EP0231176A1

EP0231176A1 - HERBICIDAL 1-ARYL-$g(d)?2 -1,2,4-TRIAZOLIN-5-ONES

Info

Publication number: EP0231176A1
Application number: EP85904377A
Authority: EP
Inventors: George Theodoridis
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1985-08-08
Filing date: 1985-08-23
Publication date: 1987-08-12
Also published as: DK390385D0; PL255346A1; ES557223A1; AU4729685A; CA1262734C; WO1987000730A1; CA1245221A; ES546768A0; TR22222A; IL76199A0; ES8802035A1; BR8507256A

Abstract

Nouveaux composés d'aryltriazolinone de formule (I) dans laquelle R est un radical sélectionné dans le groupe constitué de méthyle, éthyle, 1-méthyléthyle, méthoxyméthyle, 2-méthoxyéthyle, 1-méthyl-2-méthoxyéthyle, 2-propényle, 2-propynyle, et 1-méthyl-2-propynyle, ayant une utilité herbicide contre une variété de mauvaises herbes herbues et latifoliées dans des applications de préémergence et de post-émergence et présentant une sélectivité favorable au coton dans des applications de préémergence.Novel aryltriazolinone compounds of formula (I) wherein R is a radical selected from the group consisting of methyl, ethyl, 1-methylethyl, methoxymethyl, 2-methoxyethyl, 1-methyl-2-methoxyethyl, 2-propenyl, 2- propynyl, and 1-methyl-2-propynyl, having herbicidal utility against a variety of grassy and broadleaf weeds in pre-emergence and post-emergence applications and exhibiting cotton-friendly selectivity in pre-emergence applications.

Description

HERBICIDAL 1-ARYL-Δ²-1,2,4-TRIAZOLIN-5-ONES

The invention described in this application pertains to weed control in agriculture, horticulture, or other fields where there is a desire to control unwanted plant growth. More specifically, the present application describes novel herbicidal 1-aryl-Δ²-1,2,4-triazolin-5-ones, herbicidal compositions containing the new compounds, methods for preparing the compounds, and methods for preventing or destroying undesired plant growth by preemergence or postemergence 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. Various herbicidal 1-aryl-Δ²-1,2,4-triazolin-5-ones are known in the art. U.S. Patent No.

4,318,731 and corresponding British Patent No.

2,056,971 disclose herbicidal aryltriazolinones of the formula

wherein R ¹ is alkyl, R² is hydrogen, alkyl, or alkenyl, and X is hydroxy, alkyl, alkoxy, alkoxyalkoxy, alkenyloxy, or alkyloxycarbonylalkyloxy.

British Patent No. 2,090,250, a continuationin-part of the above British patent, adds to the above genus compounds wherein R² is alkynyl, haloraethyl, or haloethyl, and X is alkoxy, alkenyloxy, alkynyloxy, alkoxyalkoxy, hydroxy, haloraethyloxy, or haloethyloxy.

European Patent Application Publication No.

55, 105 discloses a series of herbicidal aryltriazolinones of the formula

wherein R is alkyl, alkenyl, or cycloalkyl, X is chlorine or bromine, and Y is hydrogen or alkoxy.

Japanese Kokai 81-32,468 discloses herbicidal aryltriazolinones of the formula

R

wherein R is hydrogen, alkyl, or 2-propenyl, and R¹ is methyl or alkoxy.

South African Patent Application No. 78/3182 discloses herbicidal aryltriazolinones of the formula

wherein R_n is hydrogen or represents 1 to 4 same or different radicals selected from halogen, nitro, cyano, optionally halo-substituted alkyl, alkoxy, or alkylthio, and optionally substituted phenyl or phenoxy, and R¹ is alkyl, alkoxyalkyl, dialkoxyethyl, dialkylaminoethyl, or cycloalkyl.

