Dicarboximides and their use as herbicides

A dicarboximide of the formula I ##STR30## wherein X is sulfur;

• R.sup.1 is (a) hydrogen, (b) halogen, (c) cyano, (d) C.sub.1 -C.sub.6 -alkyl which may be substituted by 1-5 halogen atoms or one or two C.sub.3 -C.sub.6 -cycloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, C.sub.1 -C.sub.4 -alkylsulfonyl, C.sub.1 -C.sub.4 -haloalkylsulfonyl or cyano groups, (e) C.sub.3 -C.sub.8 -cycloalkyl which may be substituted by 1-3 halogens or C.sub.1 -C.sub.4 -alkyl groups, (f) C.sub.2 -C.sub.6 -alkenyl which may be substituted by 1-3 halogen atoms, C.sub.1 -C.sub.3 -alkoxy or phenyl groups, wherein said phenyl groups may be substituted by one to three C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, halogen, cyano or nitro groups, (g) C.sub.2 -C.sub.6 -alkynyl which may be substituted by 1-3 halogen atoms, C.sub.1 -C.sub.3 -alkoxy or phenyl groups, wherein said phenyl groups may be substituted by one to three C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, halogen, cyano or nitro groups, (h) C.sub.1 -C.sub.4 -alkoxy, (i) C.sub.2 -C.sub.6 -alkenyloxy, (j) C.sub.2 -C.sub.6 -alkynyloxy, (k) C.sub.1 -C.sub.4 -alkylthio, (l) C.sub.1 -C.sub.4 -haloalkoxy, (m) C.sub.1 -C.sub.4 -haloalkylthio, (n) C.sub.1 -C.sub.4 -alkylsulfonyl, (o) C.sub.1 -C.sub.4 -haloalkylsulfonyl, (p) phenoxy or phenylthio which may be substituted by one to three C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, halogen, cyano or nitro groups, (q) a 5-membered or 6-membered saturated or aromatic heterocyclic group containing one or two heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, which may be substituted by one or two C.sub.1 -C.sub.3 -alkyl, halogen, C.sub.1 -C.sub.3 -alkoxy or C.sub.1 -C.sub.3 -alkoxycarbonyl groups, (r) a fused aromatic group selected from the group consisting of benzofuran-2-yl, benzofuran-3-yl, isobenzofuran-2-yl, benzothiophen-2-yl, benzothiophen-3-yl, isobenzothiophen-2-yl, indol-2-yl, indol-3-yl, 1,2-benzoisoxal-3-yl, benzoxal-2-yl, 1,2-benzoisothiazol-3-yl, benzothiazol-2-yl, indazol-3-yl, (1H)-benzimidazol-2-yl, quinol-3-yl, quinol-5-yl, quinol-6-yl, quinol-8-yl, isoquinol-1-yl and isoquinol-5-yl, which may be substituted by one or two C.sub.1 -C.sub.3 -alkyl, halogen, C.sub.1 -C.sub.3 -alkoxy or C.sub.1 -C.sub.3 -alkoxycarbonyl groups, (s) phenyl or phenyl-C.sub.1 -C.sub.4 -alkyl which may be substituted by one to three C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -haloalkyl, C.sub.1 -C.sub.6 -alkoxy, C.sub.1 -C.sub.6 -haloalkoxy, C.sub.1 -C.sub.6 -alkylthio, C.sub.1 -C.sub.6 -haloalkylthio, halogen, nitro or cyano groups;
• R.sup.2 is (t) hydrogen, (u) hydroxyl, (v) C.sub.1 -C.sub.4 -alkoxy, (w) C.sub.1 -C.sub.6 -alkyl which may be substituted by 1-3 cyano, C.sub.1 -C.sub.4 -alkoxy-C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, di-C.sub.1 -C.sub.4 -alkylamino, halogen, C.sub.3 -C.sub.8 -cycloalkyl or phenyl groups, wherein said phenyl groups may be substituted by one to three halogen, cyano, nitro, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio or C.sub.1 -C.sub.4 -haloalkylthio groups, (x) C.sub.3 -C.sub.8 -cycloalkyl which may be substituted by one to three C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, halogen, nitro or cyano groups, (y) C.sub.3 -C.sub.6 -alkenyl which may be substituted by 1-3 halogen atoms or one phenyl group, wherein said phenyl group may be substituted by one to three C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, halogen, cyano or nitro groups, (z) C.sub.3 -C.sub.6 -alkynyl which may be substituted by 1-3 halogen atoms or one phenyl group, wherein said phenyl group may be substituted by one to three C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1-C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkylthio, halogen, cyano or nitro groups, (aa) di-C.sub.1 -C.sub.4 -alkylamino, (bb) a 5-membered or 6-membered saturated or aromatic heterocyclic group containing one or two heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, which may be substituted by one or two C.sub.1 -C.sub.3 -alkyl, halogen, C.sub.1 -C.sub.3 -alkoxy or C.sub.1 -C.sub.3 -alkoxycarbonyl groups, (cc) a fused aromatic group selected from the group consisting of benzofuran-2-yl, benzofuran-3-yl, isobenzofuran-2-yl, benzothiophen-2-yl, benzothiophen-3-yl, isobenzothiophen-2-yl, indol-2-yl, indol-3-yl, 1,2-benzoisoxal-3-yl, benzoxal-2-yl, 1,2-benzoisothiazol-3-yl, benzothiazol-2-yl, indazol-3-yl, (1H)-benzimidazol-2-yl, quinol-3-yl, quinol-5-yl, quinol-6-yl, quinol-8-yl, isoquinol-1-yl and isoquinol-5-yl, where said fused aromatic group may be monosubstituted to trisubstituted by C.sub.1 -C.sub.4 -alkyl or halogen or (dd) naphthyl which may be substituted by 1-3 halogen atoms or C.sub.1 -C.sub.4 -alkyl groups;
• and plant tolerated salts thereof.