CA1079303A - Herbicidal 4-trifluoromethyl-4'-nitrodiphenyl ethers - Google Patents

Abstract

Abstract of the Disclosure Compounds of the formula

Description

3~3 TH~ DISCLOSURE
~his invention relates to novel compounds which show activitY as herbicides, to novel herbicidal compositions which contain these compounds, and to new methods of controlling weeds with these herbicidal compositions.
Certain diphenyl ethers have been shown to be effective weed control agents. However, the herbicidal effectiveness of a given diphenyl ether cannot be predicted from an examination of the substituent groups attached to the phenyl rings in the ether, and often quite closely related compounds will have quite di~ferent weed control abilities.
Various diphenyl ethers may have overlapping or complementary areas of activity or selectivity, and can thus be useful in combination to control a variet~ of weeds upon application f a single composition Furthermore, the diphenyl ethers heretofore disclosed as herbicides are not completely effective. An ideal herbicide should give selective weed control, over the full growing season, with a single admin-istration at low rates of application. It should be able to control all common weeds by killing them as the seed, the germinating seed, the seedling, and the growing plant. At the same tlme, the herblcide should not be phytotoxic to the crops to which it is applied and should decompose or other-wise be dissipated so as not to poison the soil permanently.
~: , The known diphenyl ether herbicides ~all short of these deals, and it~would thus be desirable to have new herbicides which show~even mor~e selective control of undesirable plants `among desirable crop plants or which complement the known diphenyl ~ethers ln activity.
;~ 30 ~ ~ ~In accordance w1th the present invention~ there is , ~37~3~

provided a new class of novel diphenyl ethers having the formula ~\
Y X (I) ~\ :

. wherein X is a hydrogen atom, a halogen atom, preferably a fluorine atom or a chlorine atom, a trihalomethyl : group, preferably a trifluoromethyl group, a (Cl-C4)alkyl group, preferably a methyl group, or a cyano group, : :
Y is a hydrogen atom, a halogen atom, preferably a fluorine atom or a chlorine atom, or a trihalo-methyl group, preferably a trifluoromethyl group, and Z is a hydrogen atom, a hydroxy group, an alkoxy group, preferably having 1 to 6 carbon atoms, and : most preferably 1 to 4 carbon atoms, an alkyl group, preferably having 1 to 4 carbon atoms, a halogen atom, preferably a chlorine atom or a : fluorine atom, an amino group, preferably having up~to 6 carbon atoms, an alkylthio group, pre-ferably having 1 to 4 carbon atoms, a cyano group, 20~

2- -,: , ~ , . , " : ., ~ 3 a carboxy group, a carbalkoxy group, C02R~
preferably having 1 to 4 carbon atoms in the alkoxy moiety, a carboxyalkyl group, -R'C02H, preferably having up to 4 carbon atoms, a carbalkoxyalkyl group~ -R'C02R~preferably having up to 6 carbon atoms, an alkanoyloxy group, -OCOR~ preferably h~ving up to 4 carbon atoms, optionally substituted with a halogen atom~ or a carbamoyloxy group, -OCONH2, -OCON~, or -0CONR2, preferably having up to 6 carbon atoms.
In the above deflnitions of the Z substitutent~ R.represents - an alkyl group~ and R' represents a divalent alkylene group. The alkyl or alkylene portion of the alkyl-containing X and Z substituents can have either a straight- or branched-chain or a cyclic spatial configuration.
A3 used in the present specification and claim3, tha term '~alkoxy group" is intended to include both unsub-stituted alkoxy groups as well as sub3tituted alkoxy groups : ~ .
~ which have one or:more of the hydrogen atoms replaced by , ~ :
~ ~ 20 a substi:tuent group. Among the substituted alkoxy groups ~ .
, which Z c~n represent:are alkoxy groups of preferably up to-4 carbo~ atoms substituted with a halogen atom, a hydroxy group, a (Cl-C4)alkoxy group, a carboxy group, a - :-: : ~ , carbalkoxy group~ preferably having up to 4 carbon atoms ;25 ~ in the ester~ lkoxy ~group~a trihaloalkyl groupj preferably ::
a tr~fluoromel;hyl group, ~an alkenyl group,~an alkynyl :: .
group,~prefer:clbly~n ethynyl group~ an amino group, an ~ ~
lkyl-or ~dlalkyl ~ lno group, including heterocyclic .. : :
substituents~;uch:~as:morpholi~o, piperaz:ino7 piperidino, ~3~ ~d -h~:l.k-,~ ~d D~ ra~ y having~a~total of up to ~

~ , ~

~930~

carbon atoms, an alkylthio group, preferably having up to 4 carbon atoms, a al~ylsulfonyl group, preferably having up to 4 carbon atoms~ an epoxy group, an alkylcarbonyl - group, including halo-substituted alkylcarbonyl, and preferably having up to 4 carbon atoms in the alkyl group, most preferably methylcarbony~ a carbamoyl group, including alkyl- or dialkylcarbamoyl7 preferably having a total of up to 4 carbon atoms in the alkyl substituents.
The term "amino group" as used in the present LO specification and claims is intended to include an unsub-stituted amino group9 -~H2, as well as amino groups having one or both hydrogen atoms replaced by substituent groups.
Among the substituted amino groups which Z can represent are amino groups sub9tituted with one or two alkyl groups, preferably having a total of up to 6 carbon atoms~ halo-~
hydroxy-, or alkoxy-substituted alkyl groups, preferably having a total of up to 6 carbon atoms, one or two alkyl-thio carbonyl groups~ preferably having a total o~ up to carbon atoms in the alkyl moiety, carboxy groups, carb-alkoxy groups~ preferably having up to 4 carbon atoms in the alkoxy group, carbamoyl groups, including alkyl or dialkylcarbamoyl groups~ preferably having up to ~ carbon atoms in the alkyl moiety~ alkylcarbonyl groups7 preferably ; having u? to 4 carbo~ atoms, or halo-substituted alkyl- -25~ ~ carbonyl groups7 preferably having up to 4 carb~n atoms.
The substituted amino groups can also be hetero-cycllc amino ~groups~ such as piperidino, piperazino~ morpho-lino,~pyrrolidinyl~ and the like. When the Z substituent is or contains a carboxy group, either the free acid or the

3 ~ ~s~alt form~can~be used. -~

. .

~g3~3 When Z is an alkyl yroup, it may be optionally sub-sti-tuted wi-th a hydroxy group, a (Cl-C4)alkoxy group, or a halogen atom, preferably a chlorine atom.
These novel compounds have been found to show unexpected activity as weed control agen-ts. In a preferred embodiment of the invention, X is a halogen atom or a cyano group, Y is a hydrogen atom or a halogen atom, and Z is an alkoxy group.
Examples of the compounds of the invention embraced by Form-lla I include:
a,a,a-trifluoro-p-tolyl-4-nitrophenyl ether, 2,~,a,a-tetrafluoro-p-tolyl 4-nitrophenyl ether, 2-bromo-a,a,u-trifluoro-p-tolyl-4-nitrophenyl ether, 2-chloro-a,a,a-trifluoro-p-tolyl-4-nitrophenyl ether, a,~,a-trifluoro-2-iodo-_-tolyl-4-nitrophenyl ether, 2,6-dichloro-a,a,a-trifluoro-p-tolyl-4-nitrophenyl ether, 2-chloro-6,a,~,a-tetrafluoro-_-tolyl-4-nitrophenyl ether, 2-cyano-a,a,a-trifluoro-_-tolyl-4-nitrophenyl ether, 2-cyano-6,a,a,a-tetrafluoro p-tolyl-4-nitrophenyl ether, 2-cyano-6-chloro-a,~,a-trifluoro~~-tolyl-4-nitrophenyl ether, ~,a,a,a' ,a',a'-hexafluoro-2,4-xylyl-4-nitrophenyl ether, 6-chloro-a,a,a,a',a',a'-hexafluoro-2,4-xylyl-4-nitrophenyl ether, a4,a4,a4-trifluoro-2,4-xylyl-4-nitrophenyl ether, 2-butyl-,a,~-trifluoro-p-tolyl-4-nitrophenyl ether, 2-chloro-6-ethyl-a,a,a-trifluoro-p-tolyl-4-nitrophenyl ether, and the like.

' :

~ ;'''"

~0~303 2-chloro- a~ a, a-tri~luoro-~-tolyl-4-nitro~r~-tolyl ether~
2-bromo-a~a,a-trifluoro ~-tolyi-3-butyl-4-nitrophenyl ether, 2,,a,a-tetrafluoro-~-tolyl-4-nitro-3-n-propoxyphenyl ether~
2-chloro-6 a,a,a-tetraM uoro-~-tolyl-3-methylthio-~-nitro-phenyl ether~
2-chlaro-a,a,a-trifluoro- -tolyl-3-propyl -4-nitrophenyl ether, 2-chloro-a,a,a-trifluoro-~tolyl-3-ethoxy-4-nitrodiphen~l ether, a,a,a-trifluoro-2-iodo- -tolyl-3-ethoxy-4-nitrophenyl ether, 2,6-dichloro-a~a,a-trifluoro-~-tolyl-4-nitro-3-a-propoxrphenyl ether~ .
a,a,a 7 a',a',a'-hexa~luoro-2~-xylyl-3-n-butoxy-4-nitropherlyl ether~
2-cyano-a,a,a-trifluoro-~-tolyl-3-ethoxy-4-nitrophenyl ether~
2-chloro-6-cyano-a,a,a-trifluoro-~-tolyl-4-nitro-3-~-propoxy-phenyl ether~
2-cyano-,a,a-trifluoro-~-tolyl-3-carboxy 4-nitrophenyl ether~
2~6-dibromo-a a~a-trifluoro-~-tolyl-3-methoxymethoxy-4-nitr phenyl e~he~, .
2-chloro-a,a,a-trifluoro-~-tolyl-3-(2-hydroxyethox~i4-nitrO-phenyl ether, 2,a,a,a-tetrafluoro-~-tolyl-4-nitro-3-n-propylaminophenyl ether, 2-chloro-a a~a-trifluoro-~-tolyl-3-dimethylamlno-4-nitro-pheny~ ether~
2-cyano-a,a~a-trifluoro-~-tolyl-3-carbethoxy-4-nitrophenyl ether : 2,6-dichloro-a~a,a-triPluoro-~-tolyl-3-carbethoxy-4-nitrophenyl ether :
: 2-ethyl-a~a,a-trifluoro-~-tolyl-3 (2-carboxy ethox~4 nitro-: phenyl ether, a, a, a, a', a' ~a~hexafluoro-2~4-xylyl-3-carbethoxymethyl-4-nitrophenyl ether, ~2-cyano-a~ a~ a-trifluoro-~-tolyl-3-(2-carboxy propyI~4-nitro phenyl ether, 2,a,a,a-tetraf:Luoro-~-tolyl-3-carbethoxymethoxy-4-nitro-phenyl et~er, : ~
2-chloro-,a,a-trifluoro-~ tolyl-3-(3j3 diethylureido~-4-nltrophenyl ether, ,- : ., , . -~ 3~3 2-chLoro-6-cyano-a,a,a-trifluoro-p-tolyl-3-acetamido-~-nitrophenyl ether~
2-chloro-a~a~a-trifluoro-P-tolyl-3-carbethoxyami~o-4-nitr phenyl ether~
2-chloro-a,,a-trifluoro-~-tolyl-3-chloro-4-nitrophenyl ether, 2-chloro-a,a,a-trifluoro-P-tolyl-3-hydroxy-4-nitrophenyl eth~r, 2-bromo-a,a,a-trifluoro-P-tolyl-3-butynyloxy-4-~itrophenyl ether 2-cyano-a,a,a-trifluoro-P-tolyl-3-(2-methyl)propynyloxy-4-nitrophenyl ether, '2~6-dichloro-~a a-trifluoro-P-tolyl-3-(2~2~2-trifluoro) . ethoxy-4-ni~rophenyl ether~
2-chloro-a,a,a-trifluoro-~-tolyl-3~(2-dimethylaminoethoxy)-

