CA1182820A - Pyridyloxybenzanilide derivative and herbicide containing it - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A pyridyloxybenzanilide derivative represented by the formula:

where X is a bromine atom, Y is a halogen atom, a trifluoro-methyl group, a trifluoromethoxy group, a lower alkyl group or a lower alkoxy group, and n is an integer of from 1 to 3.
The compound is useful as a herbicide primarily for the in-hibition of growth and germination of weeds.

Description

The present invention rela-tes to a novel pyridy-loxybenzanilide derivative and a herbicide containing it.

The present inventors have conducted extensive researches on the herbicidal activities oE pyridyloxy ben~
ozic acid-type compounds and have found that cer-tin specific pyridyloxybenzanilide derivatives have characteristic herbicidal activities.

Namely, the present invention provides a pyridy-loxybenzanilide derivative represented by the general for-mula:

Yn ~ ~ CONH _ ~ (I) where X is a bromine atom, Y is a halogen atorn, a trifluoro-methyl group, a trifluoromethoxy group, a lower ~ $

alkyl group or a lower alkoxy groupr and n is an integer of from 1 to 3.
Now, the present invention will be described with reference to the preferred embodiments.
In the general formula I, Y is a halogen atom such as :Eluorine, chlorine or bromine; a trifluoromethyl group; a trifluoromethoxy group; a lower alkyl group such as methyl, ethyl, propyl or isopropyl; or a lower alkoxy group such as methoxy, ethoxy or propoxy.
Representative pyridyloxybenzanilide derivatives of the present invention are shown in Table 1.

3h~

T~ble l _ _. _ _ .
Compou~d Chemical formulas ~]elting __ _. _ . P

1 '~NO~ ~ 113- l l S

2 CONH ~ 94- 96 I ~ ~~ U ~S O~U~
4 ~SCONH ~ 125-126 _ S B /~L~ C 2H 5 121 122 __. .

C ON H ~> ~

/~ ~S C 11< 3 112 llS

-- '1 --Table 1 (cont'd) Compoun~ Chemical formulas ~lelting 7 Br ~ S 3 107-110 ~ .

8 ~ C O N H {O~ 12 5 - 12 8 _ .. . . ._ _ . ... .

3 ~[~ CON H ~) 129 133 _ . . , . ~

B 1 (~S 21-125 . _ , . .~
CONH ~F
11 Br 04-108 _ . . ,,............. _ CONH ~CF3 2 ~ i ;S 109-113 ~ . , ~

The compounds of the present invention may be prepared, Eor instance, by the following two processes.
The first process comprises reacting an acid chloride, i.e. a reactive derivative, of 3~(2~bromo-pyridyloxy)benzoic acid with a substituted aniline in thepresence of from l to 4 molar ti-mes, preEerably frorn l to 2 molar times, of a suitable base e.g. an organic base such as triethyl amine or pyridine, or an inorganic base such as sodium hydrogencarbonate or sodium carbonate.
This process is preferably conducted in the presence of an inert solvent. The solvent is not critical so long as it does not interfere with the main reaction. For instance, an aromatic hydrocarbon such as benzene or toluene, an alkyl halide such as methylene chloride or chloroform, a ketone such as acetone, or an ether such as tetrahydrofuran or dioxane, rnay preferably be used. The reaction temperature is not critical, and the reaction is usually conducted at a temperature from 0C to the refluxing temperature of the solvent. Particularly preferred is a temperature around room temperature. The reaction time varies depending mainly on the reaction temperature and the type of the reagents used. However, the reaction time is usually from 30 minutes ~o 3 hours.
The second process comprises reacting 3-hydroxy-benzoic acid-substituted anilide with from l to 3 molar times, preferably from l to 1.5 molar times, of 2,6-dibromopyridine in the presence of from l to 6 molar ; times, preferably from 1 to 3 molar times, of a suitable base, e.g. an inorganic base such as potassium carbonate, sodium carbonate, calcium hydroxide or sodium hydroxide.
The reaction is preferably conducted in a solvent, for example, an ether such as dioxane or a polar aprotic solvent such as N,N-dimethylamide or dimethylsulfoxide.
The reaction temperature is not critical and is usually from 50 to 200C, preferably from 100 to 150C. The reaction time varies depending mainly on the reaction temperature and the type of the reagents used and is usually from 2 to 6 hours.

After the completion oE the reaction, the desired compound can be re~dily separated from th~ reaction mixture by a usual method.

Now, Synthetic Examples for the preparation of the compounds of the present invention will be described.

