WO1998042648A1 - 2-benzoylcyclohexane-1,3-dione compounds and their use as herbicides - Google Patents

Abstract

2-Benzoylcyclohexane-1,3-dione compounds in which the benzoyl moiety is substituted in the 2-position with groups such as halo or alkyl, in the 4-position with an alkylsulfonyl group, and in the 3-position with an acyclic or cyclic derivatized amino group, such as 2-(2-chloro-4-methylsulfonyl-3-(morpholin-4-yl)benzoyl)-5,5-dimethylcyclohexane-1,3-dione, were prepared and found to be useful for the control of a variety of broad-leaf and grassy weeds. The compounds can be applied either preemergently or postemergently and can be used to control undesirable vegetation in corn, rice, and wheat crops.

Description

2-BENZOY CYCLOHEXANE-l, 3-DIONE COMPOUNDS AND THEIR USE AS HERBICIDES

This invention relates to novel 2-benzoylcyclo- hexane-1 , 3-dione compounds and to the use of these compounds as herbicides.

A number of 2-benzoylcyclohexane-l , 3-dione compounds and their herbicidal utility have been disclosed in the art, for example, in U.S. Patents 4,957,538 and 5,110,343. The compound sulcotrione (2- (2-chloro-4-methylsulfonylbenzoyl) cyclohexane-1, 3-

-dione) , which is disclosed in U.S. Patent 4,780,127, is, perhaps, the best known example. Compounds of this general type possessing certain amino substituents have been very generically disclosed as members of large classes, for example in U.S. Patents 4,780,127 and 5,447,903, but no specific compounds or series of compounds possessing amino substituents have been disclosed. Further, compounds of this type having a 5- or 6-membered heterocyclic ring substituent attached by means of a carbon-carbon bond to the 3 -position of the benzoyl ring were disclosed in PCT Application WO 96/26200, published August 29, 1996.

The presently known 2 -benzoylcyclohexane-1 , 3- -dione compounds do not possess sufficient herbicidal activity coupled with sufficient crop selectivity and desirable toxicological and environmental properties to achieve broad commercial acceptance. It would be highly desirable to discover related compounds that are more potent, more selective, or broader spectrum in their herbicidal activity and/or that have markedly improved toxicological and/or environmental properties.

It has now been found that novel 2 -benzoyl - cyclohexane-1 , 3-dione compounds compounds possessing a derivatized amino substituent in the 3 -position and selected substituents in the 2- and 4 -positions of the benzoyl moiety are potent herbicides with a broad spectrum of weed control and excellent crop selectivity. The compounds, further, possess excellent toxicological and environmental profiles.

The invention includes novel benzoylcyclo- hexanedione compounds of Formula I :

wherein

X represents F, Cl , Br, C1-C4 alkyl, OCH3 , OC2H5, CH2OCH3, or CH(CH3)OCH3;

Y represents CH3 , C2Hs_; or CH(CH3)2. R' represents C1-C4 alkyl, C3-C4 alkenyl, or C3-C4 alkynyl; n represents 0, 1, 2, or 3; and each R independently represents H or C1-C4 alkyl, C3-C4 alkenyl, or C3-C4 alkynyl (each optionally possessing up to two substituents selected from Cl , Br, CN, C1-C4 alkoxy, and C1-C3 fluoroalkoxy and up to three

F substituents) or benzyl (optionally possessing up to three ring substituents selected from F, Cl , Br, CN, CF3 , NO2, CH3, C2H5, OCH3, and OC2H5) ; with the proviso that both of R do not represent H; or NR2 represents a 4- to 7-membered aliphatic nitrogen heterocyclic substituent optionally possessing O as a second ring heteroatom, optionally possessing one double bond, and optionally possessing up to three substituents selected from F, Cl , Br, CN, C1-C₄ alkyl, C1-C3 fluoro- alkyl _t C1-C4 alkoxy, C1-C3 fluoroalkoxy, C1-C3 alkoxy- methyl_# and phenyl (optionally possessing up to three ring substituents selected from F, Cl , Br, CN, CF3 , NO2 , CH3, C2H5, OCH3, and OC2H5) ; or

NR2 represents a pyrrol -1-yl or pyrazol-1-yl moiety optionally possessing up to two substituents selected from F, Cl, Br, I, CN, CF3 , C1-C3 alkyl, and C1-C3 alkoxy; and the agriculturally acceptable salts thereof.

The invention includes herbicidal compositions containing the benzoylcyclohexanedione compounds of Formula I in combination with an agriculturally acceptable adjuvant or carrier as well as a method of use of the compounds to kill or control undesirable vegetation by application of an herbicidal amount of the compound to the vegetation or to the locus of the vegetation. The use of the compounds to kill or control grassy weeds in corn, wheat, barley, and rice is a preferred utility and postemergence application of the compounds to the undesirable vegetation is a preferred method of application.

The herbicidal compounds of the present invention are benzoylcyclohexanedione compounds of Formula I :

These compounds are characterized by possessing a cyclohexane-1 , 3-dione moiety substituted in the 2 -position with a benzoyl moiety. Substitution in the 4-, 5-, and 6 -positions of the cyclohexanedione ring with a lower alkyl, alkenyl, or alkynyl moiety is optional. The benzoyl moiety is characterized by being substituted in the 3 -position with a derivatized amino substituent, in the 4 -position with a lower alkylsulfonyl substituent, and in the 2 -position with a halo, lower alkyl, or lower alkoxy substituent. The compounds of the invention include the salt compounds obtained by neutralization of the acidic compounds of Formula I.

The compounds of the invention are alternately named 2 -benzoyl -3 -hydroxy-2-cyclohexene-l-one compounds and are alternately depicted by Formula IA:

Formulas I and IA denote keto-enol tautomers which, as is well-established in the art, are interchangeable and have the same chemical and biological properties . These two formulas, and all other possible tautomeric formulas represent the same compound. Formula I and the benzoyl - cyclohexanedione terminoloy will be used herein to describe the compounds of the invention in order to facilitate clear communication.

The invention includes compounds of Formula I wherein the cyclohexanedione moiety is not further substituted (that is, n of R'n represents 0) or is further substituted in the 4-, 5-, and/or 6-position with 1 to 3 aliphatic hydrocarbyl groups of 1 to 4 carbon atoms each, including compounds wherein the 1 to 3 R' groups are independently selected from C1-C4 alkyl, C3-C₄ alkenyl, and C3-C4 alkynyl. Compounds wherein the substituent (s) R' are in the 5-position are often preferred. Compounds wherein R' represents methyl are sometimes preferred. Compounds wherein n represents 0 and compounds wherein n represents 2 and R' represents methyl located in the 5 -position are often more preferred.

The invention includes compounds of Formula I wherein the benzoyl moiety is substituted in the

4 -position (SO2Y) with a methylsulfonyl , ethylsulfonyl , or 1-methylethylsulfonyl group. Methylsulfonyl groups (Y represents methyl) are typically preferred.

