JPH07116132B2 - Substituted benzoyl derivatives and selective herbicides - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel substituted benzoyl derivative and a selective herbicide containing the derivative as an active ingredient.

[Conventional technology and problems]

Conventionally, a wide variety of chemicals have been put to practical use from the research and development of herbicides over many years, and these herbicides have contributed to labor saving of weed control work and improvement of productivity of agricultural and horticultural crops.

Even today, there is a demand for the development of a new drug having more excellent herbicidal properties, and as a herbicide for agriculture and horticulture, it is possible to control only target weeds selectively and at a low dose without affecting the cultivated crops. However, existing agents do not always have suitable herbicidal properties, and there is a demand for more excellent compounds as herbicides.

[Means for solving problems]

The present invention has the general formula (I): [In the above formula, Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R represents 1 to 4 carbon atoms. Represents an alkyl group of
n represents 0, 1 or 2. ] It is related with the selective benzoyl derivative represented by these, and 1 type, or 2 or more types of its salt is contained as an active ingredient.

The present inventors have studied for many years, and as a result, the present compound (I): (Wherein Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁶ , R and n have the same meanings as described above), the herbicidal effect is significantly higher than that of conventional herbicides, and the present invention It was found that many of the compounds have excellent selectivity and are practically useful for certain crops, for example, crops such as corn, wheat, rice, etc., and have completed the present invention.

That is, the compound of the present invention can significantly reduce the amount of the active ingredient applied per unit area as compared with the conventionally known compound, the phytotoxicity to crops is extremely slight compared with the conventional herbicides, and the economic effect thereof is extremely large. Is. Furthermore, the compound of the present invention can be said to be an epoch-making herbicide which can significantly reduce the risk of environmental pollution due to large-scale application of agricultural chemicals and has little influence on other crops due to soil residue.

The structure of the compound of the present invention is characterized in that the 3- and 4-positions of the benzoyl moiety are substituted with the above-mentioned —COOR group and —S (O) _n CH ₃ group.

Conventionally, it has been known that substituted benzoyl derivatives have herbicidal activity, and in particular, JP-A-61-155347 claims a derivative containing the compound of the present invention. Some of the substituents COOR are
It is not illustrated. Moreover, the present inventors have found that the introduction of the combination of substituents of the benzoyl moiety as in the present invention significantly improves the herbicidal effect and the crop selectivity of the substituted benzoyl derivative.

The compound of the present invention can be easily synthesized by any of the reactions represented by the following reaction formulas.

(In the formula, Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁶ , R and n have the same meanings as described above, and DCC represents N, N'-dicyclohexylcarbodiimide.) The general formula (Ia) is represented by the general formula (I): It is a tautomer and can be represented by any structural formula.

Reaction formula (1) represents a reaction in which a benzoic acid having an appropriate substituent and cyclohexanone-1,3-diones are reacted in the presence of DCC and a base in an inert solvent to obtain a 2-benzoylcyclohexanone derivative. DCC is 1.0 to 1.5 times the molar amount of benzoic acid and pyrazole, and the solvent may be any as long as it is inert to the reaction, but especially t-butyl alcohol, t
-Excellent amyl alcohol, isopropyl alcohol, etc. The base is not always necessary, but the use thereof generally improves the yield. Although not particularly limited, potassium carbonate, sodium carbonate and the like are excellent. The reaction temperature can be any temperature from room temperature to the boiling point of the solvent, but 50 to 100
℃ is desirable. The reaction time is usually about 0.5 to 20 hours.

Reaction formula (2) shows a reaction of a benzoyl chloride having an appropriate substituent and a substituted cyclohexanone-1,3-dione into a benzoyl ester which is rearranged to give a 2-benzoyl derivative.

Benzoyl esterification is a solvent inert to the reaction (aromatic hydrocarbons, fatty acid esters, halogenated hydrocarbons,
Ethers, acetonitrile, dimethyl sulfoxide,
N, N'-dimethylformamide, etc.) or in a two-phase system or mixture system of them and water, suitable dehydrochlorinating agent (inorganic base such as caustic soda, caustic potash, sodium hydrogencarbonate, sodium phosphate, pyridine) , An organic base such as triethylamine) at 0 ° C. to 100 ° C. in 10 minutes to 5 hours.

The rearrangement reaction is achieved by a Lewis acid represented by anhydrous aluminum chloride, a base or a cyanide represented by potassium cyanide. As the base, potassium carbonate,
Calcium hydroxide, sodium carbonate, etc. are used. The Lewis acid, base and cyanide are usually used in 0.1 to 10 moles. A solvent is not particularly required, but it is inert to the reaction, and a solvent having an appropriate boiling point may improve operability and yield. Suitable examples include the same solvent system as in the benzoyl esterification reaction or dioxane, diglyme and the like. Reaction temperature is usually 20-150 ℃, reaction time is 1
5 minutes to 10 hours.

