CA2007709A1 - 4-aryl-2-haloimidazole-5-carboxylic esters, the preparation and use thereof - Google Patents

Abstract

O.Z.0050/40534 ABSTRACT OF THE DISCLOSURE: 4-Aryl-2-haloimidazole-5-carboxylic esters of the general formulae Ia and Ib

Description

O.Z. 0050/40534 ~-Aryl-2-haloimida~zole-5-q, ~ sters, ~ =
tion and u~e_thereof The present inven~ion relates to 4-aryl-2-halo-LmLdazole-5-carboxylic ester~ of the general formulae Ia Ha1~,0~ ~}Xn Hdl I C021~1 Ia Ib where Rl i~ Cl-C~-alkyl, C3-C6-alkenyl or C3-C6-alkynyl, R2 is Cl-C6-alkyl, C3-C~-alkenyl or C3-C6-alkynyl, Hal is chlorine or bromine, n is 0 to 3, X is Cl-C4-alkyl, Cl-C4 haloalkyl, C~-C4-alkoxy, Cl-C4-haloalkoxy, C~-C4-alkylthio, Cl-C4-alkylsulfinyl, C1-C4-~lkylsulfonyl, Cl-C4-haloalkylthio, cyano, 15nitro, carbo-Cl-C4-alkoxy, N,N-di-C1-C4-alkylcarbamoyl and/or halogan~
The present invention also relates to processes for thc preparation of the compound3 Ia and Ib and to herbicidal agent3 which contain 2-(4-heteroaryloxy)- or 202-t4-aryloxy)-phenoxyacetic or -propionic acid deri~a~
tives and/or ~cyclohexenone deri~atives as herbicid~l ingredient~ and~ arylhaloimidazole derivatives as anti-dotes, and to method~ for the 3elective control of unde~ired plant growth u~ing these herbicidal agent~
25EP-A-174,562 disclos~s 1-aryltriazolecarboxylic acid derivatives with a crop-protecting action. There have also bèen de cription~ of 1-arylimidazolecarboxylic esters~with growth-rogulating prop~rties ~EP-A-243,615, EP-A-26~:,577):and 2-hal~oimidazolecarboxylic esters with 30~herbicidal ~act~ion~ (EP-A-127,44S; EP-A-18Q,787; US-A-4~:711,:962; US-A-4,5~91,;37:7 and US~A-4,57B,106).
Nerblcldal:ingredlent~ from tho ~roup of 2-(4-heteroaryloxy)-: or~2-~4-a~yloxy)-phenoxyacetic acid ;: : : :: : : :: : :

.

-: , . ~
- : : : - ....
-:: ~ - ~ . .
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.

- 2 -O.Z. Q050/~0534 derivatives of the formula IX

RC
Ra ~ H-co2Rb IX
where Ra is phenyl, pyridyl, bsnzoxazolyl, benzothiazolyl or benzopyrazinyl, it being po~sible for khese aromatic ring systems to carry up t.o two o~ the following:
halogen, nitro, Cl-C4-alkyl, Cl-C4-haloalkyl and/or Cl-C4-haloalkoxy, Rb is hydrogen, Cl-C5-alkyl, C3-C5-alkylideneimino, C3-C5-alkylidenaiminooxy-C2-C3-alkylortheequivalent of a cation which i5 tolerated by plants, and Rc is hydrogen or methyl, are u~ed to control undesired plant~ from the family of Gramineae (eg. DE-A-~,223,894, DE-A-2,433,067, DE-~-2,576,251, DE-A-3,004,770, B~-A-868,875 and BE-A-858,618). However, the tolerability of the~e substances for crop plant~ varies between commercially acceptable and not tolerable, depending on the ~ubs~i~uent~ and application rate.
Similar is true of cyclohexenona derivatives of the formula ~

~ X
where Rd is Cl-C4-a~
R is C1-C4-alkyl~ C3-C4-alkenyl, C3-C4-alkynyl, C3-~4-~; haloalkenyl, or thenyl which can be ~ubstituted once by halogen; ~ ~
R~ is C1-C4-alkyl~which can be ~ubstituted once by Cl C4-alkylthio or l-C4-alkoxy;
a~5- or 6-me~ er~d ~aturate or 6ingly un aturated rin~ ~ syst:em~ which, be~ide~ carbon ~members, can contain~ one o~ygen, ~one~ ul~ur or a uIfoxide or sul~one group,~ and which~can carry up to~three of :
:

. ~ .

~6~7'7~

- 3 - O.Z. 0050/~0534 the following: hydroxyl, halogan, Cl-C4~alkyl, Cl-C4-haloalkyl, C1-C4-alkoxy and/ox C1-C4-alkylthio;
a 10-membered saturated or ~ingly un~atur~ted heterocycle which contains two oxygens ox sulfurs and can be substituted by up to three Cl-C4-alkyl and/or methoxy groups;
phenyl, pyridyl or isoxazolyl, it being pos~ible for these to carry up to three of the following: Cl-C4-alkyl, Cl-C4-haloalkyl, Cl-C4-alkoxy~ Cl-C4-alkylthio, C3-C6-alkenyloxy, C3-C~-alkynyloxy, C1-C4~alko~y_C1-C3-alkyl, Cl-C4-dialkoxy-Cl-C3-alkyl, formyl, halcgen and/or b~nzoylamino, R~ is hydrogen, hydro~yl or, .if ~' is Cl-C6-alkyl, a Cl-C6-alkyl group, Rh is hydrogen, cyano, halogen or C1-C4~1koxycarbonyl, and R1 i~ hydrogen or the equivalent o~ an environmentally compatible cation.
They have likewi~e been de~cribed as herbicides (eg. EP-A-228,598, EP-A-230,235, EP-A-238,021, US-A-