Synthetic Example 1 (Synthesis of Compound No. 2) 3-(6-Bromo-2-pyridyloxy)benzoic acid-2'-chloroanilide 2.55 y of 2-chloroaniline and 2.42 g of triethylamine were dissolved in 100 ml of tetrahydrofuran. While cooling the solution to a temperature of no-t higher than 5C, 6.33 g of 3-(6-bromo-~-pyridyloxy)benzoic acid chloride was added. After the addition, the mixture was stirred for 2 hours, and then tetrahydrofuran was recovered under reduced pressure. A dilute hydrochloric ~5 acid aqueous solution was added to the residue, and the precipitated crystals were collected by filtration and dried to obtain 7.60 g of 3-(6-bromo-2-pyridyloxy)-benzoic acid-2'-chloroanilide. The yield was 93.2%, and the melting point was from 94 to 96C.
Synthe-tic Example 2 (Synthesis oE Compound No. 4) 3-(6-Bromo~2-pyridyloxy)berl2Oic acid-2'-methylanilide 2.14 y oE orthotoluidine was dissolved in 50 ml of dioxane, and 2.52 g of sodium hydrogencarbonate was added. While thoroughly stirring the mixture, 6.33 g of 3-(6 bromo-2-pyridyloxy)benzoic acid chloride dissolved in 20 ml of dioxane, was dropwise added at roo temperature. After the dropwise addition~ the mixture was stirred at room temperature for 3 hours, and then poured into a dilute hydrochloric acid aqueous solution.
The precipitated crystals were collected by filtration, washed with water and then dried to obtain 7.01 g of 3-(6-bromo-2-pyridyloxy)benzoic acid-2'-methylanilide. The yield was 90.6%, and the melting point was from 125 to 12~C.
Synthetic Example 3 (Synthesis of Compound No. 5) 3-~6-Bromo-2-pyridyloxy)ben~oic acid-2'-ethylanilide The reaction was conducted in the same manner as in Synthetic Example 1 by using 2.42 g of 2-ethylaniline instead of 2-chloroaniline, whereby 7.23 g of 3-(6-bromo-2-pyridyloxy)benzoic acid-2'-ethylanilide was obtained.
25 The yield was 91.1~, and the melting point was from 121 to 123C~

Synthetic Example 4 (Synthesls oE Compound No~ 6) 3-(6-Bromo-2-pyridyloxy)benzoic acid-2'-isopropylanilide The reaction was conducted in the same manner as in Synthetic Example 1 by using 2.70 g of 2-isopropylaniline instead of 2-chloroaniline, whereby 6.99 g of 3-(6-bromo-2-pyridyloxy)benzoic acid-2'-isopropylanilide was obtained. The yield was 85.1%, and the melting point was from 117 to 120C.
Synthetic Example 5 (Synthesis of Compound No. 9) 3-(6-Bromo-__~~ridyloxy)benzoic acid-3'-methylanilide

4.54 g of 3-hydroxybenzoic acid-3'-me-thylanilide and 4.74 g of 2,6-dibromopyridine were dissolved in 80 ml of dimethylformamide, and 5.52 ~ of potassium carbonate was added. The mixture was stirred under heating at 130C
for 4 hours. After cooling, the reaction product was poured into a 3% sodium hydroxide aqueous solution. The precipitated crystals were collected by filtration, washed with a dilute hydrochloric acid aqueous solution and further with water, and then dried to obtain 6.44 g of 3-(6-bromo-2-pyridyloxy)benzoic acid-3'-methylanilide.
The yield was 84.1%, and the melting point was from 129 to 133C.

