JPS58157778A - Heterocyclic esters of phenoxybenzoic acid and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel substance that can be expressed as 'i:';

In the formula, X is a halogen or trifluoromethyl group, Y is a halogen, nitro or cyano group, and R is a nitro, alkylthio, halogen or cyan group (3). n is 1 or 2.

The compounds of the present invention are very useful as selective herbicides (6) In the present invention, as preferred examples, Nitro or cyano group, R is nitro, methylthio, monoatomic, bromine or cyano group.

The compounds of the present invention are acid chlorides represented by the formula (r) (wherein X, Y, and R are as described above) (wherein n is 1 or 2). alcohol and
It is obtained by reaction in the presence of an acid acceptor such as a tertiary amine. This reaction (4) is effectively carried out by mixing about equivalent amounts of acid chloride and alcohol in an inert organic solvent such as toluene. Preferably, an excess of acid acceptor is used to ensure removal of the hydrogen chloride produced. Generally, the reaction is carried out at room temperature with stirring. After reaction path T, the desired product is obtained by first removing the salt of the acid acceptor and then evaporating the solvent used in the reaction. This product can be used as is or can be further purified by conventional methods.

The acid DIJ, which is directly useful for synthesizing the compounds of the invention, represented by Formula II, can be easily synthesized from the corresponding acid by reaction with thionyl chloride.

Examples of acids as raw materials for the acid chloride of formula 11 include 2-nitro-3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, 2-nitro-3-(2-bromo-4 -trifluoromethylphenoxy)benzoic acid, 2-nitro-3-C2,4-dichlorophenoxy)benzoic acid, 2-nitro-3-(2-nitro-4-chlorophenoxy)benzoic acid, 2-nitro -3-(2-cyano-4-trifluoromethylphenoxy)benzoic acid, 2-=)rho5-
(4-) IJ fluoromethylphenoxy)benzoic acid, 2-methylthio-3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, 2-chloro-3
-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, 2-bromo 5-(2-chloro-4
-trifluoromethylphenoxy)benzoic acid,
2-Ethylthio-3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, 2-propylthio-3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid, 2-cyano-3- (2-chloro-4-trifluoromethylphenoxy)benzoic acid and the like.

Examples of the alcohol represented by formula (1) used in the synthesis of the compounds of the present invention include 3-hydroxytetrahydrofuran, 3-hydroxytetrahydropyran, and 4-hydroxytetrahydropyran. In the compounds of the present invention, when the tetrahydrofuran or tetrahydropyran moiety is bonded to the carboxylic acid moiety at the 2-position, the acid corresponding to formula It can be synthesized by reacting with The reaction is carried out by mixing the acid and dihydrofuran or dihydropyran at room temperature in the presence of a catalytic amount of p-toluenesulfonic acid. In this case, it is desirable to use an excess of pyran or furan.
. After the reaction is completed, the reaction mixture is washed with water, and then excess raw materials are removed to obtain the desired product.

The method for synthesizing the compounds of the present invention will be explained in more detail by giving examples below.

(7) 2-Nitro-3-(2-chloro-4-trifluoromethylphenoxy)benzoic acid (80 g) and toluene C (80 ml) are placed in a reaction vessel equipped with a mechanical stirrer, thermometer and condenser. Thionyl chloride (89
mA) gradually at room temperature while stirring. After the addition is complete, the mixture is heated under reflux for 1 hour while stirring. Then stir overnight at room temperature. Removal of toluene from the reaction mixture yields the desired product as an oily substance.

3-Hydroxytetrahydrofuran (1,76 g, 0.
2-nitro-3-(2-chloro-4- Trifluoromethylphenoxy)benzoyl chloride (7.60g, 0
．． A solution of 02 mol) in toluene (10(8)rnb) is gradually added under stirring. After the dripping is finished,
- Continue stirring overnight. The reaction mixture was washed with water and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain a brown oily substance. This is purified by silica gel chromatography using toluene or ethyl acetate-toluene as an elution solvent. This purified oil was treated with ethanol to obtain the desired product, 3-tetrahydrofuryl 2-nitro-3-
(2-10 rho 4-trifluoromethylphenoxy)benzoate is obtained as a white solid with a melting point of 55°C.