4,432,786, D~-A-2,439,104) and are mainly used for controlling undesired grasses in dicotyledonous crop~ and in gra~ses not belonging to the family of Gramineae.
Depending on the ~tructure of the sub~tituents and the dose applied, compounds from thi~ group can also be employed for selective control of undesirad gr~sses in Gr~nineae crop such as wheat and rice.
The object of the invention is to provide compounds in which the disadvantages as~sociated with the use of the above-mentioned herbicide~ of the fo~nulae IX and X have been eliminated or at lea~t diminished to such an extent hat the reduction:in the ha~vest yield of tha crop plants is now zero or negligible.
In accordan~e with the ob~ect, we have found the aryl- and 1-hetero~rylimidazolecarboxylic eqtars Ia ~nd Ib def:ined in the~introduction. We ha~e also found : processes for preparing these co~pound~ Ia and Ib and for : using thése compounds together with the herbicid2~ IX and :: : : ::~ : : : :

' ~' ' , , ' , ' 77'~
- 4 - O.Z. 0050/4053~
X for in~luencing undesired plant growth. The invention also relate~ to ayents which contain the compound~ Ia and/or Ib as well a~ h~rbicides of type IX or X, it being immaterial whether the herblcidal ingredient and the antidote compound are formulated ~nd applied together or separately orl in the case of separate application, in which sequence the herbicidal ingredient and antidote are applied.
The compound~ of the ~ormulae Ia and Ib aacording to the invention can ba obtained in a var.iety of ways.
Thus, for example, compounds o~ the formula Ia are obtained by sub~ecting a carbonyl compound II succes-sively, under condition~ similar to those de~cribed in J.
Org. Chem. 28 (1963), 3041, without i~olation o~ the intermediate~, first to nitrosation with a nitrite III in an aqueous acid to give IV, then reduction to the amino keto ester V and conver~ion thereo~ directly with a cyanate VI into the arylimidazole VII which is subse-quently reacted in the presence or ab~ence o~ an iner~
organic solvent and of a base with a halogenating agent conventional in organic chemistry ~o give Ia. The indi~
vidual stages in this ~ynthesis are shown below.
O ~ Xn A6~O~ c~n~ ~ xn Co2RI HON co2~l H2N Co II IV V

a/?ocNe HN ~ [J 3 xn rhalo~enationl> Nl ~ xn ; VI ~ CO2RI ~al 1 N CO2R
VII Ia ~ A~ in formula III is an alkali metal ion, egO a lithium, sodium or pota48iu~ ion.

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_ 5 _ o.z. 0050/40534 The nitrosation can be carried out under conven-tional conditions with a nitrite III in an aqueous acid at from -10 to 60C, preferably 30 to 4()C, continuously or discontinuou~ly, under atmospheric or superatmospheric pressure (1 to 10 bar).
Examples of suitable acid~ are carboxylic acid~
such as formic acid, acetic acid or propionic acid or mineral acids such as hydrochloric acid or ~ulfuric acid, preferably acetic acid or ~ulfuric acid.
The i~onitroso compound IV can be converted without isolation into the amine V.

~ ~reductionl> 0 ~ ~n HON CO2RI n H2~ Co IV V
EXamples of reducing agents which are used are inorganic ~alt~ such as sodium dithionike, ~odium bi~ul-fite, sodium sulfite or tin(II) chloride in aqueous acid~. Sodi~m dithionite in the abovementioned aqueous acids is preferred.
However, it is also po~ible to extract the compounds IV from the reaction mixture u~ing an inert organic sol~ent which is immiscible with water, and ~o reduce the isoIated product in a catalytic hydxogenation on a noble metal catalyst such as pla~inum or palladium or nickel-containing catalyst such a~ Raney nickel in an inert sol~ent such as ace~ic acid, methanol, ethanol or tetrahydro~uran at from 25 to 50C, preferably 25C, under a pressure o~ from 1 to 100 bar, preferably 1 ~o 50 bar, continuously or discontinuou~ly.
: 30 : Th amine V can, without further purification, be : cyclized at from 25 to 100C with a cyanate VI where B~
i9, for example, an ammonium, sodium or pota~sium ion, : in the abovementioned aqueou~ acid~ with or without the addition of an inert organic solvent ~uch as methanol, ~; 35 ethanol or tetrahydro~uran, to give the compound VII.

:

,~ . . . ., , ~ , ~ ~.3 - 6 - o.æ. 0050/~0534 H2~X" VI ~ Vll The subsequent reaction of the imidazole VII with a halogenating agent yields Ia.

HN [~}Xn N. ~3xn o~C02Rl E-Hdl --~ Hal~N~C02RI
VII Ia Example~ of ~quitable halogenating agants (E-Hal) are oxyhalides such as pho~phorus oxytrichloxide or tribromide, thionyl chloride or bromide, or phosgene or halides such as phosphoru~ ~enta~hloride or pentabromide, pho~phorus trichloride or tribromide or ~ulur tetrachlo-ride or tetrabromlde.
Phoæphorus oxychloride or oxybromide i~
preferred.
The reaction can be carried out with or without solvent a~ from 0 to l80C, pre~erably 40 to 140C, under atmospheric or suporatmoqpheric pra~qure (1 to 10 bar, prefarably 1 to 3 bar)~ continuously or di~continuously, with or without the pre~ence of a ba~e.
Base3 ~uitable for this reaction are tertiary amine~ such a~ triethylamine, dii~opropylamine, N,N-; dim~thylaniline, N,~-dimethyl-p-aminopyridine, pyridine, isoquinoline,N-mathylpyrrolidine,N,N,N',N'-tetramethyl-ethylenediamine, 1,5:-diazabicyclo~4.3.0]non-5-ena or 1,8-diazabicyclo[5.4.0]undec-7-ene.
Example~ of ~uitable ~olvent~ are halogenated ~; ~ hydrocarbons :such as:~:methylene chloride, chloro~orm, : carbon : tatrachloride, l,1,1-~richloroethane ~ or : chlorobenzene; : `
:~ etherq:~ such a~ ~diethyl ether, methyl-tert-butyl ether, ::~ 30 : ethylene glycol dLmethyl ather, tetrahydro~uran or .