Synthetic Example 6 (Synthesis oE Compound No. 11) 3-(6-Bromo-2-pyridyloxy~benzoic acid-4'-fluoroanilide The reaction was conduc-ted in the same manner as in Synthe-tic Example 5 by using 4~62 g of 3-hydro~ybenzoic acid-4'-fluoroanilide instead oE 3-hydroxybenzoic acid-3'-methylanilide, whereby 6.66 g of 3-(6-bromo-2-pyridyloxy)benzoic acid-4'~fluoroanilide was ob-tained.
The yield was 86.1%, and the melting point was ~rom 104 to 108C.
According to the second aspect of the present invention, a herbicide is prepared by mixing a compound of the present invention as the active ingredient with various carriers to obtain various formulations such as a wettable powder, an emulsifiable concentrate, a dust or a granule. As liquid carriers, ordinary organic solvents may be used, and as solid carriers, ordinary fine mineral powders may be used. Further, a surEactant may be incorporated to improve the emulsifiability, dispersibility or extendability of the formulations~ It is also possible to incorporate other agricultural chemicals such as a fertilizer, a herbicide, an insecticide, a fungicide or a bactericide.
When used as a herbicide, the active compound is applied in a sufficient amount to obtain a desired herbicidal activity. The amount o~ the application, i.e.
the dose, is usually from 10 to 1000 g/10 a, pre~erably from 50 ~o 500 g/10 a, as the active ingredient.
Depending upon its particular use, the active ingredient ls formulated in various Eorms such as an emulsifiable concentrate, a wettable powder, a dus~ or a granule.
To prepare an emulsifiable concentrate, the active ingredient is dissolved in an agricul-turally acceptable organic solvent, and a solvent-soluble emulsifier is added theretoO ~ suitable solvent is usually immiscible with water, and it is usually an organic solvent such as a hydrocarbon, a chlorinated hydrocarbon, a ketone, an ester, an alcohol or an amide.
As a useful solvent, there may be mentioned toluene, xylene, naphtha, perchloroethylene, cyclohexane, isophorone and dimethylformamide, or a mixture thereo~.
Par-ticularly preferred solvents are aromatic hydrocarbons and ketones. It is common -to employ a mixture of solvents.
When used as an emulsifier, a surfactant is usually incorporated in an amount of from 0.5 to 20 parts by weight relative to the emulsiEiable concentrate, and the surfactant may be anionic, cationic or nonionic.
The anionic surfactant includes alcohol sulfates or sulfonates, or alkylarylsulfonates or sulfosuccinates, such as calcium dodecylbenzene sulfonate or sodium dioctyl sulfosuccinate~
The cationic surfactant includes aliphatic alkylamine salts and aliphatic alkyl ~uaternary salts, such as laurylamine hydrochloride or lauryldimethylbenzyl ammonium chloride.

,4~

As the useful nonionic emulsifier, there may be mentioned alkylphenols t aliphatic alcohols, mercaptan or ethyleneoxide adducts of fatty acids, such as a poly-ethylene glycol ester of stearic acid or a polyethylene glycol ether of palmityl alcohol or octylphenol.
The concentration of the active ingredient is usually from 5 to 80 parts by weiyht, preferably from lO to 60 parts by weight.
The wettable powder is usually prepared by adding the active ingredient ~o an inert ine solid carrier and a surfactant. The active ingredient is usually incorporated in an amount oE Erom 10 to 80 parts by weight, and the surfac-tant is usually incorporated in an amount of from 0.5 to 20 parts by weight.
As the solid carrier commonly employed for the combination with the active ingredient, there may be mentioned naturally produced clayr silicate or silica, or lime, a carbonate or an organic carrier. The typical representatives include kaolin, Zeeklite, fuller's earth, talc, diatom earth, magnesium lime, dolomite and kernel powder.
As a commonly employed surfactant, there may be mentioned a polyoxyethylene-modified alkylphenol, an aliphatic alcohol, a fatty acid, an alkylamine, an alkylaryl sulfonate, a dialkylsulfosuccinate, a sodium salt of a copolymer of maleic anhydride with diisobutylene, sodium lignin sulfonate or formaldehyde-sodium naphthalene sulfonate.

~ 12 ~
A granule may be prepared by mixing the active ingredient with a granular or pelletized agricultually acceptable carrier, Eor instance, bentonite, kaolin clay, diatom earth or talc having a particle size oE Erom 8 to 60 mesh. In many cases, a surfactant or a water soluble inorganic salt may be added to improve the disilltegrating property.
The herbicide oE the present invention is effective mainly for the inhibition of germination and growth of weeds. It exhibits a superior herbicidal activity not only against barnyardgrass (Echinochloa crusgalli) as the major weed ln the rice field, but also against annual broad leaf weeds such as monochoria (M. vaginalis (BURM
fil.) PRESL), rotala (R. indica KOEHNE), waterwort ~Elatine triandra) and fatse pimpernel tL. pyxidaria LINN) and other weeds such as umbrella plant (C.
difformis LINN). Yet, it does not give any phytotoxicity to transplanted rice. It is a herbicide having high selectivity. Further, it exhibits not only a high herbicidal activity as a pre-emergence herbicide for upland field but also a herbicidal activity in the post-ernergence treatment, and thus it is a herbicide having a wide usage oE herbicidal activities.
Now, specific Examples for the preparation of the herbicides of the present invention will be described.
In these Examples, "parts" means "parts by weight".

