KR810000453B1 - Fungicides hydrazinium phosphites - Google Patents

Abstract

Five fungicidal compds.[I; R1 = H or C1-4 alkyl; R2 = H, Ph (optionally substituted wth one or more NO2, C1-4 alkyl, and(or) halogen); R1 & R2 may not both be H were prepd. from R2NHNH2H2O and HP(O) (OR1)2 at 15-120≰C. Thus, H2NNH2H2O was added with stirring to HP(O) (OEt)2 and the mixt. stirred a further to give 100% R2NNH2HP(O) (OEt)OH. I gave 100% inhibition of piricularia orizae at 0.05 g/l.

Description

Method for preparing hydrazine phosphite derivatives

The present invention relates to a process for the preparation of hydrazine phosphite derivatives. Hydrazine phosphite is collectively referred to as phosphonate hydrazinium.

The compound according to the present invention is represented by the following general formula (I).

Wherein R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₂ is optionally substituted by one or more substituents selected from a hydrogen atom or a nitro group, an alkyl group C ₁ -C _4, and a halogen atom Phenyl nucleus, R ₁ and R ₂ cannot be hydrogen atoms at the same time)

The compound according to the present invention is prepared by reacting an optionally substituted hydrazine hydrate represented by the following general formula (II) with phosphorous acid or 0, 0-phosphonic acid dialkyl represented by the following general formula (III), the reaction process formula To illustrate as follows.

Wherein R ₁ and R ₂ are as defined above.

The reaction occurs spontaneously at room temperature and can be carried out in an inert organic solvent medium such as ethanol or without the use of a solvent. In any case, it is advantageous to heat the reaction mixture to promote the reaction. According to the examples good results are obtained at temperatures of 15 to 120 ° C.

It has long been known that hydrazine (or hydrazine hydrate) is a useful insecticide, in particular bactericidal. However, hydrazine and hydrazine hydrates are extremely toxic and have not been fully utilized in plant treatment.

In order to eliminate this toxicity, US Pat. No. 2,773,796 proposes a sterilization method using inorganic phosphorous and hydrazine salts selected from phosphoric acid, phosphorous acid, hypophosphoric acid and pyrophosphoric acid. This patent describes in particular the use of hydrazinium phosphite against Phytophthora infestans and Sepia graveolentis. However, since there is no information on the availability of this hydrazinite for the treatment of Plasmoparaviticola, from an economic point of view it constitutes one of the main areas of anti-bacterial disease treatment. Experiments conducted by the Applicant on vines in greenhouses have shown that hydrazinite phosphate is toxic to vine seedlings in foliar application, and thus its use is not possible in this field.

Moreover, a method of using a composition containing various phosphite derivatives as an active substance for sterilization treatment has been proposed.

Thus, in French Patent No. 2,252,056, the use of inorganic or organic salts of phosphorous acid as fungicides is within the scope of the claims. Further patent 2,285,812 claims the use of phosphites and imidazole salts, cyclohexylamine or morpholine as fungicides.

These two features as organic salts of phosphorous acid describe, in particular, phosphites of ammonium or phosphites of ammonium substituted with one or more alkyl, hydroxy alkyl or phenyl groups, wherein the phenyl group itself is optionally substituted. will be. However, there is no mention of hydrazine phosphite in the examples.

Furthermore, French Patent No. 2,254,276 covers the use of phosphite monoesters (also referred to as phosphites) of the following general formula as fungicides.

