DE2227921A1 - Benzimidazole-2-carbamates - with systemic fungicidal activity for plant, with low mammalian toxicity - Google Patents

Abstract

Title cpd. are of formula (I) or their 1H tautomers (where R and R' are is not >6C alkyl, is not >6C alkenyl, or phenyl, or one of R and R' can also be is not >4C alkylthio, or R + R' is 4-10C alkylene; and R" is H or is not >8C alkyl) (I) are prepd. by (a) subjecting a cpd. of formula II to rearrangement, (b) reacting a benzimidazole of formula (III) with an oxime carbonate of the formula (RR'C=N-O)2CO or with a cpd. of the formula X-O-CO-O-N=CRR' (where X is phenyl substd. in the 2-, 4- and 6-posns. by electron-withdrawing groups and opt. subst. in the 3- and 5-posns. by halogen is not >3C alkyl or NO2), or (c) reacting an R"-phenylene-o-diamine with an isothiourea deriv. of the formula R"'S-(C(NCOON=CRR')2 (where R"' is not >6C alkyl, alkenyl or alkynyl, or benzyl).

Description

Benzimidazol-2-yl-carbamic acid-ketone oxime esters, method for their Production and its fungicidal use The present invention relates to new ones Benzimidazol-2-ylcarbamic acid ketone oxime esters, which have fungicidal properties, and processes for their manufacture.

As has long been known, it is used as a fungicide in agriculture and in horticulture in particular zinc ethylene-1,2-bis-dithiocarbamidate is used; the compound mentioned is of great importance among commercial products (See R. Wegler, "Chemistry of Plant Protection and Pest Control Agents", volume 2, page 65, Heidelberg (1970)). The effect at low application concentrations however, it is not always satisfactory. The invention is also known Active substance related to substances N-phenylcarbamic acid acetoxime ester (cf. German Offenlegungsschrift 1,232,947), but which is preferably herbicidal.

It has now been found that the new benzimidazol-2-yl-carbamic acid ketone oxime esters with the tautomeric formulas in which R and R 'stand for alkyl and alkenyl each with up to 6 carbon atoms and for phenyl, in addition one of the substituents can stand for alkylthio with up to 4 carbon atoms, furthermore R and R' together can stand for alkylene with 4 to 10 Are carbon atoms and R "is hydrogen and alkyl with up to 8 carbon atoms, have strong fungicidal properties.

(The substances according to the invention are in a tautomeric equilibrium and therefore correspond to both formula (Ia) and formula (Ib). For the sake of simplicity, the formulas according to the tautomeric limit state of formula (Ib) are not reproduced below; for the purposes of this of the present application, the formulas given according to the tautomeric limit state of the formula (Ia) are also intended to include in each individual case the corresponding formulas according to the tautomeric limit state of the formula (Ib) of formula (Ia) (and also of formula (Ib)) is obtained if a) a 2-aminobenzimidazole-1-carboxylic acid oxime ester of the formula in which R, R 'and R "have the meaning given above, rearranged in the solid or liquid phase, or if b) a 2-aminobenzimidazole of the formula in which R "has the meaning given above, with an oxime carbonate of the formula in which R and R 'have the abovementioned meaning, or when c) a 2-aminobenzimidazole of the formula (III) is reacted with a phenyl ketone oxime carbonate of the formula in which R and R 'have the meaning given above and X, X and X "represent an electron-withdrawing substituent and X"' represents hydrogen, halogen, alkyl with up to 3 carbon atoms and nitro, or if one d) an o-phenylenediamine of the formula in which R "has the meaning given above, according to a special process (described in US Pat. No. 3,010,968 or German Offenlegungsschrift 1,812,005) with a bisacylated isothiourea of the formula in which R and R 'have the meaning given above and R "' represents alkyl, alkenyl and alkynyl, each having up to 6 carbon atoms and represents benzyl.

Surprisingly, the active ingredients according to the invention show a higher level fungicidal effect than the world-wide known zinc-ethylene-1,2-bis-dithiocarbamidate; there is also a systemic fungicidal effect. The fabrics can also be used as Find intermediates for the synthesis of other pesticides use (See the details in the preparation examples), such as methyl benzimidazol-2-ylcarbamate (known from German Offenlegungsschrift t 620 175) and the benzimidazol-2-yl isopropyl carbamic acid ester (known from British Patent 1,190,614). The substances according to the invention thus represent an enrichment of technology.