Compounds of Formula I substituted in the 2 -position of the benzoyl moiety (X) with a fluoro, chloro, bromo, methoxy, ethoxy, methoxymethyl , 1-methoxy- ethyl , or a 1 to 4 carbon alkyl group are included in the invention. Compounds wherein X represents chloro or methyl are generally preferred. Compounds wherein X represents chloro or methyl and Y represents methyl are often of special interest .

The derivatized amino substituents present in the 3 -position of the benzoyl moiety (R2N) are the most distinguishing characteristic of the compounds of the present invention. Derivatized amino substituents can be described as substituents consisting of a trivalent nitrogen atom, one bond of which is attached to the benzoyl ring, the second of which is attached to an optionally substituted aliphatic hydrocarbyl or benzyl moiety, and the third of which is attached to a hydrogen atom or to an optionally substituted aliphatic hydrocarbyl or benzyl moiety. When two optionally substituted aliphatic hydrocarbyl moieties are present, these moieties and the trivalent nitrogen atom may be joined to create an optionally substituted four to seven membered aliphatic heterocyclic moiety or a five membered aromatic heterocylic moiety.

The derivatized amino substituents of the compounds of the present invention include those wherein one or both of the R groups of the R2N moiety independently represent C1-C4 alkyl, C3-C4 alkenyl, or C3-C4 alkynyl, each of which may have one or two chloro, bromo, cyano, C1-C4 alkoxy, or C1-C3 fluoroalkoxy substituents and may also have up to three fluoro substituents. It further includes compounds wherein one or both of the R groups are benzyl having up to three ring substituents selected from fluoro, chloro, bromo, cyano, trifluoro- methyl, nitro, methyl, ethyl, methoxy, and ethoxy. One of the R groups may be hydrogen. Compounds wherein both of R represent optionally substituted hydrocarbyl or benzyl groups are sometimes preferred. Such compounds wherein both R groups are selected from methyl, ethyl, and 2-methoxyethyl are often more preferred. Compounds wherein one of R represents hydrogen and the other represents methyl, ethyl, or 2 -methoxyethyl are also sometimes preferred.

The definition of NR2 further includes compounds wherein this substituent represents a 4-, 5-,

6-, or 7-membered aliphatic nitrogen heterocyclic moiety. These heterocyclic moiety substituents may contain one ring oxygen atom and/or one ring carbon-carbon double bond. They, further, may have one, two or three substituents selected from fluoro, chloro, bromo, cyano, C1-C4 alkyl, C1-C3 fluoroalkyl, C1-C4 alkoxy, C1-C3 fluoroalkoxy, C1-C3 alkoxymethyl _# and phenyl , the phenyl optionally having up to three substituents selected from fluoro, chloro, bromo, cyano, trifluoromethyl , nitro, methyl, ethyl, methoxy, and ethoxy. Such compounds wherein NR2 represents a morpholin-4-yl , piperidin-1-yl , or pyrrolidin-1-yl moiety, each optionally substituted with one or two methyl or methoxy groups, are often preferred. Compounds wherein NR2 represents morpholin-4-

-yl are especially preferred. The aliphatic heterocyclic NR2 substituents of this type are necessarily attached to the benzoyl moiety by means of a carbon-nitrogen bond.

The term R2 further includes pyrrol -1-yl and pyrazol-1-yl moieties, which are 5-membered aromatic heterocyclic moieties having one or two nitrogen atoms. Such moieties may have one or two substituents selected from fluoro, chloro, bromo, iodo, cyano, C1-C3 alkyl, C1-C3 alkoxy and trifluoromethyl . Pyrazol-1-yl moieties are generally preferred. The aromatic heterocyclic NR2 substituents of this type are necessarily attached to the benzoyl moiety by means of a carbon-nitrogen bond.

Compounds of Formula I wherein Y represents methyl; X represents chloro or methyl; both R groups are selected from methyl, ethyl, and 2-methoxyethyl or one of R represents hydrogen and the other represents methyl, ethyl, or 2-methoxyethyl or NR2 represents a morpholin-4-

-yl, piperidin-1-yl , or pyrrolidin-1-yl moiety, each optionally substituted with one or two methyl or methoxy groups; and n represents 0 or n represents 2 and R' represents methyl located in the 5-position are often more preferred. Such compounds wherein NR2 represents a morpholin-4-yl moiety are often most preferred.

The compounds of the invention include, for example, 2- (2-chloro-3-dimethylamino-4-methylsulfonyl- benzoyl) cyclohexane-1 , 3-dione, 2- (2 -chloro-3- (N-methyl-N- - (2-methoxyethyl) amino) -4 -methylsulfonylbenzoyl) cyclo- hexane-1 , 3-dione, 2- (2-methyl-3-dimethylamino-4-methyl- sulfonylbenzoyl) cyclohexane-1 , 3-dione, 2- (2 -chloro-3- - (morpholin-4-yl) -4 -methylsulfonylbenzoyl) -5, 5 -dimethyl - cyclohexane-1, 3-dione, 2- (2 -methoxy-3- (piperidin-1-yl) -4- -methanesulfonylbenzoyl) -4-ethylcyclohexane-l, 3 -dione, 2- (2-fluoro-3- (pyrazol-1-yl) -4 -ethylsulfonylbenzoyl) - cyclohexane-1 , 3 -dione, and 2- (2-methoxymethyl-3 - (2- -methoxyethylamino) -4- (1-methylethyl) sulfonylbenzoyl) -5- - (1 , 1-dimethylethyl) cyclohexane-1 , 3 -dione .

The agriculturally acceptable salts obtainable by treating a compound of Formula I with a metal hydroxide, a metal carbonate, an amine or an aminium hydroxide compound are included in the invention. The proton on the 2 -position carbon atom of Formula I (alternatively, the proton on the hydroxy substituent attached to the 3 -position carbon atom of Formula IA) is acidic and forms salts readily. These salt compounds are interconverible with the corresponding acid form in plants or the environment and possess essentially identical herbicidal properties. Salts are often preferred forms of the compounds of Formula I because they are water soluble and lend themselves to the preparation of desirable aqueous based herbicidal compositions .

Agriculturally acceptable salts are defined as those salts of the compounds of Formula I having a cation that is not, itself, significantly herbicidal to any crop being treated and is not significantly deleterious to the applicator, the environment, or the ultimate user of any crop being treated. Suitable cations include, for example, those derived from alkali or alkaline earth metals and those derived from ammonia and amines. Preferred cations include sodium, potassium, magnesium, and aminium cations of the formula: R5R6R7NH+

wherein R⁵ , R6 _r and R⁷ each, independently represents hydrogen or C1-C12 alkyl, C3-C12 cycloalkyl, or C3-C12 alkenyl, each of which is optionally substituted by one or more hydroxy, Ci-Cβ alkoxy, CI_-CR alkylthio or phenyl groups, provided that R5 , R6 _f and R⁷ are sterically compatible. Additionally, any two of R5 , Rδ _ and R⁷ together may represent an aliphatic difunctional moiety containing 1 to 12 carbon atoms and up to two oxygen or sulfur atoms. Salts of the compounds of Formula I can be prepared by treatment of compounds of Formula I with a metal hydroxide, such as sodium hydroxide, or an amine, such as ammonia, trimethylamine, diethylamine, 2 -methyl - thiopropylamine, bisallylamine, 2-butoxyethylamine, morpholine, cyclododecylamine, or benzylamine.

