WO1987004049A1 - N-substituted tetrahydrophthalimide herbicidal compounds and intermediates therefor - Google Patents

Abstract

A herbicidal compound of formula (I), where X is F, Cl or Br, Y is Cl, Br, CHF2O or CF3, R is alkyl of 1 to 6 carbon atoms or lower halo alkyl and R' is H or lower alkyl. Related compounds, including those in which have -SR or -NR2R in place of -OR.

Description

N-SUBSTITUTED TETRAHYDROPHTHALIMIDE HERBICIDAL COMPOUNDS AND INTERMEDIATES THEREFOR

The invention described in this application pertains to weed control in agriculture, horticulture, and other fields where there is a desire to control unwanted plant growth. More specifically, the present application describes certain herbicidal aryl tetrahydrophthalimides, compositions of them, methods of preparing them, and methods for preventing or destroying undesired plant growth by preemergence or post-emergence application of the herbicidal compositions to the locus where control is desired. The present compounds may be used to effectively control a variety of both grassy and broadleaf plant species. The present invention is particularly useful in agriculture; a number of the compounds described herein show a selectivity favorable to certain crops (e.g. soybeans, corn, rice, including paddy rice, and wheat on preemergence or postemergence treatment) at application levels which inhibit the growth or destroy the growth of a variety of weeds.

A particularly effective aspect of this invention relates to the herbicidal compound of the formula:

where X is F, Y is Cl, R' is H, Z is 0 and R is C₂H₅. X may also be Cl or Br; Y may also be Br or CHF₂O or CF₃.

Instead of ethyl, R may also be another alkyl of 1 to 6 carbon atoms (e.g., methyl, propyl, isopropyl, butyl or t-butyl) or lower haloalkyl (e.g., chloroethyl or fluoropropyl ) or it may be aryl (e.g., phenyl or methoxy or chloro-substituted phenyl); or aralkyl (e.g., benzyl); alkylcarbonyl (such as lower alkyi carbonyl, e.g., CH₃CO- or C₂H₅C(O)-); haloalkylcarbonyl (such as lower haloalkylcarbonyl, e.g., ClCH₂CO-, FCH₂CO- or ClCH₂CH₂CO-) ; alkoxy (or haloalkoxy) carbonylalkyl (e.g., in which the alkoxy and alkyi moieties are each of 1 to 6 carbon atoms, such as CH₃OC(O)CH₂- or C₂H₅OC(O)CH(CH₃)- or

ClCH₂OC(O)CH₂-; alkyi- (or haloalkyl- or aryl-) aminocarbonyl (e.g., CH₃NHCO-), carboxyalkyl, e.g., -CH₂C(O)OH; aryloxycarbonylalkyl, e.g.

aralkyloxycarbonylalkyl, e.g.,

aminocarbonylalkyl, e.g., NH₂C(O)CH₂-, lower alkylaminocarbonylalkyl, e.g., C₂H₅NHC(O)CH₂-, arylaminocarbonylalkyl , e.g.,

alkylsulfonylaminocarbonylalkyl, e.g., CH₃SO₂NHC(O)CH₂, arylsulfonylaminocarbonylalkyl, e.g.

Instead of being O, Z may also be S or S(O) or

S(O)₂, with R and R' being as described above. Z may also be NR² with R² being hydrogen, lower alkyi (e.g., of 1 to 6 carbon atoms such as methyl or butyl), lower alkoxy such as methoxy), aralkyloxy (e.g., benzyloxy), or R² taken with R may be a divalent radical such as alkylene (e.g., butylene), alkylenoxyalkylene (e.g., as in compound 32 of Table 1), carbonylalkylenoxy (e.g., as in compound

33). R and R' may be as described above.

Instead of H, R' may also be lower alkyi (e.g., of

1 to 6 carbon atoms such as methyl, ethyl, propyl or butyl). In this application any alkyi moiety (e.g. the alkyl moieties of an alkylaminocarbonylalkyl group) is preferably of 1 to 6 carbon atoms, more preferably of 1 to 3 carbon atoms.

In a broader aspect of the invention, it relates to herbicidal compounds of the formula

wherein Ar is a substituted phenyl radical having the group -CH(R')ZR in its 5-position (e.g. meta to the nitrogen of said formula), with the proviso that the compound is one whose Methoxy Analog or Propargyloxy Analog is a herbicide. The term "Methoxy Analog" is used here to designate a compound which is otherwise identical to said compound of Formula II except that it has a methoxy group instead of the -CH(R')ZR group of said compound of Formula II. The term "Propargyloxy Analog" is similarly used here for a compound which is otherwise identical to said compound of Formula II except that it has a propargyloxy group instead of the -CH(R')ZR group of said compound of Formula II. Preferably, "Ar" carries a substituent (i.e. other than H) at the 2-position or the 4-position of the phenyl radical, most preferably at both the 2- and 4-positions. Also, preferably R' is H and R is ethyl. Herbicidal aryl tetrahydrophthalimides are disclosed in U.S. Patents 4,292,070 (which described compounds having a 5-propargyloxy substitute on the phenyl group) and 4,431,822.

The compounds of this invention preferably have Methoxy Analogs and Propargyloxy Analogs of marked herbicidal properties. For instance, said Analogs of the preferred compounds show at least 50% kill of at least one of the following species of plants when applied under at least one of the following modes at the rate of 0.5 kg/ha, and more preferably show such kill of at least 50% when applied at the rate of 0.1 kg/ha: Species; velvetleaf (Abutilon theophrasti), green foxtail (Setaria viridis); Modes : preemergent, postemergent. Testing for such herbicidal activity may be carried out in the manner described below (under the heading "Herbicidal Activity").

Representative compounds of this invention are listed in Table 1 below.

The compounds of this invention may be prepared by the use of steps generally described in the literature or by methods analogous or similar thereto and within the skill of the art.

In Examples 1, 8, 9 and 10 below the starting material is a substituted benzyl bromide, e.g., of the formula

which is reacted with a nucleophile (e.g., an etherify-ing agent), to form, for instance, an intermediate

then nitrated to place an NO₂ group on the benzene ring, to form, for instance, an intermediate

and then reduced to convert the NO₂ group to an amino group to form, for instance an intermediate

and then reacted with tetrahydrophthalic anhydride to form the imide. The nitration may precede the reaction with the nucleophile; thus in Example 7 one may start with a substituted nitrotoluene, e.g., of the formula

and convert the nitro group to a (protected) amino group, e.g., forming an intermediate

then convert to the benzylhalide, such as benzyl bromide, e.g., forming

and then react with the nucleophile.

Example 2, in which R' is alkyi, illustrates a process in which there is formed a substituted benzaldehyde, e.g., of the formula

which is converted in known manner (e.g., in a series of reactions involving a Grignard reagent) to the corresponding secondary alcohol, e.g.,

Nitration of the. alcohol (under mild conditions, such as with HNO₃ in a solvent at a temperature of about -20 to 5°C) before the reaction with the nucleophile not only places an NO₂ group on the aromatic ring but also converts the alcoholic OH group to an -ONO₂ group, forming,

That -ONO₂ group may then be converted to, e.g., an OR group by reaction with a nucleophile such as a conventional etherifying agent, e.g., an alkali metal alkoxide.

The reaction of the amino compound with the tetrahydrophthalic anhydride to form the tetrahydrophthalimide can be carried out, for example, with or without a solvent (e.g. acetic acid, toluene, dioxane, methanol or water) at 60 to 200ºC.

Examples 3 to 6 illustrate a process in which the substituted benzaldehyde, e.g., of the formula

is nitrated and reduced to form the corresponding nitro alcohol,

and the amino alcohol, e.g.,

and in which the alcoholic hydroxyl is reacted, to form the desired final compound, after the imide-forming reaction with the tetrahydrophthalic anhydride.

EXAMPLE 1

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5- ETHOXYMETH YLPHENYL]-3,4,5,6-TETRAHYDROPHTHALIMIDE

Step A: Synthesis of 2-chloro-4-fluorobenzyl ethyl ether

Tetrahydrofuran (50 ml) was added to stirred sodium hydride (1.26 g, 0.0.53 mole) under a nitrogen atmosphere while being cooled in an ice-water bath. Absolute ethanol (5 ml) was then added dropwise and the reaction stirred until hydrogen evolution ceased. A solution of 2-chloro-4-fluorobenzyl bromide (10.62 g, 0.0475 mole) in tetrahydrofuran (10 ml) was then added to the reaction mixture. The reaction mixture was allowed to stir at ambient temperature overnight. Ethanol and tetrahydrofuran were removed under reduced pressure. The reaction mixture was diluted with diethyl ether (200 ml), washed with water (4 x 75 ml), dried (magnesium sulfate) and concentrated under reduced pressure to remove solvent. The residue was distilled at low pressure yielding 5.27 g of 2-chloro-4-fluorobenzyl ethyl ether, b.p.67-68ºC/10mmHg. The nmr spectrum was consistent with the proposed structure.