3-hydroxytetrahydro7rane (0.04 mol),
Toluene (5QmJ) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and addition funnel. 2-nitro-3-(2-7
'Romo-4-1170 A solution of methylphenoxy)benzoyl chloride (0.04 mol) in toluene (2 Qml) was slowly added at room temperature under stirring. After the dropwise addition is complete, stirring is continued for about 8 hours. The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The dried solution is then evaporated under reduced pressure to obtain a residue. This residue was purified by silica gel chromatography using toluene and toluene-ethyl acetate as the eluent to obtain the target product, 3-tetrahydrofuryl 2-nitro-3-(2-promo-4-trifluoromethylphenoxy)penzoate. .

3-hydroxytetrahydrofuran (0.04 mol),
Toluene (50 ml) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. A solution of 2-nitro-3-(2-nitro-4-trifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (20 mg) is stirred and slowly added dropwise at room temperature. After the dropwise addition is complete, stirring is continued for approximately 8 hours. The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The dried solution is then evaporated under reduced pressure to yield a residue. This residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as an eluent to obtain the target product 3-tetrahydrofuryl 2-nide 0-5-(2-nitro-4-
) 1170 methylphenoxy)penzoate is obtained.

3-hydroxytetrahydrofuran (0.04 mol),
Toluene (50 mg) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. A solution of 2-nitro-3-(2-cyano-4-trifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (20 mg) is slowly added dropwise at room temperature with stirring. After finishing the addition, continue stirring for about 8 hours. The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off from this dried solution under reduced pressure, and the resulting residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as an eluent and E~ to obtain the target product, 3-tetrahydrofuryl. 2-2-rho 5-(2-cyano-4
-trifluoromethylphenoxy)benzoate is obtained.

Synthesis 3-hydroxytetrahydronerane (U, 04 mol),
Toluene (50 ml: ) and triethylamine (0
, 04 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-methylthio-3
-(4-)Lifluoromethylphenoxy)benzoylchloro')'' (0.04 mol) (7) l□Luene (20 m
g) Slowly add the solvent dropwise at room temperature while stirring. Stirring was continued for about 8 hours after the addition was completed.

The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The solvent of this dried solution was distilled off under reduced pressure, and the resulting residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as eluents to obtain the target product, 3-tetrahydrofuryl-2-methylthio-
3-(4-)lifluoromethylphenoxy)penzoate is obtained.

3-hydroxytetrahydrofuran (0.04 mol),
Toluene (50 mg) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-chloro-3-(2
A solution of -promo 4-trifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (20 mg) is slowly added dropwise at room temperature with stirring. After the dripping is finished,
Continue stirring for approximately 8 hours. The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off from this dry solution under reduced pressure, and the resulting residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as an eluent to obtain the desired 3-tetrahydrofuryl 2.
-chloro-3-(2-buto-4-trifluoromethylphenoxy)benzoate is obtained.

3-hydroxytetrahydrofuran (0.04 mol),
Toluene (50 mlE) and triethylamine (0
, 04 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-Promo 5-(2
-chloro-4-)lifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (20 mg)
Add the solution dropwise at room temperature while stirring. After the dropwise addition is complete, continue stirring for about 8 hours. The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. This dry solution was then distilled off under reduced pressure to remove the condensation medium, and the resulting residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as an eluent. Chloro-4-trifluoromethylphenoxy)benzoate is obtained.

3-hydroxytetrahydrofuran (0.04 mol),
Toluene (50 mg) and triethylamine (+1.
04 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-Zia Two 5-(2,
4-dichlorophenoxy)benzoyl chloride (0,0
4 mol] in toluene (20 mg) was slowly added dropwise at room temperature while stirring.