The terms alkyl , alkenyl , and alkynyl as used herein includes straight chain, branched chain, and cyclic moieties. Thus, typical alkyl groups are methyl, ethyl, 1-methylethyl, propyl , cyclopropyl, cyclopropyl- methyl, methylcyclopropyl , and the like. Methyl, ethyl, and 1-methylethyl are often preferred. Typical mono or disubstituted alkyl groups include 2-chloroethyl , methoxymethyl , 2-methoxyethyl , difluoromethyl , methoxy- carbonylmethyl , and 2 -ethoxy- 1-methylethyl . Methoxy- methyl and 2 -methoxyethyl are preferred such groups in many circumstances. The term fluoroalkyl includes alkyl groups as defined hereinabove wherein one to all of the hydrogen atoms are replaced by fluorine atoms . Examples include trifluoromethyl , mono-fluoromethyl , 3,3,3-tri- fluoroethyl, 1 , 2 , 2-trifluoroethyl and the like; tri- fluoromethyl is generally a preferred fluoroalkyl group. The compounds of Formula I can generally be prepared from an appropriately substituted benzoic acid compound of Formula II :

wherein X, Y, and R are as defined for compounds of Formula I and an appropriate cyclohexane-1 , 3-dione compound of Formula III:

R'

wherein R' and n are as defined for compounds of Formula I. The coupling can be carried out under reaction conditions known in the art for reactions of other benzoic acid compounds with cyclohexane-1, 3-dione compounds to form benzoylcyclohexanedione compounds. Suitable preparative methods are disclosed, for example, in U.S. Patents 4,780,127, 4,957,638, and 5,110,343. One of the methods involves conversion of the benzoic acid compound of Formula II to its acid chloride with thionyl chloride and coupling this acid chloride with a cyclohexanedione compound of Formula III in the presence of triethylamine to form an intermediate ester (a 3-oxo- -cyclohex-1-en-l-yl benzoate ester) . The intermediate ester obtained is subsequently isomerized with a trialkylamine compound, such as triethylamine, and a catalytic amount of cyanide ion, usually supplied by adding sodium cyanide or acetone cyanohydrin. The first step of the reaction is generally carried out with agitation in an inert solvent, such as dichloromethane, at temperatures between about 10 °C and 50 °C, usually at ambient temperature. It is generally complete in a few minutes to a few hours. The second step of the process is typically carried out in acetonitrile solvent with agitation at about 10°C and 50°C, usually at ambient temperature. The reaction is generally complete in about an hour to about 20 hours. The compounds of Formula I obtained by these methods can be recovered using the methods known in the art for related compounds.

The 3- (substituted amino) benzoic acid compounds of Formula II can be prepared by the reaction of an appropriate amine compound of Formula IV:

H-NR2

wherein R is as defined for compounds of Formula I with an appropriate 3-halobenzoic acid compound of Formula V:

wherein X and Y are as defined for compounds of Formula I and W represents chloro or fluoro. The 3 -fluoro compounds are often preferred because of their higher reactivity. When the amine compound of Formula IV is an acyclic aliphatic amine, a benzylamine, or a cyclic aliphatic amine, the reaction is generally carried out using an excess of the amine (more than two moles) .

Sodium carbonate is also sometimes as an acid acceptor. Water and/or excess amine are typically used as the solvent, but in some instances a dipolar, aprotic solvent, such as N-methyl -2 -pyrrolidinone, or an alcohol, such as methanol , can be used as well. The starting materials and the desired product of Formula II are generally soluble in the such media, particularly at higher temperatures, which promotes the reaction. The reaction is generally carried out at temperatures of about 70 °C to about 180°C, preferably at about 80 °C to about 120°C. In the case of low boiling aliphatic amines, such as dimethylamine, a pressure vessel is generally employed. The compounds of Formula II obtained can be recovered by conventional means. Typically, the reaction mixture is acidified with aqueous hydrochloric acid and extracted with dichloromethane . The dichloro- methane solvent and other volatiles can be removed by distillation or evaporation to obtain the desired compound of Formula II as a solid. The compounds of

Formula II can be purified by standard procedures, such as by recrystallization or chromatography .

Hydroxyalkylamino substituted compounds of Formulas I and II are useful intermediates for the preparation of corresponding compounds having cyclic amino substituents and (alkoxyalkyl) amino substituents. Compounds having 2 -hydroxyalkylamino substituents, such as 2 -hydroxyethylamino, react with glyoxal to produce compounds having morpholin-2-on-4-yl (2-oxo-tetrahydro- -1, 4-oxazin-4-yl) substituents. These compounds can be converted by reduction to compounds having 2 -hydroxy- morpholin-4-yl and morpholin-4-yl substituents, each optionally possessing additional alkyl substituents. Compounds having 2-hydroxymorpholin-4-yl substituents can be further converted to compounds having 2-alkoxy- morpholin-4-yl substituents with alcohols in the presence of anhydrous hydrogen chloride or boron trifluoride etherate . Compounds having 3-hydroxypropylamino substituents react with formaldehyde to give compounds having tetrahydro-1 , 3-oxazin-3-yl substituents. Compounds of Formulas I and II having a 3- (hydroxyalkyl ) - amino (including hydroxy substituted aliphatic hetero- cyclyl) substituent can be alkylated with alkyl bromides, iodides, or sulfates using standard procedures.

Salts of compounds of Formula I can be prepared by treatment with an equimolar amount of an appropriate metal hydroxide, amine, or aminium hydroxide compound. They can be recovered by standard techniques.

The amine compounds of Formula IV are known in the art or can be prepared by methods known in the art.

The compounds of Formula I have been found to be useful preemergence and postemergence herbicides. They can be employed at non-selective (higher) rates of application to control a broad spectrum of the vegetation in an area or, in some cases, at selective (lower) rates of application for the selective control of undesirable vegetation in grass crops, such as corn, wheat, barley, and rice, as well as in broadleaf crops, such as soybeans and cotton. It is. usually preferred to employ the compounds postemergence. It is further usually preferred to use the compounds to control a broad spectrum of weeds, including grassy weeds, such as barnyardgrass and giant foxtail, in corn, wheat, or barley crops. While each of the benzoylcyclohexanedione compounds encompassed by Formula I is within the scope of the invention, the degree of herbicidal activity, the crop selectivity, and the spectrum of weed control obtained varies depending upon the substituents present. An appropriate compound for any specific herbicidal utility can be identified by using the information presented herein and routine testing.