Step B: Synthesis of 4-chloro-5-ethoxymethyl-2-fluoronitrobenzene

To a cooled (-40°C) solution of fuming nitric acid (90%, 25 ml) was added dropwise 2-chloro-4-fluorobenzyl ethyl ether (2.5 g, 0.13 mole) at a rate which maintained the temperature at or below -49ºC. Th e reaction mixture was poured into ice (200 ml) and extracted with methylene chloride (7 x 40 ml). The extracts were combined, washed with water (2 x 40 ml), dried (magnesium sulfate) and was passed through a column of silica gel eluting with ethyl acetate: heptane (1:9). Appropriate fractions were combined and concentrated under reduced pressure, yielding 1.07 g of 4-chloro-5-ethoxymethyl-2-fluoronitrobenzene. The IR spectrum was consistent with the proposed structure.

Step C: Synthesis of 4-chloro-5-ethoxymethyl-2-fluoroaniline

A solution of 4-chloro-5-ethoxymethyl-2-fluoronitrotoluene (0.9 g, 0.0039 mole) in glacial acetic acid (50 ml) was added to a 250 ml Parr bottle containing platinum IV oxide (0.3 g) under a nitrogen atmosphere. The Parr bottle was placed on a Parr hydrogenation apparatus and charged with hydrogen. The reaction mixture was allowed to shake until hydrogen absorption ceased. The catalyst was removed by vacuum filtration. The 4-chloro-5-ethoxymethyl-2-fluoroaniline produced was used in the next step in acetic solution without being isolated.

Step D: Synthesis of N- [4-chloro-2-fluoro-5-ethoxymethylphenyl]-3,4,5,6-tetrahydrophthalimide Tetrahydrophthalic anhydride (0.58 g, 0.0039 mole), and 4-chloro-5-ethoxymethyl-2-fluoroaniline in glacial acetic acid from Step C was heated at

100 overnight. Acetic acid was removed under reduced pressure. The residue was dissolved in ethyl acetate (100 ml) and washed successively with a saturated aqueous solution of sodium bicarbonate (5 x 50 ml) and a 10% aqueous solution of hydrochloric acid. The dried (magnesium sulfate) organic layer was concentrated under reduced pressure. The residue was passed through a column of silica gel eluting with ethyl acetate: heptane (3:17). Appropriate fractions were combined and concentrated under reduced pressure yielding N-[4- (3:17). Appropriate fractions were combined and concentrated under reduced pressure yielding N-[4- chloro-2-fluoro-5-ethoxymethylphenyl]-3,4,5,6- tetrahydrophthalimide as an amber solid, m.p. 89- 91°C. The nmr spectrum was consistent for the proposed structure.

EXAMPLE 2

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5-(1-METHOXYETHYLPHENYL]-3,4,5,6-TETRAHYDROPHTHALIMIDE

Step A Synthesis of 2-chloro-4-fluorobenzal bromide

In a flask were placed 150 g (1.04 moles) of 2- chloro-4-fluorotoluene, 391 g (2.20 moles) of N- bromosuccinimide, 3 g (0.012 mole) of benzoyl peroxide, and 800 ml of carbon tetrachloride. This mixture was refluxed overnight and then filtered. The solvent was evaporated under reduced pressure, leaving a residue of impure 2-chloro-4-fluorobenzal bromide weighing 340 g.

Step B Synthesis of 2-chloro-4-fluorobenzaldehyde

In a flask were placed 30.25 g (0.100 mole) of 2- chloro-4-fluorobenzal bromide, 45 ml (1.2 mole) of formic acid, and

15 ml of concentrated hydrochloric acid. This mixture was heated at 100-105°C overnight. After cooling to room temperature, the reaction mixture was poured into 200 ml of an ice/water mixture which was then extracted twice with diethyl ether. The combined extracts were washed successively with a saturated, aqueous, sodium bicarbonate solution and water. After being dried over anhydrous magnesium sulfate, the extract was filtered, and the solvent was evaporated under reduced pressure, leaving 17 g of 2-chloro-4-fluorobenzaldehyde as a residue.

Step C Synthesis of 1-(2-chloro-4- fluorophenyl)ethanol

A solution of 5.25 g (0.033 mole) of 2-chloro-4-fluorobenzaldehyde in 100 ml of diethyl ether was cooled to 10°C, and 11.2 ml (0.033 mole) of a 2.95 M solution of methylmagnesium bromide in diethyl ether was added dropwise with stirring. The reaction mixture was warmed to 0ºC and was stirred for several hours. After warming to room temperature, the reaction mixture was poured into an ice/water mixture. The resulting mixture was extracted with methylene chloride. The solvent was evaporated from the extract under reduced pressure, and the residue was passed through a column of silica gel, eluting first with heptane and then with ethyl acetate/heptane (1/9). The appropriate fractions were combined, and the solvent was evaporated under reduced pressure, leaving 1.46 g of 1-(2-chloro-4-fluorophenyl)ethanol as an amber oil. The nmr and ir spectra were consistent with the proposed structure. This reaction was repeated on a larger scale to provide sufficient 1-(2-chloro-4-fluorophenyl)ethanol for Step D.

Step D Synthesis of 1-(2-chloro-4-fluoro-5-nitrophenyl)ethyl nitrate A solution of 176 ml of fuming nitric acid in 25 ml of 1,2-dichloroethane was cooled to -20ºC. To this solution was added dropwise a solution of 20 g (0.115 mole) of 1-(2-chloro-4-fluorophenyl)ethanol in 25 ml of 1,2-dichloroethane. During the addition which required 45 minutes, the reaction mixture temperature was maintained between -24°C and -20°C. Stirring was continued at this temperature for 15 minutes following completion of addition, and then 150 ml of methylene chloride was added to the reaction mixture. After warming slowly to 0°C, the reaction mixture was slowly poured into an ice/water mixture. The organic phase was separated from the aqueous phase, and the latter was extracted four times with 50 ml of methylene chloride. The organic phase and the extracts were combined and were washed successively twice with cold water and three times with a cold, aqueous solution of sodium bicarbonate. The organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure, yielding 26 g of 1-(2-chloro-4-fluoro-5-nitrophenyl)ethyl nitrate as a residue. The nmr and ir spectra were consistent with the proposed structure.

Step E Synthesis of 1-(2-chloro-4-fluoro-5- methylcarbonylaminophenyl)ethyl nitrate

In a Parr hydrogenation apparatus were placed 3.7 g (0.014 mole) of 1-(2-chloro-4-fluoro-5-nitrophenyl)ethyl nitrate, 0.35 g of platinum oxide catalyst, 35 ml of ethyl acetate, and 10 ml of acetic anhydride. The apparatus was pressurized with hydrogen, and the reaction was allowed to continue until the pressure ceased dropping. The reaction mixture was filtered, and the filtrate was concentrated under reduced pressure leaving a residue. This residue was mixed with 15 ml of water and 5 ml of 10% hydrochloric acid.

This mixture was stirred at room temperature for two hours. Following dilution with water, the mixture was extracted with methylene chloride. The extracts were combined and washed successively with water, 5% hydrochloric acid, and a saturated, aqueous solution of sodium bicarbonate. This solution was dried, filtered, and the solvent was evaporated under reduced pressure leaving a residue. This residue was passed through a column of silica gel, eluting first with ethyl acetate/heptane (1/4) and then with ethyl acetate/ heptane (1/1). The appropriate fractions were collected, and the solvent was evaporated under reduced pressure yielding 1.7 g of 1-(2-chloro-4-fluoro-5-methylcarbonylaminophenyl)ethyl nitrate as a white solid. The nmr and ir spectra were consistent with the proposed structure.

Step F Synthesis of N-[4-chloro-2-fluoro-5-(1- methoxyethyl)phenyl]acetamide

To a clear, colorless solution of 0.4 g (0.0015 mole) of 1-(2-chloro-4-fluoro-5-methylcarbonylaminophenyl)ethyl nitrate in 15 ml of absolute methanol was added dropwise 0.31 g (0.0015 mole) of a 25 weight percent solution of sodium methoxide in methanol. The reaction mixture turned pale yellow immediately and was stirred at room temperature for 2.5 hours. An additional 0.31 g (0.0015 mole) of the sodium methoxide solution was added, and stirring at room temperature continued for 18 hours. The mixture was heated at reflux for 2.5 hours and then was allowed to cool to room temperature. To the mixture was added 100 ml of diethyl ether, and this mixture was washed with water. The diethyl ether solution was dried, filtered, and the solvent was evaporated under reduced pressure, yielding 0.28 g of N-[4-chloro-2-fluoro-5-(1-methoxyethyl)phenyl]acetamide. The nmr and ir spectra were consistent with the proposed structure. This reaction was repeated to provide sufficient starting material for Step G.