Reaction (3) shows a reaction between cyclohexane-1,3-diones and benzoyl cyanide. For this reaction equimolar or more of zinc chloride and equimolar or more of a base such as triethylamine are used. The solvent is not particularly limited as long as it is inert, and preferable examples thereof include methylene chloride and ethylene chloride. The reaction time is usually 0 to 40 ° C., and the reaction time is 1 to 10 hours.

The benzoic acid, benzoyl cyanide or benzoyl chloride, which is a raw material of the compound of the present invention, can be easily synthesized by a combination of known synthetic methods of various species. As an example, it can be produced according to the following reaction formula.

(In the above formula, R represents the same meaning as described above and Hal represents a halogen atom.) These benzoic acids are easily derived to benzoyl chlorides by a chlorinating agent such as phosphorus pentachloride, thionyl chloride, and sulfuryl chloride. be able to. Further, it can be easily induced to benzoyl cyanide by trimethylsilyl cyanide.

Using the benzoic acids, benzoyl cyanides or benzoyl chlorides thus synthesized, reaction formulas (1) to
According to (4), the compound of the present invention can be easily synthesized.

The present invention will be described with reference to specific examples. However, the present invention is not limited to these.

Example 1 Synthesis of 2- (4-methanesulfonyl-3-methoxycarbonyl-2-methylbenzoyl) cyclohexane-1,3-dione (Compound No. 1) 4-Methanesulfonyl-3-methoxycarbonyl-2-
Methylbenzoic acid 1.2g, 1,3-cyclohexanedione 0.48g
0.39g of potassium carbonate and N, N'-dicyclohexylcarbodiimide 1.
1 g was added, and the mixture was stirred at 80 ° C. for 3 hours. After concentration under reduced pressure, an aqueous potassium carbonate solution was added, and the insoluble material was filtered off. The filtrate was washed with chloroform, concentrated hydrochloric acid was added to acidify, and the mixture was extracted with chloroform. The chloroform layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure to give a crude target product. This was recrystallized in ethanol to obtain 0.45 g of the desired product.

Melting point 178 to 181 ° C. Next, the compounds synthesized according to the above Examples are shown in Table 1 including the above Examples. However, the present invention is not limited to these.

The symbols in the table have the following meanings.

Me: methyl group, Et: ethyl group, Pr-n: normal propyl group, Pr-i: isopropyl group, But-t: tertiary butyl group When the compound of the present invention is used as a herbicide for agricultural and horticultural use, it is generally a suitable carrier, for example, a solid carrier such as clay, talc, bentonite, diatomaceous earth or the like, water, alcohols (methanol, ethanol, etc.), aromatic hydrocarbons. (Benzene, toluene, xylene, etc.), chlorinated hydrocarbons, ethers, ketones, esters (ethyl acetate, etc.), acid amides (dimethylformamide, etc.) , Add emulsifiers, dispersants, suspensions, penetrants, spreading agents, stabilizers, etc., if desired, and put them into practical use in any dosage form such as liquids, emulsions, wettable powders, powders, granules and flowables. Can be offered. Further, if necessary, it may be mixed with other types of herbicides, various insecticides, fungicides, plant growth regulators, synergists, etc. at the time of preparation or removal. The types of herbicides to be mixed are, for example, Farm Chemicals Handbook (Farm Chemicals H
and book), 73rd edition (1987), and the like. Some of these are atrazine, cyanadine, alachlor, metolachlor, and EPT.
C, 2,4-D, butyrate, dicamba, bromoxynil, tridifane and the like. Besides this, N-[(4,6-dimethoxypyrimidin-2-yl) -aminocarbonyl] -3-chloro-4-methoxycarbonyl-1-methylpyrazole-5 described in U.S. Pat. No. 4,668,277.
-Sulfonamide or N-[(4,6-dimethoxypyrimidin-2-yl) -aminocarbonyl] -3-bromo-4-methoxycarbonyl-1-methylpyrazole-
You may mix-apply with 5-sulfonamide etc. The amount of application varies depending on the application scene, application time, application method, cultivated crops, etc., but in general, an appropriate amount of active ingredient is about 0.001 to 10 kg per hectare.

Next, formulation examples of a herbicide containing the compound of the present invention as an active ingredient are shown, but the invention is not limited thereto. In the following formulation examples, “part” means part by weight.

Formulation Example 1 Wettable powder Compound of the present invention No.1 ...... 60 parts DIKELITE PFP …… 33 parts (Kaolin clay: product name of Sikelite Industry Co., Ltd.) Sorpol 5039 …… 5 parts (Nonionic surfactant And a mixture of anionic surfactant: Toho Chemical Industry Co., Ltd. trade name Carplex (anti-caking agent) …… 2 parts (white carbon: Shionogi Seiyaku Co., Ltd. trade name) And make wettable powder.