4-nitrophenyl ether, 2-bromo-a,a~a-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether, a ~ a ~ a ~ at~ al~ aLhexafluoro-2~4-xylyl-3-(2-hydroxyethylamino)-4-nitrophenyl ether ~ ~a4~a -trifluoro-2,4-xylyl~3-a~ino-4-nitrophenyl ether~
2-chloro-a~a~a-trifluoro-P-tolyl-3-morpholino-4-nitrophen ether, 2-cyano-a~a~a-trifluoro-P-tolyl-3-(N-methylcarbamoyloxy) ' 4-nitrophenyl ether~
25 2-chloro-6,a,a,a-tetrafluoro-p-tolyl-3-propiona~ido-4-nitrophenyl ether, 2-chloro-a,a,~-trifluoro-P~tolyl-3-chloroacetamido-4-nitro-: phenyl ether~
a4, a4 ~ a4- trifluoro-2 7 4-xylyl-3-(2,3-ePOxypropoxy)-4-nitro-phenyl ether~
2-chloro-a~a~a-trifluoro-~-tolyl-3-(2,3-dihydroxypropoxy)-4-nitrophenyl ether, ; 2-oyano~aga,a-trifluoro-p-tolyl-3-(2-methylthioethoxy)-4- ~ :
: nitrophenyl ether, 35~ ' 2-chloro-a,a,a-trifluoro-_-tolyl-3-(1-ethyl-3-methylureido)-4~nitrop'henyl ether, . ~ , ~ :: 2-bromo-a~s~a-trifluoro-~-tolyl-3-(2-methylsulfonylethoxy)-:3 ~ 4-nitrophen~l ether~
: a, a, a,a'',a',a'-hexafluoro-2~4-xylyl-3-(3-methylureido)-4- ' ::' ni~tr~ophenyl ether~ ~

, - ~ . . .,; . :: , ~0~9303 2-cyano~ -trifluoxo-p-tolyl-3-ethylthi.ocarbonylamino-4-nitrophenyl ether, 2-cyano-~,a,~-trifluoro _-tolyl-3-cyano-~-nitrophenyl ether, 2,6-dichloro-~ trifluoro-p-tolyl-3-carboxy-4-nitro-phenyl ether, 2-chloro~ trifluoro-p-tolyl-3-(1-carbamoylethoxy)-~-nitrophenyl ether, 2-bromo-~ -trifluoro-_-tolyl-3-(3-oxobutoxy)-4-nitro~
phenyl ether, and the like.
The novel diphenyl ethers of the invention are useful both as preemergence and as postemergence herbicides. Pre-emergence herbicicles are ordinarily used to treat the soil in which the desired crop is to be planted by application either before seeding, during seeding, or, as in most applications, after seeding and before the crop emerges. Postemergence herbicides are those which are applied after the plants have emerged and during their growth period.
Among the crops on which the diphenyl ethers of the :
invention can be advan-tageously employed are, for example, cotton, soybeans, peanuts, safflower, beans, peas, carrots, corn, wheat, and other cereal crops.
: Diphenyl ethers of the invention are useful for con-trolling weeds in rice crops. When used in transplanted rice crops, the ethers can be applied either preemergence or post-:~ ~ emergence to the weeds--that is, they can be applied to the growth medium of the transplanted plants either before the weed plants have emerged or while they are in their early stages of ~ -:
: ~ , ~; ~ growth. The ethers can be applied to the growth medium either .
:
~ 30 before or after the rice has been transplanted to that mediumO
~, ~
~ : The diphenyl ethers of the invention can be applied ~ ~ : : -.
:~ in any amount~which~will give the required control of weeds. A
: preferred rate of application of the herbicides of the invention is from about 0.1~to about 12, and most preferably about 0.25 to 4, pounds of the diphenyl ether per acre.
: ~ -8-~0~303 Under some conditions~ the diphenyl ethers of the inventlon may be advantageously incorporated into the soil or other growth medium prior to planting a crop. ~his incorporation can be carried out by any convenient means, including by simple miXing with the soil, by applying the diphenyl ether to the surface of the soil and then disking or dragging into the soil to the desired depth, or by employing a liquid carrier to accomplish the necessary penetration and impregnation.
A diphenyl ether of the invention can be applied to the growth medium or to plants to be treated either by itself or, as i9 generally done, as a component in a herbi-cidal composition or ~ormulation which also comprises an agronomically acceptable carrier. By agronomically acceptable carrier is meant any substance which can be used to dissolve, ; disperse~ or diffuse a herbicidal compound in the composition without impairing the effectiveness of the herbicidal compound and whic~ by itself has no detrimental effect on , the soil~ equipment, crops, or agronomic environment.- Mixtures of the dlphenyl ethers of the invention may also be used in an~ of these herbicidal formulations. The herbicidal :
; compositlons of the invention can be either solid or liquid formulatlons or solutions. For example, the diphenyl ethers can be formulated as wettable powders, emulsifiable concen-25~ ; trates, dusts, granular formulations, aerosols, or flowable emulsion concent~rates. In such formulations, the compounds ~ -are-extended with a liquid or solid carrier and, when deslred,~suitable sur~actants are incorporated.
It is usually desirable, particularly in postemergence :~ ,-~ ~ : . - -~ 9_ ., ~ .

applications, to include ad~uvants, such as wetting agents~
spreading agents, dispersing agents, stickers, adhesives, and the like, in accordance with agricultural practices.
Examples o~ adjuvants which are commonly used in the art can be found in the John W. McCutcheon~ Inc. publication "Detergents and ~mulsifiers Annual"
The diphenyl ether compounds of this i~vention can be dissolved in any appropriate solvent. Examples of solvents which are useful in the practice of this invention include alcohols, ketones, aromatic hydrocarbons, halogenaked hydrocarbons, dimethylformamide, dioxane, dimethyl sulfoxide, and the like. Mixtures of these solvents can also be used.
The concentration of the solution can vary from about 2%
to about 98% with a preferred range being about Z5~ to about 7 5~o .
For the preparation of emulsifiakle concentrates, the diphenyl ether can be dissolved in organic solvents, such as benzene, toluene, xylene, methylated naphthalene, corn oil, pine oil~ Q-dichlorobenzene, isophorone, cyclo-hexanone, methyl oleatea and the like, or in mixtures of these solvents, together with an emulsifying agent which permits dispersion in water. Suitable emulsifiers include, for exa~ple, the ethylene oxide derivatives of alkylphenols or long-chain alcohols, mercaptans~ carboxylic acids, and reactive amines and partially esterified polyhydric alcohols.
Solvent-soluble sulfates or sulfonates, such as the alkaline , earth~salts~or amine salts of alkylbenzenesulfonates and the fatty alcohol sodium sulfates, having surface-active propertles can be used as emulsifiers either alone or in conJunction wi~th an ethylene oxide reaction product. Flowable .

~ 3 emulsion concentrates are formulated similarly to the emulsi~iable concentrates and include, in addition to the above components, water and a stabilizing agent such as a water-soluble cellulose derivative or a water-soluble salt of a polyacrylic acidO The concentration of the active ingredient in emulsifiable concentrates is usually about 10% to 60% and in flowable emulsion concentrates, this can be as high as about 75%.
Wettable powders suitable for spraying, can be prepared by admixing the compound with a finely divided solid, such as clays, inorganic silicates and carbonates, and sillcas and incorporating wetting agents, sticking agents, and/or dispersing agents in such mixtures. The concentration of active ingredients ln such formulations is usually in the range of about ZO% to 98%, preferably about 40% to 75%.
dispersing agent can constitute about 0.5% to about 3~ of the composition~ and a wetting agent can constitute from about 0.1% to about ~ of the composition.
Dusts can be prepared by mixing the compounds of the invention with finely divided inert solids which~may be organic or inorganic in nature. Materials useful for this purpose include, for example, botanical flours, silicas, silicates~ carbonates and clays. One convenient method of preparing~a dust is~to dilute a wettable powder with a ~ finely dividecl carrier. Dust concentrates containing about 20% to 80%~of~ the active~ ingredient are commonly made and are ~subsequent;ly diluted to akout 1% to 10% use concentration.
Granular formulations can be prepared by impregnating a solid such as granular fuller's earch, vermiculite, ground ~ -` 3~ corn cobs, seed hulls, lncluding bran or other grain-hulls, ,, :

:: ., .. , . . . . . , ~ . ,.. , . , ..... - . -~9~3 or similar material. A solution of one or more of the diphenyl ethers in a volatile organic solvent can be sprayed or mixed with the granular solid and the solvent then removed by evaporation~ The granular material can have any suitable size, with a preferable size range of 16 to 60 mesh. The diphenyl ether will usually comprise about 2 to 15~ of the granular formulation.
The diphenyl ethers of the invention can also be mixed with fertilizers or fertilizing materials before their application. In one type of solid fertilizing composition in which the diphenyl ethers can be used, particles of a fertilizer or fertilizing ingredients, such as ammonlum sulfate, ammonium nitrate, or ammonium phosphate, can be coated with one or more of the ethers. The solid diphenyl ethers and solid fertilizing material can also be admixed in mixing or blending equipment, or they can be incorporated with fertilizers in granular formulations Any relative proportion of diphenyl ether and fertilizer can be used which is suitable for the crops and weeds to be treated. The diphenyl ether wlll commonly be ~rom about 5~ to about 25%
of the fertilizing composition. These compositions provide fertilizing materials which promote the rapid growth of desired p}ants, and at the same time control the growth of undesired plants.
~` 25 ~ ~The diphenyl ethers o~ the invention can be applied as herbicidal sprays by methods commonly employed, such as conventional high-~gallonage hydraulic sprays, low gallonage sprays, alrblast spray, aeriaI sprays and dusts. For low volume applications a solution of the compound is usually used.~The dilution and rate of application will usually .

