KR970001481B1 - 2-(4,6-dimethoxy pyrimidin-2-yl) oxyacetophenone derivative, process for preparation thereof and use thereof as a herbicide - Google Patents

Abstract

2-(4,6-dimethoxypyrimidine-2-yl)oxyacetophenone derivative of general formula(I) is prepared by (1) reacting a compound of structural formula(II) with alcohol, thiol, carboxylic acid, amine or its salt under alkali condition and solvent to produce a compound of general formula(III), (2) reacting a compound of general formula(III) with 4,6-dimethoxy-2-methylsulfonylpyrimidine at normal temperature-120deg. C under alkali condition and solvent. In the formula, X is alkyl of C2-C8, alkoxy of C1-C5, acetyl, replaced or non-replaced acyloxy by aryloxy or heteroaryl, aryloxy, alkylthio of C1-C5, arylthio, heteroarylthio, alkoxy carbonylalkylthio of C1-C5, replaced or non-replaced amino by alkyl of C1-C4, alkoxyamino of C1-C5, cyano, halogen, hydroxy or nitro group.

Description

2- (4.6-demethoxypyrimidin-2-yl) oxyacetophenone derivative, its preparation and its use as herbicide

The present invention relates to a novel 2- (4.6-dimethoxypyrimidin-2-yl) oxyacetophenone derivative of the following general formula (I), a method for preparing the same, and its use for combating plants harmful to crops.

Wherein X is heteroyl, unsubstituted or substituted by 5- to 6-membered heteroaryl containing aryloxy or nitrogen as a heteroatom, C ₁ -C ₅ alkylthio, arylthio, arylthio, nitrogen 5 to 6 membered hetero arylthio, C ₁ -C ₅ alkoxycarbonylalkylthio, C ₁ -C ₅ alkoxyamino, halogen, hydroxy, thiol, or nitro containing as an atom.

In the above definitions, the term 'alkyl', when used alone or in synthetic terms such as alkylthio, means straight or branched chain saturated hydrocarbon radicals such as methyl, ethyl, n-propyl, isopropyl or various butyl isomers; "Alkoxy" means isomers such as methoxy, ethoxy, n-propoxy, isopropoxy or various butoxy; 'Halogen' or the compound word 'halo' means fluorine, chlorine, bromine or iodine.

It is well known that 2-phenoxy pyrimidine or (pyrimidin-2-yl) oxybenzene derivatives are useful as herbicides (see eg Agr. Biol, Chem., Vol. 30, P.896 (1966). Korean Patent Publication Nos. 79-55729, US Patent Nos. 4,248,619 and 4,427,437). Of the compounds recently developed based on 2-phenoxypyrimidine, it has been found that 2- (pyrimidin-2-yl) oxy benzoic acid derivatives exhibit excellent herbicidal effects. Won 223,406, 249,708, 287,072, 287,079, 315,889, 321,846, 330,990, 335,409, 346,789, 363,040, 402,751, 435,170, 435,186, 457,505, 459,243, 468,690, British Patent No. 2,237,570 and German Patent No. 3,942,476). These known compounds show a similar mechanism of action to sulfonylurea derivatives, imidazolinol derivatives and triazolepyrimidine derivatives, which are well known as conventional amino acid biosynthesis inhibitors, and have a simple structure and easy synthesis. Attention is focused on herbicides that inhibit amino acid biosynthesis of new structures.

A feature of these compounds that has been developed recently is that carboxylic acid substituents or carboxyl ester substituents are necessary for the benzene ring of the oxybenzene derivative to have excellent herbicidal (pyrimidin-2-yl). Therefore, recently developed herbicides are focused on 2- (pyrimidin-2-yl) oxybenzoic acid derivatives.

Therefore, the present inventors, while studying the development of a novel amino acid biosynthesis inhibitor herbicide, instead of the existing 2- (pyrimidin-2-yl) oxybenzoic acid derivative, the 2- (pyrimidin-2-yl) oxyacetophenone derivative Developed. Although the herbicidal effect of these derivatives depends on which substituents are in the 2-position of the acetophenone structure, they have excellent herbicidal power as compared to known (pyrimidin-2-yl) oxybenzene derivatives.

In order for these novel acetophenone derivatives to have excellent herbicidal power, the presence of the substituent X defined in the general formula (I) is essential. For example, in the case of an acetophenone compound whose substituent is hydrogen (X = H, see EP 0,467,099), a compound in which the substituent according to the present invention is other than hydrogen, that is, a 2-hydroxyacetophenone compound ( X = OH) can be seen that the herbicidal force is lowered by more than 10 times.

The present invention provides novel 2- (4,6-dimethoxypyrimidin-2-yl) oxyacetophenone derivatives of the general formula (I).