, ~ ~ ~'YJ7 _ 7 _ o.z. 0050/40534 dioxane;
nitrated hydrocarbon~ such a~ nitrobenzene;
nitriles such as acetonitrile or benzonitrile; or hydrocarbons such hexane, heptane, cyclohexane, decalin, petroleum ether or toluene.
The reaction is preferably carried out without solvent or in chlorobenzene or toluene without a base or with triethylamine or pyridine as ba~e.
The compounds Ib can b~3 obtained, for ex~mple, from the 4-aryl-2-haloimida~ole-5-carboxylic e~ters Ia in a conventional manner (Houben-Weyl, vol. ES, pp. 998 et seq.) by alkylation, alkenylation or alkynylation.

l~Xn R2-Y H ~1 ~

Ia YIII Ib Y in formula VIII i5, or example, an ea~ily lS eliminated group such a~ halogen, eg. chloride, bromide or iodide; sulfonate, eg. to~ylate, mesylate or triflate, or alkyl sulfate, eg. me~hyl sulfate or ethyl sulfate.
The reaction of Ia with VIII i8 carrie~ out in a solvent in the presence of a base, under atmospheric or superatmospheric pre~sure (1 to 10 bar)~ continuously or di~continuously, at from -25 to 200~C, preferably -10 to 150C.
Examples of 3uitable ba~es in this context are alkali metal compounds ~uch as sodium hydride, pota~sium hydride, ~odium methylate, ~odium sthylata, pota~sium ter~-butylate, lithium amide, ~odium or potassium hydroxide,~ ~odium carbonate, sodium bicar~onate or potassium carbonate or tertiary amine~ such as triethylamine, N,N-dimethyl-p-aminopyridine, pyridine, N-methylpyrrolidine, quinoline, _ N,N,N',N'-tetramethylathylenediamine, 1,5-diazabicyclo[4.3.0]non-5-ene or 1,8-diaz~icyclo[5.4~01-.

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~0~ y}~

- 8 - O.Z- 0050/40534 undec-7-ene.
Sodium hydride, sodium methylate, potassi~
tert-butylate or 1,8-diazabicyclo[5.4.0]undec-7-ene is preferred.
Examples of suitable ~lvents are hydrocarbon~
such as hexane, heptane, cyclohexane, petroleum ether, decalin, toluene or xylene; ethers such as diethyl ether, methyl tert-butyl ether, ethylelle glycol dimethyl ether, tetrahydrofuran or dioxane; amides such as dLmethylforma-mide; sulfoxides such as dimethyl ~ulfoxide; ketone~ such as acetone or methyl ethyl ketone or alcohols ~uch as methanol, ethanol or i-prop~nol.
Tetrahydrofuxan, dimethyl~ormamide, toluene or dimethyl sulfoxide is preferred.
Suitable substituents with a view to the speci-fied use of the compounds Ia and/or Ib a crop-protection agents are the following:
Rl alkyl~ 3uch as methyl, ethyl, propyl, 1-methylethyl, butyl, l-methylpropyl, 2-methylpropyl, l,1-dLmethyl-ethyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, l,l-dimethylpropyl, 2,2-dlmethyl-propyl, 1,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dlmethylbutyl, 2,2-dimethyl-butyl, 3,3-dLmethylbutyl, 1,2-dLmethylbutyl, 1,3-dimethylbutyl, 2,3-dLmethylbu~yl, 1-ethylbutyl, or 2-ethylbutyl or l-propylpropyl~ but particularly methyl, ethyl, propyl or 1-me~hylethyl, alkenyls uch a 2-propenyl, 2~butenyl, 3-bu~enyl, 1-methyl-2-propenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, l-methyl-X-hutenyl, 2-meth~1-2-butenyl, 3-methyl~2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl or 1-methyl-2-hexen~l, but especially 2-propenyl, or alkynyl ~such a~ 2-propynyl, 2-butynyl, 3 butynyl, l-methyl-2-propynyl, 2-pe~tynyl, 3-pentynyl, : :