U.S. Patent No. 4,315,767 discloses herbicidal bicyclic compounds of the following formula

wherein V is hydrogen, halogen, methyl, or alkoxy, X is hydrogen, halogen, cyano, methyl, methoxy, or nitro, Y is hydrogen, halogen, or methyl, m and n are 0 to 4 (m plus n is 2 to 4), Q is oxygen or sulfur, and Z is oxygen, S(O)_p , or NR wherein p is 0-2 and R ¹ is alkyl, provided that when m plus n is 2 or 4 then Y and X are other than hydrogen, and when Z is S(O)_P then n is 1 to 4.

Additional herbicidal bicyclic compounds based on the aryltriazolinone nucleus are disclosed in U.S. Patent No. 4,213,773 and have the following structural formula

wherein V is hydrogen, halogen, hydroxy, alkyl, or -OR¹; R¹ is optionally substituted alkyl, cycloalkyl, cycloalkylalkyl, optionally substituted alkenyl, alkynyl, optionally substituted benzyl, alkylarainocarbonyl, (alkyl) (methyl or methoxy)aminocarbonyl, acyl, alkoxycarbonyl, or -CHR ⁷R⁸ wherein R⁷ is hydrogen or alkyl and R⁸ is cyano, acetyl, hydroxycarbonyl, alkoxycarbonyl, hydroxymethyl, alkoxymethyl, alkylcarbonyloxymethyl, hydroxycarbonylethenyl, alkoxycarbonylethenyl, or a group -CO-NR¹¹R¹² wherein R¹¹ is hydrogen, alkyl, alkenyl, or alkoxy, and R ¹² is hydrogen or alkyl; X is halogen, cyano, methyl, methoxy, or nitro; Y is hydrogen, halogen, or methyl; Z is hydrogen or halogen; n is 3-5; m is 0-2; and Q is oxygen or sulfur, with certain provisos. A class of Δ²-1,2,4-triazolin-5-ones is disclosed as fungicides in U.S. 4,098,896. The disclosed genus has the formula

wherein R is alkyl, alkenyl, alkynyl, cycloalkyl, or optionally substituted phenyl or arylalkyl, R¹ is haloalkyl or haloalkenyl, and R² is optionally substituted alkyl, alkenyl, or alkynyl, or optionally substituted aryl, arylalkyl, or alkylaryl. The compounds of this invention are 1-[4- bromo-2-fluoro-5-(substituted)oxyphenyl]-3-methyl- 4-difluororaethy1- 2-1,2,4-triazolin-5-ones of the formula

wherein R is alkyl, alkenyl, alkynyl, alkoxyalkyl, or alkyl-S(O)_n-alkyl wherein n is 0 to 2.

The present compounds are named in accordance with the numbering system shown in formula I, for the ring atoms of the heterocycle which is the same as the numbering system used in U.S. 4,318,731, supra, for similar compounds.

A subgenus of this invention comprises the compounds of formula I in which R is selected from -CH₃, -C₂H₅, -CH(CH₃-)₂, -CH₂OCH₃, -CH₂CH₂OCH₃, -CH(CH₃)CH₂OCH₃, -CH₂CH=CH₂, -CH₂C≡CH, and -CH(CH₃)C≡CH.

The presence of a bromine atom at the C-4 position of the phenyl ring in formula I was found to generally give superior cotton selectivity in preemergence applications at application rates at which a variety of weeds are controlled. A preferred aspect of the invention comprises the compounds in which R is selected from -CH₃, -C₂H₅, -CH(CH₃)₂, -CH₂OCH₃, -CH₂CH₂OC ₃, -CH₂C=CH, and -CH(CH₃)C≡CH. In a preferred specific embodiment, R is selected from -CH₃, -CH₂OCH₃, and -CH₂C≡CH.

The present compounds, which have a fluorine atom at the C-2 position of the phenyl ring, in general have herbicidal properties far superior to those of the corresponding compounds having a chlorine atom at C-2 of the phenyl ring, and are highly active at low application rates against a variety of grassy and broadleaf weed species in both preemergence and postemergence applications.

The compounds of this invention. may be prepared by methods analogous to the methods described in the references above for similar compounds or by methods within the skill of the art. The disclosures: in the above references pertaining to methods of: preparation are incorporated herein by reference.