.. . . . . .. . . . .

i~7g3~3 depend upon such factors as the type of equipment employed, the method of application~ the area to be treated ~nd the type and stage of development of the weeds.
For some applications, it may be desirable to add one or more other herbicides al.ong with diphenyl ethers of the invention. Examples of other herbicides which can be incorporated to provide additional advantages and effect-iveness include;
' 2~3~6-trichlorobenzoic acid and its salts 2,3,5,6-tetrachlorobenzoic acid and its salts j 2-methoxy~3,5,6-trichlorobenzoic acid and its salts 2-methoxy-3~6-dichlorobenzoic acid and its salts 2-methyl-3,6-dichlorobenzoic acid and its salts 15 . 2,3-dichloro-6-methylbenzoic acid and its salts : 2,4-dichlorophenoxyacetic acid and its salts and esters . .
~: 2,4,5-trichlorophenoxyacetic acid and its salts and esters ~ 2-methyl ~-chlor:ophenoxyacetic acid and its salts and esters .~ : 2-(2,~9.5-trichlorophenoxy~propioniç acid and its salts and esters ` 4-(2?4-dichlorophenoxy~butyric acid and its salts and esters .~ : 4-(2-methyl-4-chlorophenoxy1butyric acid and its salts and esters 273~6-trichlorophenylacetic acid and its salts ~.
3~6-endoxohexahydrophthalic acid ~ dimethyl 2~3~5~6-tetrachloroterephthalate trichloroacetic acid and its salts ., : ;
.
2 2-dichloropropionlc acid and its salks 2~3-dichloroLsobutyrlc acld and its salts 30~ ~èthyl::N~N-di(n-propyl)t~iolcarbamate ~ ~ . , ... .:

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

~0~93~3 propyl N,N-dl(~-propyl)thiolcarbamate ethyl N-ethyl-N-(~-butyl~thiolcarbamate propyl N-ethyl-N-t~-butyl)thiolcarbamate 2-chloroallyl N~N-diethyldithiocarbamate N-methyldithiocarbamic acid salts ethyl l-hexamethyleneiminecarbothiolate isopropyl N-phenylcarbamate isopropyl N-(m-chlorophenyl)carbamate 4-chloro-2-butynyl N~(m-chlorophenyl)carbamate methyl N-(3~4-dichlorophenyl)carbamate ~h~
dinitro-Q-~gQ~ butyl~phenol and its salts pentachlorophenol and its salts . S~ti~ute~ Ureas 3-(3,4-dichlorophenyl~-l,l-dimethylurea 3-phenyl-1,1-dimethylurea 3-(3,4-dichlorophenyl)-3-methoxy-l~l-dimethylurea .
3-(4-chlorophenyl)-3-methoxy-l,l-dimethylurea ~ 3-(3~4-dichlorophenyl~ n-butyl-l-methylurea .~ 20 3-(3,4-dichlorophenyl~ methoxy-1-methylurea : ~ 3-~4-chlorophenyl)-l-méthoxy-l-methylurea :: : 3-(3~4-dichlorophenyl)-1,1,3-trimekhylurea 3-(3,4-dichlorophenyl)~ diethylurea dichlora} urea ~ ~ fl~k_~lLL~L_L~
2-chloro4,6--bis(ethylamino)-s-triazlne 2-chloro-4-et;hylamino 6-isopropylamino.-s-triazine ::
`2-chloro-4~,6--bis:(methoxypropylamino)-~-triazine 2-me~thoxy-4,6-bis(lsopropylamino~ triazine 2-chioro-4-et;hylamino-6-(3-methoxypropylamino)w~-triazine ::: ~ ~ - -: ` : : ` ` :

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

~793~3 2-methylmercapto-4,6-bis(isopropylamino)-s-triazine 2-methylmercapto-4,6-bis(ethylamino)~s triazine 2-methylmercapto-4-ethylamino-6-isopropylamino-~-triazine 2-chloro-4,6-bis(isopropylamino)-~-triazine 2-methoxy-4j6-bis(ethylamino~-~L-triazine 2-methoxy-4-ethylamino-6-isopropylamino~-triazine 2-methylmercapto-4-(2-methoxyet;hylamino~-6-isopropylamino-~-triazine ~ , 2,4-dichloro-4'-nitrodiphenyl ether 2,4,6-trlchloro-4'-nitrodiphenyl ether 2,4-dichloro-6-fluoro-4'-nitrodiphenyl ether 3-methyl-~'-nitrodiphenyl ether 3,5-dimethyl-4'-nitrodiphenyl ether 2,~'-dinitro-4-trifluoromethyldiphenyl ether 2~4-dichloro-3'-methoxy-4'-nitrodiphenyl ether Anilide~
~ N-(3~-dichlorophenyl)propionamide :~ N-(3~4-dichlorophenyl)methacrylamide N-(3-chloro-4-methylphenyl)-2-methylpentanamide N-(374-dichlorophenyl)trimethylacetamide N-(3,~-dichlorophenyl)-ata-dimethylvaleramide N-isopropyl-N-phenylchloroacetamide ,~ . . ..
~ N-n-butoxymethyl-N (2~6-diethylphenyl~chloroacetamide .
25 ~ N-~-methoxymethyl-N-(2~6-diethylphenyl)chloroacetamide

5-bromo-3~ but~1~6-methyluracil : 5-bromo-3-cyclohexyl-I,6-dimethyluracil 3-cyclohexyl-5,6-trimethyleneuracil 5-bromo-3-isopropyl-6-methyluracil " . ~ , , , ~J93~

3-tQrt-butyl-5-chloro-6-methyluracil Nit~ile~
2,6-dichlorobenzonitrile diphenylacetonitrile 3,5-dibromo-4-hydroxybenzonitrile 3,5-diiodo-4-hydroxybenzonitril.e ~ 5__Y$~5~ hicides 2-chloro-N,N-diallylacetamide N_(l,l-dimethyl-2-propynyl)-3,5-dichlorobenzamide maleic hydrazide 3-amino-1,2,4-triazole monosodium methanearsonate disodium methanearsonate N~N-dimethyl-a?a-diphenylacetamide . N,N-di(~-propyl~-2,6~dinitro-4-trifluoromethylaniline : N,N-di(n-propyl~2~6-dinitro-4-methylaniline N,N-dl(n-propyl)-2,6-dinitro-4-methylsulfonylaniline : 0-(2,4-dichlorophenyl~-0-methyl-isopropylphosphoramidothioate , .
- 4-amino-3,5,6-trichloropicolinic acid 2,3-dichloro-1,4-naphthoquinone di(methoxythiocarbonyl)disulfide 3-lsopropyl-lH-2,1,3-benzothiadiazin-(4)3H-one-2,2-dioxide

6~7-dlhydrod}pyridol[1,2-a:2',1'-c]pyrazidinium salts dimethyl-~,4'-bipyridinium salts 25 :: 3,4,5,6-tetrahydro-3,5-dimethyl-2-thio-2H-1,3,5-thiadiazine.
When mixtures of herbi~cides are employed, the relative proportlons which are used will depend upon the crop to be treated~and t;he ~degree of selectivity in weed control which is desired.~

. : :

~ 93~3 The diphenyl ethers of the invention or their precursors can be prepared by reacting a suitably substituted phenol, or -the potassium or sodium salt of the phenol, with a suitably substituted halobenzene, such as a chloro- or fluorobenzene, in the presence of an alkaline agent.
The following examples will further illustrate this invention but are not intended to limit it in any way. In Table I, typical diphenyl ethers of the invention are listed, with their mel-ting points and elemental analyses. Specific, illustrative preparations of the compounds of Examples 3, 7, 10, 19, 21, 25, 26, 37, 47, 4~, 49, 51, 55 to 59 and 61 to 64 are described after Table I.

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l~D7~ 3 0 ~i l~ r~ ~o O ~

~2 o O ~ ~ J r~o O
O

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. , .: . . : , , . - , 93~3 ~^i Preparation of 2 Chloro-,a,a~trifluoro-~-tolyl-3-ethoxy-Method A
a3 1~3-Bis(2-chloro-a,a,a-trifluoro-~-tolyloxy)benzene A solution of potassium hydroxide ~3.26 g. 0.05 mole, 85~) in water (~ 3 g. ? is added slowly dropwise to a solution of resorcinol (2.75 g. 0.025 mole? and 3,4-dichloro-a,a,a-trifluorotoluene (10.75 g. 0.05 mole3 in sulfolane (125 ml) at 150-160C., with stirring. When the addition is complete, the strongly colored reaction mixture is stirred at 150-160C. overnight, then cooled~ diluted with benzene (200 ml), and washed cautiously with water (700 ml3. Hexane (200 ml3 is added and the mixture washed with water (600 ml), dilute sulfuric acid (600 ml), dilute sodium hydroxide solution (60~ ml), and water (600 ml)~
dried, and the solvent removed to give 1,3-bis(2-chloro-a,a,a-trifluoro-~-tolyloxy)benzene (8.6 g. 65~) b.p. 160-jOC./O.l - mm.
b~ 1~3-Bis(2-chlQro-a~a~a-trifluoro-~-tolyloxy)-4-nitrobenzene 1~3-Bis(2-chloro-a,a,a-trifluoro-~-tolyloxy)-benzene (12 g. 0.0255 mole? is added to a mixture of concen-trated nitric acid (12 g.) and sulfuric acid (15 g.~ at 50C. The temperature is then allowed to rise to 2~-30C
with manual stirring and mild ice bath cooling and after 10-20 minutes, the oil solidifies. The mixture is taken up in water/benzene (400 ml)/ hexane (400 ml3 and the organic phase is washed with water, dried, filtered through activated sillca gel (~20 g.), and the solvents removed. ~he residue is recrystallized from isopropanol to give 1,3-bis(2-chloro- -~
' ~ ~ .
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a~a~a-trifluoro-~-tolyloxy) 4-nitroben3ene~ (7.4 g. 56~) m.p. llO-111.5C.
c) 2-Chloro-~a~a-trifluoro-P-tolyl-3-ethoxy-4-nitroph3nyl eth~r _ _ _ _ _ A 10% solution of potassi~n hylroxide in ~thanol (10 ml) is adled to a solution -of 1~3-bis(2-chloro-a~a,a-trifluoro-p-tolyloxy)-4-nitroben~ene (2 g. 0.0039 mole) in dioxane (20 ml). Af~er forty minutes at room temperature, the solutlon is heated to 45OC for eight minuteis, then ; 10 cooled, diluted with benzene (50 ml) anl hexane (50 ml) and washed-with water (3 x 100 ml)~ dried, and the solvents removed. The residue is recrystallized fro~ isopropanol to give 2-chloro-a,a,a-trifluoro-p-tolyl-3-ethoxy-4-nitro-phenylether (1.21 g. 86~) m.p. 83-840C.
M-ethod B
a) A mixture o~ the di-potassium salt of resorcinol ~186.3 g., 1 mol)~ 3~4-dichloro-a,a,a-trifluorotoluene (53.7 g., 0.25 mol), and sulfolane (100 ml.) is stirrad for 30 20~ hours at 140-1600Co Benzene (500 ml ) and water (200 ml ) are added .
ar~d the organic phase is washed with water (3 x 200 ml), . ................ ..
diluted with hexane (50~ ml) and washed agair. with water, :: :
dried~ ~iltersd throu~h activated silica gel (15 ~)a the ~ solvents removed, and the residue distilled to give 2-chloro-, a~a~a-trifluoro-P-tolyl-3-hydroxypheryl ether (45.1 g.
; 62~) b~.p. 112-124C~/0.3 mm.

