KR810000835B1 - Preparing process for pyrazol derivatives - Google Patents

Abstract

Title compds. (I; R1 = lower alkyl or alkenyl; R2 = lower alkyl; R3 = IV; X = halogen, nitro, lower alkyl, halogenated lower alkyl, lower alkoxy; n = 1-2), useful as agricultural fungicide, were prepd. by the reaction of II and III. Thus, 11.2 g 1,3-dimethylpyrazolone and 20.9 g 2,4-dichlorobenzoyl chloride were stirred for 60 min in benzene in the presence of 5.3 g sodium carbonate to give 25.6 g 1,3-dimethyl-5-(2,4-dichlorobenzoyloxy)pyrazole.

Description

Preparation of Pyrazole Derivatives

The present invention relates to the preparation of novel pyrazole derivatives of the general formula (I).

Where

R ₁ represents a lower alkyl group or a lower alkenyl group,

R ₂ represents a lower alkyl group,

의 페닐기R ₃ is a general formula

Phenyl group

(Wherein X represents a halogen atom, a nitro group, a lower alkyl group, a halogenated lower alkyl group or a lower alkoxy group,

n represents an integer of 1 or 2,

when n is 2, X may be the same or different from each other)

More specifically, when the present invention is described, the compounds of the following general formula (II) may be heated without a catalyst or in a aromatic hydrocarbon solvent without a carboxylic acid or a reactive derivative thereof and without a catalyst or water-immiscible with water. A method for producing the pyrazole derivative (I), characterized by reacting in the presence of a catalyst in a chemical solvent.

Wherein R _1, R ₂ and R ₃ are as described above.

Any compound of the general formula (I) produced by the method of the present invention is a novel compound and is a compound useful as an agricultural horticultural fungicide itself. In addition, Japanese Patent Application Laid-Open No. 3776/1975 discloses a parasol compound having a structure similar to that of the compound of the general formula (I), and describes that these compounds are useful as ultraviolet stabilizers.

According to the method of the present invention, a compound of the general formula (I) is provided, and in this general formula (I), R ₁ is preferably one having 3 to 3 carbon atoms such as methyl, ethyl, n-propyl or isopropyl. Straight or branched lower alkyl groups, especially straight or branched chains having 3 or 4 carbon atoms such as methyl or aryl, 2-butenyl, 1-methyl-2-propenyl or 2-methyl-2-propenyl Lower allylyl group, in particular an atyl group. By R ₁ preferably a straight chain or a lower alkyl group on the side chain having the same carbon number of 1-3 as illustrated in R _1, in particular represents a methyl group. R ₃ is

Wherein X is suitably a halogen atom such as chlorine, cancelled, fluorine, or oxo, in particular a straight chain having 1 to 2 carbon atoms such as chlorine atom, natro group, methyl, ethyl, n-propyl or isopropyl, or Branched lower alkyl groups, in particular methyl, trichloromethyl, 2,2,2-trichloroethyl, 2,2-dibromoethyl, 2,2,2-dribromoethyl, 2-iodoethyl, 2, Lower alkyl groups having 1 or 2 carbon atoms substituted with 1 to 3 halogens such as 2-iodoethyl, bromomethyl, or dichloromethyl or carbon atoms such as methoxy, ethoxy, n-propoxy or isopropoxy Straight or branched lower alkoxy groups having 1 to 3, especially methoxy groups, are shown.

n represents the integer of 1 or 2, and when n is 2, X represents the phenyl group or naphthyl group which has same or different from each other.

Particularly suitable compounds are those wherein R ₁ is a methyl group or an aryl group, R ₂ is a methyl group, and R ₃ is 2,4-dichlorophenyl or 2-chloro-4-nitrophenyl.

The method of the present invention is a method characterized by reacting a compound of formula (II) with a compound of formula (III) or a reactive derivative thereof.

Wherein R ₁ , R ₂ and R ₃ are as defined above.

The reactive derivative of the compound of the general formula (III) is the same as an acid anhydride or an acid halide, and means to react with a compound having a hydroxyl group to produce esters. Especially preferred are acid chlorides. When chloride is used, hydrogen chloride is liberated in the reaction with the compound of general formula (II).

Interestingly, the compounds of formula (II) and chlorides of compounds of formula (III) are mixed with each other in an inert solvent (eg, xylene, tetrachloroethane) having a boiling point of 80 ° C. or higher, or Heating in the absence of a solvent facilitates the dehydrochlorination dehydrochlorination to produce pyrazole derivatives of formula (I).

