JPH0635446B2 - (Polyfluoroalkyl) imidazole derivative and herbicide containing it as an active ingredient - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [In the formula, A represents a hydrogen atom or a halogen atom, and R
¹ represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, R ² represents a hydroxyl group, a fluorine atom or a trifluoromethyl group, X represents a halogen atom, l represents an integer of 0 to 12, and m represents 0. Or represents 1, n
Represents 1 or 2, and q represents 1 or 2. ] The present invention relates to a (polyfluoroalkyl) imidazole derivative (hereinafter referred to as the compound of the present invention) and a herbicide containing the same as an active ingredient.

The compound of the present invention, in the foliage treatment after emergence of upland weeds, various weeds that are problematic, for example, buckwheat vine, sana edode, purslane, chickweed, shiroza, agatela,
Japanese radish, field peony, nazuna, hornwort, Ebisugusa, hornbill, American stag deer, field pansy, yaemgra, American morning glory, Malaba morning glory, convolvulus vulgaris, Anopheles lanceolata, Anemone vulgaris, Anemone vulgaris, Prunus densiflora, Prunus densiflora, Prunus densiflora, Prunus vulgaris. , Broadleaf weeds such as corn marigold, barnyardgrass, barnyardgrass, green foxtail, grasshopper, bluegrass, blue-green amberjack, oat, oats, oat, corn grass, weeds such as grass, weeds, corngrass, etc. On the other hand, it has herbicidal effect.

The compound of the present invention, for major crops such as corn, wheat, rice, soybean, cotton, etc., in soil treatment, since it does not show a problematic phytotoxicity, before sowing of these crops, before transplantation or before emergence. It can be used as a herbicide for controlling weeds in the growing season, for example, a herbicide for no-tillage cultivation.

The compound of the present invention has the general formula [In the formula, A, R ¹ , R ² , l and n have the same meanings as described above. ] It can manufacture by halogenating the (polyfluoroalkyl) imidazole shown by these, or halogenating and nitrating.

The reaction conditions for halogenation are as follows. That is,
The (polyfluoroalkyl) imidazole [II] and the halogenating agent are reacted for 8 to 200 hours at room temperature to 100 ° C. in an inert solvent to give a halogen atom to the imidazole nucleus.
Introduce two or two.

The reaction conditions for nitration are as follows. That is,
(Polyfluoroalkyl) imidazoles [II] and fuming nitric acid, or a mixed acid of concentrated nitric acid and concentrated sulfuric acid is reacted at 80 to 150 ° C. for 5 minutes to 80 minutes to introduce one tro group into the imidazole nucleus (that is, m. = 1).

Therefore, in the case of the compound of the present invention in which q = 1 and m = 1 in the general formula [I], it is produced by combining halogenation and nitration.

After completion of the reaction, the reaction solution can be subjected to the usual post-treatments of the halogenation reaction and nitration reaction of this kind to obtain the desired compound of the present invention. If necessary, the product is purified by operations such as chromatography, recrystallization and sublimation.

Examples of the halogenating agent in the above reaction include N-chlorosuccinimide, sodium hypozincate solution, chlorine and the like for chlorination, and N-bromosuccinimide, bromine, hydrobromic acid and oxides for bromination. Etc. In iodination, iodine and oxides (eg, periodic acid, hydrogen peroxide, etc.) and the like can be mentioned.

Examples of the inert solvent include chloroform, acetic acid, water, carbon tetrachloride and the like.

In general formula [II] The polyfluoroalkyl group represented by is -CF ₂ CF ₃ , -CF ₂ CF ₂ H, -CF ₂ CF ₂ Cl, -CF ₂ CF ₂ Br, -CF ₂ CF ₂ I, -CF ₂ CF ₂ CF ₃ , -(CF ₂ ) ₅ CF ₃ ,-(CF ₂ ) ₆ CF ₃ ,-(CF ₂ ) ₇ CF ₃ ,-(CF ₂ ) ₈ CF ₃ ,-(CF ₂ )
₉ CF _{3 and the} like.

Next, production examples of the compound of the present invention will be shown.