Wherein X is as mentioned above.

Preferred compounds among the novel compounds of general formula (I) include X is acetoxy, phenoxy cetoxy, 3-pyridylacetoxy, (4,6-dimethoxypyrimidin-2-yl) oxy, methylthio , Methoxycarbonylmethylthio, methoxycarbonylethylthio, phenylthio, 2-pyridylthio, thiol, nitro, methoxyamino, bromine and hydroxy.

The compound of general formula (I) according to the present invention can be synthesized according to the following scheme (A) or scheme (B).

Scheme (A)

A known compound α-bromo-2-hydroxyacetophenone is reacted with an alcohol, thiol, carboxylic acid or amine compound in the presence of a suitable base and solvent, or an alcohol in the presence of a suitable solvent, depending on the substituent to be substituted Reaction with a metal salt of thiol, carboxylic acid or amine compound yields a compound of formula (III). The base is preferably a metal hydride base such as sodium hydride or potassium hydride, potassium carbonate, potassium bicarbonate, sodium carbonate or the like, and the solvent is preferably methylene chloride, tetrahydrofuran, chloroform, acetonitrile or dimethyl foramide. .

Subsequently, when the compound of general formula (III) is reacted with 4,6-dimethoxy-2-methylsulfonylpyrimidine at a temperature of 15 to 120 ° C. in the presence of a suitable base and a solvent, the target compound of general formula (I) Get At this time, the base that can be used is preferably sodium hydride, potassium hydride, sodium bicarbonate, sodium carbonate and the like, and the solvent is preferably acetonitrile, tetrahydrofuran, dimethylformamide, methyl ethyl ketone or a mixed solvent thereof.

When known compound (IV) (European Patent Application No. 0,467,099) is reacted with cupric bromide at a temperature in the range of 15 to 100 ° C. under chloroform, ethyl acetate or a mixed solvent thereof, the α-bromo-acetophenone compound ( I-14) is obtained.

This compound (I-14) may be reacted with an alcohol, thiol, carboxylic acid or amine compound in the presence of a suitable base and solvent, or an alcohol, thiol, carboxylic acid or amine compound in the presence of a suitable solvent. The target compound of formula (I) is obtained by reacting with a metal salt of. The base is preferably a metal hydride base such as sodium hydride or potassium hydride, potassium carbonate, potassium bicarbonate, sodium carbonate and the like, and the solvent is preferably methylene chloride, tetrahydrofuran, methyl ethyl ketone, chloroform, acetonitrile, dimethylformamide, or the like. Do.

Specific examples of the novel 2- (4.6-dimethoxypyrimidin-2-yl) oxyacetophenone derivatives of general formula (I) prepared according to the process of the present invention are shown in Table 1 below with their respective physical properties. .

Hereinafter, the present invention will be described in more detail with reference to Preparation Examples and Examples. However, these preparation examples and examples are only for the understanding of the present invention and the present invention is not limited thereto.

Preparation Example 1

Thiophenol (762 μl, 11 mmol) was added dropwise to a tetrahydrofuran (10 mL) suspension of sodium hydride (0.26 g, 11 mmol) and stirred at room temperature for 20 minutes, followed by α-bromo-2-hydroxyacetophenone (II). ) (2.15 g, 10 mmol) was added dropwise and stirred at room temperature for 3 hours. The reaction mixture was poured into water, and the solvent of the organic layer extracted with ethyl acetate (50 mL) was removed by distillation under reduced pressure to yield 2.32 g (yield: 95%) of the title compound as a white solid.

¹ H NMR (CDC1 ₃ , δ): 4.26 (s, 2H), 6.86∼7.71 (m, 9H), 11.91 (s, 1H)

Example 1

Α-bromo-2-hydroxyacetophenone (III-9) (244 mg, 1.0 mmol) obtained in Preparation Example 1, potassium carbonate (179 mg, 1.3 mmol), and 4,6-dimethoxy-2- To a methylethylketone (25 mL) solution of methylsulfonylpyrimidine (240 mg, 1.1 mmol) was added dimethylformamide (3 mL) and heated to reflux for 3 hours. After the solvent was removed by distillation under reduced pressure, the reaction mixture was added to a saturated aqueous ammonium chloride solution, extracted with ethyl acetate, and the organic solvent was dried. The residue was subjected to column chromatography on silica gel (hexane: ethyl acetate = 5: 1, v / v) to give 191 mg (yield: 50%) of the titled compound as an oil.