The compound of formula I in which R is hydrogen., is an important intermediate to the herbicidal compounds of formula I in which R is as defined above, as illustrated in Examples 2-7 below. Other compounds useful as intermediates are the compounds corresponding to formula I in which the -CHF₂. substituent is replaced with a hydrogen atom, as illustrated in Example 1H below.

Preparation of the present compounds is illustrated in the following examples. All temperatures shown are in degrees Celcius, and reduced pressures for concentration of liquid were produced by a vacuum pump.

EXAMPLE 1 PREPARATION OF 1-(4-BROMO-2-FLUORO-5¬

METHOXYPHENYD-3-METHYL-4-DIFLUOROMETHYLΔ²-1,2,4-TRIAZOLIN-5-ONE

Step A 2-Bromo-4-fluorophenyl methyl carbonate

A stirred solution of 561 g (5.0 moles) of 4-fluorophenol in 600 mL of dioxane was cooled in an ice-water bath and 831 g (5.2 moles) of bromine was added dropwise. The complete addition required 1.5 hours, during which the reaction mixture temperature was maintained at 14-25°C. Following the addition, the ice-water bath was removed, and the reaction mixture temperature rose to 35°C. The reaction mixture was stirred for two hours, then 600 mL of water, followed by 520 mL of 10.8N aqueous sodium hydroxide were added dropwise over 30 minutes and 1 hour respectively. Upon complete addition, the reaction mixture was cooled to 0-10°C, and 591 g (6.15 moles) of methyl chloroformate was added dropwise over four hours. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature and was stirred for 17 hours. After this time, 450 g of aqueous 50% sodium hydroxide was added to neutralize the reaction mixture. The resultant solid was collected by filtration, and the filter cake washed with two 500 mL portions of water. The solid was dried under reduced pressure to give 1211 g .of 2-bromo-4- fluorophenyl methyl carbonate; m.p. 75-78°C.

The nmr spectrum was consistent with the proposed structure.

Step B 2-Bromo-4-fluoro-5-nitrophenyl methyl carbonate

A rapidly stirred solution of 946 g (3.8 moles) of 2-bromo-4-fluorophenyl methyl carbonate in 1292 mL of sulfuric acid was cooled to 5-10°C, and 368 g (4.18 moles) of 70% nitric acid was added dropwise over two hours. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature and was stirred for two hours. The reaction mixture was poured into 5000 mL of ice water. Any material remaining in the reaction vessel was washed into the ice-water with 750 mL of water. The resultant solid was collected by filtration and washed with 1000 mL of water. The solid was dried with mild heat under reduced pressure to give 1031 g of 2-bromo-4-fluoro-5-nitro- phenyl methyl carbonate.

The nmr spectrum was consistent with the proposed structure.

Step C 2-Bromo-4-fluoro-5-nitrophenol

A stirred solution of 1031 g (3.5 moles) of 2-bromo-4-fluoro-5-nitrophenyl methyl carbonate in 3000 mL of 2.3N aqueous sodium hydroxide was heated to reflux and stirred for three hours. The hot reaction mixture was filtered through diatomaceous earth. Any material remaining in the reaction vessel was washed onto the filter cake with 1000 mL of water. The filtrate was cooled to 8-10°C, and 560 mL of concentrated hydrochloric acid was added, with stirring, over one hour. The resultant solid was collected by filtration. Any material remaining in the reaction vessel was washed onto the filter cake with 1000 mL of water. The dried filter cake was recrystallized from toluene to give, in two crops, 543 g of 2-bromo-4-fluoro-5- nitrophenol, m.p. 124-126°C.

The nmr spectra were consistent with the proposed structure.

Step D 4-Bromo-2-fluoro-5-methoxynitrobenzene

A stirred solution of 30.0 g (0.127 mole) of 2-bromo-4-fluoro-5-nitrophenol, 26.9 g (0.19 mole) of methyl iodide, and 26.3 g (0.19 mole) of potassium carbonate in 200 mL of acetone was heated at reflux for five hours. The reaction mixture was filtered, and the filtrate concentrated under reduced pressure to give a residue. The residue was dissolved in methylene chloride and passed through a column of silica gel. The eluate was concentrated under reduced pressure to give 30 g of 4-bromo-2-fluoro-5-methoxynitrobenzene; m.p. 74-76°C.