Formulation Example 1 ~emulsiEiable concentrate) Compound No. 2 lO parts Xylene 50 parts Cyclohexanone 30 parts Sorpol 800-A (tradename, manufactured by Toho Chemical Co. Ltd.) lO parts The above ingredients were homogeneously mixed and dissolved to obtain an emulsiEiable concentrate oE the present invention.
Formulation Example 2 (wettable powder) Compound No. 5 20 parts Kaolin clay 70 parts White carbon 5 parts Sorpol 5039 5 parts The above ingredients were mixed and pulverized to obtain a wettable powder of the present invention.
Formulation Example 3 (granule) Compound No. 9 5 parts Bentonite 45 parts 20 Talc 44 parts Sodium lignin sulfonate 5 par-ts Dialkylsulfosuccinate l part The above ingredients were homogeneously mixed and pulverized, and after the addition of water, kneaded, granulated and dried to obtain a granule of the present invention.

~ t~

Test Example 1 tPre-emergence treatment in paddy field condition) In a pot of 150 cm2, soil was put, then covered wi-th soil containing seeds of various paddy Eield weeds i.eO
barnyardgra~s (Echinochloa crusgalli), monochoria (M.
vaginalis (BURM fil.) PRESL) r rotala (R. indica KOEHNE) and umbrella plan-t (C. difformis LINN) ~ fertilized, plowed and irrigated to a dept`n of water of 3 cm. T~o xice seedlings (varietyo Nihonbare, 2.5 leaf stage) were transplanted. On the 2nd day after the transplantation oE the rice seedlings, a predetermined amount oE the herbicide of the present invention diluted with water, was dropwise added to the water in the pot by means of a pipette.
On the 30th day aEter the application of the herbicide, the herbicidal effects and the phytotoxicity to the rice plants were examined.
The results thereby obtained are shown in Table 2.
The evaluation was made in accordance with the following evaluation standards.
_erbicidal index Ph~totoxicity index

5: 100% herbicidal effect 0: No phytotoxicity 4: 80% " 1: Slight phyto-toxicity 3: 60% " 2: Moderate phytotoxicity 25 2: 40% " 3: Substantial phytotoxicity 1: 20~ " 4: Great phytotoxicity 0: 0% " 5~ Completely killed ~a~

Test Example 2 (Pre-emergence treatment in upland condition) In a box-shaped pot oE 400 cm2, soil was put, seeded with seeds oE soybean, upland rlce and wheat, then covered with soil contai~ing seeds oE weeds i.e.
crabgrass (D. sanguinalis), livid amaranth (Amaranthus Lividus L) and common lambsquaters (Chenopodium album) in a thickness oE 1 cm, and, after moderately pressing the soil surface, uniformly watered.

A day aft.er the seeding, the herbicide of the present invention diluted with water was uniformly applied to the soil surface in an amount of 50 Q/a.
On the 30th day after the application of the herbicide, the herbicidal effects and the phytotoxicity were evaluated in accordance with the evaluation standards of Test Example 1.
The results thereby obtained are shown in Table 3.
Test Example 3 ~Post-emergence treatment) In a box-shaped pot of 400 cm2, soil was put, and seeds of upland rice, wheat, tomato, crabgrass, livid amaranth and common lambsquarters were sown. After the seeding, the plants were grown in a green house, and when the wheat, upland rice, crabgrass, livid arnavanth and common lambsquarters reached 4, 2, 2-2.5, 1-2 and 1-2 leaf stages, respectively, a diluted solution of the herbicide of the present invention having a predetermined concentration, was sprayed uniEormly to the foliages of the plants in an amount of 20 Q/a.
On the 30th day after the spraying, the herbicidal effects and tlle phytotoxicity were evaluated in accordance with the evaluation standards of Test Example 1.
The results thereby obtained are shown in Table 4.
Test Example 4 (Early post-emergence treatment in paddy Eield condition) In a Wagner pot of 200 cm , soil was put, then covered with a soil containing seeds of barnyardgrass, monocnoria, votala and umbrella plant, in a thickness of 0.5 cm and irrigated. On the 2nd day after the irrigation, the surface layer was plowed, and, on the 2nd day after the plowing, two rice seedlings of 2-leaf stage were transplanted at two locations. When the barnyard grass reached l-leaf stage i.e. when other weeds were in the initial stage of germination, a predetermined amount of a 5~ granular herbicide of the present invention was uniformly applied manually.
On the 30th day after the application, the herbicidal effects and the phytotoxicity were evaluated in accordance with the evaluation standards of Test Example l. The results thereby obtained are shown in Table 5.