¹ H NMR (CDC1 ₃ , δ): 3.79 (s, 6H), 4.29 (s, 2H), 5.79 (s, 1H), 7.16 ~ 7.77 (m, 4H)

Preparation Example 2

2- (4,6-dimethoxypyrimidin-2-yl) oxyacetophenone (IV) (274 mg, 1.0 mmol) was dissolved in a mixed solvent of chloroform (10 mL) and ethyl acetate (10 mL) and stirred. While cupric bromide (450mg, 2mmol) was added dropwise and refluxed for 1 hour. After the reaction mixture was filtered, the filtrate was distilled under reduced pressure and the residue was subjected to column chromatography on silica gel (hexane: ethyl acetate = 5: 1, v / v) to obtain the title compound.

Example 2

Α-bromo-2- (4,6-dimethoxypyrimidin-2-yl) oxyacetophenone (I-14) (353 mg, 1.0 mmol) obtained in Preparation Example 2 was diluted with dimethylformamide (10 ml). ) And sodium acetate (160 mg, 2.0 mmol) is added dropwise. After stirring the reaction mixture at room temperature for 12 hours, saturated aqueous ammonium chloride solution was added, extracted with ethyl acetate, and the solvent was dried. The residue is column chromatographed on silica gel (hexane: ethyl acetate = 5: 1, v / v) to give the title compound.

According to Example 1 or Example 2, the compound of general formula (I) shown in Table 1 was synthesized, and the physical properties thereof are also shown in Table 1.

Pot cultivation and treatment of assay plants in a greenhouse to assay the herbicidal efficacy of the novel herbicidal (4,6-dimethoxypyrimidin-2-yl) oxyacetophenone derivatives of the general formula (I) according to the present invention The effect was determined by the method, and the month evaluation was conducted according to the evaluation criteria of efficacy and harm (Table 3).

For the efficacy test, weeds include Digitaria sanguinalis, Panicum dichotomiflorum, Sataria farberi, Echinochgloa curs-galli var. Caudata, Sorghum bicolor, Aeschynomene indica ), Amaranthus retroflexus, Xanthium Strumarium, Solanum migrum, Abutilon theophrasti, Caulistegia japonica, Echinochloa crus-crusgallivar. Oryzicola (Wartweed) Aneilema Keisak, Scirpus jumcoides, Monocoria vaginalis, Cyperus difformis, Sputum (Potamogeton distinctus), Peel (Sagittaria trifolia), Swallowtail (Eleocharis kuroguwai), Beetweed Sagittaria trifolia) and Olmi (Sagittaria pygmaea) were selected.

When using the compound according to the present invention mixed with solid substances such as clay, talc, diatomaceous earth and liquid substances of water, alcohol, benzene, toluene, ether, ketone, ester, acids, amides, liquids, emulsions, powders, granules, etc. It may be formulated and used in any formulation of, wherein an emulsifier, dispersant, penetrant, electrodeposition agent, stabilizer is added as needed.

The following shows a part of the formulation examples of the herbicide containing the compound of the present invention as an active ingredient, which should not limit the present invention.

Formulation Example 1: (field conditions, 1 kg / kPa)

320 mg of the compound of the present invention was dissolved in 640 ml of an organic solvent (acetone), and then diluted in 640 ml of distilled water containing 0.2% of the nonionic surfactant Tween 20 to prepare a blend.

Formulation Example 2 (field condition, 1 kg / ha)

320 mg of the compound of the present invention was dissolved in 320 ml of an organic solvent (acetone), and then diluted in 320 ml of distilled water containing 0.2% of the nonionic surfactant Tween 20 to prepare a blend.

Experimental Example 1: Test for herbicidal power before germination by soil treatment (field conditions)

After filling a rectangular plastic container (20 × 15 × 10㎝) with sterilized field soil (sand loam, pH 5.5 to 6.0), sowing 6 weed species in one container with a surface area of 300㎠ and 0.5 Vomiting in centimeters. After 1 day of irrigation, the formulation was evenly sprayed on the soil surface with a portion (12 ml per plastic container) containing the active ingredient (1 kg / dl) corresponding to the treatment amount in the solution of 1. The herbicidal power for plant cultivation and post-observation weeds for 30 days after treatment was assessed in accordance with the evaluation criteria (Table 3), and the results are shown in Table 3.

Experimental Example 2 Test of herbicidal power after germination by foliage treatment (field conditions)

After the seeding of the assay plant in the same manner as in Experimental Example 1 and cultivation for 10 to 14 days, when the plant reaches the 3 to 4 leaf stage, the part containing the active ingredient corresponding to the amount of treatment in the compounding example 1 (1㎏ / ㏊) Spray evenly on plant foliage. The herbicidal power of the cultivated and observed weeds for 30 days after the treatment was evaluated in accordance with the evaluation criteria and the results are shown in Table 4.