Step G Synthesis of 4-chloro-2-fluoro-5-(1- methoxyethyl)aniline

A mixture of 0.6 g (0.0024 mole) of N- [4-chloro-2-fluoro-5-(1-methoxyethyl)phenyl]acetamide, 0.14 g (0.0025 mole) of potassium hydroxide, 10 ml of water, and 10 ml of methanol was heated at reflux for 24 hours. This mixture was cooled and diluted with 50 ml of water. The resulting mixture was extracted successively with methylene chloride and diethyl ether. The combined extracts were dried, filtered, and the solvent was evaporated under reduced pressure, leaving 0.58 g of 4-chloro-2-fluoro-5-(l-methoxyethyl)aniline as an oil. The nmr spectrum was consistent with the proposed structure.

Step H Synthesis of N- [4-chloro-2-fluoro-5- (1- methoxyethyl ) phenyl] -3 , 4 , 5 , 6- tetrahydrophthalimide A mixture of 0.58 g (0.0029 mole) of 4-chloro-2-fluoro-5-(1-methoxyethyl)aniiline, 0.82 g (0.0054 mole) of tetrahydrophthalic anhydride, and 15 ml of acetic acid was refluxed overnight. The acetic acid was then evaporated under reduced pressure, leaving a residue which was dissolved in diethyl ether. This solution was washed successively with water and an aqueous solution of sodium bicarbonate. The solution was dried, filtered, and the solvent was evaporated under reduced pressure leaving a residue. This residue was passed through a silica gel column, eluting with ethyl acetate/heptane (1/4). Appropriate fractions were combined, and the solvent was evaporated under reduced pressure, yielding 0.4 g of N-[4-chforo-2-fluoro-5-(1-methoxyethyl)phenyl]-3,4,5,6-tetrahydrophthalimide as a solid, m.p. 141-144ºc. The nmr and ir spectra were consistent with the proposed structure. Analysis for C₁₇H₁₇NClFO₃ Calc'd: C 60.45; H 5.07; N 4.15;

Found: C 60.29; H 5.11; N 3.94.

EXAMPLE 3

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5-(METHYLCARBONYLOXYMETHYL)PHENYL]-3,4,5,6- TETRAHYDROPHTHALIMIDE

Step A Synthesis of 2-chloro-4-fluoro-5- nitrobenzaldehyde

To 300 ml of 1,2-dichloroethane that had been cooled to 0°C was added 31.3 g (0.197 mole) of 2-chloro-4- fluorobenzaldehyde, prepared by the method of Example 2, Steps A and B. Subsequently, 19.96 g (0.197 mole) of potassium nitrate was added to the reaction mixture, and dropwise addition of 300 ml of concentrated sulfuric acid followed while maintaining the temperature between 0ºC and 5ºC. The reaction was complete after 80 minutes, and 750 ml of methylene chloride was added to the reaction mixture. The phases were separated, and the sulfuric acid phase was extracted three times with 150 ml of methylene chloride. The extracts were combined with the organic phase before being washed three times with 450 ml of water. The extracts were dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure, leaving an amber oil weighing 32.5 g as a residue. This oil was passed through a column of silica gel, eluting with ethyl acetate/heptane (1/4). The appropriate fractions were combined, and the solvent was evaporated under reduced pressure, leaving 26.0 g of 2-chloro-4-fluoro-5-nitrobenzaldehyde as an amber oil.

Step B Synthesis of 2-chloro-4-fluoro-5- nitrobenzyl alcohol

To a solution of 10.8 g (0.053 mole) of 2-chloro-4-fluoro-5-nitrobenzaldehyde in 100 ml of tetrahydrofuran was added 0.50 g (0.013 mole) of sodium borohydride portionwise. The reaction mixture was stirred for one hour after which dilute hydrochloric acid was added to destroy unreacted sodium borohydride. To this mixture was added 200 ml of methylene chloride, and the phases were separated. The organic phase was washed three times with water, dried over anhydrous magnesium sulfate, and filtered. The solvent was evaporated from the f iltrate under reduced pressure, leaving a residue weighing 10.7 g. This residue was combined with 1.67 g of a similar residue another run of the same reaction. The combined residues were passed through a silica gel column, eluting with ethyl acetate/heptane (1/4) to yield 7.7 g of

2-chloro-4-fluoro-5-nitrobenzyl alcohol as a yellow solid.

Step C Synthesis of 2-chloro-4-fluoro-5- aminobenzylalcohol

In a Parr hydrogenation apparatus were placed 6.5 g (0.032 mole) of 2-chloro-4-fluoro-5-nitrobenzyl alcohol, 0.3 g of platinum oxide catalyst, and 100 ml of glacial acetic acid. Hydrogenation required 1.5 hours after which the catalyst was removed by filtration and the solvent was evaporated under reduced pressure, leaving 5.42 g of 2-chloro-4-fluoro-5-aminobenzyl alcohol as a tan solid. The nmr and ir spectra were consistent with the proposed structure.

Step D Synthesis of N-[4-chloro-2-fluoro-5- (methylcarbonyloxymethyl)phenyl]-3,4,5,6- tetrahydrophthalimide

A mixture of 4.9 g (0.028 mole) of 2-chloro-4-fluoro-5-aminobenzyl alcohol, 4.25 g (0.028 mole) of tetrahydrophthalic anhydride, and 100 ml of tetrahydrofuran was refluxed overnight. The solvent was evaporated under reduced pressure, leaving a thick, black oil. To this residue was added 100 ml of acetic acid, and the mixture was heated at 100ºC for several hours. The solvent was evaporated under reduced pressure and was replaced with 200 ml of ethyl acetate. This solution was washed three times with 150 ml of a saturated, aqueous solution of sodium bicarbonate and three times with 150 ml of 10% hydrochloric acid. The solution was dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure, leaving 8.80 g of a viscous, black oil. This oil was passed through a column of silica gel, eluting with ethyl acetate/heptane (7/13). The appropriate fractions were combined, and the solvent was evaporated under reduced pressure, yielding 6.3 g of N- [4-chloro-2-fluoro-5-(methylcarbonyloxymethyl)phenyl]-3,4,5,6-tetrahydrophthalimide as a thick, amber oil. The nmr and ir spectra were consistent with the proposed structure.

Analysis for C₁₅H₁₃ClFNO₃ Calc'd: C 58.05; H 4.30; N

3.98;

Found: C 57.27; H 3.96; N 3.45.

EXAMPLE 4

SYNTHESIS OF N-(4-CHLORO-2-FLUORO-5-HYDROXYMETHYLPHENYL)-3,4,5,6-TETRAHYDROPHTHALIMIDE

In a flask were placed 3.5 g (0.0099 mole) of N-[4-chloro-2-fluoro-5-(methylcarbonyloxymethyl)phenyl]- 3,4,5,6-tetrahydrophthalimide, 105 drops of concentrated hydrochloric acid, and 250 ml of absolute methanol. This mixture was stirred for approximately four hours after which the solvent was evaporated under reduced pressure. The residue was dissolved in 600 ml of diethyl. ether. This solution was washed four times with 60 ml of water, dried over anhydrous magnesium sulfate, and filtered. The solvent was evaporated under reduced pressure, leaving an amber gum weighing 3.1 g as a residue. This residue was passed through a silica gel column, eluting with ethyl acetate/heptane (3/7). The appropriate fractions were combined, and the solvent was evaporated under reduced pressure, yielding 2.2 g of N-(4-chloro-2-fluoro-5-hydroxymethylphenyl)- 3,4,5,6-tetrahydrophthalimide as a yellow solid, m.p. 135-137ºC. The nmr and ir spectra were consistent with the proposed structure.

EXAMPLE 5

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5-(PHENYLAMINO -CARBON YLOXYMETHYL)PHENYL-3,4,5,6- TETRAHYDROPHTHALIMIDE

A mixture of 0.5 g (0.0016 mole) of N-(4-chloro-2- fluoro-5-hydroxymethylphenyl]-3,4,5,6- tetrahydrophthalimide, 0.66 g (0.0055 mole) of phenyl isocyanate, 0.73 g (0.0072 mole) of triethylamine, and 25 ml of methylene was stirred at room temperature overnight. Sufficient methanol was added to react with the excess phenyl isocyanate, and the reaction mixture was stirred for an additional 24 hours. The reaction mixture was diluted with ethyl acetate and was washed successively with water and 5% hydrochloric acid. The organic phase was dried, filtered, and the solvent was evaporated under reduced pressure. The residue was passed through a column of silica gel. The appropriate fractions were combined, and the solvent was evaporated under reduced pressure, leaving a white solid as a residue. This solid was recrystallized from ethyl acetate/heptane, yielding 0.29 g of N-[4-chloro-2-fluoro-5-(phenylaminocarbonyloxy)phenyl]-3,4,5,6-tetrahydrophthalimide as a white solid, m.p. 149-151ºC. The nmr and ir spectra were consistent with the proposed structure.

Analysis for C₂₂H₁₈ClFN₂O₄ Calc'd: C 61.62; H 4.23; N 6.53;

Found: C 63.49; H 4.11; N 7.72.