After the dropwise addition is complete, stirring is continued for approximately 8 hours. The reaction mixture is washed with water and dried over anhydrous magnesium sulfate.

The solvent was distilled off from this dried solution under reduced pressure, and the resulting residue was extracted with toluene and ethyl acetate-toluene as an elution solvent.
Purification by silica gel chromatography yields the desired 3-tetrahydrofuryl 2-cyano-3-(2,4-dichlorophenoxy)benzony 1.

Synthesis of 3-hydroxytetrahydrofuran (0.04 mol),
Toluene C50ml) L- and triethylamine (0,
04 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-ethylthio-3-(
A solution of 2-chloro-4-bromophenoxy)benzoyl chloride (0.04 mol) in toluene (20 mJ) was slowly added dropwise at room temperature while stirring. After the dropwise addition is complete, stirring is continued for approximately 8 hours.

The reaction mixture is washed with water and dried over anhydrous magnesium sulfate. The solvent of this dried solution was distilled off under reduced pressure, and the residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as the elution solvent.
chloro-4-bromophenoxy)benzoate is obtained,
tL le.

3-hydroxytetrahydrobilane (0.04 mol),
Toluene (5oml) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-nitro-3-(2-
A solution of chloro-4-trifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (2'omz) is slowly added under stirring at room temperature. Stirring was continued for about 8 hours after the addition was completed.

The reaction mixture is then washed with water and dried over anhydrous magnesium sulfate. The solvent of this dried solution was distilled off under reduced pressure, and the residue was purified by silica gel chromatography using toluene and toluene-ethyl acetate as an eluent to obtain the desired 3-tetrahydropyranyl-2-nitro-5-(2 -chloro-4-trifluoromethylphenoxy)benzoate is obtained.

4-hydroxytetrahydrobilane (0.04 mol),
Toluene (50 mg) and triethylamine (0,0
4 mol) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-nitro-3-(2-
A toluene (20+11i solution) of chloro-4-trifluoromethylbenzoyl chloride (0.04 mol) is slowly added dropwise at room temperature with stirring. After the addition is complete, stirring is continued for an additional 8 hours. The reaction mixture is then washed with water,
Dry with anhydrous magnesium sulfate. The dried solution was distilled off under reduced pressure, and the residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as the eluent. 4-trifluoromethylphenoxy)penzoate is obtained.

3-hydroxytetrahydropyran (0.04 mol),
Toluene (50 ml) and triethylamine (0,4
+111) into a glass reaction vessel equipped with a mechanical stirrer and dropping funnel. 2-nitro-3=(2
A solution of -chloro-4-trifluoromethylphenoxy)benzoyl chloride (0.04 mol) in toluene (2 QmJ) is stirred and slowly added dropwise at room temperature. After the addition is complete, stirring is continued for an additional 8 hours. This reaction mixture was then washed with water,
Dry with anhydrous magnesium sulfate. The solvent of this dried solution was distilled off under reduced pressure, and the residue was purified by silica gel chromatography using toluene and ethyl acetate-toluene as an eluent to obtain the desired 3-tetrahydrohyranyl 2-
Methylthio-5-(2-7/ o r+ -4-) I
J fluoromethylphenoxy)benzony 1. is obtained.

2.3-dihydropyran (2(Ilg), 2-nido o-
5=(2-rioo-4-t170romethylphenoxy)
Add benzoic acid (0.05 mol), yohyparatoluenesulfonic acid (a few medicine spoons) to a glass reaction vessel equipped with a mechanical stirrer. This mixture is stirred at room temperature at 1, at which no absorption of carboxylic acid is observed in the infrared absorption spectrum. At this point, the mixture is dissolved in methylene chloride, washed with dilute aqueous sodium carbonate solution, and dried over anhydrous magnesium sulfate. The dried solution is then distilled off under reduced pressure to remove the solvent and excess dihydropyran, yielding the desired 2-tetrahydropyranyl-2-nitro-5.
-(2-chloro-4-trifluoromethylphenoxy)benzoate.