The term herbicide is used herein to mean an active ingredient which kills, controls or otherwise adversely modifies the growth of plants. An herbicidally effective or vegetation controlling amount is an amount of active ingredient which causes an adversely modifying effect and includes deviations from natural development, killing, regulation, desiccation, retardation, and the like. The terms plants and vegetation include germinant seeds, emerging seedlings and established vegetation.

Herbicidal activity is exhibited by the compounds of the present invention when they are applied directly to the plant or to the locus of the plant at any stage of growth or before planting or emergence. The effect observed depends upon the plant species to be controlled, the stage of growth of the plant, the application parameters of dilution and spray drop size, the particle size of solid components, the environmental conditions at the time of use, the specific compound employed, the specific adjuvants and carriers employed, the soil type, and the like, as well as the amount of chemical applied. These and other factors can be adjusted as is known in the art to promote non-selective or selective herbicidal action. Generally, it is preferred to apply the compounds of Formula I postemergence to relatively immature undesirable vegetation to achieve the maximum control of weeds .

Application rates of about 1 to about 500 g/Ha are generally employed in postemergence operations; for preemergence applications, rates of about 10 to about 1000 g/Ha are generally employed. The higher rates designated generally give non-selective control of a broad variety of undesirable vegetation. The lower rates typically give selective control and, by judicious election, can be employed in the locus of crops. The herbicidal compounds of the present invention are often best applied in conjunction with one or more other herbicides to obtain control of a wider variety of undesirable vegetation. When used in conjunction with other herbicides, the presently claimed compounds can be formulated with the other herbicide or herbicides, tank mixed with the other herbicide or herbicides, or applied sequentially with the other herbicide or herbicides. Some of the herbicides that can be employed in conjunction with the compounds of the present invention include sulfonamides such as metosulam, flumetsulam, cloransulam-methyl , diclosulam, and N-2 , 6-dichlorophenyl-5-ethoxy-7-fluoro [1,2,4] triazolo- [1, 5-c] pyrimidine-2-sulfonamide, sulfonylureas such as chlorimuron, nicosulfuron and metsulfuron, imidazolidones such as imazaquin, imazethapyr and imazamox, phenoxy- alkanoic acids such as 2,4-D and MCAA, pyridinyloxyacetic acids such as triclopyr and fluroxypyr, carboxylic acids such as clopyralid and dicamba, dinitroanilines such as trifluralin and pendimethalin, chloroacetanilides such as alachlor, acetochlor, and metolachlor, and other common herbicides including acifluorfen, bentazon, clomazone,- fumiclorac, fluometuron, fomesafen, lactofen, linuron, isoproturon, and metribuzin. They can, further, be used in conjunction with glyphosate and glufosinate. It is generally preferred to use the compounds of the invention in combination with herbicides that are selective for the crop being treated and which complement the spectrum of weeds controlled by these compounds at the application rate employed. It is further generally preferred to apply the compounds of the invention and complementary other herbicides at the same time, either as a combination formulation or as a tank mix.

The compounds of the present invention can generally be employed in combination with known herbicide safeners, such as cloquintocet , furilazole, dichlormid, benoxacor, flurazole, and fluxofenim, to enhance their selectivity. They can additionally be employed to control undesirable vegetation in many crops that have been made tolerant to or resistant to them or to other herbicides by genetic manipulation or by mutation and selection. For example, corn, wheat, rice, soybean, sugarbeet, cotton, canola, and other crops that have been made tolerant or resistant to compounds that are hydroxy- phenylpyruvate dioxygenase inhibitors in sensitive plants can be treated. Many glyphosate and glufosinate tolerant crops can be treated as well .

While it is possible to utilize the benzoylcyclohexanedione compounds of Formula I directly as herbicides, it is preferable to use them in mixtures containing an herbicidally effective amount of the compound along with at least one agriculturally acceptable adjuvant or carrier. Suitable adjuvants or carriers should not be phytotoxic to valuable crops, particularly at the concentrations employed in applying the compositions for selective weed control in the presence of crops, and should not react chemically with the compounds of Formula I or other composition ingredients. Such mixtures can be designed for application directly to weeds or their locus or can be concentrates or formulations which are normally diluted with additional carriers and adjuvants before application. They can be solids, such as, for example, dusts, granules, water dispersible granules, or wettable powders, or liquids, such as, for example, emulsifiable concentrates, solutions, emulsions or suspensions.

Suitable agricultural adjuvants and carriers that are useful in preparing the herbicidal mixtures of the invention are well known to those skilled in the art. Liquid carriers that can be employed include water, toluene, xylene, petroleum naphtha, crop oil, acetone, methyl ethyl ketone, cyclohexanone, trichloro- ethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol monomethyl ether and diethylene glycol monomethyl ether, methanol, ethanol , isopropanol, amyl alcohol, ethylene glycol, propylene glycol, glycerine, and the like. Water is generally the carrier of choice for the dilution of concentrates.

Suitable solid carriers include talc, pyro- phyllite clay, silica, attapulgus clay, kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite clay, Fuller's earth, cotton seed hulls, wheat flour, soybean flour, pumice, wood flour, walnut shell flour, lignin, and the like.

. It is usually desirable to incorporate one or more surface-active agents into the compositions of the present invention. Such surface-active agents are advantageously employed in both solid and liquid compositions, especially those designed to be diluted with carrier before application. The surface-active agents can be anionic, cationic or nonionic in character and can be employed as emulsifying agents, wetting agents, suspending agents, or for other purposes. Typical surface-active agents include salts of alkyl sulfates, such as diethanolammonium lauryl sulfate; alkylarylsulfonate salts, such as calcium dodecylbenzene- sulfonate; alkylphenol-alkylene oxide addition products, such as nonylphenol-Cis ethoxylate; alcohol-alkylene oxide addition products, such as tridecyl alcohol-Cχ6 ethoxylate; soaps, such as sodium stearate; alkyl - naphthalenesulfonate salts, such as sodium dibutyl- naphthalenesulfonate; dialkyl esters of sulfosuccinate salts, such as sodium di (2-ethylhexyl) sulfosuccinate; sorbitol esters, such as sorbitol oleate; quaternary amines, such as lauryl trimethylammonium chloride; polyethylene glycol esters of fatty acids, such as polyethylene glycol stearate; block copolymers of ethylene oxide and propylene oxide; and salts of mono and dialkyl phosphate esters.

Other adjuvants commonly utilized in agricultural compositions include compatibilizing agents, antifoam agents, sequestering agents, neutralizing agents and buffers, corrosion inhibitors, dyes, odorants, spreading agents, penetration aids, sticking agents, dispersing agents, thickening agents, freezing point depressants, antimicrobial agents, and the like. The compositions may also contain other compatible components, for example, other herbicides, plant growth regulants, fungicides, insecticides, and the like and can be formulated with liquid fertilizers or solid, partic- ulate fertilizer carriers such as ammonium nitrate, urea and the like.

