DE1903169A1 - Fungicide - Google Patents

Abstract

Fungicidal composition contains derivas. of 2-hydroxymethyl-3,4,5,6-tetrachloro-benzoic acid of formula (I): (where X is -N(R)R1, -NH-(CH2)n-NH-A, -OMe or OHNR2R3R4 in which R and R1 are H, alkyl, hydroxyalkyl, alkenyl or phenylalkyl, R2, R3 and R4 are H, alkyl or hydroxyalkyl; A is the residue of (I) bonded to X; Me is an equiv. of an alkali (ne earth) metal; n is 2,3 or 4; Y is OH and XY together represent an oxygen bridge).

Description

Fungicidal Agent The present invention relates to the use of partially known 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid derivatives as a fungicidal agent. There are no biocidal effects of the known compounds so far known.

However, it is already known that one can use pentachlorobenzyl alcohol can be used to combat phytopathogenic fungi (see Japanese patent 470 399).

It has been found that the partially known 2-hydroxymethyl-3,4,5, to 6-tetrachloro-benzoe 6-tetrachloro-benzoic acid derivatives of the general formula ; -NH- (CH2) n-NH-A; -OMe or R4 stands, R and R1 stand for hydrogen, alkyl, hydroxyalkyl, alkenyl or phenylalkyl, R2. R3 and R4 represent hydrogen, alkyl or hydroxyalkyl, A represents the radical bonded to the radical X defined by formula (I), Me represents one equivalent of an alkali metal or alkaline earth metal, n represents 2, 3 or 4, Y represents OH and X and together represent an oxygen bridge, have strong fungicidal properties.

The 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid derivatives according to the invention surprisingly show a considerably higher fungicidal effect than that known from the prior art Pentachlorobenzyl alcohol, which is the chemically closest active ingredient Mode of action is. The active ingredients according to the invention are therefore a valuable asset of technology.

The active ingredients according to the invention are represented by the formula given above (I) clearly defined. In this formula, R and R1 are preferably hydrogen, Alkyl with 1-6 carbon atoms, hydroxyalkyl with 1 - 4 carbon atoms, alkenyl with 2 - 4 carbon atoms and phenylalkyl with 1-2 carbon atoms in the alkyl radical. R2, R3 and R preferably stand for hydrogen, alkyl with 1-6 carbon atoms and hydroxyalkyl with 1-4 carbon atoms. Me preferably stands for potassium, sodium, calcium and barium, n for 2, 3 and 4.

As examples of the active ingredients according to the invention are mentioned in detail: The itetrachlorophthalide to be used according to the invention is already known and can be obtained by reducing zinc dust from tetrachlorophthalic anhydride (cf. A 238, 330 (1887)), or advantageously by saponifying 3,4,5,6-2etrachloro-1,2 - bis - (dichloromethyl) -benzene can be obtained with concentrated sulfuric acid (cf. Belgian patent 719 876).

The production of the open 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid derivatives takes place by reacting tetrachlorophthalide with alkali or alkaline earth hydroxides, Ammonia or strongly basic amines in water and / or inert organic solvents, such as dioxane, dimethylformamide, ethylene glycol monoethyl ether, at temperatures between 0 and 1800C, preferably 40 and i500C. The work-up of the reaction batches is made in the usual way.

The preparation of the active ingredients to be used according to the invention is explained in more detail below with reference to a few examples: Example 1: 381 g (1 mol) of 3,4,5,6-tetrachloro-1,2-bis (dichloromethyl) benzene are introduced into 1,500 cc of concentrated sulfuric acid at room temperature. While stirring vigorously and passing through a stream of nitrogen, the reaction mixture is heated to 100 ° -1200 ° C. for about 10 hours until the evolution of hydrogen chloride has ended. After cooling, the clear, dark red reaction solution is poured onto ice and the precipitated tetrachlorophthalide is washed neutral with water. The benzene product can be redissolved for further cleaning. 225 g (82% of theory) of tetrachlorophthalide are obtained in light yellow needles with a melting point of 207-2080C.