In order to proceed the reaction at room temperature, in the presence of an acid solution, for example, alkali metal carbonates such as sodium carbonate and potassium carbonate, hydroxides of alkaline earth metals such as lime or organic bases such as pyridine, triethylamine and dimethylaniline It is preferable to carry out the reaction. The reaction is usually completed within 3 hours in 5 minutes (when using an acid acceptor).

Examples of the solvent that can be used in the method of the present invention include activities such as aromatic hydrocarbons such as benzene and xylene, halogenated hydrocarbons such as chloroform, dichloroethane and tetrachloroethane, ethers such as ether, tetrahydrofuran and dioxane. The organic solvent which does not have hydrogen is mentioned, It is especially preferable to use benzene, xylene, and dichloroethanol. Moreover, in order to remove and isolate the salt produced | generated during reaction, it is also preferable to advance reaction in the mixed solvent of water and these organic solvents.

After the reaction is completed, the reaction product can be collected from the reaction mixture by a conventional method. For example, after completion of the reaction, the solvent is distilled off to obtain the desired product. In addition, the reaction product may be further purified by a conventional method, for example, by recrystallization from a suitable solvent.

Next, the method of the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1

11.2 g of 1,3-dimethylpyrazolone, 20.9 g of 2,4-dichlorobenzoyl chloride, and 5.3 g of sodium carbonate (anhydrous) are mixed and stirred in 150 ml of benzene and 20 ml of water for 60 minutes. Next, after removing the water layer, the benzene layer is distilled off under reduced pressure to give 25.6 g of 1,3-dimethyl-5- (2,4-dichlorobenzoyloxy) pyrazole. Yield 90%

When this product is recrystallized with the benzene-hexane mixed solvent, the white needle which has melting | fusing point 99-100 degreeC is obtained.

Elemental Analysis Value (%) C ₁₂ H ₁₀ CI ₂ N ₂ O ₂

Calc .: C, 50.55; H, 3.54; N, 9.82; CI, 24.87

Found: C, 50.70; H, 3.52; N, 9.80; C1, 24.77

Example 2

11.2 g of 1,3-dimethylpyrazolone, 17.5 g of 4-chlorobenzoyl chloride, and 10.2 g of triethylamine are mixed and stirred in 200 ml of benzene for 30 minutes. Next, after washing with 100 ml of water, the solvent was distilled off under reduced pressure, and the solid residue was recrystallized from hexane to obtain 23.6 g of 1,3-dimethyl-5- (4-chlorobenzoyl oxy) pyrazole.

Melting Point 100 ~ 101 ℃, Yield 94%

Elemental Analysis Value (%) C ₁₂ H ₁₁ CIN ₂ O ₂

Calculated Value: C, 57.50 H, 4.42 N, 11.18 CI, 14.14

Found: C, 57.65 H, 4.40 N, 11.16 CI, 14.04

EXAMPLES 3-20

In the same manner as in Example 1 or the same, the compounds in the following table are synthesized.

TABLE A

TABLE b

As described above, the compound of general formula (I) according to the present invention has an excellent bactericidal effect on a wide range of filamentous fungi, which are parasitic on agricultural horticultural crops and have a detrimental effect. (紋枯病), tomato yunmun (輪 紋 病), cucumber anthrax, etc. have a high control effect. Moreover, it is effective also against various soil pathogens, and can also effectively suppress crude fungi which adversely affects the germination of rice.

The agricultural / horticultural germicide which uses the compound of General formula (I) as an active ingredient contains 0.05-90% of at least 1 sort (s) of the compound represented by Formula (I) as an active ingredient. In preparing agrohorticultural fungicide, it can be prepared in any formulation form such as powder, hydrate, granule, emulsion, etc. by the conventional method for producing pesticides.

Examples of the carrier used at this time include inert solid carriers such as clay, talc, bentonite, silica, and calcium carbonate, and liquid carriers such as benzene, toluene, xylene, methylnaphthalin, and dimethylformamide.

In order to enhance the biological effect or improve the properties of the preparation, nonionic, anionic or cationic surfactants, various high molecular compounds, etc. are added, and other fungicides, herbicides, insecticides, plant growth regulators or It can also be mixed with fertilizers and the like.

Agrohorticultural fungicides containing the compound of formula (I) as an active ingredient are applied to plants and soil by methods such as spraying, irrigation and coating. When spreading, the concentration of the active ingredient of the dispersion is usually 50 to 5000 ppm, preferably 200 to 1000 ppm, and in order to suppress fungus in the soil, it is usually 50 to 5000 ppm, preferably 200 to 1000 ppm. It is preferable to irrigate the chemical liquid of the effective ingredient concentration per 1 m 2 per liter.