Step E 4-Bromo-2-fluoro-5-methoxyaniline

To a stirred solution of 30.0 g (0.12 mole) of 4-bromo-2-fluoro-5-methoxynitrobenzene in 200 mL of acetic acid was added 40 mL of water, followed by the portionwise addition of 30.0 g (0.54 mole) of iron filings during a 2.5 hour period. Upon complete addition, the reaction mixture was stirred at 25-35°C. for one hour. Diethyl ether, 200 mL, was added, and the reaction mixture was, filtered through a pad of diatomaceous earth. The filtrate was washed with 200 mL of water. The organic layer was separated and neutralized with solid sodium bicarbonate. The mixture was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to give a residual solid. The solid was recrystallized from petroleum ether to give 23.5 g of 4-bromo-2-fluoro-5-methoxyaniline; m.p. 60-62°C.

Step F Pyruvic acid, 4-bromo-2-fluoro-5-methoxyphenylhydrazone

Under a nitrogen atmosphere, a stirred solution of 23.5 g (0.107 mole) of 4-bromo-2-fluoro-5methoxyaniline in 150 mL of concentrated hydrochloric acid was cooled to -9°C, and a solution of 7.4 g (0.107 mole) of sodium nitrite in 40 mL of water was added dropwise over two hours. Upon complete addition, the reaction mixture was stirred at -9°C for 45 minutes, then a solution of 36.0 g (0.160 mole) of stannous chloride in 50 mL of concentrated hydrochloric acid was added dropwise over one hour. The reaction mixture temperature was maintained at -9 to 0°C throughout the addition. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature and was stirred for two hours. After this time, 100 mL of water was added to the reaction mixture, followed by the dropwise addition of a solution of 9.4 g (0.107 mole) of pyruvic acid in 100 mL of water. Upon complete addition, the reaction mixture was stirred for 30 minutes at ambient temperature. The reaction mixture was filtered to collect a solid. The solid was dried to give 23.5 g of pyruvic acid, 4-bromo-2-fluoro-5-methoxyphenylhydrazone; m.p. 156-158°C.

Step G 1-(4-Bromo-2-fluoro-5-methoxyphenyl)-3- methyl-Δ²-1,2,4-triazolin-5-one

A stirred solution of 22.7 g (0.074 mole) of pyruvic acid, 4-brorao-2-fluoro-5-methoxyphenylhydrazone, 20.5 g (0.074 mole) of diphenylphosphoryl azide, and 7.5 g (0.074 mole) of triethylamine in 150 mL of toluene was heated at reflux for four hours. The reaction mixture was cooled and diluted with diethyl ether. The mixture was extracted three times with aqueous 1 molar sodium hydroxide. The combined extracts were washed with diethyl ether and made acidic with concentrated hydrochloric acid. The resultant solid was collected by filtration and washed with water. The solid was dried to give 15.0 g of 1-(4-brorao-2- fluoro-5-methoxyphenyl)-3-raethy1-Δ²-1,2,4- triazolin-5-one.

The nmr spectrum was consistent with the proposed structure.

Step H 1-(4-Bromo-2-fluoro-5-methoxyphenyl)-3- methyl-4-difluoromethyl-Δ²-1,2,4- triazolin-5-one

A stirred solution of 15.0 g (0.050 mole) of

1-(4-bromo-2-fluoro-5-methoxyphenyl)-3-methyl- Δ²-1,2,4-triazolin-5-one, 5.6 g (0.10 mole) of potassium hydroxide, and 1.6 g (0.005 mole) of tetrabutylammonium bromide in 150 mL of tetrahydrofuran was saturated with gaseous chlorodifluoromethane. The reaction mixture was stirred at ambient temperature for 16 hours. An additional 2.9 g (0.052 mole) of potassium hydroxide was added, and the reaction mixture was again saturated with chlorodif luoromethane. Upon complete saturation, the reaction mixture was stirred for two hours, then diluted with diethyl ether. The mixture was washed with water, then with aqueous saturated sodium chloride. The organic layer was dried with sodium sulfate, filtered, and the filtrate concentrated under reduced pressure to give a residue. The residue was subjected to column chromatography on silica gel. Elution was accomplished with 2:1 methylene chloride:petroleum ether. The appropriate fractions were combined and concentrated under reduced pressure to give 4.2 g of 1-(4-bromo-2-fluoro-5-methoxyphenyl)-3-methyl- 4-difluoromethyl-Δ²-1,2,4-triazolin-5-one; m.p. 129-130°C.