Production Example 1 (Production of Compound 1 of the present invention) 0.56 g of 2- (pentafluoroethyl) imidazole
1.28 g of bromine was slowly added to a mixed solution of 80 ml of chloroform and 5 ml of methanol, and triethylamine was added.
After adding 0.61 g, the mixture was allowed to stand at room temperature for 24 hours. The reaction solution was poured into an aqueous sodium hydrogen sulfite solution to which ice was added, and the mixture was shaken and then the organic layer was separated. The aqueous layer was extracted twice with dichloromethane and all organic layers were combined and dried over magnesium sulfate. After distilling off the solvent under reduced pressure, the residue was recrystallized from dichloromethane to give 4,5-dibromo-2- (pentafluoroethyl) imidazole 0.40.
g (yield 38.8%, melting point 191-198 ° C.) was obtained.

Production Example 2 (Production of Inventive Compound 5) 2.47 g of 4- (2′-bromotetrafluoroethyl) imidazole was added to 15 ml of 94% fuming nitric acid and 96% concentrated sulfuric acid 15
It was dissolved in a mixed acid consisting of ml and heated under gentle reflux for 24 hours. After allowing to cool, it was poured into ice water and neutralized (pH 5 to 6) with a 20% aqueous sodium hydroxide solution. The mixture was extracted 3 times with ethyl acetate, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. By recrystallizing the residue from ethanol, 2.05 g of 5 (4) -nitro-4 (5)-(2'-bromotetrafluoroethyl) imidazole (yield 7
0.2%, melting point 198-200 ° C).

Chloroform 20 was added to 1.46 g of 5 (4) -nitro-4 (5)-(2'-bromotetrafluoroethyl) imidazole.
dissolved in a mixed solvent consisting of 5 ml of methanol and 5 ml of methanol, to which 1.60 g of bromine and 0.61 g of triethylamine were added,
The mixture was heated under reflux for 24 hours. After allowing to cool, ice-added aqueous sodium hydrogen sulfite was poured into the solution, and the mixture was shaken and then the organic layer was separated. The aqueous layer was extracted once with dichloromethane and twice with ethyl acetate, all the organic layers were combined, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was chromatographed on silica gel (eluent: hexane-
2-Bromo-4 (5)-(2'-
Bromotetrafluoroethyl) -5 (4) -nitroimidazole 0.51 g (yield 27.5%, melting point 158-160)
C) was obtained.

Production Example 3 (Production of Compound 11 of the present invention) 2.47 g of 4- (2'-bromotetrafluoroethyl) imidazole was dissolved in 30 ml of acetic acid, and 5.07 g of iodine, 10 ml of chloroform and 3.04 g of periodate dihydrate were dissolved. Was added, and the mixture was heated with stirring and refluxed for 3 hours. After cooling, 2.54 g of iodine and 1.52 of periodic acid dihydrate were added.
g and added, heated again and refluxed for 5 hours. After cooling down,
It was poured into an aqueous sodium hydrogen sulfite solution to which ice was added, and extracted three times with ethyl acetate. After the extract was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. Hexane was added to the residue, and the evaporation was repeated. The residual acetic acid was removed by azeotropy, and the inorganic substances and the like were removed through a silica gel column (eluent: ether-dichloromethane). The solvent of the eluate was distilled off under reduced pressure, and then recrystallized from dichloromethane to give 4 (5)-(2'-bromotetrafluoroethyl) -2,5 (4) -diiodoimidazole 4.9.
1 g) (yield 98.4%, melting point 162-163 ° C).

Table 1 shows some of the compounds of the present invention which can be produced by such a production method.

General formula When the compound of the present invention is produced, the production method of the (polyfluoroalkyl) imidazole represented by the general formula [II] [In the formula, A'represents a halogen atom, Y represents a bromine atom or an iodine atom, and 1 and n have the same meanings as described above. ] It can manufacture by irradiating with a low pressure mercury lamp (15-60W, using a Vycor filter) with the halide shown by in an inert solvent for 3-10 days at room temperature.

As the inert solvent, methanol, t-butanol,
Fluorocarbons such as 1,1-trichlorotrifluoroethane can be used.

When A represents a hydrogen atom in the general formula [II], the production method is [In the formula, A'represents a bromine atom or an iodine atom, and R
¹ , R ² , l and n have the same meanings as described above. ] It can manufacture by reducing the (halogen polyfluoroalkyl) imidazole shown by these.

Examples of the reducing agent include metals such as zinc and tin.

It can also be produced by a method of irradiating the (halogenopolyfluoroalkyl) imidazole [IV] with ultraviolet light in isopropanol.

Next, a production example of this (polyfluoroalkyl) imidazole will be shown as a reference example.

