WO1988009617A1

WO1988009617A1 - 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-4-difluoromethyl-delta2-1,2,4-triazolin-5-one as herbicidal agent

Info

Publication number: WO1988009617A1
Application number: PCT/US1987/001406
Authority: WO
Inventors: Lester Lawrence Maravetz; George Theodoridis
Original assignee: Fmc Corporation
Priority date: 1987-06-12
Filing date: 1987-06-12
Publication date: 1988-12-15

Abstract

The subject matter of the invention is the use of the compound of formula (I) as a herbicidal agent as well as herbicidal compositions containing the compound. Compound (I) is especially effective for preemergent use in fields to be planted with cotton.

Description

1- (4-CHLORO-2-FLUORO-5-METHOXYPHENYL. -3-METHYL-4- DIFLUOROMETHYL-Δ²-1.2.4-TRIAZOLIN-5-ONE AS HERBICIDAL AGENT

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 the use of l-(4-chloro-2-fluoro-5- methoxyphenyl)-3-methyl-4-difluoromethyl-Δ²-l,2,4- triazolin-5-one as a herbicidal agent, herbicidal compositions containing this compound, a method for preparing the compound, and methods for preventing or destroying undesired plant growth by preemergence or post-emergence application of the herbicidal composi¬ tions 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, as the herbicidal compound described herein shows a selectivity favorable to cotton or other crops at application levels which inhibit the growth of or destroy a variety of weeds.

Compounds of the formula

in which R is a radical selected from 2-propynyl, 1- methylethyl, l-methyl-2-propynyl, methoxymethyl, 2- propenyl, and l-methyl-2-methoxyethyl and herbicidal compositions containing these compounds are disclosed in EP-A-177553 (Application No. 85901703.0). In this document the compound l-(4-chloro-2-fluoro-5-methoxy- phenyl)-3-methyl-4-difluoromethyl-Δ²-l,2,4-triazolin-5- one, the compound of the formula I

is disclosed as an intermediate for the preparation of the above mentioned herbicidally active compounds. It has now surprisingly been found that the compound of the formula I, described in EP-A-177553 as an intermediate only has very interesting herbicidal properties as it shows a selectivity favorable to cotton in preemergence applications at rates at which a variety of weeds are controlled.

The compound which is used in this invention may be prepared as described in EP-A-177553. A method of preparation exemplified herein is illustrated in the following chemical equations.

CH₃

IV

5

Preparation of compound I is illustrated further in the following example. All temperatures shown are in degrees Celcius, and reduced pressures for concentration o of liquid were produced by a vacuum pump.

Example A. 4-Chloro-2-fluoro-5-methoxyphenylhydrazine

A stirred solution of 48.0 g (0.27 mole) of 4- chloro-2-fluoro-5-methoxyaniline in 50 mL of concen- trated hydrochloric acid was cooled to -5°C, and 23.5 g (0.34 mole) of sodium nitrite in 100 L of water was added dropwise. Upon complete addition, the reaction mixture was stirred at 0°C for one hour. A solution of 154.0 g (0.68 mole) of stannous chloride in 225 L of concentrated hydrochloric acid was cooled to 0°C, and the cold solution prepared above was slowly added to it. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature, then was filtered to collect a solid. The solid was made basic and extracted with toluene. The toluene layer was separated and dried over magnesium sulfate, then filtered. The filtrate was concentrated under reduced pressure to give 22.4 g of 4- chloro-2-fluoro-5-methoxyphenylhydrazine as a solid.

The nmr spectrum was consistent with the proposed structure. 5 B. Pyruvic acid, 4-chloro-2-fluoro-5-methoxyphenyl- hydrazone

A stirred solution of 21.0 g (0.11 mole) of 4- chloro-2-fluoro-5-methoxyphenylhydrazine and 100 L of aqueous 10% hydrochloric acid in 100 L of ethanol was

10 warmed to 40°C, and a solution of 10.0 g (0.114 mole) of pyruvic acid in 20 mL of water was added. Upon complete addition, the reaction mixture was stirred for one hour. An additional 50 mL of water was added, and the reaction mixture was filtered to collect a solid. The solid was

-.c air dried to give 29.0 g of pyruvic acid, 4-chloro-2- fluoro-5-methoxyphenylhydrazone; mp 166-169°C.

