JPS628081B2 - - Google Patents

Description

[Detailed description of the invention]

One of the most important agricultural issues today is countermeasures against continuous cropping problems. Even in our country, where arable land is limited and continuous cultivation is forced, various vegetables, potatoes, peanuts, tobacco, konnyaku, etc.
The growth of various crops such as upland rice, apples, chrysanthemums, and carnations is severely inhibited, and in severe cases, there is no harvest at all, and the situation is worsening year by year. Continuous cropping failure is related to the following factors: 1. Deterioration of physical factors in the soil, 2. Deterioration of chemical factors in the soil, and 3. Biological factors in the soil, but especially soil-borne diseases and soil nematodes. In many cases, soil diseases caused by soil diseases account for more than 50% of continuous cropping failures, and conventionally, disinfection using soil fungicides such as steam disinfection, chloropicrin, and pentachlornitrobenzene is essential for continuous cropping. This is being taken as a countermeasure. Important soil diseases that inhibit continuous cropping include Verticillium alboatrum, Erwinia aroideae, Pseudomonas solanacearnm, Sclerotinia sclerotiorum, Phytophthora app, and vine rot. (Fusarium oxysporum), black rot (Xanthomonas campestris), clubroot (Plasmodiophorm brassicae), seedling damping-off (Pythium spp., Rhizoctonia spp.), white crest disease (Rosellinia necatrix), etc. As a result of extensive research on compounds having an acetylene group, the present inventors found that the general formula R ₁ -C≡C-CO-R ₂ [wherein R ₁ is a linear alkyl group having 1 to 4 carbon atoms, Phenyl group, benzoyl group, C ₂ H ₅ CH=
CH-, CH ₃ -CH=CH- or COOY (Y represents a straight-chain alkyl group having 1 to 4 carbon atoms, phenyl group or benzyl group), R ₂ is a hydrogen atom, a thienyl group, a carbon atom Several 1 to 4 straight chain alkyl groups, phenyl groups, phenyl group-substituted ethynyl groups or -OZ (Z is a hydrogen atom, carbon atoms 1 to 4
(representing straight-chain alkyl groups, phenyl groups, or benzyl groups)] If the compound represented by the formula shows an extremely strong soil bactericidal effect and has no adverse effect on the growth of living organisms, it is possible to continuously cultivate crops. The present invention was completed based on this discovery. The present inventors were able to detect an extremely excellent bactericidal effect against soil pathogenic bacteria by treating these compounds in the soil and making full use of their bactericidal and transpiration properties. It has extremely high utility value. Conventionally, chloropicrin, methyl bromide, pentachloronitrobenzene (PCNB), etc. have been widely used as fungicides for soil disinfection. Major difficulties, restrictions on the period of use to avoid drug damage, and problems with bacterial resistance (especially in the case of PCNB) pose major obstacles to practical use, and there is a strong need for the development and practical application of new soil disinfectants to replace these. has been done. The soil disinfectant of the present invention overcomes these drawbacks and has an extremely excellent soil disinfection effect. The soil fungicide according to the present invention can be used by mixing the active ingredient into soil surface soil as it is, but in reality, various inorganic or organic solids, carriers, such as diatomaceous earth, clay, talc, ammonium sulfate, urea, etc. Used by mixing with powders such as silica gel, coal, calcium carbonate, and sawdust. Furthermore, the compounds according to the present invention can be used in various liquids, carriers, such as acetone, benzene,
It can also be used by dissolving or dispersing it in xylene, kerosene, vegetable oil, paraffin, etc. Furthermore, various adjuvants such as anionic surfactants such as lignin sulfonate and sodium alkylbenzenesulfonate, nonionic surfactants such as nonylphenyl polyoxyethylene ether, and lubricants such as calcium stearate and white carbon are added. can be used. In addition, the active ingredient compound of the composition of the present invention may optionally include pentachlornitrobenzene (PCNB),
Bis(dimethylthiocarbamoyl)disulfide, tetrachloroisophthalonitrile, 3-hydroxy-5-methylisoxazole, 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazyl, N-(trichloromethylthio)-4-cyclohexene- 1,2-dicarboximide, N
-(1,1,2,2-tetrachloroethylthio)-
Bactericidal agents such as 4-cyclohexene-1,2-dicarboximide and chloropicrin, 1,2-dibromoethane, 1,3-dichloropropene and 1,2-dichloropropane, and bis(2-chloro-
1-methylethyl)-ether, bromomethane,
Mix with nematicides such as sodium N-methyldithiocarbamate (ammonium), organophosphorus insecticides, carbamate insecticides, chlorine insecticides, various herbicides, fertilizers, or use as a mixture. It is also possible. The compounds represented by the above general formula are a group of known compounds that can generally be produced as follows. For example, acetylene monocarboxylic acids are easily synthesized by reacting metal acetylide with carbon dioxide [JHWatiz, ESHudak, J.Org.Chem.,
19 , 1580 (1954)]. Acetylene monocarboxylic acid is synthesized by adding bromine to fumaric acid or maleic acid and then dehydrobromating it with potassium hydroxide [T.
W.Abbot, Org.Synth., 515 (1943)]. Acetylenaldehyde is easily synthesized by reacting metal acetylide with formic acid amide or orthoformic acid ester [ERHJones et al, J.
Chem.Soc., 3483 (1960)]. In addition, acetylene ketones are easily synthesized by reacting metal acetylides with acid halogen compounds and acid amide esters [RBDavis, DH
Scheiber, J.Am.Chem.Soc., 78, 1675
(1956)]. Next, these compounds are illustrated in Table 1.