Reference Example 1 27.2 g of imidazole and 20.8 g of 1,2-dibromotetrafluoroethane were dissolved in 40 ml of methanol, placed in a quartz container, and irradiated with a 60 W low-pressure mercury lamp with a Vycor filter for 7 days at room temperature. The solvent was evaporated under reduced pressure, brine was added to the residue, the mixture was shaken, and then extracted three times with ethyl acetate. After the extract was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The residue was separated by silica gel chromatography (eluent: ether), and 2.82 g of 2- (2'-bromotetrafluoroethyl) imidazole (yield 11.7%, melting point 154-156 ° C, resolving solvent: benzene). And 4- (2'-bromotetrafluoroethyl) imidazole 9.19 g (yield 66.2%, melting point 169-170).
C., recrystallization solvent: benzene) was obtained.

Reference Example 2 4- (2'-Bromotetrafluoroethyl) imidazole (2.47 g) was dissolved in ethanol (50 ml), and zinc powder (6.54 g) was added.
g and 1 drop of concentrated hydrochloric acid were added, and the mixture was heated and refluxed for 8 hours while stirring. After cooling, the solid was separated and the solvent was distilled off under reduced pressure. The residue was passed through a silica gel column (eluent:
Ether) inorganic substances and the like, the solvent of the eluate is distilled off under reduced pressure, and the residue is recrystallized from chloroform-ether to give 4- (1 ′, 1 ′, 2 ′, 2′-tetrafluoro). Ethyl) imidazole 1.06 g (yield: 68.1
%, Melting point 152-158 ° C.).

When the compound of the present invention is used as an active ingredient of a herbicide,
Usually, it is mixed with a solid carrier, a liquid carrier, a surfactant, and other auxiliaries for formulation to prepare an emulsion, a wettable powder, a suspension and the like.

These formulations contain the compound of the present invention as an active ingredient in a weight ratio of 1 to 90%, preferably 2 to 80%.

As the solid carrier, there are kaolin clay, attapulgite clay, bentonite, acid clay, pyrophyllite, talc, diatomaceous earth, calcite, walnut powder, urea, ammonium sulfate, fine powder or granules of synthetic hydrous silicon oxide, etc. The carrier, xylene, aromatic hydrocarbons such as methylnaphthalene, alcohols such as isopropanol, ethylene glycol, cellosolve, acetone, cyclohexanone, ketones such as isophorone, soybean oil, vegetable oils such as cottonseed oil, dimethyl sulfoxide, acetonitrile,
Water etc. can be given.

Surfactants used for emulsification, dispersion, wet extension, etc. include alkyl sulfate ester salts, alkyl sulfonates, alkyl aryl sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkyl aryl ether phosphate ester salts. And anionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene polyoxypropylene block copolymers, nonionic surfactants such as sorbitan fatty acid esters and polyoxyethylene sorbitan fatty acid esters. To be Examples of the auxiliaries for formulation include lignin sulfonate, alginate, polyvinyl alcohol, gum arabic, CMC (carboxymethyl cellulose), PAP (isopropyl acid phosphate) and the like.

Formulation examples are shown below. The compounds of the present invention are shown by the compound numbers in Table 1. Parts are parts by weight.

Formulation Example 1 50 parts of the compound of the present invention, 3 parts of calcium ligninsulfonate, 2 parts of sodium lauryl sulfate and 45 parts of synthetic hydrous silicon oxide are well pulverized and mixed to obtain a wettable powder.

Formulation Example 2 An emulsion is obtained by thoroughly mixing 10 parts of the compound of the present invention, 14 parts of polyoxyethylene styryl phenyl ether, 6 parts of calcium dodecylbenzenesulfonate and 70 parts of cyclohexanone.

Formulation Example 3 6,25 parts of the compound of the present invention, 3 parts of polyoxyethylene sorbitan monooleate, 3 parts of CMC and 69 parts of water are mixed and wet-ground until the particle size becomes 5 microns or less to obtain a suspension agent. The compound of the present invention thus formulated is
After the emergence of the weeds, the leaves are treated. The foliage treatment includes not only treatment from above the plant body but also local treatment such as treatment of only weeds so as not to adhere to crops.

In addition, the herbicidal effect can be expected to be enhanced by using it in combination with other herbicides. Furthermore, it can be used by mixing with insecticides, acaricides, nematicides, fungicides, plant growth regulators, fertilizers, soil improvers and the like.

Incidentally, the compound of the present invention, paddy field, upland, orchard, meadow,
It can be used as an active ingredient of a herbicide for lawn, forest or non-cultivated land.