(Wherein M represents a hydrogen atom or an optionally substituted ammonium cation or a metal cation, n represents an integer equal to the valence of M, and R ₃ represents an alkyl group having 1 to 18 carbon atoms)

In particular, its further patent No. 2,288,453 discloses, as a fungicide, M is an ammonium cation substituted with at least one alkyl or hydroxyalkyl group, n is an integer from 1 to 3, and R ₃ represents a C ₁ -C ₈ alkyl group. The use of the compound of (2) is in the claims. This French Patent No. 2,254,276 and further patents No. 2,288,463 specifically cover the use of ammonium ammonium phosphates in which ammonium ions are substituted with one or more alkyl, hydroxyalkyl or phenyl groups. However, in the examples, there is no mention of the alkyl phosphite hydrazinium. These phosphites or alkylphosphates described in French Patents Nos. 2,252,056 and 2,254,276 and their respective additional patents 2,285,812 and 2,288,463 are particularly markedly bactericidal against vine fungal disease, i. Without fast action, control or treatment and tissue action for most compounds. However, as a result of supplementary experiments conducted on the vine outdoors, ammonium alkylphosphate, optionally substituted according to climatic conditions, causes considerable damage to the vine, so their use in this field must be excluded.

Because of the well-known toxicity of hydrazine and because of the observations made on the vine in the case of US Pat. No. 2,773,796 and in the case of the above-mentioned phosphites or alkylammonium phosphates of ammonium or substituted ammonium phosphates, phosphate or hydrazinium Alkylphosphites or alkylphosphites of substituted hydrazins can generally be expected to exhibit a high degree of weakness, which in particular prevents their use by foliar spraying.

In general, it has been found that hydrazinium salts and phosphite salts have good antimicrobial control effects and nontoxic unexpected effects, particularly in vines.

Experiments conducted by the Applicant show that the compound of formula (1) wherein R ₁ represents an alkyl group (C ₁ -C ₄ ) and R ₂ represents a hydrogen atom is identical to the product in the aforementioned French patent and its further patents. It was found that it has a bactericidal effect. But it was not conceived that they would not cause significant harm to the vine.

Furthermore, according to the applicant's experiment, R ₁ is a hydrogen atom or an alkyl group (C ₁ -C ₄ ), and R ₂ is substituted with an arbitrary substituent selected from nitro group, alkyl group (C ₁ -C ₄ ) and halogen atom. It was found that the compounds of the general formula (1) showing the phenyl group exhibited satisfactory bactericidal action, and in particular, they exhibited antibacterial action against Piricularia oryzae of rice.

According to the control method, hydrazine phosphite and the compounds described in the aforementioned French patent and further patents thereof do not usually exhibit significant antimicrobial activity against this bacterium at about the dose.

The present invention will be described in more detail with reference to the following Examples, which are not intended to limit the invention.

Example 1

Preparation of ethyl phosphite hydrazinium of the following general formula

0.2 mol of hydrazine hydrate is added to 0.2 mol of diethyl phosphite with stirring. During this addition, the mixture is heterogeneous and the temperature rises to 70 ° C. After 10 minutes of addition, the mixture is homogeneous. The mixture is stirred for 2 hours and then alcohol and water are removed under vacuum at 80 ° C. to give a clear oil.

The structure was confirmed by NMR performed on D ₂ O. Elemental analysis for C ₂ H ₂₂ NO ₃ P is as follows.

Example 2

The following compounds were prepared following the method of Example 1 using the appropriate starting material.

Example 3

In vitro test for bactericidal action

The action of the compounds according to the invention on the spread of the following germs was examined.

Piricularia oryzae, which causes rice blasts, Botrytis cinerea, which causes vine gray fungal disease, and Colletotrichum lagenarium, which causes anthrax in gourds and vegetables, Each experiment was performed.

5 ml of gelose (malt / agar medium) is added to the test tube, and each tube is capped and sterilized for 20 minutes at 120 ° C. The test tubes are placed in a 60 ° C. water bath.

Pipette a 1% acetone solution of the test compound with the concentration of the test compound into each test tube to obtain a test compound concentration in the medium.

After 24 hours, each test tube is inoculated with a syringe with 0.5 ml of spore suspension containing 100,000 spores / cm 3 or mycelium with a diameter of 8 mm. As a control, test tubes are prepared similar to those described above. However, the gelose medium does not contain any active substance. After 9 days at 26 ° C. in the dark, the observed control site surface for the concentration of the active substance is evaluated and then expressed as a percentage of the inoculation surface.

