| 摘要 |
Novel phosphonic acid and phosphinic acid derivatives of the formula I <IMAGE> (I) wherein X is hydrogen or chlorine, n is 0 or 1, R1 and R2 are each independently hydrogen, C1-C4alkyl, C3-C4alkenyl, C3-C4alkynyl, C1-C4haloalkyl, C1-C4-alkoxy-C1-C4alkyl, C1-C4cyanoalkyl, or they are a phenyl radical, a phenyl-C1-C4alkyl radical or a naphthyl radical, each unsubstituted or substituted by halogen, C1-C4alkyl, C1-C4alkoxy, C1-C4haloalkyl, C1-C4haloalkoxy, nitro or cyano, and A is a C1-C3alkyl chain which may be substituted by one or two C1-C2alkyl radicals and/or by one or two phenyl radicals, with the proviso that R2 is not hydrogen if n is 0, have a good selective herbicidal activity. They are suitable for controlling monocot and dicot weeds pre- and postemergence in various crops of useful plants, e.g. cereals, maize, rice and soybeans. |