The concentration of the active ingredients in the herbicidal compositions of this invention is generally from about 0.001 to about 98 percent by weight. Concentrations from about 0.01 to about 90 percent by weight are often employed. In compositions designed to be employed as concentrates, the active ingredient is generally present in a concentration from about 5 to about 98 weight percent, preferably about 10 to about 90 weight percent. Such compositions are typically diluted with an inert carrier, such as water, before application. The diluted compositions usually applied to weeds or the locus of weeds generally contain about 0.0001 to about 1 weight percent active ingredient and preferably contain about 0.001 to about 0.05 weight percent. The present compositions can be applied to weeds or their locus by the use of conventional ground or aerial dusters, sprayers, and granule applicators, by addition to irrigation water, and by other conventional means known to those skilled in the art.

EXAMPLES

The following Examples are presented to illustrate the various aspects of this invention and should not be construed as limitations to the claims.

1. Preparation of 3-Chloro-2-fluorothioanisole

A solution of 10 g (grams) (76 mmol (milli- moles) ) of l-chloro-2-fluorobenzene in 75 mL (milli- liters) of dry tetrahydrofuran (THF) was cooled with a dry ice/acetone bath and 34 mL (84 mmol) of 2.5M butyl- -lithium was added dropwise under a nitrogen blanket over 45 min with stirring and cooling. The resulting solution was stirred for 2 hours at -78°C. A solution of 8.1 mL (91 mmol) of dimethyl disulfide in 10 mL of dry THF was added with stirring over a 30-min period keeping the temperature below -65°C. The mixture was allowed to warm to ambient temperature for 1 hour. It was then diluted with 75 mL of water. The resulting mixture was extracted with diethyl ether and the ether extract was dried over sodium sulfate and concentrated by evaporation under reduced pressure to obtain a yellow oil. This oil was purified by flash chromatography on 230-400 mesh silica gel eluting with a hexane/ethyl acetate mixture to obtain 9.0 g (69 percent of theory) of the title compound as a light yellow oil. Elemental Analysis C7H6CIFS

Calc: %C, 47.6; %H, 3.42; %S, 18.2 Found: %C, 47.5; %H, 3.32; %S, 18.2 lH NMR(CDCl3) : 7.12 (m, 3H) , 2.47 (s, 3H) . 2. Preparation of 4-Bromo-3-chloro-2-fluorothioanisole

A solution of 4.0 g (23 mmol) of 3-chloro-2- -fluorothioanisole in 50 mL of dichloromethane was prepared and a catalytic amount (0.15 g, 1.2 mmol) of ferric chloride and 1.5 mL (30 mmol) of bromine were added. The mixture was heated to 40°C with stirring for 2 hours. The solution was then cooled to ambient temperature and 20 mL of dilute aqueous sodium bisulfite was added. The mixture was stirred until the dichloromethane layer was colorless (15 min) . The organic phase was recovered and the aqueous phase was extracted with more dichloromethane. The organic phase and extract were combined and dried over sodium sulfate. The volatiles were removed by evaporation under reduced pressure to obtain 5.0 g (85 percent of theory) of the title compound as a tan oil . lH NMR(CDCl3) : 7.35(d, 1H, 7.2 Hz), 7.01(d, 1H, J=7.2

Hz) , 2.44 (s, 3H) .

3. Preparation of 4-Bromo-3-chloro-2-fluoromethyl- sulfonylbenzene

Hydrogen peroxide (4.0 mL of 30 percent) was added with stirring to a solution of 5.0 g (20 mmol) of 4-bromo-3 -chloro-2-fluorothioanisole in 50 mL of acetic acid. The mixture was heated at 50 °C for 3 hours and then cooled to ambient temperature. Most of the acetic acid was removed by evaporation under reduced pressure and the residue was diluted with water and extracted with dichloromethane. The extract was dried over sodium sulfate and concentrated by evaporation under reduced pressure to obtain 4.5 g (78 percent of theory) of the title compound as a white solid melting at 149°C. Elemental Analysis C7HsBrClFθ2S

Calc: %C, 29.2; %H, 1.75; %S, 11.1 Found: %C, 29.3; %H, 1.83; %S, 11.2 lH NMR(CDCl3) : 7.7 (m, 2H) , 3.23 (s, 3H) . 4. Preparation of 2-Chloro-3-fluoro-4 -methylsulfonyl- benzoic Acid

A solution of 23 g (80 mmol) of 4-bromo-3- -chloro-2-fluoromethylsulfonyl benzene in 100 mL of methanol was placed in a 300 mL stirred Parr bomb reactor and nitrogen was bubbled through the solution for 15 min. Triethylamine (28 mL, 200 mmol) , palladium (II) acetate (0.90 g, 4.0 mmol), and 1, 4 -bis (diphenylphosphino) butane (3.4 g, 8.0 mmol) were then added and the bomb was sealed. The sealed bomb was charged with 300 psig

(21,700 kiloPascals) of carbon monoxide and heated to 95 °C for 15 hours. The resulting solution was concentrated by evaporation under reduced pressure to remove the volatiles and the resulting slurry was diluted with 150 mL of 2N aqueous sodium hydroxide and stirred for 2 hr. The homogenous aqueous solution obtained was washed with dichloromethane and acidified with 2N aqueous hydrochloric acid. The resulting solution was extracted with ethyl acetate and the extract was dried over sodium sulfate and concentrated by evaporation under reduced pressure to obtain 10 g (63 percent of theory) of the title compound as a white solid melting at 204°C. Elemental Analysis C8H6CIFO4S

Calc: %C, 38.0; %H, 2.39; %S, 12.7 Found: %C, 38.3; %H, 2.50; %S, 12.3 lH NMR(CDCl3) : 3.43 (s, 3H) 7.88 (m, 2H) .

5. Preparation of 2.3-Difluoro-4 -methylsulfonylbenzoic Acid

A 2.5M solution of butyllithium in hexane (4.5 mL, 11 mmol) was added dropwise with stirring to a solution of 1.00 mL (10.2 mmol) of 1 , 2-difluorobenzene in 10 mL of dry tetrahydrofuran cooled to -70°C under a nitrogen atmosphere. After 10 min, 0.80 mL (11 mmol) of dimethyl sulfide was added dropwise with stirring. Another 11 mmol of 2.5M butyllithium was then added and, after 10 min, the reaction mixture was quenched by bubbling a stream of dry carbon dioxide into the solution. The resulting mixture was diluted with water and the mixture was washed with ether and then acidified with IN aqueous hydrochloric acid. The resulting heavy, white precipitate was recrystallized from a mixture of ethyl acetate and heptane to obtain 0.65 g (31 percent of theory) of the title compound as a white solid melting at

214-215°C. Elemental Analysis C8H6F2O2S

Calc. %C, 47.1; %H, 2.96 Found %C, 47.1; %H, 3.07 iH NMR(DMSO-de) 7.65(m, IH) , 7.22(m, IH) , 2.57(s, 3H)

