Benzoylcyclohexanedione derivatives and their use as herbicides

Details Benzoylcyclohexanedione derivatives and their use as herbicides Benzoylcyclohexanedione derivatives and their use as herbicides

2002-04-04

2004-07-27

Barts, Samuel (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Oxygen containing

C568S337000, C568S630000, C568S633000, C568S634000, C568S063000, C568S064000, C504S306000, C504S310000, C504S348000

Reexamination Certificate

active

06768025

ABSTRACT:

The invention pertains to the technical field of herbicides, particularly that of herbicides for selective control of broadleaf and grass weeds in crops.
It is already known from various publications that certain benzoylcyclohexanediones possess herbicidal properties. For instance, EP-A 0 319 075, WO 92/07837, and WO 96/22958 disclose benzoylcyclohexanediones having a haloalkoxy radical in position 3 of the phenyl ring. EP-A 0 563 817 describes salts of benzoylcyclohexanediones which likewise carry a haloalkoxy radical in position 3 of the phenyl ring. WO 91/05470, WO 92/13833, and U.S. Pat. No. 4,780,127 specify benzoylcyclohexanediones which in the 3 position of the phenyl ring may be unsubstituted or may be substituted by a variety of radicals, among them trafluoromethoxy. In addition, the last-mentioned document names the compounds 2-(3-(2,3-dibromopropoxy)-2-chloro-4-ethylsulfonylbenzoyl)-1,3-cyclohexanedione and 2-(2-chloro-3-(3-chloropropoxy)-4-ethylsulfonylbenzoyl)-1,3-cyclohexanedione.
The herbicidal activity of the compounds known from these publications, however, is frequently inadequate. It is an object of the present invention to provide herbicidally active compounds possessing herbicidal properties which—relative to those of the compounds disclosed in the state of the art—are improved.
It has now been found that benzoylcyclohexanedione derivatives whose phenyl ring is substituted in position 3 by selected radicals from the C
1
-C
4
haloalkoxy group are especially suitable for use as herbicides. The present invention accordingly provides compounds of the formula (I) or salts thereof
in which
L is a saturated carbon chain having 1, 2, 3 or 4 carbon atoms;
R
1
is iodine, bromine, chlorine, fluorine, C
1
-C
4
alkyl, C
1
-C
4
alkylthio, C
1
-C
4
alkoxy or C
1
-C
4
haloalkyl;
R
2
is bromine, chlorine, iodine or fluorine;
R
3
is bromine, chlorine, fluorine, cyano, nitro, C
1
-C
4
alkyl, methylsulfonyl or ethylsulfonyl;
R
4
is OR
5
or SR
5
;
R
5
is hydrogen, C
1
-C
4
alkyl, C
2
-C
4
alkenyl, C
2
-C
4
alkynyl, benzyl or phenyl;
m is an integer from 1 to 9, and
n is 0, 1 or 2,
 with the proviso that
a) the radical O—L—(R
2
)
m
is not to be trifluoromethoxy, and
b) the compounds 2-(3-(2,3-dibromopropoxy)-2-chloro-4-ethylsulfonylbenzoyl)-1,3-cyclohexanedione and 2-(2-chloro-3-(3-chloropropoxy)-4-ethylsulfonylbenzoyl)-1,3-cyclohexanedione
are to be excluded from the above definition.
Where R
4
is OR
5
and R
5
is hydrogen, the compounds of the formula (I) of the invention may, depending on external conditions, such as solvent and pH, occur in different tautomeric structures:
Depending on the nature of the substituents, the compounds of the formula (I) contain an acidic proton which may be removed by reaction with a base. Examples of suitable bases include hydrides, hydroxides, and carbonates of alkali metals and alkaline earth metals, such as lithium, sodium, potassium, magnesium, and calcium, and also ammonia and organic amines such as triethylamine and pyridine. Such salts are likewise provided by the invention.
In formula (I) and all subsequent formulae, alkyl radicals having more than two carbon atoms may be linear or branched. Alkyl radicals are, for example, methyl, ethyl, n- or i-propyl, n-, i-, t- or 2-butyl, pentyls, hexyls, such as n-hexyl, i-hexyl, and 1,3-dimethylbutyl. The saturated carbon chain L may likewise be linear or branched depending on the number of its carbon atoms. The m atoms from the group bromine, chlorine and fluorine that are attached to it may be located at any desired position in this chain.
Where a group is substituted plurally by radicals, this means that this group is substituted by one or more identical or different representatives of the radicals mentioned.