A mixture of 2-chloro-a,a, triflu~ro-P-tolyl-3-30 ~ ~ hydroxyphenylether (184 g.) and acetic anhydride (334 g.) is heated on a steam bath for 1 hour and cooled. ~he mixture 2i~
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is ~ashed with 5~ sodi~ carbonate solution (2 x 500 ml.) and distilled to give 2-chloro-a,a,a trifluoro-p-tolyl-3 acetoxyphenyl ether (8L3 g., 40~) b.p. 107-117C./0.09 mm.
c) 2-Chloro-a~a,a-trifluoro-.P-t;olyl-3-acetoxy-4-nitr Prhenyl ether A solution of 2-chloro-a,a,a-trifluoro-P-tolyl-3-acetoxyphenyl ether (249 g., 0~75 mol) in 1,2-dichloroetnane (1200 ml.) is stirred 2.2 hours at 20-30C. with ~ cooled mixture of concentrated sulfuric acid (276g ) and nitric acid, 70% (227 g.). Hexane (700 ml.) is added and the oil layer L0 washed once with water, 3 timas with dilute sodi~ bic~rbonate, and ~nce more with water~ dried, filtered through activated silica gel (-~ 40 g.), the solvents removed. ~he product is crystallized from hexane-benzene to give 2-chloro-a~a,a-trifluoro-E~tolyl-3-acetoxy-4-nitrophenyl ether ~207.5 g., 73~)m~p 83-89~C.
d) 2-Chloro-a,a,a-trifluoro-P-tolyl-3-hydroxy-4-nitro-phenvl ether A solutlon of 2-chloro-,,-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether (204.9 g., 0.545 mol) in ;20 methanol (2900 ml.) is stirred l hour at 200C. with potassium carbonate (103 g~ 0.745 mol). Ninety per cent of the methanol is removed~ and benzene (1 liter)~ 7-8~ sul~uric acid solution (1600 ml.) are; added and stlrred 1.5 hours at 250C. The oil layer is washed twice more with water (200 ml. each), dried, ~-filtered through activated silica gel (40 g.), the solvents ,: ~ ..
~ removed, and the residue cryst~ ed in hexane to give - ~
~ 2-chloro-a~a,a-trifluoro-P-tolyl-3-h~droxy-4-nitrophenyl -i ~ : , ~ ether (165.3 g~ 90%)m.p. 68.5-73~C~
i ~: ~ , , . ~, e) 2-Chloro-a,a,a-trifluoro-P-tolyl-3-ethexy-4-nitrophenyl 3 ~ A solutlon o~ 2-chloro-a,a,a-trifluoro-p-tri-:

93~3 fluoro-p-tolyl-3-hydroxy-4--nitroph2nyl ether (60 g., 0.018 mol, 73% pure) and dimethylformamide (100 g.) is converted to the potassium phenoxide and stirred with ethyl bromide (35 g., 0.32 mol) 3 hours at 600C. and 5 hours at 800C.
Perchlorethylene (150 g.) is added and the solution wahsed twice with water (~ 250 ml. each) at 50oC. The solvents are removed to give 2-chloro-a,a,a-t;rifluoro-~-tolyl-3-ethoxy-4-nitrophenyl ether (56 g.~ 83%, 71% pure).
Example 7 Preparation of 2-Cyano-a,a,a-trifluoro-P--tolyl-3-ethoxy-4 nitrophen~l ether A solution of potassium hydroxide (2.6 g., 0.04 mole) 87.3~ pure and 3-ethoxy-4 nitrophenol (7.3 g., 0.04 mole) in methanol (30 ml) is stripped to dryness under reduce pressure. A residue of potassium 3-ethoxy-4-nitro-phenoxide is dissolved in sulfolane (200 g.) and 4-chloro-3-cyano-benzotrifluoride (8.2 g., 0.04 mole) is added.
Gas-liquid chromotography shows the reaction to be complete ~; after stirring at 110C for 4 1/2 hours and 135C for 2 1/2 hours. The reaction mixture is cooled and poured into de-ionized water and the precipitate which forms is filtered off and air dried. Recrystallization ~rom isopropanol yields 2-cyano-a,a~a-trifluoro-P-tolyl-3-ethoxy-4-nitrophenyl ether (7.~ g. 53~) mOp. 143-145C.
~ L~
Preparation ~f 2-Chloro-a~a~a-trifluoro- -tolyl-3-ethyl-amino-4-nitr~p ~
A solution of 1,3-bis(2-chloro-a,a,a-trifluoro-p-tol-yloxy)-4-nitrobenzsne (12.8 g. 0.025 mol)~ and ethyl-~amine (6.7~g. 0.15 mol) in dioxane (120 ml.) is heated in :
.
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~0~93~3 a pressure bottle 4.5 hours at 50-5~oC. and 4.3 hours at 90-950C. Benzene (2()0 ml.), hexane (70 ml.) and water (500 ml.) are added and the organic phase is washed with water (500 ml.)~ 10~ sodium bicarbonate solution (200 ml.) and water (200 ml)~ dried, filtered through activated silica gel (25 g.)~ the solvents removed, and the residue is crystallized from hexane to give 2-chloro-u~~a-trifluoro-p-tolyl-3-ethylamino-4-nitrophenyl ether (7.9 g. 88~) m~p. 82-830C.
1 ~xample 21 Preparation of 2-Chloro-a,a,a-trifluoro-~-tolyl~3 diethyl-A solution of 1,3-bis(2-chloro~a,a,a-trifluoro-p-tolyloxy)-4-nitroben~ene (12a8 g. 0.025 mol) in p-dioxane (130 ml.) is heated under reflux for 26 hours at 65-950C.
with diethylamine (50 ~. 0.66 mol). Ben~ena (~ 200 ml.) and water (~ 500 ml.) are added followed by hexane (~ 70 ml.) and the oil layer is separated, washed with water (500 ml)~
10~ sodium bicarbonate solution (200 ml), and water (200 ml.)~
dried, filtered through activated silica gel (~ 25 g.), the solvents removed. The residual oil is distilled in vacuo to give 2-chloro-a7a,a-trifluoro-~-tolyl-3-dleth~Jlamino-4-nitrophenyl ether (8015 g 84~) b~p. 180-190Co/0~01 mm.
Exam~le_2 ~Preparation of 2-Chloro-a~a~a-trifluoro-P-tolyl-3-( 2-Chloro-a~,a-tri~luoro-P-tolyl-3~ carbethoxy-ethoxy)-4-nitrophenyl ether (806 g. 0.02 mol), potassium hydroxide 86~ (2.6 g. 0.04 mol), ethanol (8 ml.), dioxane ~(8 ml.), ~and water (100 mlO) are heated at 90-950C. for 30 minutes. Ether (200 ml.~) and water (200 ml.) are added _ l~g3~33 an~ the mixture acidifled with dilute sulfuric acid, the water layer extracted three times with ether (2G0 ml. each), dried, and the ether removed to give 2-chloro-a,a,a-tri-fluoro-E-tolyl-3-(1-carboxyethoxy)-4-nitrophenyl ether (6.4 g. 79%) m.p. 108-109C~
Exa~ple 26 Preparation of 2-Chloro-a,a,-trifluoro-~-tolyl-3-(1-carbethoxYetho~4-nitrophen~l ether Potassium 2-nitro-5-(2-chloro-a,a,a-trifluoro- -tolyloxy)phenoxide (7.4 g. 0.02 mol)~ e-thyl 2-bromopropionate (3.6 g. 0.02 mol) and sulfolane (50 ml.) are heated 1.5 hours at 90-950C. Bsnzene (100 ml.~ and hexane (100 ml~) are added and the solution is w~shsd wlth dilute sodium carbonate solution then with water~ dried, and ths solvents removed.
The residue is crystallized from pentane to give 2-chloro-a,;~,a-trifluoro-~-tolyl-3-(l-carbathoxyeth3xy)-4-nitrephenyl ether (6.2 g., 71~) m.p. 71-74C.
~ .
Preparation of 2-chloro-a,a,a-trifluoro-~-tolyl-3-chloro-a) ~-Chloro-~-nitrofluorobenzene m-Chlorofluorobenzene (240 g. 1.85 moles) is added .
to a mixture of sulfuric acid (185 g. 1.85 moles) and nitric acid (166 g., 1.85 mo~es) at -50C~ i~ 3.5 hours~ stirred 13 ~ hours, then benzene (200 ml~) and hexane (200 ml.) are added.
The~extract i; washed wlth water (1 x 300 ml.)~ sodium carbonate~ solutlon (l x 300 ml.), and water (1 x 300 ml.), dried and the~ solvents removed. The residue is distilled to give l38 g~ ~o~ mixed~ isomers. The 4-nitro isomer 3C ~ ~ crystQllizes and is~filtered off to give 3-chloro-4-nitro-luorobenzène (51 g. 16.7~) m.pO 36-380C~

.

; , . .

107~303 Examples 47-49 Preparation of 2-chloro-~,a,~-trlfluoro-p-tolyl-3-carbomethoxy-4-nitrophenyl ether -a) 3-Cyano-4-nitrofluorobenzene m-Fluorobenzonitrile (96.8 g., 0.8 mole) is added in two and one-half hours to a mi~ture of concentrated sulfuric acid (600 ml.) and potassium nitrate (80.9 g., 0.8 mole) at 3-6C., then allowed to warm to 25C. The mixture is poured over cracked ice (3000 ml.), extracted with chloroform (5 x 250 ml.), dried and the solvent removed. The residue is extracted with pentane and dried to give 3-cyano-4-nitrofluorobenzene (115 g., 86.5%) m.p. 102-104C.
b) 2-Chloro-~ -trifluoro-p-tolyl-3-cyano-4-nitrophenyl ether The potassium phenoxide of 2-chloro-~ -trifluoro-~-cresol (13.5 g 0.0688 mole) prepared in sulfolane at 5C. is added to a solution of 3-cyano-4-nitrofluorobenzene (11.4 g., 0.0688 mole) in sulfolane at 120C. in four hours, stirred 18 hours and cooled. Benzene (200 ml.) and hexane (100 ml) are added and the solution is water washed (5 x 250 ml.), dried, filtered and the solvents removed. The residue is crystallized to give 2-chloro-a,~,a-p-tolyl-3-cyano-4-nitrophenyl ether (16.3 g., 69%) m.p. 95-103C. 85% pure.
c) 2-Chloro-~,a,~-trifluoro-p-toly1-3-carboxy-_-nitrophenyl ether 2-Chloro-~ -trifluoro-p tolyl~3-c~a~o-4-hitrophenyl ether ~11.2 g, 0!0327 mole), acetic acid (25 ml.), and hydrobromic acid (12 ml. of 47.8% purity) are heated at 120C., ;~ in a pressure bottle, for two days, poured over cracked ice and extracted with benzene (2 x 150 ml). The benzene solution is driedl filtered, the solvent removed, and the residue -~
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~93~

crystallized Erom pentane -to yive 2-chloro-a,a,a-trifluoro-_-tolyl-3-carboxy-4-nitrophenyl ether (7.5 g. 63.5%) m. p. 140-150C., 85% pure.

d) 2-Chloro-a,a,a-trifluoro-_-tolyl-3-carbomethoxy-4-nitrophenylether -Hydrogen chloride is bubbled thru a solution of 2-chloro-a,a,a-trifluoro-_-tolyl-3-carboxy-4-nitrophenyl ether (2.3 g. 0.0064 mole) in methanol (50 ml.) for ten hours at 32C., stirred overnite and the solvent removed to give 2-chloro-a~a~a-trifluoro---tolyl-3-carbomethoxy-4-nitrophenyl ether (1.5 g. 40~).

Example 51 Preparation of 2-chloro-a,a,a-trifluoro-_-tolyl-3-(1-carbamoly-ethoxy)-4-nitro~henvl ether a) 2-Chloro-a,a,a-trifluoro-~-tolyl-3-(1-chloroformyle-thoxy)~
4-nitrophenyl ether 2-Chloro-a,a,a-trifluoro-_-tolyl-3-(1-carboxyethoxy)-4-nitrophenyl ether (34.8 g. 0.086 mol), thionyl chloride (20.4 g. 0.172 mol), and benzene (150 ml.) are stirred 5 hours at 95C. and sixteen hours at 25C. The benzene is removed to give 2-chloro-a,a,a-trifluoro-p--tolyl-3-(1-chloroformyl-ethoxy)-4-nitrophenyl ether (33.4 g. 92~).

b) 2-Chloro-a,a,a-trifluoro-~--tolyl-3~ carbamoylethoxy)-4-nitropheny1 ether A solution of 2-chloro-a,a,a-trifluoro-_-tolyl-3-(l-chloroformylethoxy)-4-nitrophenyl ether (4.2 g. 0.01 mol) in ether (50 ml.) is added to an ether solution (200 ml.) saturated with gaseous ammonia at zero temperatures. After 30 , .
; ~ minutes, water (100 ml.) is added and the ether layer separated.