In the case of compounds 2 to 5 of the present invention and the following two control compounds, the lowest dose that can give 100% control of the infestation of the germ is shown in g / liter in the following table.

A: Hydrazinium phosphite described in US Pat. No. 2,773,796.

B: Aluminum ethyl phosphite described in page 17 of French Patent No. 2,288,463.

Measurements of active substance doses of 0.01 to 0.02 g / liter were made. An indication of> 0.2 indicates that the product is inert at 0.2 g / liter.

Example 4

In Vitro Experiment on Plasmopara viticola in Seedlings

Using a vine seedling (growth: Kamai) spray gun grown in the pot, an aqueous suspension of a hydrated powder having the following composition is sprayed on the lower surface of the leaf.

20% by weight of active substance

Suspension control agent (calcium sulphate sulfate) 5

Hydrating agent (sodium alkyl lauryl sulfonate) 1

Filler (Aluminum Silicate) 74

This suspension is a suspension diluted to a predetermined concentration and containing the test active substance. Each test is repeated three times. After 48 hours, the aqueous suspension containing about 80,000 units / cm 3 of germ spores is sprayed onto the leaf underside.

The pot was left for 48 hours at 100% relative humidity and 20 ° C inoculation.

Seedlings were examined 9 days later. Under these conditions, when the dose was 0.5 g / liter, it was found that the compound of Example 1 exhibited complete control rate without showing any damage.

Example 5

In vitro testing for blast germs in rice seedlings

The same method as in Example 4 was used, but both sides of the rice seedling leaves were treated (not only the bottom surface was simply processed in the above example).

Under these conditions, when the dose was 0.5 g / liter, the control rates of the compounds 2, 3 and 5 were good. At this dose no adverse effects on rice seedlings were observed.

Example 6

In vitro testing for soil germs

The action of compound 3 on pythium debaryanmu in cucumber green parisian varieties is reduced.

Each experiment is carried out in the following manner.

The medium containing the germ medium is mixed with the sterilized soil and the pot is filled with this mixture. Infect the soil after 8 days. It is treated by irrigation with suspensions of test substance at various concentrations. This suspension consists of a hydrating powder prepared in Example 4. Next, cucumber seeds are sown in the treated soil.

15 days after sowing, untreated and uninfected controls are evaluated according to the number of dead or infected plants.

Under these conditions, it is observed that when the dose is 0.5 g / liter, the control rate of Compound 3 is good, and when it is 1 g / liter, the control rate is complete. No harm at this dose was observed.

Example 7

In vitro test of tissue action against vine fungal disease by root uptake.

Several vines (variety: Kamai) are grown in vermi culite and nutrient pots and irrigated to the base using 40 cm 3 of a solution containing 0.5 g / liter of test substance. After 2 days, the vine is infected with an aqueous suspension containing 10,000 spores / cm 3 of Downy mildew. Mature for 48 hours at 20 ° C and 100% relative humidity. The damage to the control plants irrigated with 40 cm 3 of distilled water is observed after 9 days.

Under these conditions, upon absorption of the root, Compound 1 indicates complete control of the vine leaves against the fungus, which clearly indicates the tissue function of the compound.

Example 8

The vine bacteria (variety: Kamai), planted two years ago, are naturally damaged on May 25 and July 19, then rained heavily and watered daily. These vine groups are treated every 12 days with aqueous solutions containing 200 g / hl of active substance from May 16 to August 18. At the end of the treatment, the ratio of the number of leaves infected with the bacteria in the treated samples was 6.1% relative to the number of leaves infected with the bacteria in the untreated samples.

Eight days after the end of the treatment, the infection rate of the fungal infection on newly grown leaves was 1.7% in the treated and 32% in the untreated, respectively.