Dihydrofuran (U, 03 mol), 2-nitro 5-(
2-Chloro-4-) fluoromethylphenoxy) benzoic acid (0,025 mol), methylene chloride (25 ml) and para-toluenesulfonic acid (a few medicine spoons) were added to a glass reaction vessel equipped with a cooler. The mixture is stirred at room temperature at such a temperature that the absorption of the carboxylic acid is no longer observable with an infrared absorber.The reaction mixture is then washed with dilute aqueous carbonic acid solution and water. The washed solution is dried, and then the solvent and unreacted raw materials are removed to obtain the desired 2-tetrahydrofuryl 2-nitro-3-(2-1'rolo-4-trifluoromethylphenoxy)benzoate.

In practical use as herbicides, the compounds of this invention are generally formulated into herbicidal compositions comprising an inert carrier and a herbicidally effective amount of the compound.

Such herbicidal compositions, also referred to as preparations, are convenient for applying the required amount of the above-mentioned active compounds to areas where weeds have grown. These compositions can be in solid forms such as powders, granules, and wettable powders, or in liquid forms such as solutions, aerosols, and emulsions.

For example, powder compositions are prepared by mixing the active compound with a solid, inert carrier such as Merck, clay, silica, pyrophyllite, etc. and pulverizing it. Granular compositions are prepared by dissolving the active compound in a suitable solvent and impregnating it into a granular carrier such as attapulgite or vermiculite (generally having a particle size of about 0.3 to 1.5 mm). do. Wettable powder compositions have the advantage that the active compound can be dispersed in water or organic solvents to any desired concentration and are prepared by adding a wetting agent to a highly concentrated powder composition.

Some of the active compounds of the present invention are sufficiently soluble in common organic solvents such as kerosene, xylene, so that they can be applied directly as solutions in these solvents. Herbicide solvents are often sprayed as aerosols under superatmospheric pressure. However, as a liquid herbicide composition, an emulsion prepared from the active compound of the present invention and an inert carrier, namely water and an emulsifier is preferable.The above emulsion can be applied to areas where weeds grow. In this case, it can be diluted with water or an organic solvent to any desired concentration.

The emulsifiers most commonly used in these emulsions are nonionic surfactants or mixtures of nonionic and anionic surfactants.

With certain emulsifiers, inverse emulsions (water in organic solvent) can also be prepared for direct application to weed areas.

Typical herbicide compositions of the present invention are illustrated below.

Note that the amounts are shown in weight ratios.

EXAMPLE 16 Preparation of a powder composition 10 parts of the product of Example 2 and 90 parts of powdered talc are mixed in a mechanical grinder-pregnancy until a uniform free-flowing powder of a given particle size is obtained. Grind with. The powder thus obtained is suitable for direct application to areas where weeds grow.

The compounds of the present invention can be used in any form known as a herbicide;
It can also be used in the usage.

One method for controlling weeds is to apply a herbicide composition consisting of an inert carrier and the compounds of the present invention as essential active ingredients in an amount that has a herbicidal effect on the specified weeds, and contact the weeds. It is to let The concentration of the novel compounds of the invention in herbicidal compositions varies widely depending on the form of the formulation and the purpose for which it is designed, but in general herbicidal compositions contain about 0% by weight of the active substance of the invention. The content is preferably from .5% to about 95%. In practical use of the invention, the herbicidal composition preferably comprises from about 5% to about 75% active compound by weight. As with other herbicides, this composition can be used to treat pesticides such as insecticides, nematicides, fungicides, stabilizers, spreading agents, deactivators, adhesives, etc.
Additives such as fixing agents, fertilizers, activators, synergists, etc. can also be included.