EXAMPLE 6

SYNTHESIS OF N-(4-CHLORO-2-FLUORO-5- PHENOXYMETHYL-PHENYL)-3,4,5,6- TETRAHYDROPHTHALIMIDE

Step A Synthesis of N-(4-chloro-2-fluoro-5-bromomethylphenyl)-3,4,5,6- tetrahydrophthalimide

To a stirred solution of 3.0 g (0.0097 mole) of N-(4-chloro-2-fluoro-5-hydroxymethylphenyl)-3,4,5,6-tetrahydrophthalimide, prepared by the method of Example 4, and 6.4 g (0.0194 mole) of carbon tetrabromide in 30 ml of diethyl ether was added portionwise 5.1 g (0.0194 mole) of triphenylphosphine. This mixture was stirred overnight and was then filtered to remove the solid which had formed, and the solvent was evaporated under reduced pressure. The residue was passed through a column of silica gel. Appropriate fractions were combined, and the solvent was evaporated yielding 1.1 g of N-(4-chloro-2-fluoro-5-bromomethylphenyl)-3,4,5,6-tetrahydrophthalimide as a white solid, m.p. 126-128ºC. The nmr and ir spectra were consistent with the proposed structure,

Step B Synthesis of N-(4-chloro-2-fluoro-5- phenoxymethylphenyl)-3,4,5,6- tetrahydrophthalimide

To a mixture of 0.6 g (0.0016 mole) of N-(4-chloro-2-fluoro-5-bromomethylρhenyl)-3,4,5,6-tetrahydrophthalimide and 0.22 g (0.0016 mole) of potassium carbonate in acetone was added 0.15 g (0.0016 mole) of phenol. The mixture was stirred overnight at room temperature and then was heated at 50ºC for approximately 24 hours. The reaction mixture was filtered, and the filter cake was washed with ethyl acetate. The filtrate was washed with water, dried, and the solvent was evaporated under reduced pressure, leaving a residue weighing 0.7 g. Preparative thin layer chromatography was used to separate the components of this residue, eluting with ethyl acetate/heptane (3/7). The product, 0.18 g of N-(4-chloro-2-fluoro-5-phenoxymethylphenyl)-3,4,5,6-tetrahydrophthalimide, was isolated as an oil. The nmr and ir were consistent with the proposed structure. EXAMPLE 7

SYNTHESIS OF N-(4-CHLORO-2-FLUORO-5- DIISOPROPYL AMINOMETHYLPHENYL)-3,4,5,6- TETRAHYDROPHTHALIMIDE

Step A Synthesis of 2-chloro-4-fluoro-5- nitrotoluene

To a mixture of 20.0 g (0.138 mole) of 2-chloro-4-fluorotoluene in 50 ml of 1,2-dichloroethane which had been cooled to 0°C was added 50 ml of concentrated sulfuric acid. While maintaining the temperature below 10°C, 14.0 g (0.138 mole) of potassium nitrate was added slowly to the mixture. After three hours the reaction mixture was poured into ice, and the resulting mixture was extracted with methylene chloride. The extract was dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure. The residue was passed through a silica gel column, eluting with heptane. Appropriate fractions were combined, and the solvent was evaporated under reduced pressure, yielding 13.0 g of 2-chloro-4-fluoro-5-nitrotoluene as a yellow solid. The nmr spectrum was consistent with the proposed structure.

Step B Synthesis of 2-chloro-4-fluoro-5- diacetylaminotoluene

In a Parr hydrogenator were placed 10 g (0.053 mole) of

2-chloro-4-fluoro-5-nitrotoluene, 0.39 g of platinum oxide catalyst, and 125 ml of ethyl acetate. The reaction vessel was pressurized with hydrogen. When the hydrogen pressure ceased dropping, the reaction mixture was stirred with magnesium sulfate and filtered. The solvent was evaporated under reduced pressure, and 100 ml of acetic anhydride was added to the residue. This mixture was heated overnight at 100°C and then cooled to room temperature. After being poured into 300 ml of ice and stirring overnight, the mixture was extracted with methylene chloride. The extract was washed successively with water, an aqueous solution of sodium bicarbonate, and water. The extract was then dried, filtered, and the solvent was evaporated under reduced pressure, leaving a residue weighing 11 g. This residue was passed through a column of silica gel, eluting with ethyl acetate/heptane (1/4). Appropriate fractions were combined, and the solvent was evaporated under reduced pressure, yielding 7.8 g of 2-chloro-4-fluoro-5-diacetylaminotoluene.

Step C Synthesis of 2-chloro-4-fluoro-5- diacetylaminobenzyl bromide.

A mixture of 7.8 g (0.032 mole) of 2-chloro-4-fluoro-5-diacetylaminotoluene, 6.2 g (0.035 mole) of N-bromosuccinimide, 0.5 g of benzoyl peroxide, and 200 ml of carbon tetrachloride was heated at reflux for two days. This mixture was filtered, and the filtrate was washed with water. The filtrate was dried, and the solvent was evaporated under reduced pressure. The residue was passed through a column of silica gel, eluting with ethyl acetate/heptane (1/4). Appropriate fractions were combined, and the solvent was evaporated under reduced pressure. yielding 0.82 g of 2-chloro-4-fluoro-5-diacetylaminobenzyl bromide. The nmr was consistent with the proposed structure.

Step D Synthesis of N,N-diisopropyl-2-chloro-4- fluoro-5-diacetylaminobenzylamine

A mixture of 0.82 g (0.0025 mole) of 2-chloro-4-fluoro-5-diacetylaminobenzyl bromide, 0.28 g (0.0028 mole) of diisopropylamine, 0.39 g (0.0028 mole) of potassium carbonate, and 25 ml of acetonitrile was heated at reflux overnight. The reaction mixture was diluted with ethyl acetate, and the resulting mixture was washed with water. After being dried, the solvent was evaporated under reduced pressure, yielding 0.82 g of N,N-diisopropyl-2-chloro-4-fluoro-5-diacetylaminobenzylamine.

Step E Synthesis of 4-chloro-2-fluoro-5- (diisopropylaminomethyl)aniline

A mixture of 0.72 g (0.0021 mole) of N,N-diisopropyl-2-chloro-4-fluoro-5-diacetylaminobenzylamine, 1 g (0.018 mole) of potassium hydroxide, 20 ml of methanol, and 5 ml of water was refluxed for six hours. After cooling to room temperature, the reaction mixture was diluted with diethyl ether and was washed with water. The aqueous washes were combined and extracted with methylene chloride. These extracts were combined with the diethyl ether solution. This mixture was dried, filtered, and the solvents were evaporated under reduced pressure, yielding 0.50 g of 4-chloro-2-fluoro-5-(diisopropylaminomethyl)aniline. The nmr and ir spectra were consistent with the proposed structure.

Step F Synthesis of N-[4-chloro-2-fluoro-5- (diisopropylaminomethyl)phenyl]-3,4,5,6- tetrahydrophthalimide

By the method of Example 2, Step H, 0.50 g (0.0020 mole) of 4-chloro-2-fluoro-5-(diisopropylaminomethyl)aniline and 0.85 g (0.0056 mole) of tetrahydrophthalic anhydride in 20 ml of acetic acid were reacted yielding 0.052 g of N-[4-chloro-2-fluoro-5-(diisopropylaminomethyl)phenyl]-3,4,5,6-tetrahydrophthalimide. The nmr and ir spectra were consistent with the proposed structure.

EXAMPLE 8

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5- [(4,4-DIMETHYL-3-OXOISOXAZOLIDIN-2-YL)- METHYL]PHENYL]-3,4,5,6-TETRAHYDROPHTHALIMIDE

Step A Synthesis of 2-chloro-4-fluorobenzyl bromide

By the method of Example 7, Step C, 141.4 g (0.978 mole) of 2-chloro-4-fluorotoluene, 175.8 g (0.978 mole) of N-bromosuccinimide, and 5.0 g of benzoyl peroxide in 15 liters of carbon tetrachloride were reacted, yielding 165 g of 2-chloro-4-fluorobenzyl bromide as a white solid.

Step B Synthesis of 2-[(2-chloro-4- fluorophenyl)methyl]-4,4-dimethyl-3- isoxazolidinone By the method of Example 6, Step B, 95.6 g (0.83 mole) of 4,4-dimethyl-3-isoxazolidinone, 186 g (0.83 mole) of

2-chloro-4-fluorobenzyl bromide, 114.7 g (0.83 mole) of potassium carbonate, and 2.2 g (0.008 mole) of 1,4,7,10,13,16-hexaoxacyclooctadecane were reacted at room temperature in 1500 ml of acetonitrile, yielding 230 g of impure 2-[(2-chloro-4-fluorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone. The nmr spectrum was consistent with the proposed structure.