The nmr spectrum was consistent with the proposed structure. C. l-(4-Chloro-2-fluoro-5-methoxyphenyl)-3-methyl-Δ²-

20 l,2,4-triazolin-5-one.

A stirred solution of 27.0 g (0.104 mole) of pyruvic acid, 4-chloro-2-fluoro-5-methoxyphenylhydra- zone, 29.0 g (0.105 mole) of diphenylphosphoryl azide, and 11.0 g (0.108 mole) of triethylamine in 500 mL of

25 toluene was heated under reflux for four hours. The reaction mixture was cooled to ambient temperature and extracted with aqueous 10% sodium hydroxide. The aqueous layer was separated and neutralized with gaseous carbon dioxide, and a solid was collected by filtration. 0 The solid was air-dried to give 11.0 g of l-(4-chloro-2- fluoro-5-methoxyphenyl)-3-meth l-Δ -l,2, -triazolin-5- one; mp 193-195°C. _* z ." The nmr spectrum was consistent with the proposed structure. D. 1-(4-Chloro-2-fluoro-5-methoxyphenyl) -3-methyl-4- difluoromethyl-Δ -l,2,4-triazolin-5-one.

A stirred mixture of 10.0 g (0.039 mole) of l-(4- chloro-2-fluoro-5-methoxyphenyl) -3-methyl-Δ²-l,2,4- triazolin-5-one, 10.0 g ((0.031 mole) of tetrabutyl- ammonium bromide, and 10.0 g (0.25 mole of sodium hydroxide in 250 L of cyclohexane was warmed to 60°C, and 10.0 g (0.116 mole) of chlorodifluoro ethane was bubbled into the reaction mixture. Upon complete addition, the reaction mixture was warmed to reflux temperature and stirred for one hour. The hot solution was decanted from a pot residue and was allowed to cool to ambient temperature. Methylene chloride was added to the cooled mixture to dissolve a solid precipitate, and the whole was washed with aqueous 10% hydrochloric acid, then with aqueous 10% sodium hydroxide. The organic layer was separated and dried over magnesium sulfate, the filtered. The filtrate was concentrated under reduced pressure to give 5.0 g of 1-(4-chloro-2-fluoro- 5-methoxyphenyl) -3-methyl-4-difluoromethyl-Δ²-l,2, 4- triazolin-5-one; mp 86-88°C.

The nmr spectrum was consistent with the proposed structure.

Compound I was tested for herbicidal activity as a solution in a 50/50 mixture of acetone and water containing a small amount of sorbitan monolaurate. The test was carried out according to the procedure described in EP-A-177553 for the compounds of Examples 3-7. Phytotoxicity data were taken as 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 University,- Auburn, Alabama, 1977; see also EP-A-177553, page 25. Herbicidal data for compound I are given in the following table I:

Table I

Percent Control at 0.5 kg/ha

Preemercrence Postemerσence

Species Application Application

Cotton 0 60

Soybean 100 40

Field Corn 100 100

Rice 100 100

Wheat 100 100

Field Bindweed 95 100

Morningglory 100 100

Velvetleaf 100 100

Barnyardgrass 100 100

Green Foxtail 100 100

Johnsongrass 100 100

Yellow Nutsedge 100 90

From the data in table I it can be seen that compound I shows a surprising selectivity favorable to cotton in preemergence applications at rates at which a variety of weeds are controlled.