The nmr and the ir spectra were consistent with the proposed structure. Analysis calc'd for C₁₁H₉BrF₃N₃O₂:

C37.52, H 2.58, N 11.93;

Found: C37.38, H 2.35, N 11.52.

EXAMPLE 2

PREPARATION OF 1-(4-BROMO-2-FLUORO-5-METHOXY-

METHOXYPHENYL)-3-METHYL-4-DIFLUOROMETHYL-Δ²- 1,2,4-TRlAZOLIN-5-ONE

Step A 1-( 4-Bromo-2-fluoro-5-hydroxyphenyl)-3- methyl-4-difluoromethy1-Δ²-1,2,4-tria- zolin-5-one

A stirred solution of 7.3 g (0.029 mole) of boron tribromide in 30 mL of methylene chloride was cooled to -40°C, and a solution of 3.0 g (0.009 mole) of 1-(4-bromo-2-fluoro-5-raethoxyphenyl)-3- methyl-4-difluoromethy1-Δ²-1,2,4-triazolin-5-one

(Example 1) in 25 mL of methylene chloride was added dropwise. The reaction mixture temperature was maintained at -40°C throughout the addition. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature and was stirred for 16 hours. The reaction mixture was poured into ice-water, and the mixture extracted with diethyl ether. The extract was dried with sodium sulfate, filtered, and the filtrate concentrated under reduced pressure to give a residue. The residue was dissolved in diethyl ether, and the solution was passed through a pad of silica gel. The eluate was concentrated under reduced pressure to give 2.9 g of 1-(4-bromo-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethy1-Δ²-1,2,4-triazolin-5-one.

The nmr and the ir spectra were consistent with the proposed structure. Step B 1-(4-Bromo-2-fluoro-5-methoxymethoxyphenyl)--3--methyl--4--d fluoromethyl-Δ²- 1,2,4-triazolin-5-one

To a stirred suspension of 0.15 g (0.003 mole) of sodium hydride (50% in mineral oil) in 10 mL of toluene was slowly added 1.1 g (0.003 mole) of

1-(4-bromo-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one. N,N-dimethylacetamide (1-2 mL) was added and the reaction mixture was stirred at ambient temperature until it became clear. The reaction mixture was cooled to 20°C, and 0.8 g (0.006 mole) of methoxymethyl bromide was added. Upon complete addition, the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was poured onto ice and allowed to stand for one hour. The organic layer was separated and dried with magnesium sulfate. The mixture was filtered, and the filtrate subjected to column chromatography on silica gel. Elution was accomplished with 4:1 methylene chloride:heptane. The appropriate fractions were combined and concentrated under reduced pressure to give 0.9 g of 1-(4-bromo-2-fluoro-5-methoxymethoxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one as an oil.

The nmr spectrum was consistent with the proposed structure. Analysis calc'd for C₁₂H₁₁BrF₃N₃O₃:

C 37.72, H 2.89, N 10.99; Found: C 38.32, H 2.86, N 10.91. EXAMPLE 3 PREPARATION OF 1-(4-BROMO-2-FLUORO-5-

PR0PARGYL0XYPHENYL)-3-METHYL-4-DIFLUORO¬

METHYL-Δ²-1,2,4-TRIAZOLIN- 5-ONE A stirred solution of 2.5 g (0.008 mole) of 1-(4-bromo-2-fluoro-5-hydroxvphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4- triazolin-5-one (prepared as in Step A, Example 2), 1.6 g (0.012 mole) of potassium carbonate, and 1.9 g (0.017 mole) of propargyl bromide in 30 mL of acetone was heated at reflux for 16 hours. The reaction mixture was cooled and concentrated under reduced pressure to give a residue. The residue was dissolved in methylene chloride and subjected to column chromatography on silica gel. Elution was accomplished using methylene chloride. The appropriate fractions were combined and concentrated under reduced pressure to give 2.3 g of 1-(4-bromo-2-fluoro-5- propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-

1,2,4-triazolin-5-one; m.p. 70-72°C.