The aqueous phase is extracted with ether (3 x 200 ml.) and the combined extracts dried, filtered through activated silica gel (~ 20 g.), and the solvent removed to give 2-chloro-a,a,a-, .

: :

~O~)3~3 trifluoro-p-tolyl-3-(1-carbamoylethoxy)-4-nitropherlyl ether (2.4 g. 60%) m.p. 108-111C.

Example 55 Preparation of 2-Chloro-~ -trifluoro-p-tolyl-3-(3-methyl-l-ethylureido)-4-nitrophenyl ether a) 2-Chloro-~,a,~-trifluoro-_-tolyl-3-(N-ethylchloroform-amido)-4-nitrophenyl ether . _ . . . _ _ . . . ...
A mixture of 2-chloro-~ -trifluoro-p-tolyl-3-ethylamino-4-nitro phenyl ether (3 6 g. 0.01 mol), phosgene (18.9 g. 0.19 mol), 2,6-lutidine (2.2 g. 0.02 mol), and benzene (~ 130 ml.) are heated in a pressure bottle 64 hours at 90-95C.
The mixture is cooled, filtered and the solvent removed to give 2-chloro-~ -trifluoro-_-tolyl-3-(N-ethylchloroformamido)--4-nitrophenyl ether.

b) 2-Chloro-a,~ trifluoro-p-tolyl-3-(3-methyl-1-ethylureido)-4-nitro~henvl ether A solution of 2-chloro-~ -trifluoro-p-tolyl-3-(N-ethylchloroformamide)-4-nitrophenyl ether (4.4 g., 0.01 mol), methylamine (3.3 g 0.11 mol) and benzene (~ 60 ml.) is allowed to stand twenty-five minutes at zero C., filtered, and the solvent removed. Benzene (~ 100 ml.) and hexane (50 ml.) are added and the solution is washed with water (100 ml.) and aqueous 10% sodium carbonate solution (2 x 100 ml.), dried, and the product absorbed on activated silica gel (~ 25 g.). The product is eluted with a mixture of benzene (400 ml.) and i methanol (40 ml) the solvents removed and the product recrystal-; lized to give 2-chloro~ ,a-trifluoro-_-tolyl-3-(3-methyl-1-ethylureido)-4-nitrophenyl ether (2.6 g. 62%) m.p. 127.5-128.5C.

-: ' - '', - i ' ' : -. . , ~ . ., ~93~3 Example ~6 Preparation of 2~6-Dichloro-a~a~a-trifluoro-P-tolyl-3-ethox~-4-nitrophen~l ether a) ~ 4-Dichlor~ tro-aqa ? -trifluorotoluene 3~4-Dichloro-a~a~a-trifluorotoluene (862 g. 4.0 mols) is added to a stirred mixture of concentrated sulfuric acid (~00 g.) anl nitric acid (3400 g.) at 350C. The mixture is stirred 70 minutes at 950C. and allowed to separate. The oil layer is washed once with water anl twice with 5~0 sodlum carbonate solution, dried, and fractionally distilled to give 3,4-dichloro-5-n~tro-a,a,a-trifluorotoluene (188 g. 18%) b.p. 115_1180C /15 mm, 88% pure.
b) 5-~mino-3,4-dichloro-a~a~a~trifluor toluene 500 ml. of an ethanolic solution ~ontaining 3~4-dichloro-5-nitro-a,a,a-trifluorotoluene (188 g 0~72 mol), and platinum oxide (Adam's catalyst) (0.2 g.) is reduced at room temperature in a low pressure hydrogenation apparatus to give 5-~mino-3,4-dichloro-a~a,a-trifluorotoluene (129.9 g.
78%) b~p. 65-70C./1-2 mmO
c) ~+~-Trichloro ~a~a-trifluorotoluene A solution of sodium nitrite (39 g.) in water (85 ml.) is added over 1 hour to a solution of 5-amino-3,4-dichloro-a,a~a-trifluorotoluene (117~5 g., 0.51 mol) in ;~ 1700 ml~ concentrated hydrochloric acid at -60C. and the solution stirred for 1 hour then filtered. The filtrate is . . . . .
added to a solution of cuprous chloride (76.5 ~.) in concentrated hydrochloric acid (500 mI.) over 5 minutes at . ~ .
. Oo to 80C. and gradualIy heated to 800C. over 80 minutes.
The reaction mixture is cooled to 350C. and extracted with ~ ~hexane (2 x 300 ml )~ The extract lS washed with water, 2~ sodium hydroxide solution~ dried and distilled to give .
; ~ -34-~ 3~

3,L~,5-trichloro-a,a,a-trifluorotoluene (70 g., 55~) b.p.
82-860C./10 mm~ 95~ pure.
d) =~3C~ b=D~ ~,9,__trifluoro-~-tol~lox~J)benzene _ A mixture of 3~4~5-trichloro-a~a~a-trifluoro-toluene (10 g. 0.04 mol), and the dipotassium salt of 1~3-dihylroxybenzene (~ g. 0.021 mo]) in 150 ml. sulfolane is stirred and heated 70 minutes at ~ 120C. The cooled reaction mixture is diluted with benzene (350 ml.) and ~~
washed once with water (lOOOmL),Hexane (200 ml.) is added, and the solution washed with water (3 x 500 ml.) dried~
filtered through activated sillca gel (~J25 g.)~ and the solvents removed. ~he residual oil is crystallized from a mixture of pentane and benzene to give 1,3-bis(2~6-dichloro-a,a,a-trifluoro-P-tolyloxy)benzene (5.3 g. 49~) m~p. 121-122Co - e) 1?3-Bis(2,6-dichloro a,a,a-trifluoro-p-tolyloxy)-4-A cooled mixture of concentrated sul~uric acid t6.5 ml.) and nitric acid (4.4 ml.) is added with stirrin~ to an ice cold solution of 1,3-bis(2,6-dichloro-,a,a-trifluoro--tolyloxy)-benzene (ll.l g.~ 0.021 mol) in 1~2-dichlorethane ;-(30 ml.j. After thirty minutes at room temperature, the phases are allowed to separate and the organic phase washed twice with water. Benzene (200 ml.) is added and the solution washed twice with dilute sodium carbonate solution, dried, ~iltered through activated silica gel (-J 25 g.), and the~solvents removed. The rasidual crystals are triturated wlth~pentane, flltered, and dried to ob-tain 1,3-bis(2,6-dichloro-a~a~-tri~luoro-P-tolyloxy)-~-nitrobenzene (9.9 g., 30~ ~ 82~) m0p. 137.5-1~0.50G.~ 90~ pure.

3~-: , ~
: : ..

.

' ~ 93~3 E) 2,6-Dichloro-a,a,a-trifluoro-p--tolyl-3-ethoxy-4-nitrophenyl ether ~~
. ~
~ solution of po-tassium hydroxide, 86% (1.9 g., 0.029 mol) in ethanol (20 ml.) is added to a solu-tion of 1,3-bis (2,6-dichloro-a,a,a-trifluoro-p-tolyloxy)-4-ni-trobenzene (8.0 g., 0.014 mol) in p-dioxane (70 ml.) and warmed 1 hour a-t 50C.
The solution is cooled and benzene (~ 250 ml.) is added and crystals of potassium 2-nitro-5-(2,6-dichloro-a,a,a-trifluoro-_-tolyloxy)phenoxide (2.9 g. 52%) are collected. Treatment wi-th acid yields the free phenol, 2,6-dichloro-a,a,a-trifluoro-~-tolyl-3-hydroxy-4-nitrophenyl ether (2.0 g. 40~) m.p. 84.5-86.5C.
This phenol (1.7 g. 0.0046 mol) is reconverted to the potassium salt, dissolved in dimethylformamide (20 ml.) and treated with ethyl iodide (1.2 g. 0.0077 mol) 2.5 hours at 50-70C. The reaction mixture is diluted with benzene (~ 100 ml.) and hexane (~ 50 ml.), washed with water (3 x 100 ml.), dried, filtered through activated silica gel (rJ15 g.), and the solvents removed to give 2,6-dichloro-a,a,a-trifluoro-p-tolyl~3-ethoxy-4-nitro-phenyl ether (0.8 g. 44~) m.p. 100.5-102C.
From the Eiltrate of the 2.9 g. of phenoxide there is recovered ethyl 2,6-dichloro-a,a,a-trifluoro-p-tolyl ether (3.0 g. 82%) b.p. 78C./5 mm, and an additional amount of the product 2,6-dichloro-a,a,a-trifluoro-~-tolyl-3-ethoxy-4-nitrophenyl ether (0.35 g. 6~) m.p. 88-93C.

30~
:
~ -36-.. ; , . . : , .
: , ., : . , :

93~3 Example 57 Preparation of 2-cyano-~,a,~~trifluoro-p-tolyl-4-nitrophenyl ether A solution of potassium hydroxide (3.2 g. 0.05 mole of 89.3% puri-ty) and p-nitrophenol (7.0 g. 0.05 mole) in methanol (25 ml.) is stripped under reduced pressure. The residue is dissolved in sulfolane, 4-chloro-3-cyano-a,a,a--trifluorotoluene (10.3 g. 0.05 mole) added, and the resulting solution heated at 150C for five hours. After cooling, -the solution is diluted wi-th benzene (350 ml.) washed wi-th wa-ter (6 X 250 ml.), dried, and the solvent removed. The residue (12.5 g.) is recrystal-lized from isopropanol to give 2-cyano-a,a,~-trifluoro-_-tolyl-4-nitrophenyl ether (7.6 g., 49%) m.p. 93-98C.

Example 58 Preparation of 2-chloro-a,a,a--trifluoro-p-tolyl-4-nitrophenyl ether Ia) 2-Chloro-a,~,a-trifluoro-p-cresol Chlorine gas is passed through a flow meter into a solution of a,~,~-trifluoro-_-cresol (4.05 g. 0.025 mole) in ethylene dichloride (200 ml.) at 0C. until the theoretical volume has been absorbed. The solvent is stripped off and the residue distilled to give 2-chloro-a,a,a-trifluoro-_-cresol (3.5 g. 71~) b.p. 80-82C. at 33 mm. -Ib) 2-Chloro-a,~,a-trifluoro-p-tolyl-4-nitrophenyl ether ..
Potassium hydroxide (1.08 g. 0.0166 mole, 86% pure) is dissolved in methanol (10 ml.) and a solution of 2-chloro-a,a,a-trifluoro-p-cresol (3.27 g. 0.0166 mole) in methanol added. The solvent is removed under pressure and sulfolane (100 ml.) added followed by -fluoronitrobenzene (2.34 gO, .~ . . .
~30 ... -..-: ~ '.' , g303 0.0166 mole) and the mixture heated at 130--150C ~or seven hours.
After cooling, the solution is poured into water (200 ml.) and extracted with benzene. The extract is dried, filtered through activated silica gel (10 g.) and the solvent removed. The residue is taken up in isopropanol/hexane (1:3) cooled to ~20C, decanted from an oily precipitate, and the solvents stripped off.
The residue (2.9 g.) is distilled to give 2-chloro-a,a,a-tri-fluoro-_-tolyl-4-nitrophenyl ether (1.6 g. 31%) b.p. 23-85C/
0.3 mm which when induced to crystallize has a melting range of 62-68C. An impurity isolated from a preparation following this procedure has been identified as 4-carbomethoxy-2-chlorophenyl-4-nitrophenyl ether.