Next, the reference example of the agricultural / horticultural germicide which uses the compound of Formula (I) by this invention as an active ingredient is demonstrated. As used herein, the term "parts" means parts by weight.

Reference Example 1. Rice Blast Control Test

10 parts of the compound of formula (I) shown below, 4 parts of sodium dodecylbenzene sulfonate, 2 parts of polyvinyl alcohol, and 84 parts of clay were mixed uniformly, and pulverized three times with an impact grinder to obtain a homogenizing powder again. . Diluted solution containing 1000ppm or 300ppm as an active ingredient of the above-mentioned hydrating agent was sprayed 10ml per grape, and spore suspension of pyricularia oryzae was sprayed after 3-4 leafy rice seedlings (breed: Agriculture and Forestry No. 20). It is hybridized and left for 48 hours in a room with a temperature of 20 to 22 ° C and a humidity of 100%. Subsequently, it transferred to the greenhouse of the temperature of 24-26 degreeC, and after 3 days, the number of leaves was examined about the upper 2 leaves of a test plant. The average value was shown to the 1st table by repeating 1 time 3 times.

TABLE 1

Reference Example 2. Rice Tooth Disease Control Test

Ten parts of the compound of formula (I) shown below, 3 parts of calcium dodecylbenzene sulfonate, 7 parts of polyoxyethylene nonylphenyl ether, 10 parts of dimethylformamido and 70 parts of xylene were mixed and dissolved uniformly to obtain a fluid.

Spread a diluent containing 500 ppm of the active ingredient of the emulsion into 4 to 5 leaves of rice seedlings (variety: Geumnam wind) at 15 ml per pot, and air-dried. 4-5 particles of the oat grains cultured with pellicularia sasakii in advance were placed on the stems of rice, kept in a greenhouse at 25-27 ° C for 10 days, and the height of advanced lesion formation from the ground was examined. The average value was shown in Table 2 repeatedly for 3 times.

TABLE 2

Reference Example 3. Cucumber Seedling Disease Control Test

5 parts of the compound of the formula (I) and 95 parts of the clay shown below were mixed uniformly, crushed twice with an impact mill, and mixed uniformly again to obtain a powder.

Evenly mixed seedlings (Fusarium oxysporum or Rhizoctonia solani) incubated on the cover for 2 hours at 28 ℃ in the soil uniformly, and mixed the above powdered powder 30g per 1㎡, and cucumber seeds in this soil Seed 100 grains per eggplant. After two weeks, the number of tendon seedlings that did not suffer from seedling disease was examined.

The results are shown in Table 3.

TABLE 3

Reference Example 4. Cucumber Anthrax Control Test

The first leaf of the main leaf planted in a pot of 10 cm in diameter is spread on cucumbers (variety: superficial plaques), each containing 50 ml of 3 pots, and a blank reagent containing 300 ppm and 100 ppm of the following compounds, and then dried by anthrax after air drying. The spore suspension of colletotrichum lagen-arium) was sprayed and inoculated and left for 24 hours in a room with a temperature of 20 to 22 ° C and a humidity of 100%. Thereafter, the mixture was transferred to a room temperature of 26 ° C, and 7 days after the inoculation, the presence or absence of the cotyledon and the first leaf of the main leaf were examined, and the area of disease was calculated. The results are shown in Table 4.

TABLE 4

As is apparent from the above Reference Examples 1 to 4, the compound of formula (I) shows excellent control effect against various diseases of crops, and a wide range of application is expected. Moreover, in any test, the damage of a crop was not recognized.

Claims (1)

The compound of the following general formula (II) is heated either in the presence of a catalyst in a carboxylic acid of the general formula (III) or a reactive derivative thereof and without solvent or in an aromatic hydrocarbon solvent, without a catalyst, or in water and a water immiscible solvent. A process for producing a pyrazole derivative of the general formula (I), characterized by

Wherein R ₁ represents a lower alkyl group or a lower alkenyl group, R ₂ represents a lower alkyl group, and R ₃ represents a general formula

Phenyl group (wherein X represents a halogen atom, a nitro group, a lower alkyl group, a halogenated lower alkyl group or a lower alkoxy group, n represents an integer of 1 or 2, and when n is 2, X may be the same or different from each other) Or naphthyl group.