Experimental Example 3: Herbicide efficacy and control drug experiments before germination

As a control agent, a known compound (A) of 2- (4,6-dimethoxypyrimidin-2-yl) oxyacetophenone (A), which is not included in the present invention, is a compound in which the substituent X is hydrogen in general formula (I). According to the method of Experimental Example 1, the control of the herbicidal efficacy with the compounds according to the present invention as a result of the novel acetophenone derivative of the general formula (I) according to the present invention far superior to the control agent It could be confirmed that the effect. The results are shown in Table 5 below.

Compound A used as a control agent in Table 5 is as follows.

Control Compound A:

Experimental Example 4: Test of herbicidal efficacy before germination by soil treatment (field conditions)

Fill the sterilized paddy soil (plant soil, pH 5.5-6.0) into each of the four pots (30 × 15㎝), and plant the paddy weeds in the state with a surface area of 450 cm2 and mix in the soil. After 1 day of watering of 4 cm, a part of the solution containing the active ingredient corresponding to the treatment amount (1 kg / kPa) is dipped in the solution of Formulation Example 2. After 4 weeks of treatment, after cultivation management and observation, the herbicidal effect on weeds was evaluated in accordance with the criteria, and the results are shown in Table 6.

Claims (12)

Novel 2- (4,6-dimethoxypyrimidin-2-yl) oxy acetophenone derivatives of the general formula (I) Wherein X represents acyloxy, C ₁ -C ₅ alkylthio, arylthio, nitrogen containing 5 to 6 heteroaryl substituted or unsubstituted by 5 to 6 membered heteroaryl containing aryloxy or nitrogen as a heteroatom. To heteroarylthio, C ₁ -C ₅ alkoxycarbonylalkylthio, C ₁ -C ₅ alkoxyamino, halogen, hydroxy, thiol, (4,6-dimethoxypyrimidin-2-yl) oxy or nitro Indicates. The compound of claim 1, wherein X is acetoxy, phenoxycetoxy, 3-pyridylacetoxy, (4,6-dimethoxypyrimidin-2-yl) oxy, methylthio, methoxycarbonylmethylthio, A compound of formula (I) representing methoxycarbonylethylthio, phenylthio, 2-pyridylthio, thiol, nitro, methoxyamino, bromine or hydroxy. Reacting a compound of formula (II) with an alcohol, thiol, carboxylic acid or amine in the presence of a base and a solvent, or reacting a compound of formula (II) with a metal salt of alcohol, thiol, carboxylic acid or amine in the presence of a solvent To obtain a compound of the general formula (III), and then react the compound of the general formula (III) with 4,6-dimethoxy-2-methylsulfonylpyrimidine in the presence of a base and a solvent at room temperature to 120 ° C. Method for producing a compound of formula (I) characterized in that. Wherein X is as defined in claim 1. 4. A process according to claim 3, wherein the base for preparing the compound of formula (III) is sodium hydride, potassium hydride, potassium carbonate, potassium bicarbonate or sodium carbonate. The method of claim 3, wherein the solvent for preparing the compound of formula III is dichloromethane, tetrahydrofuran, chloroform, acetonitrile, dimethylformamide. 4. The process according to claim 3, wherein the base for preparing the compound of formula (I) from the compound of formula (III) is sodium hydride, potassium hydride, sodium bicarbonate or sodium carbonate. The method of claim 3, wherein the solvent for preparing the compound of formula (I) from the compound of formula (III) is acetonitrile, tetrahydrofuran, dimethylformamide, methylethylketone or a mixture thereof. . In the presence of a solvent at room temperature to 100 ° C., the compound of formula (IV) is reacted with cupric bromide to obtain a compound of formula (I-14), followed by a structure of formula (I-14) in the presence of a base and a solvent. Is reacted with an alcohol, thiol, carboxylic acid or amine, or a compound of formula (I-14) is reacted with a metal salt of alcohol, thiol, carboxylic acid or amine in the presence of a solvent. Process for preparing the compound of I). Wherein X is as defined in claim 1. The method of claim 8, wherein the solvent for preparing the compound of formula (I-14) is chloroform, ethyl acetate or a mixture thereof. The method of claim 8, wherein the base for preparing the compound of formula (I) from the compound of formula (I-14) is sodium hydride, potassium hydride, potassium carbonate, potassium bicarbonate or sodium carbonate. The solvent for preparing a compound of formula (I) from the compound of formula (I-14) is dichloromethane, tetrahydrofuran, methylethylketone, chloroform, acetonitrile, dimethylformamide. How to. A herbicide composition comprising the compound of formula (I) as claimed in claim 1 as an active ingredient.