6. Preparation of 3 -Dimethylamino-2 -methyl -4 -methyl - sulfonylbenzoic Acid

Sodium borohydride (1.4 g, 36 mmol) was carefully added to a suspension of 1.53 g (6.30 mmol) of 3-methylamino-2-methyl-4-methylsulfonylbenzoic acid and 1.8 g (60 mmol) of paraformaldehyde in 75 mL of dry tetrahydrofuran under a nitrogen atmosphere. A 30 mL aliquot of trifluoroacetic acid was then added dropwise over 1 hour. Gas evolution was vigorous at first, but then subsided as the grey-white suspension was allowed to stir at room temperature. After 8 hours, the reaction was found to be complete by high pressure liquid chromatographic analysis (HPLC) . The mixture was poured into 90 mL of a 25 percent aqueous sodium hydroxide solution containing ice, diluted with water and washed with ethyl acetate. The aqueous solution was then acidified with concentrated aqueous hydrochloric acid and the resulting mixture was extracted with ethyl acetate. The organic extract was mixed with dilute aqueous sodium bicarbonate solution and the aqueous phase was collected, acidified with IN aqueous hydrochloric acid, and extracted with ethyl acetate. The organic extract obtained was dried over sodium sulfate and concentrated by evaporation under reduced pressure. The resulting residue was purified by flash column chromatography on silica gel, eluting with a 1:1 mixture of ethyl acetate and petroleum ether containing 1 percent acetic acid, to obtain 1.49 g (92 percent of theory) of the title compound as a yellow syrup which solidified on standing and melted at 113-114°C. Elemental Analysis C11H15O4S Calc: %C, 51.4; %H, 5.88; %N, 5.44

Found: %C, 51.0; %H, 6.39; %N, 5.36 iH NMR(CDCl3) : 8.00(d, IH, J=8.4 Hz), 7.92 (d, IH, J=8.4

Hz), 3.29(s, 3H) , 3.10(s, 6H) , 2.59(s, 3H) .

7. Preparation of 2-Chloro-3- (2 -methoxyethylamino) -4- -methylsulfonylbenzoic Acid

A solution of 5.0 g (19 mmol) of 2 , 3-dichloro- -4 -methylsulfonylbenzoic acid in 50 mL of 60 percent aqueous 2-methoxyethylamine was heated at reflux with stirring for 4 days. The dark mixture was then acidified with aqueous hydrochloric acid and extracted with dichloromethane. The extract was dried over magnesium sulfate and concentrated by evaporation under reduced pressure to obtain 8 g of the title compound as an impure dark oil. A 5.7 g portion of the this was converted to the methyl ester by refluxing overnight in 100 mL of a

50:1 mixture of methanol and concentrated sulfuric acid. The volatiles were removed by evaporation under reduced pressure and the residue obtained was partitioned between diethyl ether and water. The ethereal phase was dried over magnesium sulfate and concentrated by evaporation under reduced pressure. The residue was purified by flash column chromatography eluting with a mixture of ethyl acetate and hexane . The product fractions were then hydrolyzed by heating with stirring in 70 mL of a 5:2 mixture of methanol and IN aqueous sodium hydroxide solution. The methanol was removed by evaporation under reduced pressure. The aqueous residue was washed with diethyl ether, acidified with concentrated hydrochloric acid and extracted with dichloromethane. The dichloro- methane extract was dried over magnesium sulfate and concentrated by evaporation under reduced pressure to obtain 2.8 g the title compound as a light green solid. iH NMR(CDCl3) : 8.75 (bs, IH) , 7.91 (d, IH, J=8.2 Hz),

7.40(d, IH, J=8.2 Hz), 3.65(m, 4H) , 3.41(s, 3H) , 3.24(s, 3H) .

8. Preparation of 2-Chloro-3- (3-methylpiperidin-l-yl) -4- -methylsulfonylbenzoic Acid

A solution of 3.0 g (12 mmol) of 2-chloro-3- -fluoro-4 -methylsulfonylbenzoic acid in 15 mL of 3-methylpiperidine was heated at 70 °C with stirring for 6 days. The reaction mixture was diluted with aqueous hydrochloric acid and extracted with dichloromethane. The organic extract was dried over magnesium sulfate and the solvent was removed by concentration under reduced pressure. The residue obtained was crystallized from acetonitrile to obtain 2.4 g (60 percent of theory) of the title compound as a solid. iH NMR(CDCl3) : 8.08 (d, IH, J=9 Hz) 7.76(d, IH, J=9 Hz),

3.52(m, IH) , 3.35(s, IH) , 3.20(m, IH) , 2.90(m, 2H) , 1.80(m, 4H) , 1.05(m, IH) , 0.85(d, 3H, J=5 Hz).

9. Preparation of 2-Chloro-4-methylsulfonyl-3- (pyrazol- -1-yl) benzoic Acid

Pyrazole (210 mg, 3.09 mmol) was added to 190 mg (4.75 mmol) of 60 percent oil dispersed sodium hydride suspended in 7 mL of dry dimethylformamide . After the gas evolution had subsided, 500 mg (1.98 mmol) of 2-chloro-3-fluoro-4 -methylsulfonylbenzoic acid was added and the mixture was stirred at 50°C overnight. The mixture was then concentrated by evaporation under reduced pressure and the residue was partitioned between ethyl acetate and IN aqueous hydrochloric acid. The aqueous phase was extracted with ethyl acetate. The organic phases were combined and extracted with dilute aqueous sodium bicarbonate solution. The aqueous extract was acidified with IN aqueous hydrochloric acid and extracted with dichloromethane. The organic extract was concentrated by evaporation under reduced pressure. The crystalline residue obtained was purified by rinsing with ethyl acetate to obtain 540 mg (91 percent of theory) of the title compound as a white powder. Elemental Analysis C11H9CIN2O4S

Calc: %C, 43.9; %H, 3.02; %N, 9.32 Found: %C, 43.9; %H, 2.97; %N, 9.18 iH NMR(CDCl3) : 8.16(d, IH, J=8.2 Hz), 8.08(d, IH, J=8.2

Hz), 7.82(d, IH, J=2.0 Hz), 7.71(d, IH, J=2.5 Hz), 6.57(dd, IH, J=2.0 & 2.5 Hz), 3.02(s, 3H) .

10. Preparation of 2-Chloro-3- (4-methoxypiperidin-l-yl) -4- -methylsulfonylbenzoic Acid 2-Chloro-3- (4-hydroxypiperidin-l-yl) -4-methyl- sulfonylbenzoic acid (0.70 g, 2.1 mmol) was added with stirring to a suspension of 0.25 g (6.3 mmol) of sodium hydride in a mixture of 0.40 mL (6.4 mmol) of methyl iodide and 10 mL of dry tetrahydrofuran. The mixture was heated to reflux and stirred for 24 hr. The resulting mixture was treated with water, acidified with IN aqueous hydrochloric acid and extracted several times with dichloromethane. The organic layers were combined and dried over magnesium sulfate, the solvent was removed by concentration under reduced pressure, and the residue was rinsed with petroleum ether to obtain 0.70 g (96 percent of theory) of the title compound .