. - , . , : :
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, - ~ , -- .. . , '' ~ ~3~ ~t~3~3 _ 9 _ o ~. 0050/40534 4 pentynyl or 2-hexynyl but especially 2-propynlyl;
R2 alkyls such as those mentioned for Rl, but e~pecial-ly methyl, ethyl or 1-methylethyl;
alkenyls such as those mentionad for R1, but espe-cially 2-propenyl, or alkynyls ~uch as tho3e mentioned for Rl, especially 2-propynyl;
X cyano or nitro, alkyls such a~ methyl, ethyl, propyl, l-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl or 1,1-dimethylethyl, especially~nethyl, 1-methylpropyl and l,l-dimethylethyl;
haloalkyl~ ~uch as trifluoromethyl, difluoromethyl, fluorometh~l, trlchloromethyl, dichloromethyl, chloromethyl, 2,2,2-trifluoroethyl, 2,2-difluoro-ethyl, 2-fluoroethyl, 2,2,2-trichloroethyl, 2-chloroethyl ox 2-bromoethyl, especially trifluoro-methyl, difluoromethyl or 2,2,2 trifluoroe~hyl;
alkoxy groups such as methoxy~ ethoxy, propoxy, 1-methylethoxy, butoxy, l-methylbutoxy, 2-methylbutoxy or 1,1-dLm~thylethoxy, e~pecially methoxy, ethoxy or 2-propoxy;
: haloalkoxy group~ such a~ trifluorometho~y, tri-chloromethoxy,fluorome~hoxy,2,2,2~trifluoroethoxy, 1j2,2-tri~luoroethoxy or 1,1 r 2,2-tetra1uoroetho~y, : ~ especially trifluorome~hoxy or 2,2,2-trifluoro-ethoxy;
alkylthio groups ~uch as methylthio, ethylthio/
propylthio,~2-propylthiol butylthio, l-methylpropyl-thio, 2-methylpropylthio or l,l-dimethylethylthio, especially methyl~hio or ethylthio~
alkylsul~inyl~ ch a~ m~thyl~ulfinyl or ethyl-sulfinyl, alkyl~ul:Eonyls:such a~ methylsulfonyl or ethyl-35~ sulfonyl,~
:~ : : haloalky:Lthio group~ 3uch as~trifluoromethylthio vr trichloromethylthiof ~ ~ :

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- lO O.Z. 0050/40534 carbalkoxy groups such as carbom~thoxy or carbo-ethoxy, N,N-dialkylcarbamoyl~ such as N,N-dimethylcarbamoyl or N,N-diethylcarbamoyl or halogen3 such a~ fluorine, chlorine, bromine or iodine, e~pecially fluorine, chlorine or bromine n 0, 1, 2 or 3, especially 0, 1 or 2.
Specific example~ of herbicidal (heteroaryloxy)-or aryloxy-phenoxyacetic acid derivatives of the formula IX whose tolerability by crop plant~ can be improved by haloimidazolecarboxylic esters of the formulae Ia and Ib are li~ted in Table A which follows:

TABLE A

R ~ ~4O2Rb IX

No. Ra b R c R Lit IX.1 ~ l CH3 CH3 DE-A 22 23 894 Ct IX.2 ~ F3 n-C4Hg CH3 ~E-A 868 875 IX.3 ~ C2H~ CH3 BE-A 858 618 P~ .
IX.4 ~Cf3 ~ CH3 CH3 BE-A 868 875 Cl : :
IX.5 ~ I C2H~ CH3 DE-~ 30 04 770 ~: Specific ex~mples of cyclohexenones of ~he : formula X who~e tolerability by crop plants can be : improved : by haloimidazolecarboxylic esters of the fo D lae Ia and:Ib are listed in:Table B which follows.

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a) ~ o o o o L ct c~ ~ CC ~ c~
~IIIIII
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L 1~ ~ t ~t ~ C~ E 00 c ~1 _ ~ C~ t~ ~ W ~V
L~ J LLJ W LL LIJ ~ ~CL L~ ~ L~
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S T T I I I I -r X ~ ~ ,~, T I I X

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O.Z.0050/40534 The herbicidal active ingredients and antidotes may be applied toge-ther or separately to the leaves and shoots of the crop plants and unwanted plants. Preferably, the antidote is applied together with the herbicidal active ingredient. If the components are applied separately, the antido-te

5 is applied first to the field and then the herbicidal active ingredient.
The herbicidal active ingredient and antidote may be formulated together or separately as spray agents in the form of suspensions, emulsions or solutions.
10 Treatment of the crop plant seed with the antidote prior to sowing is also feasible. The herbicidal active ingredient is then applied to the field on its own in conventional manner.
For herbicidal (heteroaryloxy)-phenoxyacetic or -propionic acid 15 derivatives of the formula IX, the amount of antidotally active compound varies, depending on the crop. The ratios may vary over a wide range, and are also dependent on the structure of the (heteroaryloxy)phenoxyacetic or -propionic acid derivatives IX and on the crop involved. Suitable ratios of herbicidal active ingredient to antidote are from 1:4 to 1:0.01, and 20 preferably from 1:4 to 1:0.1, parts by weight.
For the same cyclohexenone derivative X, the amount of antidote varies, depending on the crop. The ratios in which a cyclohexenone derivative and a haloimidazolecarboxylic ester of the formula la and/or Ib are used may 25 vary over a wide range, and are dependent on the structure of the cyclo-hexenone derivative, the haloimidazolecarboxylic ester of the formula Ia and/or Ib, and the crop involved. Suitable ratios of herbicidal acti~e ingredient to safener are from 1:4 to 1:0.01, and prefsrably from 1:4 to 1:0.25, parts by weight.
The novel herbicidal agents may contain, in addition to the haloimidazole-carboxylic ester of the formula Ia and/or Ib as safener and the herbicide from the group of the (heteroaryloxy)phenoxyacetic or -propionic acids IX
or cyclohexenones X, other herbicidal or growth-regulating active ingre-35 dients having a different chemical structure without the safening effectbeing impaired.~
~; The agents according to the ;inventionj or - when applied separately - the ~herbicidal active ingredients and the safener, are applied for instance in 40~the form of directly sprayable solutions, powders, suspensions (including high-percentage aqueous, oily or others), dispersions, emulsions, oil dis-persions,~ pastes, dusts, broadcasting agents or granules by spraying, a-tomizing, dusting, broadcasting or pouring. The forms of application de-pend entirely on the purpose~for which ths active ingredients are to be ~used.
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16 O.Z 0050/~053~