Depending on the nature and linkage of the substituents, the compounds of the formula (I) may be present in the form of stereoisomers. Where, for example, there are one or more asymmetric carbon atoms present, enantiomers and diastereomers may occur. Stereoisomers may be obtained from the synthesis mixtures by customary separation methods, such as by chromatographic separation techniques. Stereoisomers may likewise be prepared selectively through the use of stereoselective reactions using optically active reactants and/or auxiliaries. The invention also relates to all stereoisomers and mixtures thereof which are embraced by the formula (I) though not defined specifically.
Compounds of the formula (I) which have proven advantageous are those not present in salt form.
Compounds which have likewise proven advantageous are those wherein the substituents R
1
and R
3
have the same definition.
Preference is given to compounds of the formula (I) wherein
R
2
is bromine, chlorine or fluorine.
Likewise preferred compounds of the formula (I) are those wherein
L is a saturated carbon chain having 1, 2 or 3 carbon atoms;
R
1
is bromine, chlorine, fluorine, methyl, methylthio, methoxy or trifluoromethyl;
R
3
is bromine, chlorine, fluorine, methylsulfonyl or ethylsulfonyl, and
m is an integer from 1 to 7.
Particularly preferred compounds of the formula (I) are those wherein
R
2
is chlorine or fluorine and
R
3
is chlorine, fluorine, methylsulfonyl or ethylsulfonyl.
Very particularly preferred compounds of the formula (I) are those wherein
R
1
is bromine or chlorine;
R
5
is hydrogen, and
n is 0.
Further very particularly preferred compounds of the formula (I) are those wherein R
1
is chlorine.
Another group of very particularly preferred compounds of the formula (I) comprises those wherein R
4
is OR
5
.
In all of the formulae below, the substituents and symbols have the same definition as described under formula (I), unless otherwise defined.
Compounds of the invention in which R
5
is hydrogen may be prepared, for example, in accordance with the method indicated in scheme 1, by base-catalyzed reaction of a benzoic halide (III) with a cyclohexanedione (II) in the presence of a cyanide source. Methods of this kind are described, for example, in EP-A 0 186 117.
Compounds of the invention in which R
5
has a meaning other than that of hydrogen are prepared in accordance with scheme 2, appropriately from the compounds obtainable by scheme 1, by halogenation of a suitable halogenating agent followed by base-catalyzed reaction of an alcohol R
5
—OH or thiol R
5
—SH. Methods of this kind are known, for example, from J. Fluorine Chem. 66 (1984) 1, 39-46 and Khim. Farm. Zh. 30 (1996) 2, 27-30.
The starting compounds used in the above schemes are either commercially available or can be prepared by methods which are known per se. The benzoyl chlorides (III), for example, may be prepared from the corresponding benzoic acids or benzoic esters of the formula (IIIa), in which T is hydroxyl or alkoxy. These benzoic acids and benzoic esters of the formula (IIIa) may be prepared, for example, in accordance with scheme 3 from the hydroxy derivatives (V) by reaction with compounds of the formula (VI), in which M
1
is a leaving group such as halogen, mesyl, tosyl, triflate or nonaflate. Methods of this kind are known, for example, from Houben-Weyl Volume 6/3, pp. 54 to 69, Volume 9, pp. 103 to 115, and Volume 11, p. 97.
Compounds of the formula (IIIa) may also be prepared in accordance with scheme 4 by reacting compounds of the formula (V) with olefins of the formula (VII), in which L′ is a saturated carbon chain having 1 to 2 carbon atoms and R
2a
and R
2b
are each chlorine or fluorine. Methods of this kind are described, for example, in Zh. Org. Khim. 27 (1991) 4, 781-788.
Compounds of the formula (IIIa) in which T is hydroxyl or alkoxy may be prepared in accordance with scheme 5 by reacting compounds of the formula (VIII) in which M
1
is a leaving group such as halogen, mesyl, tosyl, triflate or nonaflate. Methods of this kind are known, for example, from WO 98/42648, and Houben Weyl Volume 6/3, pp. 75 to 78, Volume 9, pp. 103 to 105.
The compounds of the formula (I) according to the invention have an outstanding herbicidal activity against a broad spectrum of economicall

Affiliated with

Also associated with

Rating

Benzoylcyclohexanedione derivatives and their use as herbicides does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Benzoylcyclohexanedione derivatives and their use as herbicides, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Benzoylcyclohexanedione derivatives and their use as herbicides will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3248650