The nmr spectrum was consistent with the proposed structure.

Analysis calc'd for C₁₃ H₉BrF₃N₃O₂:

C 41.51, H 2.41, N 11.17;

Found: C 41.33, H 2.19, N 11.35.

The following compounds were prepared from

1-(4-bromo-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4- triazolin-5-one (Example 2A) by an alkylation procedure analogous to that described above in either Example 2B or Example 3:

Example 4, 1-(4-BROMO-2-FLQORO-5-ETHOXY¬

PHENYL)-3-METHYL-4-DIFLU0R0METHYL-Δ²-1,2,4-TRIA¬

ZOLIN-5-0NE, m.p. 106-108°C. The ir and nmr spectra were consistent with the proposed structure,

Analysi s calc ' d f or C₁₂H_{1 1} BrF₃N3O₂ :

C 39. 36 , H 3. 03 , N 11. 48 ;

Found : C 39. 65 , H 2. 82 , N 11. 22.

Example 5, 1-[4-BROMO-2-FLUORO-5-(1-METHYLETHOXY) -PHENYL]-3-METHYL-4-DIFLU0R0METHYL-Δ²-

1,2,4-TRIAZ0LIN-5-ONE, obtained as an oil. The ir and nmr spectra were consistent with the proposed structure.

Analysis calc'd for C,₁₃H,₁₃BrF₃N₃O₂:

C 41.07, H 3.45, N 11.05; Found: C 41.03, H 3.19, N 10.93.

Example 6, 1-[4-BROMO-2-FLUORO-5-(1-METHYLPROPARGYLOXY)PHENYL ]-3-METHYL-4-DIFLUOROMETHYL-Δ²- 1,2,4-TRlAZOLIN-5-ONE, m.p. 80-82°C. The ir and nmr spectra were consistent with the proposed structure. Analysis calc'd for C₁₄H₁₁BrF₃N₃O₂:

C 43.10, H 2.84, N 10.76; Found: C 43.32, H 2.83, N 10.54.

Example 7, 1-[4-BROMO-2-FLUORO-5-(2-METHOXYETHOXY) PHENYL ]-3-METHYL-4-DIFLUOROMETHYL-Δ²- 1,2,4-TRIAZOLIN-5-ONE, m.p. 81-82°C. The ir and nmr spectra were consistent with the proposed structure. Analysis calc'd for C₁₃H₁₃BrF₃N₃O₃:

C 39.41, H 3.31, N 10.61; Found: C 39.25, H 3.08, N 10.31. 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), rice (Oryza sativa var. Labelle), wheat (Triticum aestivium var. Prodax), 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. The flats had been filled to a depth of about 6.5 cm with the soil. 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 tests were watered, then drenched with the appropriate amount of a solution of the test compound in a 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 submultiplies thereof. The flats were placed in a greenhouse and watered regularly at the soi l surface for 21 days at which time phytotoxicity data were recorded.

The flats for the postemergence tests were placed in a greenhouse and watered for 8-10 days, then the foilage of the emerged test plants was sprayed with a solution of the test compound in 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 as percent control. Percent control was determined by a method similar to the o to 100 rating system disclosed in "Research Methods in Weed Science," 2nd ed., B. Truelove, Ed.; Southern Weed Science Society; Auburn University, Auburn, Alabama, 1977. The present rating system is as follows: Herbicidal data are given for various compounds of the invention in Tables 1 and 2 below. The test compounds are identified in the tables by Example numbers. In the tables "kg/ha" is kilograms per hectare and "% C" is percent control.

*The compound number is the number of the Example in which the particular compound was prepared.