Step C Synthesis of 2-[(2-chloro-4-fluoro-5- nitrophenyl)methyl]-4,4-dimethyl-3- isoxazolidinone

By the method of Example 3, Step A, 20 g (0.078 mole) of

2-[(2-chloro-4-fluorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone, 7.8 g (0.78 mole) of potassium nitrate, and 100 ml of concentrated sulfuric acid were reacted, yielding 12 g of 2-[(2-chloro-4-fluoro-5-nitrophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone as a light yellow solid. Passage through a column of silica gel was omitted since the product was crystalline. Purification was accomplished by recrystallization from ethyl acetate/hexane. This reaction was repeated, and the products were combined.

Step D Synthesis of 2-[(2-chloro-4-fluoro-5- aminophenyl)methyl]-4,4-dimethyl-3- isoxazolidinone By the method of Example 3, Step C, 16.0 g (0.052 mole) of 2-[(2-chloro-4-fluoro-5-nitrophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone was hydrogenated in the presence of 0.2 g of platinum oxide in 250 ml of ethanol, yielding 2-[(2-chloro-4-fluoro-5-aminoρhenyl)methyl]-4,4-dimethyl-3 -isoxazolidinone.

Step E Synthesis of N-[4-chloro-2-fluoro-5-[(4,4- dimethy1-3-oxoisoxazolidin-2- yl)methyl]phenyl]-3,4,5,6- tetrahydrophthalimide

By the method of Example 2, Step H, 3.0 g (0.011 mole) of 2-[(2-chloro-4-fluoro-5-aminophenyl)methyl-4,4-dimethyl-3-isoxazolidinone and 1.84 g (0.012 mole) of tetrahydrophthalic anhydride were reacted in 10 ml of acetic acid, yielding 3.0 g of N-[4-chloro-2-fluoro-5-[(4,4-dimethyl-3-oxoisoxazolidin-2-yl)methyl]phenyl]-3,4,5,6-tetrahydrophthalimide as a yellow solid, m.p. 136-138ºC. The nmr and ir spectra were consistent with the proposed structure. Analysis for C₂₀H₂₀ClFN₂O₄ Calc'd: C 59.04; H 4.96; N 6.89;

Found: C 59.18; H 4.70; N 6.66.

EXAMPLE 9

SYNTHESIS OF N-[4-CHLORO-2-FLUORO-5-(N-METHYL- N-METHYLSULFONYLAMINOMETHYL)PHENYL] - 3,4,5,6-TETRAHYDROPHTHALIMIDE

Step A Synthesis of N-methyl-N-(2-chloro-4- fluorophenyl)methylsulfonamide By the method of Example 6, Step B, 10.0 g (0.045 mole) of 2-chloro-4-fluorobenzyl bromide, prepared by the method of Example 8, Step A, 4.88 g (0.045 mole) of N-methylmethylsulfonamide, 6.18 g (0.045 mole) of potassium carbonate, and 0.50 g (0.0019 mole) of 1,4,7,10,13,16-hexaoxacyclooctadecane were reacted in 125 ml of acetonitrile. This mixture was refluxed overnight. The solid product, N-methyl-N- (2-chloro-4-fluorophenyl)methylsulfonamide, weighed

6.95 g, m.p. 88-90°C. The nmr and ir spectra were consistent with the proposed structure.

Step B Synthesis of N-methyl-N-(2-chloro-4- fluoro-5-nitrophenyl)methylsulfonamide

By the method of Example 2, Step D, 6.80 g (0.027 mole) of N-methyl-N-(2-chloro-4-fluorophenyl)methylsulfonamide and 75 ml of fuming nitric acid were reacted in 50 ml of 1,2-dichloroethane, yielding 2.42 g of N-methyl-N-(2-chloro-4-fluoro-5-nitrophenyl)methylsulfonamide as a white solid, m.p. 141-142º C. The nmr and ir spectra were consistent with the proposed structure.

Step C Synthesis of N-methyl-N-(2-chloro-4- fluoro-5-aminophenyl)methylsulfonamide

By the method of Example 3, Step C, 1.0 g (0.0034 mole) of N-methyl-N-(2-chloro-4-fluoro-5-nitrophenyl)methylsulfonamide was hydrogenated in the presence of 0.3 g of platinum oxide in 90 ml of glacial acetic acid, yielding 0.75 g of N-methyl-N-(2-chloro-4-fluoro-5-aminophenyl)methylsulfonamide as a yellow-tan solid, m.p. 108-109°C. The nmr spectrum was consistent with the proposed structure, Step D Synthesis of N- [4-chloro-2-fluoro-5- (N- methyl-N- methylsulfonylaminomethyl )phenyl] -3 , 4 , 5, 6- tetrahydrophthalimide

By the method of Example 2, Step H, 0.75 g (0.0021 mole) of N-methyl-N-(2-chloro-4-fluoro-5-aminophenyl)methylsulfonamide and 0.33 g (0.0021 mole) of tetrahydrophthalic anhydride were reacted in 100 ml of glacial acetic acid, yielding 0.15 g of

N-[4-chloro-2-fluoro-5-(N-methyl-N-methylsulfonylaminomethyl)phenyl]-3,4,5,6-tetrahydrophthalimide.

EXAMPLE 10

SYNTHESIS OF N-(4-BROMO-2-FLUORO-5-ETHOXYMETHYLPHENYL)3,4,5,6-TETRAHYDROPHTHALIMIDE

Step A Synthesis of 2-bromo-4-fluorobenzyl bromide

By the method of Example 7, Step C, 75 g (0.40 mole) of 2-bromo-4-fluorotoluene, 70.6 g (0.40 mole) of N-bromosuccinimide, and 2.5 g (0.03 mole) of benzyl peroxide were reacted in 450 ml of carbon tetrachloride, yielding 107.8 g of impure 2-bromo-4-fluorobenzyl bromide (68% assay).

Step B Synthesis of ethyl 2-bromo-4-fluorobenzyl ether

By the method of Example 1, Step A, 10.9 g (0.041 mole) of 2-bromo-4-fluorobenzyl bromide and 18.2 ml of a 21 % by weight solution of sod ium ethox ide in ethanol were reacted in 50 ml of tetrahydrof ur an , yielding 7. 18 g of ethyl 2-bromo-4-fluorobenzyl ether .

Step C Synthesis of ethyl 2-bromo-4-fluoro-5- nitrobenzyl ether

By the method of Example 2, Step D, 7.18 g (0.0308 mole) of ethyl 2-bromo-4-fluoro benzyl ether, 2 ml of fuming nitric acid, and 18 ml of concentrated sulfuric acid were reacted in 20 ml of 1,2-dichloroethane, yielding 3.11 g of ethyl 2-bromo-4-fluoro-5-nitrobenzyl ether.

Step D Synthesis of ethyl 2-bromo-4-fluoro-5- aminobenzyl ether

To a flask containing 50 ml of glacial acetic acid heated to 80°C was added 4 g (0.07 mole) of iron powder. This was followed by the dropwise addition of a solution of 2 g (0.007 mole) of ethyl 2-bromo-4-fluoro-5-nitrobenzyl ether in 60 ml of acetic acid while maintaining the temperature between 80°C and 85°C. After 30 minutes the reaction mixture was cooled to room temperature and was filtered. The solvent was evaporated under reduced pressure, and the residue was dissolved in 250 ml of diethyl ether. This solution was washed successively twice with 50 ml of water, once with 50 ml of a saturated, aqueous solution of sodium bicarbonate, and twice with 50 ml of water. The solution was dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure. yielding 1.51 g of ethyl 2-bromo-4-fluoro-5-aminobenzyl ether. An additional 0.1 g of product was obtained by extracting the water washes with diethyl ether.

Step E Synthesis of N-(4-bromo-2-fluoro-5-ethoxymethylphenyl)-3,4,5,6- tetrahydrophthalimide

By the method of Example 2, Step H, 1.61 g (0.00649 mole) of ethyl 2-bromo-4-fluoro-5-aminobenzyl ether and 1.08 g (0.0071 mole) of tetrahydrophthalic anhydride were reacted in 30 ml of glacial acetic acid, yielding 1.01 g of N-(4-bromo-2-fluoro-5-ethoxymethylphenyl)-3,4,5,6-tetrahydrophthalimide as a yellow solid, m.p. 104-106°C. The nmr and ir spectra were consistent with the proposed structure. Analysis for C₁₇H₁₇BrFNO₃ Calc'd: C 54.42; H 4.48; N

3.66;

Found: C 53.45; H 4.16; N 3.53

HERBICIDAL ACTIVITY The plant test species used in demonstrating the herbicidal activity of compounds of this invention include cotton (Gossypium hirsutum var. Stoneville), soybean (Glycine max var. Williams), field corn (Zea mays var. Agway 595S), wheat (Triticum aestivium var. Prodax), rice (Oryza sativa var. Labelle), field bindweed (Convolvulus arvensis) , morningglory ( Ipomea lacunosa or Ipomea hederacea) , velvetleaf (Abutilon theophrasti) , barnyardgrass (Echinochloa crus galli) , green foxtail (Setaria viridis) , johnsongrass ( Sorghum halepense) , and yellow nutsedge (Cyperus esculentus).