For herbicidal application, the active compound I is 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 formula¬ tion 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 - ° compound may be formulated as granules of relatively^" large^* particle size,- as water-soluble or water-disperεi- ble 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. These herbicidal compositions may be applied either as water-diluted sprays, or dusts, or granules in the areas in which suppression of vegetation is desired. These formulations may contain as little as 0.1%, 0.2% or 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 or less 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 5-90% 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. Other wettable powder formulations are: Component: % by Wt. Active ingredient 40. ,00 Sodium ligninsulfonate 20. ,00 Attapulgite clay 40. ,00 Total 100. ,00

Active ingredient 90. .00 Dioctyl sodium sulfosuccinate 0. .10 Synthetic fine silica 9. .90 Total 100. .00

Active ingredient 20, .00 Sodium alkylnaphthalenesulfonate 4, .00 Sodium ligninsulfonate 4. .00 Low viscosity methyl cellulose 3. .00 Attapulgite clay 69. .00 Total 100, .00

Active ingredient 25. .00

Base: 75. .00

96% hydrated aluminum magnesium silicate 2% powdered sodium lignosulfonate 2% powdered anionic sodium alkyl- naphthalenesulfonate Total 100.00

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.'

■⁷- Other, useful formulations for herbicidal applica¬ tions are «muls^*ifiable concentrates (ECs) which 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 emulsify- ing agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthas, isophorone, or other non-volatile organic solvent. For herbicidal applica¬ tion 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.

For instance an e ulεifiable concentrate may have the following composition (in % by weight) :

Active ingredient A 40.00 Antimicrobial agent 0.05

Foam suppressant 0.10

Surfactant C 2.60

Surfactant D 0.40

Thickener 0.35 Suspending agent 0.45

Propylene glycol (antifreeze) 6.00

Water 50.05

Total 100.00

The antimicrobial agent is sodium o-phenylphenate tetrahydrate sold under the trademark and designation "Dowacide A". The foam suppressant is a water dilutable silicone emulsion sold under the trademark and designa¬ tion "Dow Corning AF" . Surfactant C is a non-ionic paste of a condensate of ethylene oxide with a hydro- phobic base formed by condensing propylene oxide with propylene glycol, sold under the trademark and designa¬ tion "Pluronic P-84." Surfactant D is an anionic liquid comprising the sodium salt of a complex organic phos- phate ester, sold under the trademark and designation "GAFAC LO-529." The thickener is a xanthan gum sold under the trademark and designation "Kelzan-M". The suspending agent is a colloidal magnesium aluminum silicate sold under the trademark and designation "Veegum."

Other emulsifiable concentrate formulations are as ollows:

Component: % by Wt.

Active ingredient 53.01 Blend of alk lnaphthalenesulfonate and polyoxyethylene ethers 6.00

Epoxidized soybean oil 1.00

Xylene 39.99

Total - 100.00

Active ingredient 10.00

Blend of alkylnaphthalenesulfonate and polyoxyethylene ethers 4.00

Xylene 86.00 Total 100.00

Flowable formulations are similar to ECs except that the active ingredient is suspended in a liquid carrier, generally water. Flowables, like ECs, may include a small amount of a surfactant, and contain active ingredient in the range of 0.5 to 95%, frequently from 10 to 50%, by weight of the composition. For application, flowables may be diluted in water or other liquid vehicle, and are normally applied as a spray to the area to be treated.

The following are specific examples of flowable . formulations: Component: % bv ⁱ Wt . Active ingredient 46 . 00

Colloidal magnesium aluminum silicate 0 . 40 Sodium alkylnaphthalenesulfonate 2 . 00 Paraformaldehyde 0 . 10 Water 41 . 42

Propylene glycol 7 . 50 Acetylenic alcohols 2 . 50 Xanthan gum 0 . 80 Total 100 , . 00

Component: % bv Wt . Active ingredient 45 . . 00 Water 48 . , 50 Purified smectite clay 2 . 00 Xanthan gum 0 . 50

Sodium alkylnaphthalenesulfonate 1. 00 Acetylenic alcohols 3 . 00 Total 100 . 00

Typical wetting, dispersing or emulsifying agents used in agricultural formulations include, but are not limited to, the alkyl and alkylaryl εulfonates and sulfates and their sodium salts; alkylaryl polyether alcohols; sulfated higher alcohols; polyethylene oxides; εulfonated animal and vegetable oils; sulfonated petroleum oils, fatty acids esters of polyhydric alcohols and the ethylene oxide addition products of εuch eεterε; and the addition product of long-chain mercaptans and ethylene oxide. Many other types of useful surface-active agents are available in commerce. The surface-active agent, when used, normally comprises from 1 to 15% by weight of the composition.