Formulation Example 2 Emulsion Compound No. 1 …… 1.5 parts Xylene …… 78.5 parts N, N-Dimethylformamide …… 15 parts Solpol 2680 …… 5 parts (Nonionic surfactant and anionic surfactant Mixture: trade name of Toho Chemical Industry Co., Ltd. The above is uniformly mixed and ground to give an emulsion.

Formulation Example 3 Flowable agent Compound of the present invention No.1 ...... 40 parts Agrisol B-710 ...... 10 parts (Nonionic surfactant: Kao Co., Ltd. trade name) Lunox 1000C ...... 0.5 parts (Anionic surface active agent) Agent: Toho Chemical Industry Co., Ltd. product name) 1% Rhodopol water ...... 20 parts (Thickener: Lone Poulean company product name) Water ...... 29.5 parts Mix evenly to make a flowable agent.

The compound of the present invention can be applied to the control of various weeds in non-agricultural fields such as fields, paddy fields, orchards other than agricultural and horticultural fields such as orchards, and the application amount of the application scene, Although there are differences depending on the time of application, target grass species, cultivated crops, etc., it is generally appropriate to spray so that the amount is about 0.001 to 5 kg per hectare.

Next, the herbicidal effect of the compound of the present invention will be specifically described with reference to test examples.

Test Example-1 Herbicidal effect test by soil treatment Put sterilized diluvial soil in a plastic box of 15 cm in length, 22 cm in width, and 6 cm in depth, and sow seeds of Nobie, Ohishiba, Mehishiba, Okisakibi, Ichibi, Inubiyu, Academia japonica, and Toromokoshi , Furthermore, tuberous tubers were placed on the ground, covered with 1.5 cm of soil, and then sprayed uniformly on the soil surface so that the amount of active ingredient was a predetermined ratio. The chemical solution for spraying was prepared by diluting the wettable powder, emulsion, solution or flowable agent of the above-mentioned formulation example with water and spraying it over the entire surface with a small spray. The herbicidal effect against various weeds was investigated 3 weeks after spraying the chemical solution according to the following criteria.
The results are shown in Table 2.

Criteria 5 …… Weeding rate 90% or more (almost complete death) 4 …… Weeding rate 70 to 90% 3 …… Weeding rate 40 to 70% 2 …… Weeding rate 20 to 40% 1 …… Weeding rate 5 to 20 % 0 …… Less than 5% of the herbicide rate (almost no effect) However, the above-mentioned herbicide rate is calculated by the following formula by measuring the above-ground weed weight of the chemical-treated area and the above-ground weed weight of the untreated area. It is a thing.

Test Example-2 Herbicidal effect test by foliar treatment 15 cm in height, 22 cm in width, 6 cm in depth and put in sterilized diluvial soil in a plastic box, to remove Nobie, Ohishiba, Mejishiba, Okisakibi, Onamomi, Ichibi, Inubiyu, Academia japonica, and Toromokoshi The seeds were sown in spots, and the tubers of Astragalus chinensis were further placed and covered with soil for about 1.5 cm. When various plants reached the 2-3 leaf stage, the active ingredients were sprayed uniformly on the foliage so that the amount of the active ingredient became a predetermined ratio.

The chemical solution for spraying was prepared by diluting the wettable powder, emulsion, solution or flowable agent of the above-mentioned formulation example with water and spraying it over the entire surface of the foliage of various weeds and crops with a small spray. Two weeks after spraying the chemical solution, the herbicidal effect on various weeds was examined according to the criteria of Test Example-1, and the chemical damage to various crops was also examined according to the criteria of Test Example-1. The results are shown in Table 3.

The control compounds in Tables 2 and 3 are as follows.

Control compound A: Control compound B:

Front page continued (72) Inventor Koichi Suzuki 1470 Shiraoka, Shiraoka-cho, Minamisaitama-gun, Saitama Inside Biochemical Research Laboratory, Nissan Chemical Industry Co., Ltd. Company Biochemistry Research Institute (72) Inventor Shigeomi Watanabe 1470 Shiraoka, Shiraoka-cho, Minamisaitama-gun, Saitama Nissan Chemical Industry Co., Ltd. Biochemistry Research Institute Examiner Osamu Sato

Claims (2)

[Claims] 1. General formula (I): [In the above formula, Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R represents 1 to 4 carbon atoms. Represents an alkyl group of
n represents 0, 1 or 2. ] The substituted benzoyl derivative and its salt represented by these. 2. General formula (I): [In the above formula, Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R represents 1 to 4 carbon atoms. Represents an alkyl group of
n represents 0, 1 or 2. ] The selective herbicide which contains 1 type (s) or 2 or more types of the substituted benzoyl derivative and its salt represented by these as an active ingredient.