For the preparation of solutions, emulsions, pastes and oil dispersions to be sprayed direct, mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, further coal-tar oils, and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons 5 such as ben~ene, toluene, xylene, paraffin, tetrahydronaphthalene, alkyl-ated naphthalenes and their derivatives such as methanol, ethano1, propan-ol, butanol, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., and strongly polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, water, etc. are suitable.
Aqueous formulations may be prepared from emulsion concentrates, pastes, oil dispersions or wettable powders by adding water. To prepare emulsions, pastes and oil dispersions the herbicidal active ingredient and/or anti-dote as such or dissolved in an oil or solvent may be homogenized in water 15 by means of wetting or dispersing agents, adherents or emu1sifiers. Con-centrates which are suitable for dilution with water may be prepared from herbicidal active ingredient and/or antidote, wetting agent, adherent, emulsifying or dispersing agent and possibly solvent or oil.
20 Examples of surfactants are: alkali metal, alkaline earth metal and ammonium salts of aromatic sulfonic acids, e.g., ligninsulfonic acid, phenolsulfonic acid, naphthalenesulfonic acid and dibutylnaphthalene-sulfonic acid, and of fatty acids, alkyl and alkylaryl sulfonates, and alkyl, lauryl ether and fatty alcohol sulfates, alkali metal and alkaline 25 earth metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sul-fate, fatty alcohol sulfates, and satts of sulfated hexadecanols, hepta- -decanols, and octadecanols, salts of fatty alcohol glycol ethers, conden-sation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic 30 acids with phenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctylphenol, ethoxylated octylphenol and ethoxylated nonyl-phenol, alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ethers, 35 ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin-sulfite~ waste liquors and methyl cellulose.
, Powders, dusts and broadcasting agents may be prepared by mixing or grinding the herbicidal active ingredient and/or antidote with a solid 40 carrier.
Granules, e.g., coatedj impregnated or homogeneous granules, may be prepared by bonding the active ~ingredients to solid carriers. Examples of solid carriers are mineral earths such as silicic acid, silica gels, silicates, talc, kaolin, attapulgus clay, limestone, lime, chalk, bole, loess, clay, dolomite, dlatomaceous earth, calF~um sulfate, magnesium :

.

~t7~7~2~
17 O.Z.0050/40534 sulfate, magnesium oxide, ground plastics, ferti1izers such as am~onium sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable products such as grain meals, bark meal, wood meal, and nutshell meal, cellulosic powders, etc.

Synthesis examples The directions given in the examples which follow were used with appro-priately modified starting compounds to obtain further compounds of the 10 formulas Ia and Ib. The compounds obtained are given with their physical data in the tables below; compounds without these data may be prepared analogously from the appropriate materials. In view of their close struc-tural relationship to the compounds which have been prepared and investi-gated, they are expected to have a similar action.
Example 1 d) Ethyl 4-phenyl-2-imidazolone-5-carboxylate 20 At 35 to 45C, a solution of 35 g of sodium nitrite in 100 ml of water was added to 112 g (0.582 mol) of ethyl benzoylacetate in 130 ml of acetic acid. The mixture was stirred for 30 minutes at this temperature, and then 500 ml of water was added.
25 After the mixture had been stirred for one hour, 302 g of sodium dithion-ite in 600 ml of water was added, the resulting mjxture was stirred for 30 minutes and then 157 9 of potassium cyanate was introduced. The solution was heated briefly to 70 to 80C, and then left to stand overnight at room temperature. Extraction with ethyl acetate gave ethyl 4-phenyl-2-imid-30 azolone-5-carboxylate of m.p. 109 to 112C.
b) Ethyl 2-chloro-4-phenylimidazole-5-carboxylate 20 g (0.086 mol) of ethyl~4-phsnyl-2-imidazolone-5-carboxylate was 35 refluxed for 5 hours with 250 ml of phosphorus oxychloride. The excess phosphorus oxychloride was removed under reduced pressure, the residue was poured onto ice, the pH was adjusted to 5 - 6 with ammonia, and the crude product was extracted with ethyl acetate, dried and evaporated down.
Chromatography of the residue on silica gel (developer: ethyl acetate/-40 pentane) gave ethyl 2-chloro-4-phenylimidazole-5-carboxylate (compound no.
1.001) of m.p. 128 to 129C.
:

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.

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18 ~.Z.0050/~0534 Example 2 Ethyl 2-chloro-1-methyl-4-phenylimidazole-5-carboxy1ate 5 0.6 g of sodium hydride was added to a solution of 7 y (0.028 mol) of ethyl 2-chloro-4-phenylimidazole-5-carboxylate in 25 ml of dimethylform-amide. Upon completion of gas evolution, 4.2 g (0.033 mol) of dimethyl sulfate was added and the mixture was heated at 80C for 1~ hours. The dimethylformamide was removed under reduced pressure and the residue was lO poured into dilute ammonium hydroxide. After extraction with ethyl acet-ate, drying and removal of the solvent, chromatography on silica gel (developer: ethyl acetate/pentane) gave ethyl 2-chloro-1-methyl-4-phenyl-imidazole-5-carboxylate (compound no. 2.001) of m.p. 54 to 55C.