Seeds or tubers of the plant test species were planted in furrows in steam sterilized sandy loam soil contained in disposable fiber flats. A topping soil of equal portions of sand and sandy loam soil was placed uniformly on top of each flat to a depth of approximately 0.5 cm.

The flats for the preemergence test were watered, then drenched with the appropriate amount of a solution of the test compound in a 50/50 mixture of acetone and water containing a small amount (up to 0.5% v/v) of sorbitan monolaurate emulsifier/solubilizer. The concentration of the test compound in solution was varied to give a range of application rates, generally 8.0 kg/ha and submultiples thereof. The flats were placed in a greenhouse and watered regularly at the soil surface for 21 days at which time phytotoxicity data were recorded. The flats for the postemergence test were placed in a greenhouse and watered for 8-10 days, then the foliage of the emerged test plants was sprayed with a solution of the test compound in 50/50 acetone-water containing up to 0.5% sorbitan monolaurate. After spraying the foliage was kept dry for 24 hours, then watered regularly for 21 days, and phytotoxicity data recorded. Phytotoxicity data were taken either as percent kill or percent control. Percent control was determined by a method similar to the 0 to 100 rating system disclosed in "Research Methods in Weed Science," 2nd ed., B. Truelove, Ed.; Southern Weed Science Society; Auburn Unversity, Auburn, Alabama, 1977. The present rating system is as follows:

Herbicide Rating System

Rating Description

Percent of Main Crop Weed

Control Categories Description Description

0 No effect No crop reduction No weed control or injury

10 Slight discoloraVery poor weed tion or stuating control

20 Slight Some discoloraPoor weed effect tion, stunting or control stand loss

30 Crop injury more Poor to defipronounced but not cient weed lasting control

40 Moderate injury, Deficient weed crop usually control recovers

50 Moderate Crop injury more Deficient to effect lasting, recovery moderate weed control

60 Lasting crop Moderate weed injury no recovery control

70 Heavy injury and Control somestand loss what less than satisfactory

80 Severe Crop nearly desSatisfactory effect troyed a few to good weed survivors control

90 Only occasional Very good to live plants left excellent control

100 Complete Complete crop Complete weed effect destruction destruction Tests of the effectiveness of weed control of paddy rice were done in pots containing clay loam paddy soil under water maintained at a depth of 3 cm. In one test tubers of narrowleaf arrowhead (Sagittaria pymaea) and rhizomes of flatsedge (Cyperus serotinus) were planted in pots at depth of 2 cm and 0.5 cm respectively, rice seedlings of 2.2 leaf stage were transplanted in depth of 2 cm and 0 cm and a controlled amount of a 10% wp (wettable powder) formulation of the herbicidal compound in water was dropped into the water over the soil at 1 day and 11 days, respectively, after transplanting. In another test, seeds of various weed species (including barnyardgrass, Enchinochpa crus-galli ; small flower umbrellaplant, Cyperus difformis; bulrush, Scripus juncoides ; Japanese ducksalad, Monochoria vaginal is ; annual broadleaf weeds; and narrowleaf waterplantain, Alisma canaliculatium) were sown on the surface of the soil and the same (1 day and 11 day) herbicide applications were made. In tests of compound 1 (of Table 1 below) very high activity against weeds of wide spectrum were shown for both the 1 day and 11 day treatments at rates (e.g., .03 kg/ha) which gave little or no phytoxicity to rice transplanted at a depth of 2 cm. Herbicidal data at selected application rates are given for various compounds of the invention in the tables below. The test compounds are identified in the tables of herbicidal data below by numbers which correspond to those used above in those tables. "kg/ha" is kilograms per hectare.

For herbicidal application, the active compounds as above defined are formulated into herbicidal compositions by admixture in herbicidally effective amounts with adjuvants and carriers normally employed in the art for facilitating the dispersion of active ingre dients for the particular utility desired, recognizing the fact that the formulation and mode of application of a toxicant may affect the activity of the material in a given application. Thus, for agricultural use the present herbicidal compounds may be formulated as granules of relatively large particle size, as water-soluble or water-dispersible granules, as powdery dusts, as wettable powders, as emulsifiable concentrates, as solutions, or as any of several other known types of formulations, depending on the desired mode of application.

For preemergence application these herbicidal compositions are usually applied either as sprays, dusts, or granules in the areas in which suppression of vegetation is desired. For postemergence control of established plant growth, sprays or dusts are most commonly used. These formulations may contain as little as 0.5% to as much as 95% or more by weight of active ingredient. Dusts are free flowing admixtures of the active ingredient with finely divided solids such as talc, natural clays, kieselguhr, flours such as walnut shell and cottonseed flours, and other organic and inorganic solids which act as dispersants and carriers for the toxicant; these finely divided solids have an average particle size of less than about 50 microns. A typical dust formulation useful herein is one containing 1.0 part of the herbicidal compound and 99.0 parts of talc. Wettable powders, also useful formulations for both pre- and postemergence herbicides, are in the form of finely divided particles which disperse readily in water or other dispersant. The wettable powder is ultimately applied to the soil either as a dry dust or as an emulsion in water or other liquid. Typical carriers for wettable powders include Fuller's earth, kaolin clays, silicas, and other highly absorbent, readily wet inorganic diluents. Wettable powders normally are prepared to contain about 5-80% of active ingredient, depending on the absorbency of the carrier, and usually also contain a small amount of a wetting, dispersing or emulsifying agent to facilitate dispersion. For example, a useful wettable powder formulation contains 80.8 parts of the herbicidal compound, 17.9 parts of Palmetto clay, and 1.0 part of sodium lignosulfonate and 0.3 part of sulfonated aliphatic polyester as wetting agents. Frequently, additional wetting agent and/or oil will be added to the tank-mix for postemergence application to facilitate dispersion on the foliage and absorption by the plant. Other useful formulations for herbicidal applications are emulsifiable concentrates. Emulsifiable concentrates are homogeneous liquid or paste compositions dispersible in water or other dispersant, and may consist entirely of the herbicidal compound and a liquid or solid emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthas, isophorone, or other non-volatile organic solvent. For herbicidal application these concentrates are dispersed in water or other liquid carrier, and normally applied as a spray to the area to be treated. The percentage by weight of the essential active ingredient may vary according to the manner in which the composition is to be applied, but in general comprises 0.5 to 95% of active ingredient by weight of the herbicidal composition.

Typical wetting, dispersing, or emulsifying agents used in agricultural formulations include, for example, the alkyi and alkylaryl sulfonates and sulfates and their sodium salts, polyhydric alcohols, and other types of surface active agents, many of which are available in commerce. The surface active agent, when used, normally comprises 1% to 15% by weight of the herbicidal composition.

Other useful formulations for herbicidal applications include simple solutions of the active ingredient in a solvent in which it is completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene, or other organic solvents. Granular formulations, wherein the toxicant is carried on relatively coarse particles, are of particular utility for aerial distribution or for penetration of cover crop canopy. Pressurized sprays, typically aerosols wherein the active ingredient is dispersed in finely divided form as a result of vaporization of a low boiling dispersant solvent carrier, such as the

Freons, may also be used. Water-soluble or water-dispersible granules are also useful formulations for herbicidal application of the present compounds. Such granular formulations are free-flowing, non-dusty, and readily water-soluble or water-miscible. The soluble or dispersible granular formulations described in U.S. patent No. 3,920,442 are useful herein with the present herbicidal compounds, e.g. for paddy rice.

The active herbicidal compounds of this invention may be formulated and/or applied with insecticides, fungicides, nematicides, plant growth regulators, fertilizers, or other agricultural chemicals and may be used as effective soil sterilants as well as selective herbicides in agriculture. In applying an active compound of this invention, whether formulated alone or with other agricultural chemicals, an effective amount and concentration of the active compound is of course employed; the amount may be as low as, for example, 7 g/ha or lower. The active herbicidal compounds of this invention may be used in combination with other herbicides, e.g. they may be mixed with, say, an equal or larger amount of a known herbicide such as chloroacetanilide herbicides such as 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyϊ)acetamide (alachlor), 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl)acetamide (metolachlor), and N-chloroacetyl-N-(2,6-diethylphenyl)glycine (diethatyl-ethyl); benzothiadiazinone herbicides such as 3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4-(3H)-one-2,2-dioxide (bentazon) ; triazine herbicides such as 6-chloro-N-ethyl-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine), and 2- [4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino -2-methylpropanenitrile (cyanazine); dinitrolaniline herbicides such as 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzeneamine (trifluralin) ; and aryl urea herbicides such as N'-(3,4-dichlorophenyl)-N,N-di-methylurea (diuron) and N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea ( fluometuron). It is apparent that various modifications may be made in the formulation and application of the compounds of this invention without departing from the inventive concepts herein as defined in the claims.

TABLE 1

Gnpd.