Examples 1, 7 and 8 clearly show that the anti-bacterial bacterium activity of the methyl phosphite hydrazinium salt of the compound of Example 1 is remarkable, which is effective in controlling and preventing the bacterium. The alkyl phosphite hydrazinium according to the present invention is, for example, plant protection against bacterial diseases caused by coarse fungi and asymptomatic fungi, in particular vines, aspirates or tobacco plants, such as downy mildew, Peronospora tabacii or Pseudoperonospora. It can be used together in the treatment and treatment to protect against fungus of Pseudoperonospora humuli type.

Phenylhydrazine phosphite optionally substituted with a phenyl nucleus may be used for the treatment of bacterial diseases caused by rice blast germs. It can also be used for diseases caused by other bacterial diseases such as gray mold, anthrax and stocking bacteria.

Depending on the toxicity of the bacteria and the climatic conditions, its use is extensive.

In general, dosages containing 0.1 to 3 g / liter of active substance are very suitable.

As used herein, the term “carrier” refers to an organic or inorganic, natural or synthetic material intended to be mixed with the active ingredient to facilitate its use in plants, seeds or soil, or to facilitate transport or handling. The carrier may be a solid (clay, natural or synthetic silicates, resins, waxes or solid fertilizers) or a fluid (water, alcohols, ketones, petroleum fractions, chlorinated hydrocarbons and liquefied gases).

The surfactant may be an emulsifier, a dispersant or a hydrating agent. It may also be ionic or nonionic. For example, there are condensates of salts of polyacrylic acid and salts of lignin sulfonic acid with ethylene oxide and fatty alcohols, fatty acids or fatty amines.

The composition according to the present invention may be prepared in the form of a hydrating agent, a soluble powder, a liquid, an emulsifying thickener, an emulsion, a suspending thickening agent and a suspending agent.

Hydrating agents usually contain from 20 to 95% by weight of active substance, and in addition to solid carriers contain from 0 to 5% by weight of wetting agent and from 3 to 10% by weight of dispersant, if necessary, at least one stabilizer and other auxiliaries, ie penetrants, adhesives or It is prepared to contain 0 to 10% by weight of anti-caking agent, dye and the like. For example, one example of the hydrating agent composition is as follows.

50% of active substance

Calcium lignin sulfonate (floating remover) 5%

Anionic Hydration (Alkyl Naphthalene Alkali Metal Salt) 1%

5% anti-caking silica

Kaolin 39%

The water-soluble powder is mixed with 20 to 95% by weight of the active substance, 0 to 10% by weight of the anti-caking filler, 0 to 1% by weight of the hydrating agent, and the balance is converted into a water-soluble filler, in principle a salt.

The composition of the water-soluble powder is as follows.

70% active substance

Anionic Hydration 0.5%

Anti-Static Silica 4%

Sodium sulfate (solid carrier) 24.5%

For example, water-soluble dispersants and water-soluble emulsions which are compositions obtained by diluting a hydrating or emulsifying thickener with water according to the present invention are generally within the scope of the present invention. Emulsions can be of the W / O type or the O / W type, which have a rich hardness such as mayonnaise.

The compositions according to the invention may contain other ingredients, such as protective colloids, adhesives or thickeners, thixotropic agents, stabilizers or antisettling agents and other active substances with pesticidal action, in particular antimicrobial agents or insect killers. Can be.

Claims (1)

Preparation of the hydrazine phosphite derivative represented by the following general formula (I), characterized by reacting the compound represented by the following general formula (II) and the compound represented by the following general formula (III) at a temperature of 15 to 120 ℃ Way.

(Wherein R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom or a nitro group, an alkyl group (C ₁ -C ₄ ) and one or more substituents selected from halogen atoms) Phenyl nucleus optionally substituted by R ₁ and R ₂ cannot be hydrogen atoms at the same time)