IIa) 2-Chloro-a,ala-trifluoro-p-tolyl phenyl ether _ _ . _ . . . .. .. _ _ ..
Potassium phenoxide, prepared by stripping a solution of phenol (4.7 g. 0.05 moles) and potassium hydroxide (3.3 g.
0.05 moles 86.2% purity) in methanol (20 ml.) is dissolved in sulfolane (75 g), and 3,4-dichloro-a,a,a-trifluorotoluene (10.8 g., 0.05 mole) added. The mixture is heated at 170C overnight then cooled, diluted with benzene (250 ml.), and washed with water (3 x 600 ml.). The organic phase is dried, filtered through activated silica gel (20 g.) and the solvent removed.
The residue (12.4 g.) is distilled to give 2-chloro-a,a,a-tri-fluoro-_-tolyl phenyl ether (9.9 g. 72%) b.p. 85-90C/0.25 mm.
contaminated with about 5% of 6-chloro-a,a,a-trifluoro m-tolyl phenylether.

Found: C, 57.13; H, 3.09; C1, 13.17; F, 20.86 Calculated for ~-C13H8ClF3O; C, 57.27; H, 2.95; Cl, 13.00; F, 20.91.

.

10~303 b) 2-Chloro-~,a,~-trifluoro-p-tolyl-4-ni-trophenyl ether A mix-ture of fuming nitric acid (10 g. 0.16 mole) and concen-trated sulfuric acid (10 g.) is added with vigorous stirring to 2-chloro~ -trifluoro-p~tolyl phenylether (27.3 g. 0.01 mole) initially at 75C, maintaining a rate of addition such that the temperature does not rise above 85C. After stirring at 80C for one half hour, further mixed acid (5 g. ~ 5 g.) is added and the mixture stirred for fifteen minutes, cooled, diluted with water, and extracted with benzene (2 x 200 ml.).
The extract is washed with water and bicarbonate solution, dried, and the solvent removed. The residue (29.1 g.) is recrystallized from isopropanol to give 2-chloro-~ -trifluoro-_-tolyl-4-nitrophenyl ether (12.7 g. 40%) m.p. ~7-70C. Analytical and spectroscopic data confirm the identity of the products from Routes I and II.

Example 59 Preparation of 2,~ -Tetrafluoro-p-tolyl-4 nitrophenyl ether .... _ _ . _ . _ . _ _ . . ........................ ... _ _ a) 2-Amino-~ -trifluoro-_-tolylphenyl ether . _ . ~ . _ _ 2-Nitro-~ trifluoro-p-tolylphenyl ether (57.0 g., 0.209 mole) is dissolved in ethanol (200 ml.) and shaken in an atmosphere of hydroyen in a Parr apparatus in the presence of platinum oxide (100 my.) until uptake is complete. The catalyst is removed by filtration and the solvent stripped off to give 2-amino~ -trifluoro-_-tolyl phenylether (50.3 g. 99%) which is used without further purification.
Found: C, 61.76; H, 3.65; F, 22.35; N, 5.52. Calculated for C13HloF3NO; C, 61.66; H, 3.98; F, 22.51; N, 5.53.

' : :
j -39-.: :: -l~q~303 h) 2,~ te-trafluoro~ tolylphenyl ether _ _ _ 2-Amino-~ trifluoro-_-tolylphenyl ether (25.3 g., 0.1 mole) is added to concen-trated hydrochloric acid (100 ml.) and the mixture cooled to -15C. A solution of sodium nl-tri-te (7.5 g. 0.1 + mole) in water (5 ml ) is added dropwise with stirring, and after a total of 2 hours at -15C, the diazonium chloride solution is filtered and t:reated with a solution of sodium fluoborate (25 g. 0.2~ mole) in water (30 ml.) and the dense fluoborate salt filtered off and washed with ethanol and ether, then air dried, yield 23.0 c3., decomposition point ~ 190C.
The salt is then added portionwise to a flask maintained in an oil bath at 200C, and when decomposition i'3 complete, the residue is taken up in benzene (150 ml.), washed with water (4 x 100 ml.), dried, and the solvent removed. The residue (10.3 g.) was extracted with isopropanol/hexane to give a residue whi'ch on distillation gives 2,N,~,a-tetrafluoro-p-tolylphenyl ether (3.4 ~. 14%), b.p. 90C/0.25 mm.
c) 2,~ te~rafluoro-p-tolyl-4 nitrophen~l ether . ~
The above material is nitrated by the procedure des-cribed in Example 2 above for 2-chloro-~ -tetrafluoro-_-tolyl-4-nitrophenyl ether.

Example 62 Preparation of 2,6-Dichloro~ trifluoro-p-tolyl-4-nitro-phenyl ether a) 3,4-Dichloro-~,a,~-trifluoro-5-nitro toluene and 3,4-dichloro- -a,~,~-trifluoro-'6'-nitro_t'olu`ene _ _ __ A mixture of 3,4-dichloro-a,~,~-trifluorotoluene .
(430 g., 2.0 mole~3), concentrated sulphuric acid (1200 ml.) and concentrated nitric acid (1200 ml., excess) was stirred at 30-100C~for one half hours. The mixture was then .

~ ' ' " ', . .

cooled and the acid phase discarded. The organic phase was washed with water, dilute sodium bicarbonate solution, potassium carbonate solution, dried, and distilled to give an approximately equal mixture (456 g.~ 89~) of 3,4-dichloro-a~a,a-tri~luoro-5-nitrotoluene and 3,4-dichloro-a,a,a-tri-fluoro~6-nitrotoluene, b~p. 86''C/3 mm.
b) 2-chloro-a~a~a-trifluoro-6-nitro-~-tol~lphenyl ether .. ... . . ~ _ .... .
A solution of potassium hydroxide (43.2 g. of 86 pure~ 0.665 moles) in water (20 mlO) was added slowl~ to a mixture of phenol (62.5 g~ 0.665 mole) and the product from (a~ above (450 gO total, equivalent to 0.665 mole of 3,4-dichloro-a~,a trifluoro-5-nitro toluene) in sulfolane (300 ml.) at 30-680C. with stirring. After stirring at ; 42-68OC for a total of one hour the mixture was dlluted with hexane (400 ml.) and water (600 ml.). The resulting layers -were separated and the aqueous phase extracted once with ; hexane. The combined organic phases were washed with water and dilute caust1c soda solution, dried and the solvent removed. The residue (471 3 g.) was distilled through a . ~ . ~ . . . .
; 20 vacuum iacketed Vigreux column. No. 1 (272.2 g.) bp ~ 100C/
0.2 mm ~consisted essentially of unreacted 3,1t-dichloro-a,a~a trifluaro 6-nitrotoluene. No. 2 (196.2 g.) b.p. 109-119C/0.2 . ~ ~ , , -mm. was essentially pure desired diphenylether~ A small residue (3~5-g.) was discarded. No. 2 crystallized and was 25~ recrystallized from 2-propanol (600 mlO) at OoC. to give 2-chloro-a,a,a-trif1uoro-6-nitro- -tolylphenyl ether (144 g.
;6~ m.p~. 57--61C.

A~solut1on of 2-chloro-a,a,a-trifluoro-6 nitro-~-1~7~3~3 tolylphenyl ether (150 g., 0.472 mole) in ethanol (1200 ml ) was shaken in an atmosphere of hydrogen in a Parr apparatus in the presence of Pt02 (600 mg.) until uptake ceased. The catalyst was filtered off, the solvent removed, and the residue taken up in pentane (600 ml.) and filtered through activated silica gel (~ 15 g~) and the solvent removed. The residue was recrystallized from pentane at -20oc. to glve 2-amino-6-chloro-a,a,a-trifluoro-~-tolylphenyl ether (9~.1 g., 70%) m.p. 47-53OC
d) 2,6-Dichloro-a,a,a-trifiuoro-~-tolylphenyl ether 2-Amino-6-chloro-a,a,a-trifluoro-~-tolylphen~l ether (5.8 g., 0.0~ moles) was ground with concentrated hydrochloric acid (70 ml.) to give a suspension of the amine hydrochloride. A solution of sodium nitrite (1.5 g., 0.022 moles) in water (3 ml.) was added dropwise to the stirred suspension at -15C then the mixture was s~irred for fifty minutes at +3 - -10C then filtered through a sintered glass filter~ ~he fiItrate was slowly added to a suspension of cuprous chloride (3.0 g.) in concentrated hgdrochloric acid (20 ml.) at -3- -10C, then the temperature was slowly ~ raised, finally to 90C for twenty minutes. The mixture was - : :
then cooled and neutralized wlth so~id sodium bicarbonate and extracted w1th ather. The extract was washed with water and sodium carbonate solution, dried and stripped.
Z5~ The residue was distilled, to give the diphen~lether (3.5 g.) as an oil which crystallizedO The solid was taken up in pentane (l0 ml.3 and filtered through activated silica gel . ~ . . -( ~ 5 g.~) and the sol~ent removed. The residue (3.3 g.) was recrysta11iz~d from 2-propanol to give 2,6-dichloro-ala,a-~0'~93~

trifluoro-p-tolylphenyl ether (2.75 g. 45%) m.p. 4~-50C.
e) 2,6-Dichloro-a,a,a-trifluoro-p-toly]-4-nitrophenyl ether _ _ 2,6-Dichloro-a,a,a--trifluoro~ tolylphenyl ether (1.7 g., 0.0055 mole) was added -to a cold (0C) mixture of concen-trated sulphuric acid (1.7 g.) and concen-trated nitric acid (1.2 g.). The mixture was warmed -I:o 30-35C and stirred a-t this temperature for thirty minutes, -then diluted with wa-ter and extracted with benzene/pentane, and the ex-tract washed wi-th -sodium bicarbonate solution and wat:er, then dried and stripped.
The residue was combined with the result of a similar experimen-t on 500 mg. of starting material and recrys-tallized from 2~-propanol to give 2,6-dichloro-a,a,a-trifluoro-~-tolyl-4-nitro-phenyl ether (1.9 g., 75%) m.p. 83-86C.