When the compound of the present invention is used as an active ingredient of a herbicide, the treatment amount varies depending on weather conditions, formulation form, treatment time, method, place, target weed, target crop, etc., but usually 1
1 g to 500 g per are, preferably 2 g / 20
The amount of emulsion, wettable powder, suspension, etc. is usually diluted with 1 liter / 10 liter of water per 1 are (adding an auxiliary agent such as a spreading agent if necessary). The granules and the like are usually treated as they are without any dilution.

Examples of the spreading agent include polyoxyethylene resin acid (ester), lignosulfonate, abietic acid salt, dinaphthylmethane disulfonate, and paraffin in addition to the above-mentioned surfactant.

Next, Test Examples will show that the compound of the present invention is useful as an active ingredient of a herbicide. The compounds of the present invention are shown by the compound numbers in Table 1, and the compounds used for comparison and control are shown by the compound symbols in Table 2.

Regarding the herbicidal efficacy, the degree of budding and growth inhibition of the test plant at the time of the survey was visually observed, and when there was no or almost no difference from when the compound was not tested, the test plant died. Or, the one whose growth is completely inhibited is defined as "5" and evaluated in 6 levels of 0 to 5, 0, 1, 2,
Shown as 3, 4, and 5.

Test Example 1 Field foliage treatment test Field soil was filled in a cylindrical plastic pot having a diameter of 10 cm and a depth of 10 cm, and seeds of millet, oats, radish, and velvetleaf were sown and grown in a greenhouse for 10 days. Then, Formulation Example 2
The test compound was made into an emulsion in accordance with (1), and a predetermined amount thereof was diluted with water containing 10 liters of spreading agent per are, and the leaves were treated from above the plant with a small sprayer. After processing 20
The plants were cultivated in a greenhouse for one day and the herbicidal efficacy was investigated. The results are shown in Table 3.

Test Example 2 Stem and leaf treatment test before crop germination A field soil was packed in a vat having an area of 33 × 23 cm ² and a depth of 11 cm, and Malaba morning glory, Onami fir, velvetleaf, Ebisugusu, Inobie and Enochologsa were sown and grown for 18 days. Soybean, cotton, corn, and wheat seeds were embedded in the soil between growing weed strains and covered with soil, and then the test compound was emulsified in accordance with Formulation Example 2 and a predetermined amount thereof was spread per areal containing a spreading agent. It was diluted with water equivalent to 5 liters, and the whole foliage was uniformly treated from above the plant with a small sprayer. At this time, the growth condition of the weeds varied depending on the grass species, but at the 1 to 4 leaf stage, the plant height was 4 to 12 cm. Process 2
The herbicidal efficacy was investigated after 0 days. The results are shown in Table 4. The test was conducted in a greenhouse throughout the entire period.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshige Muramatsu 350 Moritaka, Moriyama-ku, Aichi Prefecture Moriyama-ku 350 Hakusan Nitta Hakusan 85 (72) Inventor Yasuo Maki 115-2 Terugaoka, Meito-ku, Nagoya Aichi Prefecture (72) ) Inventor Naonori Hirata 704-2, 7-510, Kanaoka-cho, Sakai-shi, Osaka (72) Inventor Katsuzo Kamoshita 2-3-11 Kofudai, Toyono-cho, Toyono-gun, Osaka (72) Inventor Tatsuhiro Hamada Amagasaki-shi, Hyogo Muko Motomachi 3-4-8-306 (72) Inventor Ryo Yoshida 19 examiner Tomoki Saeki, 5-5 Jizoyama, East Uneno, Kawanishi City, Hyogo Prefecture

Claims (2)

[Claims] 1. A general formula [In the formula, A represents a hydrogen atom or a halogen atom, and R
¹ represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, R ² represents a hydroxyl group, a fluorine atom or a trifluoromethyl group, X represents a halogen atom, l represents an integer of 0 to 12, and m represents 0. Or represents 1, n
Represents 1 or 2, and q represents 1 or 2. ] The (polyfluoro alkyl) imidazole derivative shown by these. 2. General formula [In the formula, A represents a hydrogen atom or a halogen atom, and R
¹ represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, R ² represents a hydroxyl group, a fluorine atom or a trifluoromethyl group, X represents a halogen atom, l represents an integer of 0 to 12, and m represents 0. Or represents 1, n
Represents 1 or 2, and q represents 1 or 2. ] A herbicide characterized by using the (polyfluoroalkyl) imidazole derivative shown by these as an active ingredient.