The reaction schemes are shown using specific examples. If, according to process a), 2-aminobenzimidazol-1-yl-carboxylic acid methylisobutyl-ketone oxime ester is used as the starting product, the course of the rearrangement reaction can be represented by the following equation: If, according to method b), 2-aminobenzimidazole and acetone oxime carbonate are used as starting materials, the following reaction takes place: The reaction according to process c) of 2-aminobenzimidazole and 3-chloro-2,4,6-tribromophenyl (methyl-ethyl-ketone oxime) carbonate takes place according to the following formula: The reaction according to process d) of o-phenylenediamine and a bisacylated isothiourea can be represented, for example, by the following formulas: All of the starting materials to be used in reaction a) 2-aminobenzimidazole-1-carboxylic acid oxime esters are defined by the general formula (II). In this formula, R and R 'preferably stand for alkyl with up to 4 carbon atoms and for phenyl, furthermore R and R' together preferably stand for tetramethylene and pentamethylene. R "preferably represents hydrogen and alkyl with up to 6 carbon atoms. The compounds of the formula (II) have not yet been described; 1971); the compounds are obtained by reacting the 2-aminobenzimidazoles of the formula (III) known (for example from US Pat inert organic solvents such as methylene chloride or chloroform are preferred.

The 2-aminobenzimidazoles to be used as starting materials according to reaction b) are defined by the general formula (III); as examples are in detail to be mentioned: 2-aminobenimidazole; 2-amino-4-methyl-, -4-ethyl-, -4-propyl-, -4-isopropyl-, -4-butyl-, -4-isobutyl-, -4-sec-butyl-, -4-tert-butyl-benzimidazole, 2-amino-5-methyl-, -5-ethyl-, -5-propyl-, -5-isopropyl-, -5-butyl-, -5-isobutyl-, -5-sec-butyl-, -5-tert-butyl-, -5-sec-amyl-, -5-tert-amyl-, -5-n-hexyl-benzimidazole. The 2-aminobenzimidazoles are widely known or can be obtained by known methods (e.g., according to US Pat 3,455,948).

The oxime carbonates also required for reaction b) are through defines the general formula (IV). The connections and their making is partly known (cf. Z. Chemie 1, 344-345 (1967)), new compounds can still be used can be produced in an analogous manner.

The carbonic acid phenyl ketone oxime esters required as starting materials for reaction c) are defined by the general formula (V). In this formula, R and R ' the preferred meaning given above, X, X 'and X "preferably represent Halogen and the nitro group and XIII is preferably hydrogen, chlorine, Bromine, nitro and the methyl group. The production can be carried out according to the literature (cf. German Offenlegungsschrift 1 809 385); the ketone oxime carbonic acid ester chlorides which can be used as precursors can also be produced according to regulations from the patent literature (cf. Belgian Patent specification 709 182).

The bisacylated ones required as starting materials for reaction d) Isothioureas are defined by the general formula (VII). The above at the definition of the formula (II) given preferred meanings of the substituents R and R 'also apply to formula (VII); R "" preferably represents alkyl with up to 4 carbon atoms and for benzyl.

For the preparation of the benzimidazol-2-ylcarbamic acid ketone oxime ester according to the invention according to method a), the 2-aminobenzimidazole-1-carboxylic acid ketone oxime ester is obtained at 0 ° rearranged to 1500C, preferably at a temperature between 70 and 110 ° C. the Conversion can be done by IR analysis, e.g. by eliminating the intense carbonyl absorption can be tracked in the range -1 from about 1730 to 1780 cm. One can also use the starting compound, dissolved in an inert solvent such as alcohol-free chloroform or methylene chloride, optionally in the presence of small amounts of tertiary amines, such as pyridine, picoline, quinoline, triethylamine, benzyldimethylamine or cyclohexyldimethylamine leave to stand in the temperature range between 0 ° and 1300C, preferably at about 40 to 60 ° C. Finally, the rearrangement can also be brought about in a tertiary amine.

According to method b), the 2-aminobenzimidazole derivative of the formula (III), dissolved or suspended, in an inert solvent, such as e.g. B. Toluene, in the temperature range between 20 and 1500C, preferably at 40 to 800C treated with the ketone oxime carbonate (IV). The reaction can also be carried out in the presence catalytic amounts of tertiary amines can be carried out, finally, too a tertiary amine can be used as the sole solvent. The reaction runs even in the presence of water. The benzimidazol-2-yl-carbamic acid ketone oxime esters can in many cases easily be removed from the reaction mixtures due to their poor solubility separated and obtained pure by washing, in other cases they must by carefully concentrating the solutions and, if necessary, treating with a slightly polar solvent can be deposited.

Process c) is carried out analogously to process b), accordingly the phenol split off during the reaction must be separated from the substances according to the invention if necessary by treating with the equivalent amount of cold alkali.

To carry out process d), the procedure described in the literature is followed (See. U, S. Patent 3 010 968), where 1 to 2 mol of a ketone oxime carbonic acid ester chloride, for example acetone oxime carbonic acid ester chloride, in a solvent such as e.g. Methylene chloride or chlorobenzene, 1 mol of an S-substituted isothiourea salt, e.g.