Example 2: 16 g (0.4 mol) of sodium hydroxide are dissolved in 500 cc of water.

108 g (0.4 mol) of tetrachlorophthalide are carried into this solution at room temperature and the reaction mixture boils for 6 hours.

on the reflux condenser. After the dark red, clear reaction solution has cooled down The precipitated 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid sodium is sucked off away.

Concentrating the mother liquor makes another portion of the above Won the salt. A total of 95 g (72% of theory) of 2-hydroxymethyl-3,4,5,6-tetrachloro-benzoic acid are obtained Sodium in colorless, shiny flakes.

Analysis: 08H30l403Na H20 (329.9) Calc .: C: 29.2 H: 1.5 Cl: 42.9 0: 19.4 Na: b.9 Found: C: 29.7 H: 1.9 Cl: 43.2 0: 18.9 Na: ti.8 Can in an analogous way the other alkali and alkaline earth salts of 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid being represented.

Example 3: 27.1 g (0.1 mol) of tetrachlorophthalide are suspended in 100 cc of dioxane. 100 cc of a 31% aqueous methylamine solution are added dropwise to this suspension at 30-4OOC while stirring. The tetrachlorophthalide dissolves and the clear reaction solution solidifies after a few minutes to form a colorless crystal paste. The mixture is stirred for a further 3 hours at 300 a and the solid product formed is filtered off with suction. 25 g (83% of theory) of 2-hydroxymethyl-3,4,56-tetrachloro-N-methylbenzamide with a melting point of 2090 "are obtained.

The other 2-hydroxymethyl-3,4,5,6-tetrachlorobenzamides can be used in an analogous manner can be obtained.

The active ingredients according to the invention are highly fungitoxic Effect on. They damage crops in the areas necessary for combating fungi Concentrations do not and have a low toxicity to warm blooded animals. For these reasons they are suitable for use as pesticides for combating fungi. Fungitoxic agents in crop protection are used to control Archimycetes, Phycomycetes, Ascomycetes, Basidiomycetes and Fungi imperfecti.

The active compounds according to the invention can be used against parasitic ones Fungi that attack the above-ground rows of plants or attack the plants from the ground and seed-borne mushrooms. The active ingredients according to the invention prove their worth especially in the fight against rice diseases. So they show an excellent effect against the mushrooms Piricularia oryzae.

In contrast to pentachlorobenzyl alcohol, which after use in Rice causes severe plant damage in subsequent crops, e.g. vegetables such secondary damage was not found in the compounds according to the invention will.

Also effective and of practical importance are the active ingredients when used as a seed dressing or soil treatment agent against phytopathogens Fungi are used that adhere to the seeds or occur in the soil and on Cultivated plants seedling diseases, root rot, tracheomycoses, stem, culm, Cause leaf, flower, fruit or seed diseases.

The active ingredients according to the invention are effective against Cochliobolus myiabeanus, Mycosphaerella musicola, Cerospora personata, Botrytis cinerea and Alternaria species.

Depending on their intended use, the new active ingredients can be converted into the usual ones Formulations such as solutions, emulsions, emulsifiable concentrates, Suspensions, wettable powders, soluble powders, dry dressings, dusting pastes and granules. These are prepared in a known manner, for example by mixing of the active ingredients with extenders, i.e. liquid solvents and / or solids Carriers, possibly with the use of surface-active agents Emulsifiers and / or dispersants, e.g. in the case of using water as an extender, optionally organic solvents as co-solvents can be used. The main liquid solvents that can be used are: Aromatics (e.g. xylene, benzene), chlorinated aromatics (e.g. chlorobenzenes) paraffins (e.g. petroleum fractions), alcohols (e.g. methanol, butanol), strongly polar solvents such as dimethylformamide and dimethyl sulfoxide and water; as solid carriers: natural rock flour (e.g. kaolins, clays, talc, chalk) and synthetic Rock flour (e.g. finely divided silica, silicates); as emulsifier: non-ionic and anionic emulsifiers such as Polyoxyethylene fatty acid ester, Polyoxyethylene bed alcohol ethers (e.g. alkylaryl polyglycol ethers, alkyl sulfonates and aryl sulfonates) as dispersants: e.g. lignin, sulfite waste liquors and methyl cellulose.