No. X Y R¹ Z R R²

1 F Cl H O ethyl

2 F Cl H O methyl

3 F Cl H O n-propyl

4 F Cl H O isopropyl

5 F Cl H O n-butyl

6 F Cl H O CH₂CH₂F

7 F Br H O ethyl

8 Cl Cl H O ethyl

9 F Br H O isopropyl

10 F Cl CH₃ O ethyl

11 F Cl CH₃ O isopropyl

12 F Cl CH₃ O methyl

13 F CF₃ H O ethyl

14 Br CL H O ethyl

15 Cl CL H O CH₂C(O)OCH₃

16 F a. H O Ehenyl

17 F CL H O 4-methoxyjhenyl

18 F Cl H O C(O)CH₃

19 F a. H O C(O)NHC₆H₅

20 F CL H O CH₂C(O)OCH₃

21 F CL H O CH₂C(O)OC₂H₅

22 F CL H O CH₂C(O)OCH(CH₃)₂

23 F CL H O CH₂C(O)OC₄H₉

24 F Cl H S methyl

25 F Cl H S ethyl

26 F Cl H S(O) ethyl

27 F Cl H S(O)₂ ethyl

28 F Cl H NR² ethyl hydrogen

29 F Cl H NR² isopropyl isopropyl TABLE 1 (Oontinued)

Cmpd.

No. X Y R¹ Z R R²

30 F Cl H NR² S(O)₂CH₃ methyl

31 F Cl H NR² C(O)₂CH₃ methoxy

32 F Cl H NR² R-R²=-CH₂CH₂OCH₂CH₂-

33 F Cl H NR² R-R²=-C(O)C(CH₃)₂CH₂O-

34 F Cl CH₃ O ethyl

35 F Cl CH₃ O n-propyl

36 F Cl CH₃ O n-butyl

37 F Cl CH₃ O phenyl

38 F Cl CH₃ O benzyl 39 F Cl CH₃ S methyl

40 F Cl CH₃ S ethyl

41 F Cl CH₃ S phenyl

42 F Cl C₂H₅ O methyl

43 F Cl C₃H₇ O methyl

44 Cl Cl CH₃ O methyl

45 Cl Br CH₃ O methyl

46 F Br CH₃ O methyl

47 F Cl CH₃ NR² ethyl hydrogen

48 F Cl CH₃ NR² phenyl hydrogen

49 F Cl H NR² C(O)CH₃ hydrogen

50 F Cl H O CH₂C(O)OH

51 F Cl H O CH₂C(O)OC₆H₅

52 F Cl H O CH₂C(O)OCH₆H₅

53 F Cl H O CH₂C(O)NH₂

54 F Cl H O CH₂C(O)NHC₂H₅

55 F Cl H O CH₂C(O)NHCH(CH₃) ₂

56 F Cl H O CH₂C(O)NHC₆H₅

57 F Cl H O CH₂C(O)NHSO₂CH₃

58 F Cl H O CH₂C(O)NHSO₂C₆H₅ TABLE 1 (Continued)

Cmpd. No. X Y R¹ Z R R²

59 F Cl H O CH₂C(O)NHSO₂

60 F Cl H O CH₂C(O)NHSO₂ methoxy

61 F Br H O CH₂C(O)OCH₃

62 F Cl H S CH₂C(O)OCH₃

63 F Cl H NR² CH₂C(O)OCH₃ hydrogen

64 F Cl H S CH₂C(O)NHC₂H₅

65 F Cl H S CH₂C(O)NHSO₂CH₃

66 F CL H S CH₂C(O)NHC₆H₅

67 F Cl H S(O) CH₂C(O)OCH₃

68 F Cl H S(O)₂ CH₂C(O)OCH₃

69 F Cl H NR² C(O)C₂H₅ methoxy

70 F Cl H NR² C(O)C₃H₇ methoxy

71 F Cl H NR² C(O)CH₂Cl methoxy

72 F CL H NR² C(O)CHCl₂ methoxy

73 F Cl H NR² C(O)C(CH₃)₂CH₂Cl methoxy

74 F Cl H NR² C(O)CH₃ benzyloxy

75 F Br H NR² C(O)CH₃ methoxy

76 F CHF₂O H O ethyl

77 F Cl H O C(O)C₂H₅

78 F Cl H O C(O)CH₂Cl

79 F Cl H O C(O)CH₂F

80 F CL H O C(O)CH₂CH₂Cl

81 F Cl H O CH(CH₃)C(O)OC₂H₅

82 F Cl H O CH₂C(O)OCH₂CH₂Cl

83 F Cl H O C(O)NHCH₃

84 F Cl H O 2-chlorophenyl

85 F Cl H O 4-chloropheny TABLE 2

Compound M.P_. Elemental Analysis Empirical No. (ºC) C H N Formula

1 89-91 C 60.45 5.07 4.15 C₁₇H₁₇ClFNO₃ P 58.30 5.00 4.03

2 90-92 C 59.36 4.67 5.44 C_1SH₁₅ClFNO₃ F 58.92 4.42 4.40

3 Oil C 61.45 5.44 3.98 C₁₈H₁₉ClFNO₃

F 60.08 5.45 3.89

5 Oil C 62.38 5.79 3.83 C₁₉H₂₁ClFNO₃

F 62.19 5.63 3.76

6 107-108 C 57.39 4.53 3.94 C₁₇H₁₆ClF₂NO₃

F 56.11 4.61 3.88

7 104-106 C 54.42 4.48 3.66 C₁₇H₁₇BrFNO₃ F 53.45 4.16 3.53

8 116-118 C 57.64 4.84 3.95 C₁₇H₁₇Cl₂NO₃

57.35 4.95 4.10

12 1-144 C 60.45 5.07 4.15 C₁₇H₁₇ClFNO₃

F 60.29 5.11 3.94

16 Oil C₂₁H₁₇ClFNO₃

17 147-149 C₂₂H₁₉ClFNO₄ Compound M.P. Elemental Analysis Empirical

No. (°C) C H N Formula

18 Oil C 58.05 4.30 3.98 C₁₅H₁₃ClFNO₃

F 57.27 3.96 3.45

19 149-151 C 61.62 4.23 6.53 C₂₂H₁₈ClFN₂O₄

F 63.49 4.11 . 7.72

20 116-117 C₁₈H₁₇ClFNO ₅

21 78-30 C 57.65 4.84 3.54 C₁₉H₁₉ClFNO₅

F 57.22 4.68 3.53

22 Oil C₂₀H₂₁ClFNO₅

23 Oil C₂₁H₂₃ClFNO₅

29 Oil C₂₁H₂₆ClFN₂O ₂

30 Oil C₁₇H₁₈ClFN₂O₄S

33 136-138 C 59.04 4.96 6.89 C₂₀H₂₀ClFN₂O₄

F 59.18 4.70 6.66

Table 3

Preemergence Evaluation (% Control)

Compound No. 1 2 3

Rate (kg/ha) 1.0 1.0 0.5

Species

Cotton 60 30 50

Soybean 70 40 20

Field Corn 70 20 10

Rice 80 70 20

Wheat 80 80 40

Field Bindweed 100 100 100

Morningglory 100 80 100

Wild Mustard - - -

Velvetleaf 100 100 100

Barnyardgrass 100 100 95

Green Foxtail 100 95 100

Johnsongrass 100 100 95

Compound No. 5 6 7 12

Rate (kg/ha) 0.5 1.0 1.0 1.0

Species

Cotton 30 90 30 40

Soybean 20 70 70 50

Field Corn 10 60 60 40

Rice 20 80 50 50

Wheat 10 90 60 40

Field Bindweed 100 100 - -

Morningglory 90 100 100 90

Wild Mustard - - 100 100

Velvetleaf 95 100 100 100

Barnyardgrass 50 100 90 100

Green Foxtail 95 100 100 100

Johnsongrass 90 95 80 90

Compound No. 16 17 18 19

Rate (kg/ha) 0.5 1.0 1.0 1.0

Species

Cotton 0 10 60 0

Soybean 0 10 20 0

Field Corn 0 0 10 0

Rice 0 20 50 10

Wheat 0 20 50 0

Field Bindweed - - 95 30

Morningglory 10 30 60 0

Wild Mustard 30 80 - -

Velvetleaf 50 100 100 10

Barnyardgrass 0 50 50 10

Green Foxtail 40 50 20 30

Johnsongrass 0 40 70 0 Table 3

(Continued)

Compound No. 20 21 22 23

Rate (kg/ha) 1.0 0.5 1.0 1.0

Species

Cotton 0 0 10 10

Soybean 0 0 10 0

Field Corn 50 0 0 0

Rice 50 20 20 10

Wheat 20 0 0 0

Field Bindweed 95 60 - -

Morningglory 90 40 40 50

Wild Mustard - - 0 0

Velvetleaf 70 20 20 10

Barnyardgrass 20 20 10 0

Green Foxtail 20 0 0 0

Johnsongrass 30 30 0 0

Compound No. 30 33

Rate (kg/ha) 1.0 2.0

Species

Cotton 50 100

Soybean 20 100

Field Corn 40 50

Rice 40 70

Wheat 60 50

Field Bindweed - 100

Morningglory 70 100

Wild Mustard 100 -

Velvetleaf 100 100

Barnyardgrass 95 100

Green Foxtail 70 100

Johnsongrass 70 90

Table 4

Postemergence Evaluation (% Control)