- 17 ~
Table 2 addy Eield treatment Dose of Response of plants Compound active No ingredi- Trans- Barn- Mono- Ro-tala Umbrella ent(g/a) planted yard~ choria plant rice plant grass . .

.
3 10 0 5 ~ 5 . .

_

6 10 0 ~ 4.5 4 2

7 10 0 1 2 _

8 10 0 1 ~ 4 3 .

9 10 0 2 ~.5 4.5 4 ..... _ _ _ 0 0 ~.5 4.5 2 __ 12 10 0 1 4.5 4.5 2 Table 3 Urland treatment -Com- Dactive - Response oE plants pNoOn ingredi- Upland Soy- Wheat Crab- Livid Common ent(g/a) rice bean grass amaranth lambs-- plant quarter3 .

0 0 0 4 5 4.5 3 10 0 0 0 1 5 ~.5 .

0 1 0 4.~ 5 5 0 o 0 3 5 5 6 30 0 o 1 4.5 5 5 ~ _ _ 7 10 0 0 0 0 2 ' 2 .

.
0 0 o o o o _ _ 12 10 0 o O o 1 0 Table 4 Foliage treatment Com- Dose of Response of plants PNoound ingredi- Upland Wheat Tomato Crab- Livid Common ent (%) rice grass amaranth lambs-- plant quarters 0.1 0 0 5 1 5 5 0.1 0 0 2 1 ~.S 4 . _ 3 0.05 0 0 5 1 4 3 0.1 0 1 5 3 5 5 _ 4 0.05 0 0 5 1 4 3 0.1 0 0 5 1 5 5 . ~
0.05 0 0 5 3 5 5 0.1 0 o 5 5 5 5 ~ _ 0.1 0 0 5 2 5 4.5 7 0.05 0 ~ 5 1 3 3 0.1 o ~ 5 3 5 5 8 0 05 4.5 2 4 0.1 0 0 5 4 5 5 9 0.05 0 1 5 4.5 4.5 4.5 0.1 2 3 5 5 5 5 .

0.1 0 0 5 3 5 5 . _ . _ . .
11 0'05 5 1 5 5 0.1 0 0 5 3 5 5 . _ 0.1 0 o 5 3 5 5 3t~n;

~ 20 ~
Table 5 Early post-emergence treatment with granular herbicide in paddy field _ Compound Granular Response of plants No. herbi~
cide Trans- Barn- Mono- Rotala Umbrella (kg/a) plan-ted yard- choria plant rlce plant grass 0.3 0 4.5 5 5 5 2 0.4 0 5 5 5 5 0.6 0 5 5 5 5 _ _ 0.3 0 4.5 5 5 4 3 0.4 0 5 5 5 5 0.3 0 5 5 5 5 0.4 0 5 5 5 5 0.6 0 5 5 5 5 0.~ 0 5 5 5 5 0.4 ~ 5 5 5 5 0.6 0 5 5 5 5 G.3 0 4.5 5 5 4.5 9 0.4 0 5 5 5 4.5 0.~ 0 5 5 5 5

Claims (18)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A pyridyloxybenzanilide derivative represen-ted by the formula:

where Y is a halogen atom, a trifluoromethyl group, a tri-fluoromethoxy group, a lower alkyl group or a lower alkoxy group, and n is an integer of from 1 to 3.

2. The pyridyloxybenzanilide derivative accord-ing to claim 1, which is represented by the formula:

3. The pyridyloxybenzanilide derivative accord-ing to claim 1, which is represented by the formula:

4. The pyridyloxybenzanilide derivative accord-ing to claim 1, which is represented by the formula:

5. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

6. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

7. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

8. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

9. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

10. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

11. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

12. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

13. The pyridyloxybenzanilide derivative according to Claim 1, which is represented by the formula:

14. A method of killing weeds which comprises applying thereto or to the ground containing them, a compound as claimed in Claim 1, 2 or 3.

15. A method of killing weeds which comprises applying thereto or to the ground containing them, a compound as claimed in Claim 4, 5 or 6.

16. A method of killing weeds which comprises applying thereto or to the ground containing them, a compound as claimed in Claim 7, 8 or 9.

17. A method of killing weeds which comprises applying thereto or to the ground containing them, a compound as claimed in Claim 10, 11 or 12.

18. A method of killing weeds which comprises applying thereto or to the ground containing them, a compound as claimed in Claim 13.