【table】

[Table] Production examples of these compounds are shown below. Preparation Example 1 Preparation of Compound No. 14 In an ethereal solution of ethylmagnesium bromide (prepared from 6 g of magnesium, i.e. 0.25 gram atom, excess ethyl bromide, 150 ml of anhydrous ether), 1.
- 20.5 g (0.25 mole) of hexine in anhydrous ether 50
ml solution was added dropwise. The reaction was completed by refluxing for 1 hour, and the mixture was transferred to a dropping funnel. DMF55g (0.75mole)
The Grignard solution was added dropwise to a 100 ml solution of anhydrous ether while stirring and cooling with an ice-salt cooling agent. After the reaction was completed by further stirring at 20° C. for 4 hours, the mixture was gradually added to vigorously stirred 5% sulfuric acid 1 for decomposition. After 18 hours, the mixture was extracted with ether, the extract was washed with water, and the ether was distilled off using a short distillation tube. The remaining aldehyde was distilled under reduced pressure. Yield 14.1g (yield 51
%) bp 54-55℃/16mmHg Production example 2 Method for producing compound No. 2 36g of phenylacetylene under nitrogen stream
(0.35 mole) of ethylmagnesium bromide in an anhydrous ether solution (magnesium 7.3
g, ie 0.3 gram atom, excess ethyl bromide, prepared from 180 ml of anhydrous ether) was added dropwise.
After refluxing for 1.5 hours, 14 g of acetaldehyde
(0.3 mole) was added dropwise at -20°C. After stirring for 2 hours, saturated ammonium chloride aqueous solution was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure.
The crude carbinol thus obtained was dissolved in acetone, and Johns reagent was added dropwise under ice cooling until the solution took on an orange-green color. After stirring for 2 hours, excess oxidizing agent was decomposed with isopropyl alcohol, and sodium hydrogen carbonate was added to neutralize the sulfuric acid. The precipitate was removed and acetone was distilled off from the filtrate to obtain a crude product. This was distilled under reduced pressure to obtain 28g (yield 65%) of 1-
Phenyl-1-butyn-3-one was obtained. bp 120℃/14mm Production example 3 Process for producing compound No. 1 Phenyl acetylene 30g (0.29mole), ethylmagnesium bromide (magnesium 6g, i.e.
(adjusted from 0.25 gram atom) and 28 g (0.24 mole) of 2-thiophene aldehyde were subjected to Grignard reaction and Johns oxidation in the same manner as in Production Example 2 to obtain a crude product. This was adsorbed onto a silica gel column, and 39 g (yield: 77%) of the target product was obtained from the 10% ethyl acetate-n-hexane elution section. mp 57-58℃ Production Example 4 Method for producing compound number 20 10g (0.09mole) of acetylene dicarboxylic acid and n
- 10 g of propyl alcohol and 100 ml of benzene
A catalytic amount of para-toluenesulfonic acid was added to the mixture, and the mixture was refluxed for 7 hours using a Dean-Stark water separator. After cooling, it was diluted with water and the organic layer was separated. This was washed with an aqueous sodium hydrogen carbonate solution, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a reaction mixture. This was distilled under reduced pressure and 6g (yield 33
%) of diester was obtained. bp 116℃/5mm Production Example 5 Method for producing compound number 10 Phenyl acetylene 8.7g (0.085mole) Ethylmagnesium bromide (prepared from 2.0g magnesium) and phenylpropargyl aldehyde 10.0g
(0.077 mole) was subjected to Grignard reaction and Johns oxidation in the same manner as in Production Example 2 to obtain a crude product. This was adsorbed on a silica gel column, and 30
% benzene-n-hexane elution area, target object 8.0
g (68% yield) was obtained. mp 65℃ Production Example 6 Process for producing compound number 8 Ethylmagnesium bromide (magnesium 2.5g
Purified dry acetylene was introduced into the ether solution (prepared by the method) at room temperature while stirring vigorously, and the acetylene was introduced for about 20 hours until the ether-insoluble oil was separated and the amount became almost constant. The thus produced acetylene dimagnesium bromide and 10.0 g (0.094 mole) of benzaldehyde were subjected to Grignard reaction and Johns oxidation in the same manner as in Production Example 2 to obtain a crude product. This was recrystallized from benzene-n-hexane to obtain 4.7 g (yield: 43%) of the desired product. mp 110-111°C Next, examples of the present invention will be shown. Example 1 10 parts by weight of 1-(2'-thienyl)-3-phenyl-2-propyn-1-one (compound number 11), 1 part by weight of polyvinyl alcohol, 3 parts by weight of sodium higher alcohol sulfonate, and 86 parts by weight of clay The mixture was ground and mixed to make a powder. Example 2 20 parts by weight of 5-octen-3-yn-2-one (compound number 4), 70 parts by weight of xylene and 10 parts by weight of polyoxyethylene nonyl phenyl ether were mixed to prepare an emulsion. Example 3 20 parts by weight of 1,4-diphenyl-2-butyne-1,4-dione (compound number 8), 1 part by weight of polyvinyl alcohol, 3 parts by weight of sodium higher alcohol sulfonate, and 76 parts by weight of clay were ground and mixed. It was made into a powder. Example 4 1,5-diphenyl-1,4-dipentyne-3
An emulsion was prepared by mixing 15 parts by weight of -one (Compound No. 10), 75 parts by weight of xylene, and 10 parts by weight of polyoxyethylene nonyl phenyl ether. Example 5 Phenylpropiol aldehyde (compound no.
11) A wettable powder was prepared by mixing and pulverizing 30 parts by weight of polyoxyethylene alkyl allyl ether, 45 parts by weight of diatomaceous earth with kaolin added at a ratio of 5:1, and 20 parts by weight of white carbon. Example 6 20 parts by weight of 1-phenyl-2-butyn-1-one (compound number 6), 1 part by weight of polyvinyl alcohol, 3 parts by weight of sodium higher alcohol sulfonate, and 76 parts by weight of clay were ground and mixed to make a powder. . Example 7 4-octenal-2-yne (compound number 15)
20 parts by weight, 70 parts by weight of xylene, and 10 parts by weight of polyoxyethylene nonyl phenyl ether were mixed to prepare an emulsion. Next, the effects of the soil fungicide of the present invention will be shown using test examples. Test soil disease: Plasmodiophora brassicae Test crop: Chinese cabbage Test method: In a 14 cm diameter plastic pot, add approximately 1.5 ml of sterilized soil to a dormant spore density of 1 x 10 ⁴ /ml soil. The soil was inoculated as described above and treated with a predetermined amount of chemicals. Each compound used in the present invention
Process it into a 20% hydrating agent, and add the specified amount to 30% per pot.
ml of water and irrigated onto the soil. Gas was removed on the third day after treatment, and on the next day Chinese cabbage seeds were added at 5% per pot.
Seeds were sown in grain size. Investigations were carried out 40 days after the chemical treatment to measure the aboveground fresh weight and the degree of root nodule formation. However, the method of Williams et al. was followed to investigate the degree of root nodule formation. In other words, the degree of root nodule formation: 0: Healthy: Mild nodules on the branch root: Moderate nodules on the branch root or tap root: Severe nodules on the branch root or tap root Degree of root nodule formation = (Number of seedlings x 10) + (Number of seedlings) × 80) + (number of seedlings × 100) / total number of surveyed seedlings Above ground production is the average value of 10 surveyed seedlings District system, 2 pots per district (10 seedlings), 1 continuous test result:

