Herbicidal 2-(2-imidazolin-2-yl)-benzo-(5-membered)-heterocycles and the use thereof

A compound having the structure ##STR59## wherein R.sub.1 is hydrogen, di(C.sub.1 -C.sub.4)alkylimino,

• C.sub.1 -C.sub.12 alkyl optionally substituted with one to three of the following:
• C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio, halogen, hydroxy, C.sub.3 -C.sub.6 cycloalkyl, benzyloxy, furyl, phenyl, optionally substituted with one nitro, one to three halogens, C.sub.1 -C.sub.4 alkyl groups or C.sub.1 -C.sub.4 alkoxy groups, carboxy, C.sub.1 -C.sub.4 alkoxycarbonyl, cyano or tri(C.sub.1 -C.sub.4)alkylammonium halide,
• C.sub.3 -C.sub.12 alkenyl optionally substituted with one to three of the following:
• C.sub.1 -C.sub.4 alkoxy, phenyl, halogen or C.sub.1 -C.sub.4 alkoxycarbonyl,
• C.sub.3 -C.sub.6 cycloalkyl optionally substituted with one to three C.sub.1 -C.sub.4 alkyl groups,
• C.sub.3 -C.sub.16 alkyl optionally substituted with one to three C.sub.1 -C.sub.3 alkyl groups or
• a cation;
• R.sub.2 is C.sub.1 -C.sub.4 alkyl;
• R.sub.3 is C.sub.1 -C.sub.4 alkyl or C.sub.3 -C.sub.6 cycloalkyl, and when R.sub.2 and R.sub.3 are taken together with the carbon to which they are attached they may represent C.sub.3 -C.sub.6 cycloalkyl optionally substituted with methyl;
• B is hydrogen, COR.sub.4 or SO.sub.2 R.sub.5 with the proviso that when B is COR.sub.4 or SO.sub.2 R.sub.5, R.sub.3 is other than hydrogen or a cation;
• R.sub.4 is C.sub.1 -C.sub.11 alkyl, chloromethyl or phenyl optionally substituted with halogen, nitro or C.sub.1 -C.sub.4 alkyl;
• R.sub.5 is C.sub.1 -C.sub.4 alkyl or phenyl optionally substituted with C.sub.1 -C.sub.4 alkyl;
• X, Y and Z are each independently CR.sub.6,CR.sub.7 R.sub.8, NR.sub.9, N O or S with the provisos that at least one of X, Y and Z must be O or S, at least one of X, Y and Z must be CR.sub.6 or CR.sub.7 R.sub.8, when X or Y are O or S, then Z cannot be O or S and when X and Y are both O and Z is CR.sub.7 R.sub.8, the structure must be a, c or e;
• the configuration represents either a single bond or a double bond with the proviso that when any of X, Y or Z is CR.sub.7 R.sub.8, NR.sub.9, O or s, then the configuration attached thereto represents a single bond and with the further proviso that at least one of the configurations represents a single bond;
• R.sub.6, R.sub.7 and R.sub.8 are each independently hydrogen, halogen, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 alkyl optionally substituted with one hydroxy or one to three halogens, C.sub.1 -C.sub.4 alkoxy groups, or C.sub.1 -C.sub.4 alkylthio groups;
• R.sub.9 is hydrogen or C.sub.1 -C.sub.4 alkyl optionally substituted with one hydroxy or one to three halogens, C.sub.1 -C.sub.4 alkoxy groups or C.sub.1 -C.sub.4 alkylthio groups;
• Q is hydrogen, halogen, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 alkyl optionally substituted with one or more of the following:
• halogen, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio, or C.sub.2 -C.sub.4 alkenyl;
• the optical isomers thereof when R.sub.2 and R.sub.3 are not the same or when R.sub.7 and R.sub.8 are not the same;
• the tautomers and geometric isomers thereof and the acid addition salts thereof except when R.sub.1 is a salt forming cation.