The compounds of the present invention are effective when used in the above-mentioned herbicidal composition in combination with another herbicide, defoliant, desiccant, or growth inhibitor. These other types of materials can be used in the herbicidal composition to cover about 5 to about 95 parts of the active ingredient. When these other herbicides, defoliants, desiccants, etc. are used in combination with the compounds of the present invention, herbicidal compositions that are more effective in controlling weeds can be obtained. The compositions often provide results that cannot be achieved with individual herbicidal compositions alone. Other herbicides, defoliants, desiccants and plant growth inhibitors that can be used with the compounds of this invention in herbicidal compositions to control weeds are listed below. 2.
4-D, 2, 4.5-T, MCBA, MCPB, 4(2
, 4-DB), 2.4-DEB, 4-CPB, 4-CP
P, 2゜(25〕r,, 1 4.5-TB, 2,4.5-TES, 3,4-D
A, chlorophenoxy herbicides such as silυex, IPC, CIPC, swe
p), barban, BCPC.

Carbamate herbicides such as CEPC, CI) PC, D-
CEC, methane sodium
), EPTX, dialy) Cd1allate),
P.E.B.C.

perbulate, peru root (
dithiocarbamate herbicides such as Vernolate), Lua Cnorea), and 5iduron
, dichloral, urea
ea), ri00 chloroxuron
), cychbron, 7 enyu o 7
(f enuron), monimoron Cmonuron
), MONURON T
CA), diuron, linuron, monolinuron (rn, onol)
inuron, neburon, buturon, trim
Substituted urea herbicides such as etu-ron, simazine, chlorazine, etc.
zine), atraone, desmetrine, simazine (noraz)
ine), (26) ipazin (e), promethrin (prt
ymetryn), atrazine
e), trietadine (-1rieta-zine), dimedone (simetone), brometone (p
rome one), propazine (propaz
ine), symmetrical triazine herbicides such as ametrine (a, metr'tn, e), alpha chloro-N, N
-1-methylacetamide, CDEA, CDAA, alpha-chloro-Nl-nopropylacetamide, 2-chloro-N-inopropylacetanilide, 4-(chloroacetyl)-morpholine, '1-(chloroacetyl)pyranysine, etc. Chloroacetamide herbicides, TCA, Cdalapon, ), 2,3-zine a.

Chlorinated chain carboxylic acid herbicides such as fluoropionisocuando, 2,2.3-TPA, 2,3.6-'I'BA,
2,8,5.6-TEA, dicamba
), tricamba, amiben (a,
mi b e 7+,), fenac),
PBA, 2-methoxy-3,6-dichlorophenyl acetic acid E
L: l methoxy-2,6-dichlorophenylic acid e, 2-
Methoxy-3,4,6-)lichlorophenylacetic acid, 2.
Chlorinated benzoic acid and phenylacetic acid herbicides such as 4-dichloro-3-nitrobenzoic acid, as well as aminotriazole, maleic hydrazide, phenylmercuric acetate-1-, endo that, biuret , ), technical chlordane/ (technical chlordane), dimethyl 2.3,5.6-titrachloroterephthalate 1.
, Jinae) (cliquat), Nilbon (erbo)
n), D.N.C.

DNBP, jinoobe=-ru (dichloro
banil), DPA, diphenamide (dA, p
hena, m1d), dibrovaline (dipropal
in), trifluralin (trifl-uraline)
), furan (solan), cyclyl (dicryl)
merphos, DMPA, DSMA
, MSMA, sodium azide, acrolein, benefin, bensulide
ide), AMS, pu0? Schiff 1z (brom(
LCZ l ), 2-(3,4-dichlorophenyl]-
4-Methyl-1,2,4-oxadiazolidine-3,5
-dione, bromoxynil (bromox'/ni l
), cacodylic ac
id), DMA, DPMF, cypromide (cyprom
id), DCB, DCPA, dichlon
e), diphenatril, 1
)MTTX DNAP, EBEP, EXD, HCA
, ioxynil, IPX, isosyl (1soc1/il), potassium cyanate, MA
A. MAMA.