11. Preparation of 2- (2 -Chloro-3-dimethylamino-4 -methylsulfonylbenzoyl) cyclohexane-1.3 -dione (Compound 1) A solution of 0.63 g (2.4 mmol) of 2-chloro-3- -dimethylamino-4 -methylsulfonylbenzoic acid in 5 mL of thionyl chloride was heated at reflux with stirring for 1 hour. The volatiles were then removed by evaporation under reduced pressure and the residue was dissolved in a few mL of dichloromethane. The resulting solution was added with stirring to a solution of 0.32 g (2.9 mmol) of cyclohexane-1 , 3 -dione in 6 mL of a mixture of 4.5 mL of dichloromethane and 1.5 mL of triethylamine. After a few minutes, the reaction mixture was diluted with dichloromethane and the resulting solution was washed with dilute aqueous sodium hydroxide containing a little potassium carbonate, washed with water, and dried over sodium sulfate. The volatiles were removed by evaporation under reduced pressure and the residue obtained was dissolved in a few mL of ethyl acetate. The resulting solution was washed with dilute hydrochloric acid, dried over sodium sulfate, and concentrated by evaporation under reduced pressure. The residue obtained was purified by flash column chromatograpy on silica gel eluting with a mixture of ethyl acetate and hexane to obtain 0.62 of an intermediate ester as a yellow syrup. A 0.54 g (1.5 mmol) portion of this syrup was dissolved in a few mL of dry acetonitrile and excess triethylamine and a few grains of potassium cyanide were added. After 18 hours, the volatiles were removed by evaporation under reduced pressure. The residue obtained was dissolved in dichloromethane and the resulting solution was washed with dilute aqueous hydrochloric acid. It was then extracted with dilute aqueous sodium bicarbonate solution. The aqueous extract was acidified with aqueous hydrochloric acid and extracted with dichloromethane. The organic extract was dried over sodium sulfate and concentrated by evaporation under reduced pressure to obtain a yellow syrup. This syrup was crystallized from ethanol to obtain 0.32 g (56 percent of theory) of the title compound as light yellow crystals melting at

140-142°C.

Elemental Analysis C16H18CINO5S Calc: %C, 51.7; %H, 4.88; %N, 3.77

Found: %C, 51.5; %H, 4.80; %N, 3.76

The following compounds were prepared similarly: 2- (2-chloro-3- (N-methyl-N- (2-methoxyethyl) amino) -4-methyl - sulfonylbenzoyl) cyclohexane-1.3 -dione (Compound 2) , an orange, glassy solid;

!H NMR(CDCl3) : 8.03 (d, IH, J=8.4 Hz), 7.10 (d, IH, J=8.4

Hz), 3.60(m, 2H) , 3.50(m, IH) , 3.35(m, 3H) , 2.90(s, 3H) , 2.80(t, 2H, J=3.6 Hz), 2.40(t, 2H, J=3.6 Hz), 2.02(q, 2H, J=3.6 Hz); ¹³C NMR(CDCl3) 197.3, 196.1, 193.4, 148.4, 146.3, 142.5, 132.5, 128.0, 123.7, 113.7, 71.1, 58.6, 54.7, 43.3, 41.1, 37.7, 32.3, 19.1.

2- (2 -methyl -3 -dimethylamino-4 -methylsulfonylbenzoyl) - cyclohexane-1.3 -dione (Compound 3) , a white powder melting at 157-159°C; !H NMR(CDCl3) 7.90(d, IH, J=4.8 Hz), 7.00(d, IH, J=4.8

Hz), 3.25(s, 3H) , 2.90(s, 6H) , 2.80 (bt, 2H) , 2.45 (bt, 2H) , 2.05(q, 2H, J=3.6 Hz).

2- (2-chloro-3- (morpholin-4-yl) -4 -methylsulfonylbenzoyl) - -5 , 5 -dimethyleyelohexane-1 , 3 -dione (Compound 4), an off-white crystalline solid melting at 198-200°C; Elemental Analysis C16H18CI O5S

Calc: %C, 54.1; %H, 5.29; %N, 3.14 Found: %C, 54.4; %H, 5.44; %N, 3.17.

12. Evaluation of Postemergence Herbicidal Activity Seeds of the desired test plant species were

® planted in Grace-Sierra MetroMix 306 planting mixture, which typically has a pH of 6.0 to 6.8 and an organic matter content of about 30 percent, in plastic pots with a surface area of 64 square centimeters. When required to ensure good germination and healthy plants, a fungicide treatment and/or other chemical or physical treatment was applied. The plants were grown for 7-21 days in a greenhouse with an approximately 15 hr photo- period which was maintained at about 23-29°C during the day and 22-28°C during the night. Nutrients and water were added on a regular basis and supplemental lighting was provided with overhead metal halide 1000 Watt lamps as necessary. The plants were employed for testing when they reached the first or second true leaf stage.

A weighed amount, determined by the highest rate to be tested, of each test compound was placed in a 20 mL glass vial and was dissolved in 4 mL of a 97:3 v/v (volume/volume) mixture of acetone and dimethyl sulfoxide to obtain concentrated stock solutions. If the test compound did not dissolve readily, the mixture was warmed and/or sonicated. The concentrated stock solutions obtained were diluted with an aqueous mixture containing acetone, water, isopropyl alcohol, dimethyl sulfoxide, Atplus 411F crop oil concentrate, and Triton X-155 surfactant in a 48.5:39:10:1.5:1.0:0.02 v/v ratio to obtain spray solutions of known concentration. The solutions containing the highest concentration to be tested were prepared by diluting 2 mL aliquots of the stock solution with 13 mL of the mixture and lower concentrations were prepared by dilution of appropriate smaller portions of the stock solution. Approximately 1.5 mL aliquots of each solution of known concentration were sprayed evenly onto each of the test plant pots using a DeVilbiss atomizer driven by compressed air pressure of 2 to 4 psi (140 to 280 kiloPascals) to obtain thorough coverage of each plant . Control plants were sprayed in the same manner with the aqueous mixture. In this test an application rate of 1 ppm results in the application of approximately 1 g/Ha.

The treated plants and control plants were placed in a greenhouse as described above and watered by sub- irrigation to prevent wash-off of the test compounds. After 2 weeks the condition of the test plants as compared with that of the untreated plants was determined visually and scored on a scale of 0 to 100 percent where 0 corresponds to no injury and 100 corresponds to complete kill. Some of the compounds tested, application rates employed, plant species tested, and results follow: (Compound Number/Application rate (ppm) /Percent control on the species chickweed (Stellaria media), cocklebur (Xanthium strumarium) , lambsquarters (Chenopodium album) , pigweed (Amaranthus retroflexus) , velvetleaf (Abutilion theophrasti) , viola (Viola tricolor), wild buckwheat (Polygonum convolvulus), blackgrass (Alopecurus myosuroides) , barnyardgrass (Echinochloa crus-galli) , crabgrass (Digitaria sanguinalis) , giant foxtail (Setaria faberi) , and Rox orange sorghum (Sorghum bicolor) :

1/62.5/85, 80, --, 98, 83, 70, 75, 60, 95, 98, 78, 99; 2/31.2/65, 90, 100, 90, 95, 78, 60, 55, 95, 90, 78, 95; 3/31.2/90, 95, 100, 100, 95, 85, 70, 45, 95, 95, 20, 80; 4/31.2/78, 90, 90, 90, 78, 80, 60, 78, 90, 80, 70, 95.