[Table] Test example 2 Test soil disease: Cucumber seedling damping-off (Pythium aphanidermatum) Test crop: Cucumber Test method: Fill a white porcelain pot with a diameter of 9 cm with autoclaved soil, inoculate with damping-off fungus, and After sowing 10 cucumber seeds per pot, each pot was immediately irrigated with each chemical at a ratio of 3/m ³ . Each plot had two pots in one row, and an investigation was conducted two weeks after sowing to check the rate of diseased seedlings and the presence or absence of chemical damage. Test results:

【table】

Claims (1)

[Claims] 1 General formula R ₁ -C≡C-CO-R ₂ [In the formula, R ₁ is a linear alkyl group having 1 to 4 carbon atoms, a phenyl group, a benzoyl group, or a C ₂ H ₅ CH =
CH-, CH ₃ -CH=CH- or -COOY (Y represents a straight-chain alkyl group having 1 to 4 carbon atoms, phenyl group or benzyl group), and R ₂ is a hydrogen atom, a thienyl group, a carbon Straight chain alkyl group having 1 to 4 atoms, phenyl group, phenyl group-substituted ethynyl group or -OZ (Z is a hydrogen atom, 1 to 4 carbon atoms
At least one compound selected from the group of compounds represented by
A soil fungicide characterized by containing seeds or two or more kinds of compounds as active ingredients.