Herbicidal imidazolinones

Claim 1

An imidazolinone of the formula I ##STR7## in which A denotes N or C-R 4 ; B denotes halogeno (C 1 -C 2 ) alkyl, wherein halogen means fluorine, chlorine or bromine, or (C 1 -C 4 ) alkoxymethyl, cyanomethyl or thiocyanatomethyl; X denotes (C 1 -C 4 ) alkyl; and Y denotes (C 1 -C 6 )alkyl, cyclo (C 3 -C 6 ) alkyl, (C 2 -C 4 ) alkenyl, (C 2 -C 4 ) alkinyl, phenyl or benzyl; or X and Y, together with the carbon atom to which they are bonded, denoted a spirocyclo (C 3 -C 6 ) alkyl group which is optionally substituted by --CH 3 ; Z denotes hydrogen, (C 1 -C 4 ) alkyl, which can be substituted by (C 1 -C 4 ) alkoxycarbonyl, or (C 3 -C 4 ) alkenyl, propargyl, --CO--R 5 or --SO 2 --R 6 ; R 1 , R 2 , R 3 and R 4 independently of one another denote hydrogen, halogen, (C 1 -C 4 ) alkyl, (C 1 -C 6 ) alkoxy, (C 1 -C 6 ) alkoxycarbonyl, halogeno (C 1 -C 2 ) alkyl, nitro, cyano, phenoxy or phenyl, which can optionally be substituted by (C 1 -C 4 ) alkyl, (C 1 -C 4 ) alkoxy or halogen, it also being possible for in each case two radicals R 1 , R 2 , R 3 and R 4 in the o-position relative to one another together to form the grouping --CH═CH--CH═CH--; R 5 denotes (C 1 -C 12 ) alkyl, which is optionally substituted by up to two (C 1 -C 4 ) alkoxy groups or by up to three halogen; phenyl, which can be substituted by up to two halogen or a methyl, nitro or methoxy group; or cyclo (C 3 -C 7 ) alkyl, (C 1 -C 4 ) alkoxy, (C 1 -C 4 )alkoxycarbonyl, benzyloxy, phenoxy or --NR 7 R 8 ; R 6 denotes (C 1 -C 4 ) alkyl, CF 3 , CCl 3 , phenyl, chlorophenyl or methylphenyl; R 7 denotes hydrogen or (C 1 -C 4 ) alkyl; and R 8 denotes (C 1 -C 4 ) alkyl, phenyl, chlorophenyl, methylphenyl, amino or mono- or di(C 1 -C 4 ) alkylamino, or an optical isomer thereof (if X≠Y), an acid addition salt or N-oxide (if A represents N).