MCPE5. MCPP, MH, molinate (moli-
nate), NPA, 0CII, Barakny) (pa
raquat), P C1), picloram (pi
c l oram), DPA, PCA.

pyrichlor, seson (s, e
s on, e), terbacil,
Terbutol, TCBA,
Brominil, CP-5CH44
, II-176-1, H-732, A/-2091,
planavin, sodium borate,
Calcium cyanamide, DEF, ethylxanthogen disulfide, synthon (s 1ndone), synthon BCsin, tion, e B), propanyl (pr
openil), etc.

] The herbicides mentioned in 2 can also be used in the method and composition of the present invention in the form of their esters, esters, amides or other derivatives, as long as they are suitable for each herbicide.

Weeds are economical 1+Ij that grow in undesirable places.
It is an undesirable weed that has no i value and interferes with the production of cultivated plants, the growth of ornamental plants (1a), or the prosperity of homesteads.Many types of weeds are known as shown below. Namely p♂gweed, lambsqua, rt er, foxtail, crab.
grass), wild mustard
v, st ard ), field wave Ni-Cress (j
'1eld penn, ycress), rayclas (
gooseg
rass), chickweed,
wild oats, velvet leaf, perselan (-p)
urselane), barnyard grass (barny
ard grass), smar weed (smar
t-weed), non-tweed (knatweed)
), cocklebur, wild buckwheat, kochia, mesoic corn
dic corn cockle), ragweed (r
aOrneed), Nautinosuru(sowthist)
le), coffee-weed
), Rio 1. craton, cup air
hea), dodder, fumitori (,
fum, 1tor'/), ground cell (-groun
d-sel), hemnettle (h, em, net t t
l e ), Norwell (kn, otne l ),
Spurge, Subry (57yur
r'/), emex, jungle rice, pon
dweed), Cdog fennel
), carpetweed, morning glory,
bed straw, lucksalad and na
iatl)-like-older, wild carrot (
wild carrot), 71゛Licaria (ma, t
ricaria), wild ba
rley), campion (campio7+,), chamoi, /lz (chamomile burdock, mullein crnttll
eiη), Roundleaped Mallow (roundl e
a, veclmal low), pluteinosul (bu
llthistle), Hounds Tank (houndl
s-1ongue), mothmullein (mothmullein)
lein), purple starch inosul (purple
5 tar histle), white cockle (ite cockle), perennial ray-gras (rye-gra, ss), quackgrass, John non-grass (
j oh, n, s Q? l.

grass), Canadian whistle (cana, da t)
histle), hedgepin weed (hedge
bin, cltneerl), Bermuda Dallas (Be
rmuda grass), Sieve Sorrel (-sh,
eep 5orrel), curly dotsuku (cur11
/ dock), nutgrass
, field chick
weetl), Dandelion (danrle l)
i (171), campanula (c a, m, 1] a,
n, ul a, ), field bindweed (f
ielrl bindweed), Russian Knapweerl, mesquie) (rn, esquite), toad flaxox (
toadflrtx), yarrow (') arrow), aster, rl)-,') ell (g
romwe l l), horsetail (h, orse
tail), ironweed (sesba, n, ia,), pullulanone-11- (bulrush), caratoil (co, t-1ail), winterfless (wi
perennial weeds such as tercress (tercress).

Similarly, these weeds can be classified into broad-leaved weeds and rice weeds. It is economically desirable to control these weeds without harming beneficial plants or livestock.

The novel compounds of this invention are particularly valuable for weed control in that while they are harmful to many species and genera of weeds, they are relatively harmless to many beneficial plants. The exact amount of compound required will depend on many factors, including the resistance of the target weed to the herbicide, weather, soil type, method of administration, and the types of beneficial plants present at the location.

Therefore, under unfavorable conditions, mild infestations of weeds may be adequately controlled by applying no more than about 1 or 2 ounces of active compound per kneeker. On the other hand, if a favorable environment is infested with high densities of hardy perennial weeds, the use of 10 pounds or more of active compound per knee may be required to control the weeds.

The herbicidal efficacy of the novel compounds of the present invention has been demonstrated by a number of well-established tests known in the art, such as pre-emergence or post-emergence tests (33).
--Heru.