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880~48 19 O.Z. 0050/40534 Table 1 ~ Xn N_~
Hal~N~C02Rl Comp.no. Hal Xn R1 mp [C]
1.001 Cl H CH2CH3 128-129 1.002 Cl H CH3 1.003 Cl H CH2CH2CH3 1.004 Cl H CH(cH3)2 1.005 Cl 2-F CH3 1.006 Cl 2-F CH2CH3 130-132 1.007 Cl 3-F CH3 1.008 Cl 3-F CH2CH3 1.009 Cl 4-F CH3 1.010 Cl 4-F CH2CH3 77- 80 1.011 Cl 2-Cl CH3 1.012 Cl 2-CI CH2C~3 1.013 Cl 3-Cl CH3 1.014 Cl 3-Cl CH2CH3 1.015 Cl 4-CI CH3 1.016 Cl 4-CI CH2CH3 1.017 Cl 2-Br CH3 1.018 Cl 2-Br CH2CH3 1.019 Cl 3-Br CH3 1.020 Cl 3-Br CH2CH3 1.021 Cl 4-Br CH3 1.022 Cl 4-Br CH2CH3 1.023 Cl 2-F, 4-F CH3 1.024 Cl 2-F, 4-F CH2CH3 1.02$ Cl 2-F, 4-F CH2CH2C~l3 1.026 Cl ~ 2-Fj 4-F CH2CH=CH2 1.027 Cl 2-F, 4-F CH2C-CH
1.028 Cl 3-F! 4-F ~ CH3 1.029 CI 3-F, 4-F CH2CH3 1.030 Cl 2-F, 3-F CH3 1.031 Cl ~ 2-F, 3-~ CH2CH3 1.032 Cl 2-F, 5-F~ CH3 1.033 Cl 2-F, 5-F CH2CH3 .034 Cl 2-F, 6-F~ CH3 1.035 ~CI 2-F,;6-F ~ CH2CH3 : ~ : ~: :

:- , ~)80448 o.z. 0050/~,0534 Table 1 (contd.) Comp.no. Hal Xn R1 mp ~C]
1.036 Cl 2-CI,3-Cl CH3 1.037 Cl 2-CI,3-CI CH2CH3 1.038 Cl 2-CI,4-CI CH3 1.039 Cl 2-CI,4-CI CH2CH3 1.040 Cl 2-CI,4-Cl CH2C~12C~3 1.041 Cl 2-CI,4-CI CH(C~13)2 1.042 Cl 2-CI,4-CI CH2CH-CH2 1.043 Cl 2-CI,4-CI CH2C_CH
1.044 Cl 2-CI,5-Cl CH3 1.045 Cl 2-CI,5-CI CH2CH3 1.046 Cl 2-CI,6-CI CH3 1.047 Cl 2-CI,6-CI CH2CH3 1.048 Cl 3-CI,4-CI C~13 1.049 Cl 3-CI,~I-Cl CH2CH3 1.050 Cl 3-CI,5-Cl CH3 1.051 Cl 3-CI,5-CI CH2CH3 1.052 Cl 2-Cl,4-Cl,6-Cl CH3 1.053 Cl 2-CI,4-CI,6-CI CH2CH3 1.054 Cl 2-Br,4-Br CH3 1.055 Cl 2-Br,4-8r CH2CH3 1.056 Cl 2-F,4-CI CH3 1.057 Cl 2-F,4-CI CH2CH3 l.Q58 Cl 2-N02 CH3 l.OS9 Cl 2-N02 CH2CH3 1.060 Cl 3-NO2 CH3 1.061 Cl 3-NO2 C~12CH3 1.062 Cl 4-NO2 CH3 1.063 Cl 4-N02 C~12CH3 1.064 Cl 2-No2~4-No2 CH3 1.065 Cl 2-No2~4-No2 CH2CH3 1.066 Cl 2-CI,4-N02 CH3 1.067 Cl 2~Cl,4-N02 C~l2CH3 1.068 Cl 2-NO2,4-Cl CH3 1.069 Cl 2-NO2,4-CI CH2CH3 1.070 Cl 2-CN CH3 1.071 Cl 2-CN CH2CH3 1.072 CI 4 CN CH3 1.073 Cl 4-CN CH2CH3 172 - 173 1.074 Cl 2-01,4-CN CH3 1.075 Cl 2-Cl, 4-CN CH2CH3 :
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~80448 21 o z. 0050/40534 Table 1 (contd.) Comp.no. Hal Xn Rl ~"p [C]
1.076 Cl 2-F,4-CN CH3 1.077 Cl 2-F,4-CN CH2CH3 1.078 Cl 2-CH3 CH3 1.079 Cl 2-CH3 CH2CH3 1.080 Cl 3-CH3 c~l3 1.081 Cl 3-CH3 CH2CH3 1.082 Cl 4-CH3 CH3 1.083 Cl 4-CH3 C~12CH3 150-151 1.084 Cl 4-C(CH3)3 CH3 1.085 Cl 4-C(CH3)3 CH2CH3 1.086 Cl 2-CH3,4-C~l3 CH3 1.087 Cl 2-CH3,4-C~13 CH2CH3 1.088 Cl 2-CH3,6-CH3 CH3 1.089 Cl 2-CH3,6-c~l3 CH2CH3 1.090 Cl 2-CH3,4-CH3,6-CH3 CH3 1.091 Cl 2-CH3-4-CH3,6-CH3 CH2CH3 1.092 Cl 2-CF3 CH3 1.093 Cl 2-CF3 CH2CH3 1.094 Cl 3-CF3 c~l3 1.095 Cl 3-CF3 CH2CH3 1.096 Cl 4-CF3 CH3 1.097 Cl 4-CF3 CH2CH3 1.098 Cl 2-CI,4-CF3 CH3 1.099 Cl 2-CI,4-CF3 CH2CH3 1.100 Cl 2-F,4-CF3 c~l3 1.101 Cl 2-F, 4-CF3 CH2CH3 1.102 Cl 4-CFzCI CH3 1.103 Cl 4-CF2CI CH2CH3 1.104 Cl 4-ocF2cHf2 CH3 1.105 C1 4-ocF2cHcF2 CH2CH3 1.106 Cl 4-OCF3 CH3 1.107 ~ Cl 4-OCF3 CH2CH3 1.108 Cl 2-OCH3 c~3 1.109 Cl 2-OCH3 CH2~H3 1.110 Cl 3-OCH3 CH3 1.111 Cl 3-OCH3 CH2CH3 1.112 ~CI 4-t)CH3 ~ 5H3 1.113 Cl 4-OCH3 CH2CH3 1.114 Cl 2-t)CH3,4-oCH3 CH3 1.115 Cl 2-()CH3,4-OCH3 CH2CH3 .
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22 O.Z. 0050/~0534 T~ble I (contd.) Comp.no. H~l Xn R1 mp [C]
1.116 Cl 2-OCH3,6-OCH3 CH3 1.117 Cl 2-ocH3~6-ocH3 CH2CH3 1.118 Cl 4-0CH2CH3 C~3 1.119 Cl 4-0CH2CH3 CH2CH3 1.120 Cl 2-SCH3 c~l3 1.121 Cl 2-SCH3 CH2CH3 1.122 Cl 4-SCH3 CH3 1.123 Cl 4-SCH3 CH2CH3 1.124 Cl 2-SOCH3 CH3 1.125 Cl 2-SOCH3 CH2CH3 1.126 Cl 2-S02C~13 CH3 1.127 Cl 2-S02CH3 CH2CH3 1.128 Cl 2-C02CH3 CH3 1.129 Cl 2-C02CH3 C~12CH3 1.130 Cl 2-coN(cH3)2 CH3 1.131 Cl 2-CON(CH3)2 CH2CH3 1.132 Br H CH3 1.133 Br H CH2CH3 1.134 Br 4-F CH2CH3 1.135 Br 4-CI CH3 1.136 Br 4-CI CH2CH3 1.137 Br 4-8r CH2CH3 1.138 Br 2-Cl,4-CI CH3 1.139 Br 2-C1,4-CI CH2CH3 1.140 Br 2-CI,6-CI CH3 1.141 8r 2~CI,6-CI CH2CH3 1.142 Br 2-F,4-F CH3 1.143 Br 2-F,4-F CH2CH3 1.144 8r 2-F,6-F CH2CH3 1.145 Br 2-C1,4-CI,6-CI CH2CH3 1.146 Br 4-N02 CH2CH3 1.147 Br 2-No2r4-No2 CH2CH3 1.148 Br 2-CI,4-N02 CH2CH3 1.149 Br 2-N02,4-Cl CH2CH3 1.150 Br 2--CH3,4-CH3 CH2C~13 1.151 Br 2-CH3,6-CH3 C~l2CH3 1.152 Br 4--CF3 CH2CH3 1.153 Br 3-CF3 CH2CH3 1.154 Br 2--F,4-CF3 C~12CH3 :: :
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8~0448 23 O.Z. 0050/4053 Table 1 (contd.) Comp.no. Hal Xn R1 mp [C]
1.155 Br 2-OCH3,4-OCH3 C1~2CH3 1.156 Br 2-OCH3,6-OCH3 CH2CH3 1.157 Br 4-SCF3 C~12C~13 :