13. Evaluation of Preemergence Herbicidal Activity

Seeds of the desired test plant species were planted in a soil matrix prepared by mixing a loam soil which was composed of about 43 percent silt, 19 percent clay, and 38 percent sand and had a pH of about 8.1 and an organic matter content of about 1.5 percent and sand in a 70 to 30 ratio. The soil matrix was contained in plastic pots with a surface area of 161 square centimeters. When required to ensure good germination and healthy plants, a fungicide treatment and/or other chemical or physical treatment was applied.

A weighed amount, determined by the highest rate to be tested, of each test compound was placed in a 20 mL glass vial and was dissolved in 8 mL of a 97:3 v/v (volume/volume) mixture of acetone and dimethyl sulfoxide to obtain concentrated stock solutions. If the test compound did not dissolve readily, the mixture was warmed and/or sonicated. The stock solutions obtained were diluted with a 99.9:0.1 mixture of water and Tween 155 surfactant to obtain application solutions of known concentration. The solutions containing the highest concentration to be tested were prepared by diluting 4 mL aliquots of the stock solution with 8.5 mL of the mixture and lower concentrations were prepared by dilution of appropriate smaller portions of the stock solution. A 2.5 mL aliquot of each solution of known concentration was sprayed evenly onto the soil of each seeded pot using a Cornwall 5.0 mL glass syringe fitted with a TeeJet TN-3 hollow cone nozzle to obtain thorough coverage of the soil in each pot. Control pots were sprayed in the same manner with the aqueous mixture. A highest application rate of 4.48 Kg/Ha is achieved when 50 mg of test compound is employed.

The treated pots and control pots were placed in a greenhouse with an approximately 15 hr photoperiod which was maintained at about 23-29°C during the day and 22-28°C during the night. Nutrients and water were added on a regular basis and supplemental lighting was provided with overhead metal halide 1000 Watt lamps as necessary. The water was added by top-irrigation. After 3 weeks the condition of the test plants that germinated and grew as compared with that of the untreated plants that germinated and grew was determined visually and scored on a scale of 0 to 100 percent where 0 corresponds to no injury and 100 corresponds to complete kill or no germination. Some of the compounds tested, application rates employed, plant species tested, and results follow: (Compound Number/Application rate (kg/ha) /Percent control on the species cocklebur (Xanthium strumarium) , lambs- quarters ( Chenopodium album) , morningglory ( Ipomoea hederacea) , pigweed {Amaranthus retroflexus) , velvetleaf (Abutilion theophrasti ) , blackgrass (Alopecurus myosuroides) , barnyardgrass (Echinochloa cms - gall i ) , crabgrass (Digi tari a sanguinalis) , giant foxtail ( Setaria faberi ) , Rox orange sorghum ( Sorghum bicolor) , and wild oats (Avena fatua) : 1/0.070/60, 100, 70, 100, 100, 30, 100, 70, 30, 50, 20; 2/0.14/100, 100, 78, 95, 100, 40, 100, 100, 50, 100, 55; 3/0.070/100, 100, 90, 100, 100, 20, 90, 45, 0, 20, 20; 4/0.14/45, 100, 50, 100, 100, 45, 20, 100, 20, 100, 45.

Claims

1. A benzoylcyclohexanedione compound of the formula :

wherein

X represents F, Cl , Br, C1-C4 alkyl, OCH3 , 0C2Hs_; CH2OCH3, or CH(CH3)OCH3;

Y represents CH3 , C2Hs, or CH(CH3)2; R' represents C1-C4 alkyl, C3-C4 alkenyl, or C3-C4 alkynyl ; n represents 0, 1, 2, or 3; and each R independently represents H or C1-C4 alkyl, C3-C4 alkenyl, or C3-C4 alkynyl (each optionally possessing up to two substituents selected from Cl, Br, CN, C1-C4 alkoxy, and C1-C3 fluoroalkoxy and up to three

F substituents) or benzyl (optionally possessing up to three ring substituents selected from F, Cl , Br, CN, CF3 , NO2, CH3, C2H5, OCH3, and OC2H5) ; with the proviso that both of R do not represent H; or

NR2 represents a 4- to 7-membered aliphatic nitrogen heterocyclic substituent optionally possessing 0 as a second ring heteroatom, optionally possessing one double bond, and optionally possessing up to three substituents selected from F, Cl , Br, CN, C1-C4 alkyl, C1-C3 fluoroalkyl, C1-C4 alkoxy, C1-C3 fluoroalkoxy, C1-C3 alkoxy- methyl, and phenyl (optionally possessing up to three ring substituents selected from F, Cl , Br, CN, CF3 , NO2 , CH₃, C₂H₅ OCH3, and OC₂H₅) ; or

NR2 represents a pyrrol -1-yl or pyrazol-1-yl moiety optionally possessing up to two substituents selected from F, Cl, Br, I, CN, CF3 , C1-C3 alkyl, and C1-C3 alkoxy; and the agriculturally acceptable salts thereof.

2. A compound according to Claim 1 wherein Y represents methyl .

3. A compound according to Claim 1 wherein X represents chloro or methyl .

4. A compound according to Claim 1 wherein n represents 0 or wherein n represents 2 and R' represents methyl located in the 5-position.

5. A compound according to Claim 1 wherein each R independently represents methyl, ethyl, or 2-methoxyethyl or wherein one of R represents hydrogen and the other represents methyl, ethyl, or 2 -methoxy- ethyl .

6. A compound according to Claim 1 wherein NR2 represents a 5- or 6-membered aliphatic nitrogen heterocyclic substituent optionally having one ring oxygen heteroatom and optionally substituted by one or two methyl or methoxy substituents.

7. A compound according to Claim 6 wherein NR2 represents morpholin-4-yl .

8. A composition comprising an herbicidally effective amount of a benzoylcyclohexanedione compound of any one of Claims 1 to sevenand the agriculturally acceptable salts thereof in admixture with an agriculturally acceptable adjuvant or carrier.

9. A method of controlling undesirable vegetation which comprises contacting the vegetation or the locus thereof with an herbicidally effective amount of a benzoylcyclohexanedione compound of any one of Claims 1 to 7.

10. A method according to Claim 9 wherein the undesirable vegetation is contacted in the presence of a corn, wheat, barley, or rice crop and is contacted postemergently .