The herbicidal activity of the compounds of the present invention was established through pre-emergence tests on a number of weeds. In these experiments, seeds of various weeds were placed in small greenhouse pots filled with dry soil. Within 24 hours after sowing, the pots were watered to moisten the soil and then the test compound, formulated as an aqueous emulsion of acetone solution containing an emulsifier, was applied to the soil surface at the indicated concentration. .

After application, pots of this soil were placed in a greenhouse, warmed if necessary, and watered once or several times - a day.

The plants were maintained in the above conditions for 15 to 21 days, at which point the condition of the plants and the degree of damage to the plants ranged from 0 to 10
Ranked 'E'. 0 is no damage, 1.2 is slightly damaged, 3.46 is moderately damaged, 5.6 is slightly severely damaged, 7.8.9 is severely damaged, 10 is weeds dying and NE means no exam. The effectiveness of these compounds is demonstrated by the data set forth in Table 1. Numbers expressed in decimal notation are based on repeated experiments (14)
(34) This is the average result of two or more rankings.

The herbicidal activity of the compounds of the present invention was also demonstrated in experiments conducted on the weed side of various weeds after germination.

In these experiments, the test compounds were formulated as aqueous emulsions and applied at the indicated doses to the leaves of various weed species grown to the indicated sizes. After spraying, the weeds were placed in a greenhouse and watered daily or more frequently. Water was not applied to the treated weed leaves. The degree of damage is 10 after treatment.
Examined on days 1-15 and ranked from 0 to 10 as described above.゛The herbicide activities of these compounds are shown in Table 11.
This was proven by the following data published in The numbers on a 10-point scale are the average results of repeated experiments as before.

Table 11 Weed abbreviations WMSD Wild mustard CBGS
Clap Dallas BDWD Jindoweed
5PGT Subrankrtsop PIGW Piddaweed CTGS Cheat Geras JMWD
Jindo Weed 5UBT Sugar Peat VTLF' Velvet Leaf C0TN
Kotsuton MNGY Morning Glory
5OYB Soy Bean YLFX Yellow Foxtail PTBN Pinto Bean BNGS Barnyard Grass A, LFA Alfalfa J
NGS Johnson Glass 5ORG Tulgam QKGS Quick Glass WHT
Wheat WOAT Wild Oat

Claims (9)

[Claims] (1) General formula, O 1 (wherein X is...rogen or trifluoromethyl group, Y is selected from the group consisting of hydrogen, halogen, nitro and cyano group, and R is nitro, alkylthio,... selected from the group consisting of
11 or 2). (2) 3-tetrahydrofuryl 2-nitro-3-(2-
Chloro-4-trifluoromethylphenoxy compound. (3) 3-tetrahydrofuryl 2-nitro-3-(2-
The compound of claim (1) rf-J which is bromo-4-trifluoromethylphenoxy)benzonite. (4) 3-tetrahydrofuryl 2--1・rJ-5-(
Claim No. 1 (0) Compound which is 2-nitro (4-1-1 fluoromethylphenol)benzoate. (5) 3-tetrahydrofuryl 2-21 rho 5-(2
-cyano-4-trifluoromethylphenoxy)benzonite. (6) 3-tetrahydrofuryl 2-methylthio-5
-(4-) 11-Fluoromethylphenoxy7) The compound according to claim (1), which is benzoate. (7) 2-tetrahydropyranyl 2-nitro-3-
(2-Chloro-4-trifluoromethylphenoxy)benzoate (a compound of claim (1)). (8) 2-tetrahydrofuryl 2-nide 0-5-(2-
The compound of claim (1) which is chloro-4-)lifluoromethylphenoquine)benzoate. (9) an amount effective as an inert carrier and a defrosting agent of the general formula (wherein X is a halogen or a trifluoromethyl group, and Y is selected from the group consisting of hydrogen,... , R is from the group consisting of nitro, alkylthio,...rogen and cyano groups, n is an integer 1
or 2).