The active compounds according to the invention can be mixed in the formulations with other known active ingredients, the formulations generally contain between 0.1 and 95 percent by weight of active ingredient, preferably between 0.5 and 90 %.

The active ingredients can be used as such, in the form of their formulations or in the application forms prepared therefrom, such as ready-to-use solutions, emulsions, Suspensions, pastes, dusts and granules can be used. The application This is done in the usual way, e.g. by spraying, atomizing, atomizing, dusting, Scattering, smoking, gasifying, pouring, pickling or encrusting.

The active ingredient concentrations in the ready-to-use preparations can be varied in larger areas.

In general they are between 0.0001 and 10%, preferably between 0.01 and 1.

In the treatment of seeds, amounts of active ingredient of 0.1 to 10 g per kg of seed, preferably 0.5 to 5 g, are required. For soil treatment Active ingredient quantities of 1 - 500 g per cubic meter of soil, preferably 10 - 200 g, are required.

The active ingredients can also be used with good success in the ultra-low-volume process (ULV) used where possible, formulations up to 95 & or even to apply the 100% active ingredient alone.

Example Piricularia test / liquid active substance preparation solvent: 4 parts by weight of acetone dispersant: 0.05 parts by weight of sodium oleate other Additions: 0.2 parts by weight gelatin Water: 95.75 parts by weight H20 Mix the amount of active substance required for the desired concentration of active substance in the spray liquid with the specified amount of solvent and dilute the concentrate with the specified amount of water containing the additives mentioned.

30 rice plants about 14 days old are sprayed with the spray liquid until dripping wet. The plants remain in a greenhouse until they have dried off at temperatures of 22 to 240 and a relative humidity of about 70 .

After that, they are treated with an aqueous suspension of 100,000 to 200 000 spores / ml of Piricularia oryzae and inoculated in a room at 24-260 a and 100 ffi relative humidity.

5 days after the inoculation, the infestation is in all at the time of Inoculation leaves as a percentage of the untreated, but also inoculated leaves Control plants determined. 0 means no infestation, 100% means that the infestation is exactly as high as in the control plants.

Active ingredients, active ingredient concentrations and results are shown in the table below: Table Piricularia test / liquid active ingredient preparation Infestation in ffi of the infestation of the acted acted control at one Active ingredient Active ingredient concentration (in) of 0.05 0.025 C1 C1 C1dCH20H 0 17 C1 C1 (known) C1 Cl Ä C0 > 0 OO C1 ~ ssCH2 Ci Cl Cl ß - 1.CH20H 0 0 C1 COoca / + coo (3rd ci Cl Cl C1 A CO NH (CH2) 2 NHOO <C1 0 0 CH20H HOH2C C1 C1 1

Claims (1)

Claims 1) Fungicidal agent characterized by a content of 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid derivatives of the general formula in which X for ; -NH- (CH2) n-NH-A; -OMe or flTTNR2R3R4 stands Run <1 R1 stands for hydrogen, alkyl, hydroxyalkyl, alkenyl, alkenyl or phenylalkyl, R2, R3 and R4 stand for hydrogen, alkyl or hydroxyalkyl, A stands for is the radical defined by formula (I) bound to the radical X, Me stands for one equivalent of an alkali metal by alkaline earth metal, n stands for 2, 3 or 4, Y stands for OH, and XY together stand for an oxygen bridge 2) Process for Combating fungi, characterized in that 2-hydroxymethyl-3,4,5,6-tetrachlorobenzoic acid derivatives according to Claim 1 are allowed to act on fungi or their habitat. 3) Use of 2-hydroxymethyl-3,4,5,6-tetrachloro-benzoic acid derivatives according to claim 1 for the fight against Piizen. 4) Process for the preparation of fungicidal agents, characterized in that that 2-hydroxymethyl-3y4,5,6-tetrachlorobenzoic acid derivatives according to claim 1 mixed with extenders and / or surfactants.