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 ingredients 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, watersoluble or water-dispersible granules, as powdery dusts , as wettable powders , as emulsif i able 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 to the areas in which suppression of vegetation is desired. For posteraergence 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 eraulsifiable 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 alkyl 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 dispersant 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. These soluble or dispersible granular formulations described in U.S. patent No. 3,920,442, incorporated herein by reference are useful herein with the present herbicidal compounds.

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 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-(methoxymethyl)acetamide (alachlor), 2-chloro-N-(2-ethyl-6-methylphenyl)- N-(2-raethoxy-1-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-ylamino- 2-methylpropanenitrile (cyanazine); dinitrolaniline herbicides such as 2,6-dinitro-N,N-dipropyl-4-(trifluoromethy1) benzeneamine (trifluralin); and aryl urea herbicides such as N'-(3,4-dichlorophenyl)-N,N-dimethylurea (diuron) and N,N-dimethyl-N'-3-(trifluoromethyl)phenylurea (fluometuron).

It is apparent that various modifications may be made in the formulation and application of the novel compounds of this invention, without departing from the inventive concepts herein, as-defined in the following claims.

Claims

Claims:

1. A compound of the formula

in which R is a radical selected from the group consisting of methyl, ethyl, 1-methylethyl, methoxymethyl, 2-methoxyethyl, 1-methyl-2-methoxyethyl, 2-propenyl, 2-propynyl, and 1-methyl2-propynyl.

2. The compound of claim 1 in which R is selected from the group consisting of methyl, ethyl, 1-methylethyl, methoxymethyl, 2-methoxyethyl, 2-propynyl, and 1-methyl-2-propynyl.

3. The compound of claim 2 in which R is selected from the group consisting of methyl, methoxymethyl, and 2-propynyl.

4. The compound of claim 2 in which R is methyl.

5. The compound of claim 2 in which R is ethyl.

6. The compound of claim 2 in which R is 1-methylethyl.

7. The compound of claim 2 in which R is methoxymethyl.

8. The compound of claim 2 in which R is 2-methoxyethyl.

9. The compound of claim 2 in which R is 2-propynyl.

10. The compound of claim 2 in which R is 1-methyl-2-propynyl.

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

12. A method for controlling undesired plant growth which comprises applying to the locus where control is desired an herbicidally effective amount of a composition of claim 11.

13. The method of claim 12 in which the composition is applied preemergently to the locus where control is desired and said locus is planted or to be planted with cotton.

14. A compound of the formula

in which R is a radical selected from the group consisting of methyl, ethyl, 1-methylethyl, methoxymethyl, 2-raethoxyethyl, 1-methyl-2-methoxyethyl, 2-propenyl, 2-propynyl, and 1-methyl2-propynyl.

15. The compound of claim 14 in which R is selected from the group consisting of methyl, ethyl, 1-methylethyl, methoxymethyl, 2-methoxyethyl, 2-propynyl, and 1-methyl-2-propynyl.

16. The compound of claim 15 in which R is selected from the group consisting of methyl, methoxymethyl, and 2-propynyl.

17. The compound of the formula

18. A process for producing a compound of the formula

in which R is a radical selected from 2-propynyl,

1-methylethyl, 1-methyl-2-propynyl, methoxymethyl,

2-propenyl, and 1-methyl-2-methoxyethyl, characterized by

(a) reacting the compound of the formula

with R-X, in which R is as defined above and X is a good leaving group, in the presence of a base, or alternatively,

(b) reacting a compound of the formula

in which R is as defined above, with CHF₂-X, in which X is a good leaving group, in the presence of a phase transfer catalyst and a base selected from sodium hydroxide and potassium hydroxide.

19. The process of claim 18 characterized in that X is a chlorine, bromine, or iodine atom.

20. The process of claim 19 characterized in that in method (a) the base is an alkali metal carbonate, an alkali metal bicarbonate, or an alkali metal hydride, and in method (b) the phase transfer catalyst is a tetraalkylammonium halide and the base is sodium hydroxide.

21. The process of claim 20 characterized in that in method (a) the base is sodium carbonate or potassium carbonate and in method (b) the phase transfer catalyst is a tetrabutylammonium halide or a (triethyl)(benzyl)ammonium halide in which halide is bromide or chloride.