Other useful formulations include simple solutions or suspensions of the active ingredient in a relatively non-volatile solvent such as water, corn oil, kerosene, propylene glycol, or other suitable solvents. The following illustrate specific suspensions:

Oil Suspension: % bv Wt. Active ingredient 25.00

Polyoxyethylene sorbitol hexaoleate 5.00

Highly aliphatic hydrocarbon oil 70.00

Total 100.00 Aqueous Suspension: Active ingredient 40.00

Polyacrylic acid thickener 0.30

Dodecylphenol polyethylene glycol ether 0.50

Disodium phosphate 1.00

Monosodium phosphate 0.50 Polyvinyl alcohol 1.00

Water 56.70

Total 100.00

Other useful formulations for herbicidal applica- tions 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. Thus a suitable solution may contain, for instance, some 65% of the active ingredient, together with a minor proportion (say 1 to 10%) of a surfactant.

Granular formulations, wherein the toxicant is carried on relatively coarse particles, are of parti- cular utility for aerial distribution or for penetration of cover crop canopy.

Pressuriz-ed sprays, typically aerosols wherein the active .ingredient is diεperεed in finely divided form as a result of vaporization of a low^;boiling ^'dispersant solvent carrier'., such aε the Freons,. may alεo be uεed. Water-εoluble or water-dispersible granules are alεo 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 5 formulations described in U.S. patent No. 3,920,442 are useful herein with the present herbicidal compounds.

In use by the farmer on the field, the water- dispersible/soluble granular formulations, emulsifiable concentrates, flowable concentrates, solutions, etc.,

10 may be diluted with water to give a concentration of active ingredient in the range of say 0.1% or 0.2% to 1.5% or 2%.

The active herbicidal compound of this invention may be formulated and/or applied with insecticides,

15 fungicides, nematicides, plant growth regulators, fertilizers, or other agricultural chemicals and may be used as effective soil sterilantε as well as selective herbicides in agriculture. In applying an active compound of this invention, whether formulated alone or

20 with other agricultural chemicals, an effective amount and concentration of the active compound is of course employed; the amount may be as low as 50 g/ha or lower, usually about 50 to 1000 g/ha, preferably 100 to 500 g/ha.

25 The active herbicidal compound of this invention may be used in combination with other herbicides, e.g. it 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-(methoxy-

30 methyl)acetamide (alachlor) , 2-chloro-N-(2-ethyl-6- methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor) , and N-chloroacetyl-N-(2,6-diethylphenyl)- glycine (diethatyl-ethyl) ; benzothiadiazinone herbicides such as 3-(l-methylethyl)-(1H)-2,1,3-benzothiadiazin-4-

, (3H)-one-2,2-dioxide (bentazon) ; triazine herbicides such as 6-chloro-N-ethyl-N-(1-methy1ethyl)-1,3,5- triazine-2,4-diamine (atrazine) , and 2-[4-chloro-6-

(ethylamino)-1,3,5-triazin-2-yl]amino-2-methylpropane- nitrile (cyanazine) ; dinitrolaniline herbicides such as 2,6-dinitro-N, -dipropyl-4-(trifluoromethyl)benzeneamine

(trifluralin) ; and aryl urea herbicides such as N'-(3,4- dichlorophenyl)-N,N-dimethylurea (diuron) and N,N- dimethyl-N'-[3-(trifluoromethyl)phenyl]urea (fluo- meturon) ; and other heterocyclic nitrogen herbicides such as 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3- isoxazolidone.

Claims

Claims ;

1. The use of the compound of the formula I

as a herbicidal agent.

2. The use of the compound of the formula I as a herbicidal agent for preemergent uεe in fields to be planted with cotton.

3. A herbicidal composition characterized by a herbicidally effective amount of the compound of the formula I according to claim 1 in admixture with a suitable carrier.

4. A method for controlling undesired plant growth characterized by applying to the locus where control is desired a herbicidally effective amount of the composition of claim 3.

5. The method of claim 4 wherein the locus is a field to be planted with cotton.