Example 63 Prepara~tion of a4,a4 ! a4-trifluoro-2 ! 4-xylyl-4-nitrophenyl ether a) 2-sromo-a~a~a-trif-luoro-~--tolylphenyl ether . _ . . . _ . . _ . _ _ . _ .
A solution of 3-bromo-4-chloro-a,a,a-trifluoro-toluene (143 g., 0.55 mol), potassium phenoxide (72.6 g. 0.55 -;
mol), in sulfolane (200 ml.) is heated and stirred 3 hours a-t 165-170C. The solution is cooled. Benzene (250 ml.) and hexane (250 ml.) are added, and the solution washed with dilute sulfuric acid (500 ml.), the solvent removed, and the oil dis-tilled to give 2-bromo-a,a,a-trifluoro-_-tolylphenyl ether (124 g., 71%) b.p. 100-105C./0.45mm.
b~ a4,a4,~a4-t_ fluoro-2,4-xylylphen~l ether ~;;n-Butyl lithium,~15%/hexane solution (50 ml., 0.033 mol) is added to a stirred solution of 2-bromo-a,a,a-trifluoro- - ~-, .:

, ... . ~ ,. , , .,.................... . , ~ , 93~3 _-tolylphenyl e-ther (25.36 g., 0.08 mol) and hexane (300 ml.) under ni-troge~ and stirred 10 minu-tes at 25C. Dimethylsulfate (25 g. 0.2 mol) is added in one lot and the mixture is refluxed gently for 10 minutes, poured onto ice and the aqueous phase discarded. The hexane solution is washed with water, dried, the solve~t removed and the oil distilled to give ~4,~ trifluoro-2,4-xylylphenyl ether, b.p. 86-8gC./0.3 mm.
c) ~4,~4,~4-trifluoro-2,4-xylyl-4-nitrophenyl ether A cooled mixture of concentrated sulfuric acid (14 ml., 0.25 mol) and concentrated nitric acid (14 ml, 0.22 mol) is added to a stirring solution of 2-methyl-~ -trifluoro-p-tolylphenyl ether (17.8 g., 0.07 mol) and 1,2-dichloroethane (60 ml.) at 6-14C. in 74 minutes and stirred for 70 minutes at 10-15C. I'he oil layer is separated, washed with water, 10~
sodium carbonate solution, and twice with water; the solvent is removed, and the product crystallized from hexane-isopropanol to give ~4,~4,~4-trifluoro-2,4-xylyl-4-nitrophenyl ether (6.3 g., 30%) m.p. 5g-63.5C. ~

Example 64 ' 20 Preparation of ~ '-hexafluoro-2,4-xylyl-4-nitrophenyl ether = ....... .... _ ...... . . _ . . . . _ ._ . __ . __ ~
a) ~ hexafluoro-2,4-xylylphenyl ether ::
A solution of potassium phenoxide (15.0 g. 0.1 m) and 4-chloro-~ '-hexafluoro-_-xylene in sulfolane (50 ml.) is heated 60 hours at 140-160C. The solution is cooled and benzene (400 ml.) and hexane (250 ml.) are added and the solution washed twice with water (1 liter, 500 ml.), twice with 10% sodium carbonate solution (~ 200 ml. each~, and water, dried, filtered through activated silica gel '~

:

:

~ 3~3 (~ 25 g.), the solvents removed, and the residue distilled to give ~ ' ,QI -hexafluoro-2,4~xyly:Lphenyl ether (22.4 g., 73%) b.p. 81-85C./-- 1 mm.
b) ~,a,~ '-hexafluoro-2,4-xylyl-4 nitrophenyl ether ~ ,a,~ ',a'-Hexafluoro-2,4-xylyl phenyl ether ether (16.1 g. 0.0525 mol), concentrated sulfuric acid (12 ml.
0.22 mol), concentrated nitric acid (12 ml. 0.19 mol) and ethylene dichloride (65 ml) are st:irred 30 minutes at room temperature and allowed to separat:e. The ethylene dichloride layer is washed with water, 10% sodium carbonate solution, and water and the solvent removed. The residual oil is dissolved in hexane, filtered through activated silica gel (~ 25 g.) and the solvent removed to give ~,a,~,a',a',a'-hexafluoro-2,4-xylyl-4-nitrophenyl ether (11.4 g. 62%) m.p. 72-73C.

Examples 65 to 80 Following the procedures of Examples 1 to 56, other diphenyl ethers of Formula I are prepared. Among the compounds :j which are prepared by these procedures are: -, ':

:

.

33~3 a, ~ hexafluoro-2l4-xylyl-3-ethoxy-4-nitrQphenyl ether ,~4,~4-trifluoro-2,4-xylyl-3-n-propoxy-4-nitrophenyl ether, 2-chloro-6,~ tetrafluoro-p-tolyl-3-ethyl-4-nitrophenyl ether, 2-iodo-~ -trifluoro-p-tolyl-3-methoxy-4-nitrophenyl ether, 2-chloro-6-cyano~ -trifluoro-p tolyl-3-methylthio-4-nitro-phenyl ether, 2-bromo-~,4~,4~4-trifluoro-4,6-xylyl-3-ethoxy-4-nitrophenyl ether, 2-chloro-~ ' hexafluoro-4,6-xylyl-3-methoxy-4-ni-tro-phenyl ether, 2-bromo-~ -trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl e-ther, 2-chloro-~ -trifluoro-p-tolyl-3 n-butyl-4-nitrophenyl ether, 2-chloro-~a,~-trifluoro-_ tolyl-3-bromo-4-nitrophenyl ether, 2-cyano-~ -trifluoro-_-tolyl-3-acetoxy-4-nitrophenyl ether, 2-bromo-~ -trifluoro-_-tolyl-3-diethylamino-4-nitrophenyl ether, 2,6-dichloro-~ -trifluoro-p-tolyl-3-ethylamino-4-nitrophenyl ether, 2-cyano-a,~,~-trifluoro-p-tolyl-3-(1-carbethoxyethoxy) 4-nitro-phenyl ether, -2-cyano-~ -trifluoro-p-tolyl-3-carbomethoxy-4-nitrophenyl ether, and 2-bromo-~ -trifluoro-p-tolyl-3-carboxy-4 nitrophenyl ether. ~ -These diphenyl ethers have herbicidal properties.
It should be noted that the diphenyl ethers of the invention can also be named correctly using difEerent systems of nomenclature. For example, the diphenyl ether of Example 3 can : also be named as 2-cyano-4-trifluoromethyl-3'-ethoxy-4'-nitro-diphenyl ether. However, within the specification and claims of this invention the system of nomenclature examplified in the 30 Examples has been followed. -~
'.,' "' ., . . , .~ .. .

~V'~3~3 Examples 81-86 Follow.ing the procedures of ~xamples 57 to 59 o-ther diphenyl ethers of Formula I are prepared. Among the compounds which are prepared by these procedures are:
6-chloro-a,a,a,a',a',a'-hexafluoro--2,4-xylyl-4-nitrophenyl ether, 2-chloro-6,a,a,a-tetrafluoro-_-tolyl-4-nitrophenyl ether, a,a,a-trifluoro-2-iodo-p-tolyl-4-ni.trophenyl ether, 2-cyano-6-chloro-a,a,a-trifluoro-p-tolyl-4-nitrophenyl ether, 2-bromo-a4,a4,a4-4,6-xylyl-4-nitrophenyl ether, and 2-chloro-a,a,a,a',a',a'-4,6-xylyl-4-nitrophenyl ether.
These diphenyl ethers have herbicidal properties.
The following examples show -the herbicidal properties of the diphenyl ethers of the invention.

Example 87 This example shows the herbicidal activity of diphenyl ethers of the invention towards a number of common weeds. Using the procedure described below, diphenyl ethers were evaluated for control of the following weeds:

At 10 pounds per acre:
Monocots barnyardgrass (Echinochloa crusgalli) crabgrass (~igitaria sppO) ~nutsedge (Cyperus esculentus) ~' wild oats (Avena fatua) Dicots bindweed (Convolvulus arvensis) ~ ' curly dock ('Rum'ex'cri'spus) ~

., velvetleaf (Abu'tilon theophrasti) mild mustard'(B'ras'sica' haber) 30 ~At 2 and 4 pounds~per acre~

~ _47_ : .

.
~ 93 Monocots barnyardgrass (Echinochloa _rusgalli) **Bermudagrass (Cynodon dacty__n) crabgrass (Digitaria spp.) *downy brome (Bromus tectorum) foxtail (Setaria faberii) Johnsongrass (Sorghum halepense) nutsedge (Cyperus esculentus) quackgrass (Agropyron repens) *ryegrass (Lolium perenne) *wild oats (Avena fatua) *yellow millet (Pan'icum mi'liaceum) Dicots bindweed (Convolvulus'arvensis) cocklebur (Xanth'i'um pensylvan.icum) **coffeeweed (Sesbania macrocar'pa) *curly dock (Rumex c'rispus) *lampsquarters (Chenopodium album) morningglory (Ipomoea purpurea) *pigweed (Amar'ant us''re'tro'fl'exus) **ragweed (Ambrosia art'emisilfolia) *smartweed (Poly'gonum 'pe'n'sylvani'__m) ~ **tomato (Lycoper'sicon esculentum) 1 velvetleaf (Abutilon _heophrasti) : *wild carrot (Daucus 'caro'-ta) ~ .
wild mustard (~ra'ssica haber) *.Examples 1 to 9 and 57 to 61 only. .
~ ** Examples 10 to 56 and 62 to 64 only. .. ~

;~ The following test procedure i5 employed. Seeds of ., 30 selected crops and weeds are planted in soil in flats. For .

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preemergence tests, the flats are -treated with the -test compound immediately after the planting. For posternergence -tests, the seeds are allowed to germinate, and after two weeks the flats are treated with the test compound. The compound to be evaluated is dissolved in acetone, diluted wi.th water, and sprayed over the flats using a carrier volume equivAlent to 50 gallons per acre at the rate of application (pounds per acre, lb/A.~ speci-fied in the tables. About two weeks after the application of the test compound, the state of growth of the plants is observed and the phytotoxic effect oE the compound is evaluated. Table II gives the average percent control achieved by the -test compounds in terms of the percent of the plants which are killed by the compounds.

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1~'7931)3 TABLE :LI
HERBICIDAL ACTIVI~'Y
(~ con-trol) Compound of Preemergence Postemergence Example No. ~ _ 4 2 10 4 2 1 M* 42 76 82 57 D* 35 45 100 58 3 M 99 89**84100 99 ~96 D 100 99 **66 100 100 ~97

7 M 61 65 65100 75 82

8 M 81 61 5285 48 35

9 M 99 90 81100 97 82 : 11 M 81 88 82 100 ~; D 98 99 99 100 :
: ~12 M 86 72 77 99 **1/4:lb./A.
1/2 lb./A.

.

93~3 TA3LE II (cont ' d) Compound of ~ _s ExamPle No . lb . /A. _ 2 4 2 D 1()0 100 86 98 : D 98 77 99 L00 24 M . 91 62 86 84 M . 87 40 97 88 ~: D 88 93 100 100. :
:: 15 26 M 98 75 99 93. D 100 99 100 100 , , .
27 M ~76 74 8~ 99 98 90 10~ 100 28 ~ M 74 79 73 73 : D ~ 95 79 99 100 29 M~ 74 66 79 97 D ~; 73 84 100 100 30: M ~ 81 78 75 91 D 99 9~ 100 100 ~ 31 ~ M ~ ~ 74 68 61 68 : D~ 99 69 100 100 32: ~M ~ 86 81 86 100 D ~ ~ : 100 81 100 100 ~0~3~3 TABLR II (cont ' ~) Compound of Preemer~ence Po~t_ç~rgenc~
Exam~le No. ~ 2 _ ~

D . 99 74 98 100 D 52 85 ~9 90 38 M 47 62 4~ 51 D 86 68 9~ 58 D 99 80 9~ 100 : 40 1~ 36 88 6It 81 : D 92 98 L00 100 ~: D 96 62 95 94 : D 80 60 93 88 :~:: 43 : 1~ 0 99 2 61 ~ D 48 100 47 oO
:~ 15~ 41t M . 66 0 60 7 : M 13 68 17 53 46 M : 0 34 0 0 : D 20 87 30 4 47 ~: M ~ ~ 61 80 11 24 . D ~ 0 80 72 81t 48 ~ ~ M : 99 100 75 8It D~ 97 100 100 97 0 ~:~ 49 ~ : M ~ 9? 100 86 ~77 ; 95~ 100 100 ~ 100 : 50 ~ M : 90 98 97 100 D : : ~ 83 100 100 100 ~ .
,; :, : : , , ~,. .. . . .
- " , ~ . .... . . . . . . . . . . .
, : . : , , , , , . , . : . . , 1~)'7~3~3 TABLE II (cont'd) Compound of Preemergence Postemeryence Example No. lb./A. 10 4 2 10 4 2 57 M* 96 82 71 99 75 74 D* 97 52 51 100 74 81 58 M 77 96 96 100 99 92 .