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7~3 0.Z.0050/~0534 Use examples The influence of various representatives of the herbicidal agents, or combinations of herbicide and antidote, according -to the invention on the 5 growth of unwanted and crop plants compared with the herbicidal active ingredient alone is illustrated in the following greenhouse experiments.
The vessels employed were plastic flowerpots having a volume of 300 cm3 and filled with a sandy loam containing about 3.0% humus. The seeds of -the 10 test plants were sown separately, according to species, and then moistened. The vessels were then covered with transparent plastic hoods until the plants had taken root.
For the postemergence treatment, the plants were grown, depending on 15 growth form, to a height of 3 to 20 cm before being treated with the active ingredients, which were suspended or emulsified in water and sprayed through finely distributing nozzles.
As herbicidal active ingredient, the cyclohexenone derivative X.2 was used 20 in the biological experiments:

H5C2SCHC~ ~ C\ X.2 o c 3H7n The formulations contain from 0.1 to 95, and preferably from 0.5 to 90, wt% of herbicidal active ingredient and antidote. The application rates of herbicidal active ingredient are from 0.001 to 0.5 kg/ha.
The herbicidal active ingredient X.2 was used (on its own and together with the ~afener) in the spray liquor as a commercially formulated product (184 g/l EC) together with the same amounts of solvent system XXII given in the table for the safener.
All the safeners were formulated in a mixture consisting of 80% of cyclo-hexenones and 20% of Emulphor EL (formulation XXII? with 10wt% of ac-tive ingredient.
35 The vessels were set up in the greenhouse, heat-loving species at from 18 to 35C and species from more moderate climates at from 10 to 25~C.

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31 O.Z.0050/4053~

The experiment was run for from 3 to 5 weeks. During this period, the plants were tended and their reactions to -the various -treatments assessed.
Damage by the chemical agents was assessed on a scale from 0 to 100%
cornpared with the untreated control plants, 0 denoting no damage and 100 5 denoting complete destruction of the plants (Triticum aestivum - wheat).
The table below documents the safening action; compound no. 1.001 also greatly improves the tolerance of the cyclohexenone derivative X.2 by crop plants.
Table A
Reduction in the damage to wheat caused by the herbicide X.2 as a result of combination with compound 1.001 according to the invention.
App!ic. rate [kg/ha] _ Damage -to wheat in %
Herbicidal Safener act. ingr.
X.2 1.001 _ . . . .
0~015 ~ 44 n_ _ 25 0~015 0~06 0 0~03 0~ 125 10 _ _ _ _ _ _ :

'~ .