Compound No. 1 2 3

Rate (kg/ha) 1.0 1.0 0.5

Species

Cotton 100 100 95

Soybean 100 90 100

Field Corn 50 50 70

Rice 80 90 80

Wheat 80 100 40

Field Bindweed 100 100 95

Morningglory 100 100 100

Wild Mustard - - -

Velvetleaf 100 100 100

Barnyardgrass 100 100 60

Green Foxtail 100 100 100

Johnsongrass 100 95 100

Compound No. 5 6 7 12

Rate (kg/ha) 0.5 1.0 1.0 1.0

Species

Cotton 100 100 100 100

Soybean 95 90 70 100

Field Corn 80 100 60 60

Rice 50 90 90 70

Wheat 40 100 70 90

Field Bindweed 100 100 - -

Morningglory 90 100 100 90

Wild Mustard - - 100 100

Velvetleaf 100 100 100 100

Barnyardgrass 60 95 90 80-

Green Foxtail 100 100 95 100

Johnsongrass 80 90 80 80

Compound No. 16 17 18 19

Rate (kg/ha) 0.5 1.0 1.0 1.0

Species

Cotton 100 100 100 40

Soybean 20 40 30 30

Field Corn 20 30 10 10

Rice 20 20 40 10

Wheat 20 30 50 20

Field Bindweed - - 95 20

Morningglory 60 50 100 50

Wild Mustard 80 20 - -

Velvetleaf 100 90 100 90

Barnyardgrass 10 30 20 30

Green Foxtail 80 20 30 70

Johnsongrass 50 10 20 20 Table 4

(Continued)

Compound No. 20 21 22 23

Rate (kg/ha) 1.0 0.5 1.0 1.0

Species

Cotton 100 100 100 100

Soybean 90 60 80 70

Field Corn 80 20 50 40

Rice 95 40 90 50

Wheat 100 100 95 80

Field Bindweed 100 100 - -

Morningglory 100 60 100 100

Wild Mustard - - 100 100

Velvetleaf 100 100 100 100

Barnyardgrass 70 90 70 90

Green Foxtail 90 100 90 100

Johnsongrass 100 50 50 60

Compound No. 29 30 33

Rate (kg/ha) 1.0 1.0 2.0

Species

Cotton 100 100 100

Soybean 50 80 90

Field Corn 40 30 100

Rice 40 50 90

Wheat 40 50 100

Field Bindweed - - 100

Morningglory 100 100 90

Wild Mustard 100 100 -

Velvetleaf 100 100 100

Barnyardgrass 70 40 100

Green Foxtail 95 80 100

Johnsongrass 80 30 100

Claims

Claims:

1. A herbicidal compound of the formula

where X is F, Cl or Br, Y is Cl, Br, CHF₂O or CF₃,

Z is O, S, S(O), S(O)₂ or NR², R is alkyl of 1 to 6 carbon atoms, lower halo alkyl, aryl, aralkyl, alkylcarbonyl, haloalkylcarbonyl ; alkoxy- or haloalkoxycarbonylalkyl ; alkyl-, haloalkyl- or aryl- aminocarbonyl, carboxyalkyl ; aryloxycarbonylalkyl, aralkyloxycarbonylalkyl, aminocarbonylalkyl, lower alkylaminocarbonylalkyl, arylaminocarbonylalkyl, alkylsulfonylaminocarbonylalkyl or arylsulfonylaminocarbonylalkyl, and R' is H or lower alkyl and R² is hydrogen, lower alkyl, lower alkoxy or aralkyloxy, or R² taken with R is alkylene, alkylenoxyalkylene or carbonylalkylenoxy.

2. Compound as in claim 1 in which Z is O.

3. Compound as in claim 1 in which Z is S, S(O) or S(O)₂.

4. Compound as in claim 1 in which Z is NR².

5. Compound as in claim 2 in which R is ethyl.

6. Herbicidal compound as in claim 5 in which X is F, Y is Cl, R' is H and R is ethyl.

7. Compound as in claim 3 in which X is F, Y is Cl or Br and R' is H.

8. Compound as in claim 4 in which X is F, Y is Cl or Br and R' is H.

9. An herbicidal composition containing an herbicidally effective amount of a compound of claim 1 in admixture with a suitable carrier.

10. An herbicidal composition containing an herbicidally effective amount of a compound of claim 9 in admixture with a suitable carrier.

11. A method of controlling weeds which comprises applying to the locus where control is desired an herbicidally effective amount of the composition of claim 9.

12. A method of controlling weeds which comprises applying to the locus where control is desired an herbicidally effective amount of the composition of claim 10.

13. The method of claim 12 wherein the locus where control is desired is planted with soybeans, corn, rice or wheat.

14. The method of claim 12 wherein the locus where control is desired is planted with soybeans.

15. The method of claim 12 wherein said locus is planted with paddy rice.

16. A compound of the formula

where X is F, Cl or Br , Y is Cl , Br , CHF₂O or CF₃, Z is O, S, S(O), S(O)₂ or NR², R is alkyl of 1 to 6 carbon atoms, lower halo alkyl, aryl, aralkyl, alkylcarbonyl, haloalkylcarbonyl ; alkoxy- or haloalkoxycarbonylalkyl; alkyl-, haloalkyl- or aryl- aminocarbonyl; carboxyalkyl , aryloxycarbonylalkyl, aralkyloxycarbonylalkyl, aminocarbonylalkyl, lower alkylaminocar bonylalkyl, arylaminocarbonylalkyl, alkylsufonylaminocarbonylalkyl or arylsulfonylaminocarbonylalkyl, and R' is H or lower alkyl and R² is hydrogen, lower alkyl, lower alkoxy or aralkyloxy or R² taken with R is alkylene, alkylenoxyalkylene or carbonylalkylenoxy.

17. A compound as in claim 16 in which X is F, Y is Cl, Z is O and R' is H.

18. A compound of the formula

where X is F, Cl or Br, Y is Cl, Br, CHF₂O or CF₃, Z is O, S, S(O), S(O)₂ or NR², R is alkyl of 1 to 6 carbon atoms, lower halo alkyl, aryl, aralkyl, alkylcarbonyl, haloalkylcarbonyl ; alkoxy- or haloalkoxycarbonylalkyl; alkyl-, haloalkyl- or aryl- aminocarbonyl, carboxyalkyl ; aryloxycarbonylalkyl, aralkyloxycarbonylalkyl, aminocarbonylalkyl, lower alkylaminocarbonylalkyl, arylaminocarbonylalkyl, alkylsufonylaminocarbonylalkyl or arylsulfonylaminocarbonylalkyl, and R¹ is H or lower alkyl and R² is hydrogen, lower alkyl, lower alkoxy or aralkyloxy, or R² taken with R is alkylene, alkylenoxyalkylene or carbonylalkylenoxy.

19. A compound as in claim 18 in which X is F, Y is Cl, Z is O and R' is H.

20. A compound of the formula

where X is F, Cl or Br and Y is Cl, Br, CHF₂O or CF₃.

21. A compound as in claim 20 in which X is F and Y is Cl.

22. A compound of the formula

where X is F, Cl or Br and Y is Cl, Br, CHF₂O or CF and R' is H or lower alkyl.

23. A compound as in claim 22 in which X is F, Y is Cl and R' is methyl.

24. A compound of the formula

where X is F, Cl or Br, Y is Cl, Br, CHF₂O or CF₃, Z is O, S, S(O), S(O)₂ or NR², R is alkyl of 1 to 6 carbon atoms, lower halo alkyl, aryl, aralkyl, alkylcarbonyl, haloalkylcarbonyl ; alkoxy- or haloalkoxycarbonylalkyl ; alkyl-, haloalkyl- or aryl- aminocarbonyl, carboxyalkyl; aryloxycarbonylalkyl, aralkyloxycarbonylalkyl, aminocarbonylalkyl, lower alkylaminocarbonylalkyl, arylaminocarbonylalkyl, alkylsufonylaminocarbonylalkyl or arylsulfonylaminocarbonylalkyl, and R' is H or lower alkyl and R² is hydrogen, lower alkyl, lower alkoxy or aralkyloxy, or R² taken with R is alkylene, alkylenoxyalkylene or carbonylalkylenoxy.

25. A compound as in claim 24 in which R' is methyl and R is alkyi.

26. Process for producing a compound of the formula

where X is F, Cl or Br, Y is Cl, Br, CHF₂ or CF₃, R is alkyl of 1 to 6 carbon atoms or lower halo alkyl and R' is H or lower alkyl, which comprises reacting tetrahydrophthalic anhydride with a compound of the formula