59 M 94 96 100 87 :

: 60 M 87 99 100 94 D 100 83 100 94 . ..

D 0 39 90 49 :
62 M 100 86 : :
; ;;~ D 100 99 63 : M ~ 86 75 34 46 *M =~Monocots; D , Dlcots : :

Example 88 This example shows the selective herbicidal activi-ty of diphenyl ethers of the invention in a number of agronomic crops. Following the general test procedure of Example 87 di-phenyl ethers are evaluated for significant tolerance (as shown by 50~ or less kill of the test crop at levels of application which give more than 50~ kill of many or all of the weeds of Example 73) towards some or all of the following common agro-nomic crops (not all compounds tested against all crops):
alfalfa, snapbeans, corn, cotton, cucumbers, peanuts, rape, rice, safflower, soybeans, tomatoes, and wheat.
Tolerance to snapbeans in preemergence applications is shown by the compounds of Examples 4, 26, 57, 58 and 62.
Tolerance to corn in preemergence applications is shown by the eompounds of Examples 4, 11, 19, 21, 34, 40, 52, 54, 57 and 58 and in postemergence applications by the compounds of Examples 4, 18, 19, 21, 26, 34, 36, 40, 49/ 52, 53, 54, 56, 57, 58 and 62.
Tolerance to cotton in preemergence applications is shown by the compounds of Examples 3, 4, 30, 57, 58 and 62 and in post-emergence or layby applications by the compound oE Example 3and 57. Tolerance to peanuts in preemergence applications is shown by the compounds of Examples 3, 19, 21, 30, 34, 36, 40, 48, 49, 50, 52, 53, 56, 57 and 58, and in postemergence applications by the eompounds of Examples 4, 18, 34, 36, 37, 40, 48, 53 and 54. Toleranee to riee in preemergence applications is shown by the eompounds of Examples 4, 19, 21, 30, 34, 40, 52, 54, 57 . -and 58 and in postemergenee applications or in applications on :
transplanted rice by the eompounds of Examples 3, 11, 18, 20, ~ 30, 34, 40, 48, 53, 54, 57, 58 and 62. Toleranee to safflower ; 30 in preemergenee applieations is shown by the compound of Example 3. Tolerance to soybeans in preemergence applications is shown ..
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by the compounds of Examples 3, 4, 11~ 18, 19, 21, 26, 30, 34, 40, 48, 49, 50, 52, 53, 54, 57 and 58, in postemeryence or layby applicatlons by -the compounds oE Examples 3, 34 and 58.
Tolerance to wheat in preemergence applications is shown by the compounds of Examples 4, 18, 19, 26, 34, 40, 50, 54, 56, 57, 58 and 59 and in postemergence applications by the compounds of Examples 4, 18, 21, 30, 34, 36, 48, 54, 57, 58 and 59.
It is to be understood that changes and variations may be made without departing from the spirit and scope of -the invention as defined by the appended claims.

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Claims (52)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A compound of the formula wherein X is a hydrogen atom, a halogen atom, a trifluoromethyl group, a (C1-C4)alkyl group, or a cyano group;
Y is a hydrogen atom, a halogen atom, or a trifluoro-methyl group; and Z is a hydrogen atom; a hydroxy group; an alkoxy group having up to 6 carbon atoms; an alkoxy group having up to 6 carbon atoms, in which one or more of the hydrogen atoms are substituted by a group selected from a halogen atom, or a hydroxy, (C1-C4) alkoxy carboxy, carbalkoxy, trihaloalkyl, alkenyl, alkynyl, amino, alkylamino, dialkylamino, a 5- or 6-membered N-containing heterocyclic, alkylthio, alkylsulfonyl, epoxy, alkylcarbonyl, halo-substituted alkylcarboxyl, carbamoyl, alkylcarbamoyl or dialkylcarbamoyl group;
an alkyl group having up to 4 carbon atoms; a halogen atom; an amino group, an amino group in which one or both hydrogen atoms are substituted with a group selected from alkyl, haloalkyl, hydroxyalkyl, alkoxy-alkyl, alkylthio, carbonyl, carboxy, carbalkoxy, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, alkyl-carbonyl, and haloalkylcarbonyl groups; an N-containing heterocyclic group, an alkylthio group having up to 4 carbon atoms; a cyano group; a carboxy group; a carbalkoxy group having up to 4 carbon atoms in the alkoxy moiety; a carboxyalkyl group having up to 4 carbon atoms; a carbalkoxyalkyl group having up to 6 carbon atoms; an alkanoyloxy group having up to 4 carbon atoms; or a carbamoyloxy group having up to 6 carbon atoms; and in the event that Z is or contains a carboxy group, the salts of said compound.

2. A compound according to claim 1 wherein Y is a hydrogen atom.

3. A compound according to claim 2 wherein X is a halogen atom or a cyano group.

4. A compound according to claim 3 wherein Z is an ethoxy group and X is a cyano group.

5. A compound according to claim 3 wherein X is a chlorine atom.

6. A compound according to claim 3 wherein Z is an alkoxy group.

7. A compound according to claim 6 wherein Z is an unsubstituted (C1-C4)alkoxy group.

8. A compound according to claim 7 wherein Z is an ethoxy group and X is a chlorine atom.

9. A compound according to claim 6 wherein Z is a halo-, hydroxy-, alkoxy-, carboxy-, carbalkoxy-, trihalomethyl-, alkenyl-, alkynyl-, amino-, alkylamino-, dialkylamino-, alkylthio-, alkylsulfonyl-, epoxy-, alkylcarbonyl-, or carbamoyl-substituted alkoxy group.

10. A compound according to claim 9 wherein Z is a carbalkoxy-substituted alkoxy group.

11. A compound according to claim 3 wherein Z is an amino group.

12. A compound according to claim 11 wherein Z is an (C1-C4)alkyl-, di(C1-C3)alkyl, carboxy-, carb(C1-C4)-alkoxy, or (C1-C4)carbamoyl-substituted amino group.

13. A compound according to claim 12 wherein Z is a diethylamino group.

14. A compound according to claim 1 wherein Y is a halogen atom and X is a halogen atom, a trifluoromethyl group, a (C1-C4)alkyl group, or a cyano group.

15. A compound according to claim 1 wherein Z is hydrogen.

16. A compound according to claim 15 wherein Y is a hydrogen atom.

17. A compound according to claim 16 wherein X is a halogen atom.

18. A compound according to claim 17 wherein X is a chlorine atom.

19. A compound according to claim 16 wherein X is a cyano group.

20. A compound according to claim 16 wherein X is a methyl group.

21. A compound according to claim 15 wherein Y is a halogen atom and X is a halogen atom, a trifluoromethyl group, a (C1-C4)alkyl group, or a cyano group.

22. A method of controlling weeds which comprises applying to the surface of the growth medium prior to the emer-gence of the weeds from the growth medium a compound according to claim 1 in an amount sufficient to control the growth of the weeds.

23. The method of claim 22 wherein the compound is applied at a rate of about 0.1 to about 12 pounds per acre.

24. A method of controlling weeds which comprises applying to weed seedlings a compound according to claim 1 in an amount sufficient to control the growth of the seedlings.

25. The method of claim 24 wherein the compound is applied at a rate of about 0.1 to about 12 pounds per acre.

26. A method of controlling undesirable plant growth which comprises applying to the area in which growth is to be controlled a growth controlling amount of a compound as defined in claim 1 in association with an agronomically acceptable carrier.

27. A method of selectively controlling weeds in an agronomic crop which comprises incorporating into the growth medium prior to planting the crop and prior to the emergence of the weeds from the growth medium a compound according to claim 1 in an amount sufficient to control the growth of the weeds.

28. The method of claim 27 wherein the compound is incorporated at a rate of about 0.1 to about 12 pounds per acre.

29. A compound of the formula wherein A is halogen B is hydrogen or halogen and C is hydrogen, halogen, lower alkyl, lower alkoxy, lower alkoxyalkoxy, lower alkenyloxy, lower alkynyloxy, amino, lower alkylamino, di-lower alkylamino, hydroxy, lower alkylthio or acetyl-amino.

30. 2-Chloro-4-trifluoromethyl-4'-nitrodiphenylether.

31. 2-Chloro-4-trifluoromethyl-3'-methoxy-4'-nitrodi-phenylether.

32. 2-Chloro-4-trif1uoromethyl-3'-ethoxy-4'-nitrodi-phenylether.

33. 2-Chloro-4-trifluoromethyl-3'-i-propoxy-4'-nitro-diphenylether.

34. 2-Chloro-4-trifluoromethyl 3'-n-propoxy-4t-nitro-diphenylether.

35. 2-Chloro-4-trifluoromethyl-3'-n-butoxy-4'-nitro-diphenylether.

36. 2-Bromo-4-trifluoromethyl-4'-nitrodiphenylether.

37. 2,6-Dichloro-4-trifluoromethyl-4'-nitrodiphenylether.

38. 2-Chloro-4-trifluoromethyl-3'-hydroxy-4'-nitro-diphenylether.

39. 2-Chloro-4-trifluoromethyl-3'-allyloxy-4'-nitro-diphenylether.

40. 2-Chloro-4-trifluoromethyl-3'-(2-propynyl)oxy-4'-nitrodiphenylether.

41. 2-Chloro-4-trifluoromethyl-3'-ethoxyethoxy-4'-nitro-diphenylether.

42. 2-Chloro-4-trifluoromethyl-3'-(2-dimethylamino)ethoxy -4'-nitrodiphenylether.

43. 2,6-Dichloro-4-trifluoromethyl-3'-ethoxy-4'-nitro-diphenylether.

44. 2-Chloro-4-trifluoromethyl-3'-amino-4'-nitrodiphenyl-ether.

45. 2-Chloro-4-trifluoromethyl-3'-ethylamino-4'-nitro-diphenylether.

46. 2-Chloro-4-trifluoromethyl-3'-dimethylamino-4'-nitrodiphenylether.

47. 2-Chloro-4-trifluoromethyl-3'-diethylamuno-4'-nitrodiphenylether.

48. 2-Chloro-4-trifluoromethyl-3'-di-n-propylamino-4'-nitrodiphenylether.

49. 2-Chloro-4-trifluoromethyl-3' methyl-4'-nitrodi-phenylether.

50. 2,3'-Dichloro-4-trifluoromethyl-4'-nitrodiphenyl-ether.

51. A process for preparing a compound of the formula wherein A is halogen, B is hydrogen or halogen, and C is hydrogen, halogen, lower alkyl, lower alkoxy, lower alkoxyalkoxy, lower alkenyloxy, lower alkynyloxy, amino, lower alkylamino, di-lower alkyl-amino, hydroxy, lower alkylthio or acetylamino which comprises reacting an ether of the formula where A, B and C are as above, with a nitrating agent to substitute the 4'-position with a nitro group.

52. A method of killing weeds which comprises applying thereto a compound of the formula wherein A is halogen B is hydrogen or halogen and C is hydrogen, halogen, lower alkyl, lower alkoxy, lower alkoxyalkoxy, lower alkenyloxy, lower alkynyloxy, amino, lower alkylamino, di-lower alkylamino, hydroxy, lower alkylthio or acetylamino.