenylthio, a 5-membered or 6-membered saturated or aromatic heterocyclic radical containing one or two hetero atoms selected from the group consisting of oxygen, sulfur and nitrogen, where the stated organic radicals may be further substituted, andR.sup.2 is hydrogen, hydroxyl, alkoxy, alkyl, cycloalkyl, alkenyl, alkynyl, di-C.sub.1 -C.sub.