Substituted benzoylcyclohexanediones as herbicides

1 . A compound of the formula (I) or salt thereof

in which the radicals and indices have the following definitions:

R 1 and R 2 independently of one another are hydrogen, mercapto, nitro, halogen, cyano, thiocyanato, (C 1 -C 6 )-alkyl, (C 1 -C 6 )-haloalkyl, (C 2 -C 6 )-alkenyl, (C 2 -C 6 )-haloalkenyl, (C 2 -C 6 )-alkynyl, (C 3 -C 6 )-haloalkynyl, (C 3 -C 6 )-cycloalkyl, OR 4 , OCOR 4 , OSO 2 R 4 , S(O) n R 4 , SO 2 OR 4 , SO 2 N(R 4 ) 2 , NR 4 SO 2 R 4 , NR 4 COR 4 , (C 1 -C 6 )-alkyl-S(O) n R 4 , (C 1 -C 6 )-alkyl-OR 4 , (C 1 -C 6 )-alkyl-OCOR 4 , (C 1 -C 6 )-alkyl-OSO 2 R 4 , (C 1 -C 6 )-alkyl-SO 2 OR 4 , (C 1 -C 6 )-alkyl-SO 2 N(R 4 ) 2 or (C 1 -C 6 )-alkyl-NR 4 COR 4 ;

R 3 is hydrogen, (C 1 -C 6 )-alkyl, (C 2 -C 6 )-alkenyl or (C 2 -C 6 )-alkynyl;

R 4 is hydrogen, (C 1 -C 6 )-alkyl, (C 2 -C 6 )-alkenyl, (C 2 -C 6 )-alkynyl, (C 3 -C 6 )-cycloalkyl, phenyl or phenyl-C 1 -C 6 alkyl, the six last-mentioned radicals being substituted by s radicals from the group consisting of hydroxyl, mercapto, amino, cyano, nitro, thiocyanato, OR 3 , SR 3 , N(R 3 ) 2 , NOR 3 , OCOR 3 , SCOR 3 , NR 3 COR 3 , CO 2 R 3 , COSR 3 , CON(R 3 ) 2 , (C 1 -C 4 )-alkyliminooxy, (C 1 -C 4 )-alkoxyamino, (C 1 -C 4 )-alkylcarbonyl, (C 1 -C 4 )-alkoxy-(C 2 -C 6 )-alkoxycarbonyl and (C 1 -C 4 )-alkylsulfonyl;

Het is a fully saturated heterocyclic group whose ring atoms are composed of 2 oxygen atoms and 2, 3, 4 or 5 carbon atoms, and Het is substituted by n radicals R 5 ;

n is 0, 1 or 2;

s is 0, 1, 2 or 3;

R 5 is hydroxyl, mercapto, amino, cyano, nitro, halogen, formyl, (C 1 -C 6 )-alkylamino, (C 1 -C 6 )-dialkylamino, (C 1 -C 6 )-alkoxycarbonyl, (C 1 -C 6 )-alkylcarbonyl, (C 1 -C 4 )-alkylcarbonyloxy, (C 1 -C 6 )-alkyl, (C 1 -C 6 )-haloalkyl, (C 1 -C 6 )-alkylthio, (C 1 -C 6 )-haloalkylthio, (C 1 -C 6 )-alkoxy or (C 1 -C 6 )-haloalkoxy

or R 5 together with the carbon atom to which it is attached forms a carbonyl group,

or two R 5 s together with the carbon atom to which they are attached form a 3- to 6-membered spiro ring.

2 . A compound as claimed in claim 1 in which

R 1 and R 2 independently of one another are hydrogen, nitro, halogen, (C 1 -C 4 )-alkyl, (C 1 -C 4 )-haloalkyl, (C 2 -C 6 )-alkenyl, (C 2 -C 6 )-haloalkenyl, (C 2 -C 6 )-alkynyl, (C 2 -C 6 )-haloalkynyl, (C 3 -C 6 )-cycloalkyl, —OR 4 , S(O) n R 4 , SO 2 OR 4 , SO 2 N(R 4 ) 2 , NR 4 SO 2 R 4 or C 1 -C 6 alkyl-S(O) n R 4 ;

R 4 is hydrogen, (C 1 -C 4 )-alkyl, (C 2 -C 4 )-alkenyl, (C 2 -C 4 )-alkynyl, (C 3 -C 6 )-cycloalkyl, phenyl or phenyl-(C 1 -C 4 )-alkyl, the six last-mentioned radicals being substituted by s radicals from the group consisting of cyano, nitro, R 3 , OR 3 , SR 3 and N(R 3 ) 2 .

3 . A compound as claimed in claim 1 in which

R 3 is hydrogen or methyl;

R 5 is cyano, nitro, halogen, (C 1 -C 4 )-alkoxycarbonyl, (C 1 -C 4 )-alkylcarbonyl, (C 1 -C 4 )-alkylcarbonyloxy, (C 1 -C 4 )-alkyl, (C 1 -C 4 )-haloalkyl, (C 1 -C 4 )-alkylthio, (C 1 -C 4 )-haloalkylthio, (C 1 -C 6 )-alkoxy or (C 1 -C 6 )-haloalkoxy,

or R 5 together with the carbon atom to which it is attached forms a carbonyl group,

or two R 5 s together with the carbon atom to which they are attached form a 5-6-membered spiro ring.

4 . A compound as claimed in claim 1 in which

R 5 is methyl, methoxy, ethyl, hexyl or chloromethyl,

or R 5 together with the carbon atom to which it is attached forms a carbonyl group,

or two R 5 s together with the carbon atom to which they are attached form a 5-6-membered spiro ring.

5 . A compound as claimed in claim 1 in which

R 1 is chlorine, bromine, iodine, nitro, methyl or thiomethyl;

R 2 is chlorine, methylsulfonyl or ethylsulfonyl.

6 . A herbicidal composition comprising a herbicidally effective amount of at least one compound of the formula (I) as claimed in claim 1 .

7 . The herbicidal composition as claimed in claim 6 as a mixture with formulating assistants.

8 . A method of controlling unwanted plants, which comprises applying to the plants or to the locus of unwanted plant growth an effective amount of at least one compound of the formula (I) as claimed in claim 1 .

9 . (canceled)

10 . The method as claimed in claim 8 , wherein the unwanted plants are located in crops of useful plants.

11 . The method as claimed in claim 10 , wherein the useful plants are transgenic plants.

12 . A method of controlling unwanted plants, which comprises applying to the plants or to the locus of unwanted plant growth an effective amount of a herbicidal composition as claimed in claim 6.