Claims (9)

CA,KR
32 O.Z.0050/40534 We claim:

1. 4-Aryl-2-haloimidazole-5-carboxylic esters of the general formulae Ia and Ib Ia Ib where R1 is C1-C6-alkyl, C3-C6-alkenyl or C3-C6-alkynyl, R2 is C1-C6-alkyl, C3-C6-alkenyl or C3-C6-alkynyl, Hal is chlorine or bromine, n is 0 to 3, X is C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-haloalkoxy, C1-C4-alkylthio, C1-C4-alkylsulfinyl, C1-C4-a1kylsulfonyl, C1-C4-haloalkylthio, cyano, nitro, carbo-C1-C4-alkoxy, N,N-di-C1-C4-alkylcarbamoyl and/or halogen.

2. A process for manufacturing compounds Ia as set forth in claim 1, wherein a carbonyl compound II

II

is nitrosated in conventional manner without isolation of the inter-mediate stages first in an aqueous acid with a nitrite III
A?NO2? III, where A? is an alkali metal ion to give IV

IV, CA,KR
33 O.Z.0050/40534 which is then reduced to V

V, and converted directly with a cyanate VI
B?OCN? VI, where B? is an alkali metal cation or an ammonium cation, in the presence of or without the addition of an inert organic solvent to an imidazolone VII

VII, which is then reacted to Ia with a halogenating agent.

A process for the manufacture of compounds Ib as set forth in claim 1, wherein a 4-aryl-2-haloimidazole-5-carboxylic ester Ia is reacted with an alkylating agent VIII
R2-Y VIII, where Y is halogen or a sulfonate or sulfate group, to give compounds Ib.

4. Herbicidal agents containing at least one 4-aryl-2-haloimidazole-5-carboxylic aster Ia and/or Ib as set forth in claim I and at least one herbicidal active ingredient from the group a) of 2-(4-heteroaryloxy)- or 2-(4-aryloxy)-phenoxyacetic acid derivatives of the formula IX

IX, where CA,KR
34 O.Z.0050/40534 Ra is phenyl, pyridyl, benzoxazolyl, benzothiazolyl or benzopyrazin-yl, it being possible for these aromatic ring systems to carry up to two of the following: halogen, nitro, C1-C4-alkyl, C1-C4-halo-alkyl and/or C1-C4-haloalkoxy, Rb is hydrogen, C1-C5-alkyl, C3-C5-alkylideneimino, C3-C5-alkyl-ideneiminooxy-C2-C3-alkyl or the equivalent of a cation which is tolerated by plants, and Rc is hydrogen or methyl, and/or b) of cyclohexenone derivatives of the formula X

X

where Rd is C1-C4-alkyl;
Re is C1-C4-alkyl, C3-C4-alkenyl, C3-C4-alkynyl, C3-C4-haloalkenyl or thenyl which can be substituted once by halogen;
Rf is C1-C4,-alkyl which can be substituted once by C1-C4-alkylthio or C1-C4-alkoxy;
a 5- or 6-membered saturated or monounsaturated ring system which, besides carbon members, can contain one oxygen, one sulfur or a sulfoxide or sulfone group, and which can carry up to three of the following: hydroxy, halogen, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy and/or C1-C4-alkylthio;
a 10-membered saturated or monounsaturated heterocycle which contains two oxygens or sulfurs and can be substituted by up to three C1-C4-alkyl and/or methoxy groups;
phenyl, pyridyl or isoxazolyl, it being possible for these to carry up to three of the following: C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-alkylthio, C3-C6-alkenyloxy, C3-C6-alkynyl-oxy, C1-C4-alkoxy-C1-C3-alkyl, C1-C4-dialkoxy-C1-C3-alkyl, formyl, halogen and/or benzoylamino;

CA, KR
0.Z. 0050/40534 R9 is hydrogen, hydroxy or, if Rf is C1-C6-alkyl, a C1-C6-alkyl group;
Rh is hydrogen, cyano, halogen or C1-C4-alkoxycarbonyl, and Ri is hydrogen or the equivalent of an environmentally compatible cation.

5. Herbicidal agents as set forth in claim 4, containing a haloimidazole derivative Ia or Ib and a herbicide a) of the formula IX or a herbi-cide b) of the formula X, the weight ratio of Ia or Ib:IX or X being from 4:1 to 0.01:1 parts.

6. A process for the selecetive control of unwanted plant growth, wherein a haloimidazole derivative of the formula Ia and/or Ib as set forth in claim 1 and a 2-(4-heteroaryloxy)- or 2-(4-aryloxy)-phenoxyacetic acid derivative of the formula IX or a cyclohexenone derivative of the formula X as set forth in claim 4 are applied - either simultaneously or one after the other - before, during or after the sowing of the crop plants, or before or during emergence of the crop plants.

7. A process for preventing damage to crop plants by herbicidal 2-(4-heteroaryloxy)- or 2-(4-aryloxy)-phenoxyacetic acid derivatives of the formula IX or cyclohexenone derivatives of the formula X as set forth in claim 4, wherein the seed of the crop plants is treated with a safening amount of a haloimidazole derivative of the formula Ia and/or Ib as set forth in claim 1.

8. A process for the selective control of unwanted plant growth, wherein the leaves of the crop plants and the unwanted plants are treated, either simultaneously or one after the other, with a haloimidazole derivative of the formula Ia and/or Ib as set forth in claim 1 and with a 2-(4-heteroaryloxy)- or 2-(4-aryloxy)-phenoxyacetic acid derivative of the formula IX or a cyclohexenone derivative of the formula X as set forth in claim 4.

9. A process as set forth in any of claims 6 to 8, wherein the crop plants are barley, wheat, Indian corn, sorghum and rice.