S-methyl-isothiourea-off-sulfate or S-ethylisothiourea-ethyl sulfate, Water and optionally a water-miscible organic solvent, such as e.g. dioxane or acetonitrile, and preferably with thorough stirring 10 to 25 ° C. sodium hydroxide solution is added dropwise until the pH of the reaction mixture is reached 7.5 to 8 does not fall below. If the pH of the mixture is not when stirring more abainkt, the o-Phonylondlamine to be converted or a salt of o-Phenylenediamine is used added, and duroh addition of a weak carboxylic acid, such as z.3. Acetic acid or Propionic acid, or its sodium salts, set a pH of approx. 5.5 to 7 and the mixture under pipes to a temperature of oa. 55 to 70 ° C heated, whereby optionally the low-boiling solvent used together with the mercaptan distilled off. But you can also use the acylated Isothicharnetoffderivat together with the weak carboxylic acid required for pH adjustment in the mixture Heat to 55 to 70 ° C and the o-phenylenediamine as dissolved in water flow in permit.

The compounds according to the invention form with acids and with halophenols Salts. These salts are also fungicidally active, especially with the salts of the halophenols, in which the vapor pressure of the halophenols is sharply reduced interesting fungicidal effects can be achieved.

The active ingredients according to the invention are highly fungitoxic Effect on and are characterized by a wide range of effects. Fungitoxic Means in crop protection are used to combat pills from the most diverse Fungal classes such as archimyoetes, phycomyoots, ascomycetes, basidiomycetes and fungi imperfecti.

The active ingredients according to the invention not only have the good properties excellent commercial preparations, but also have considerable Advantages. These lie primarily in the ability of the substances according to the invention, to penetrate the plant, be systemically directed and away from the location of the Application to come to the fungitoxic effect. You can be included from the surface of the material, from the roots and also from aboveground plant organs after external application. Also own you the beneficial Ability to have a locosystemic effect, i.e. a deep effect in the plant tissue exercise while eliminating fungal pathogens that are already in the Tissues of the host plant have penetrated.

In addition, the substances according to the invention show against various fungal infections Pathogens of plant diseases, e.g. against apple scab, against piricularia and Pellicularia, against wheat stone brandy and several phytopathogenic soil fungi one considerably better effectiveness than the known commercial preparations.

The substances according to the invention can be used as plant protection agents for soil treatment, be used for seed treatment and for the treatment of above-ground parts of plants. They are effective against Pellicularia sasakii, Tilletf: a caries, Eryeiphe graminis, Sclerotinia scleçotiorum, Verticillium alboatrum, Thielaviopsis basicola, Fusarium culmorum, Fusarium oxysporum, Fusarium dianthi, Phialophora cinerescens and against the bacterium Xanthomonas oryzae.

The substances according to the invention are well tolerated by plants.

They have only a low toxicity to warm blooded animals and are because of their low smells and their good tolerance for human skin uncomfortable to handle.

The active compounds according to the invention can be used in the customary formulations such as solutions, emulsions, suspensions, powders, pastes and granulates. These are made in a known manner, e.g. B. by mixing the active ingredients liquefied pressurized liquids with extenders, i.e. liquid solvents Gases and / or solid carriers, optionally using surface-active substances Agents, that is to say emulsifiers and / or dispersants. In the case of use of water as an extender can .3. also organic solvents can be used as co-solvents. The liquid solvents used are essentially in question: aromatics such as xylene, toluene, benzene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons such as chlorobenzenes, chloroethylenes or methylene chloride.

aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. Petroleum fractions, alcohols such as butanol or glycol and their ethers and esters, Ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, are strong polar solvents such as dimethylformamide and dimethyl sulfoxide, and water; with Liquefied gaseous extenders or carriers are such liquids meant which are gaseous at normal temperature and under normal pressure, e.g. Aerosol propellants such as halogenated hydrocarbons, e.g.

Freon; as solid carrier materials: natural rock flour, such as kaolins, Clays, talc, chalk, quartz, attapulgite, montmorillonite, or diatomaceous earth and synthetic minerals such as fumed silica, alumina and Silicates; as emulsifiers: non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, Polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol ethers, alkyl sulfonates, Alkyl sulfates and aryl sulfonates; as a dispersant: e.g. lignin, sulphite waste liquors and methyl cellulose.

In addition to the above information, it should be noted that the invention Substances can be advantageously formulated with dextrose and sucrose. The formulation should have a pH of 3 to 7, preferably 4 to 5.

The active compounds according to the invention can be mixed in the formulations present with other known active ingredients, such as fungicides, insecticides, acaricides, Nematicides, herbicides, Protective substances against bird damage, growth substances, Plant nutrients and soil structure improvers.

The formulations generally contain between 0.1 and 95 percent by weight Active ingredient, preferably between 0.5 and 90%, The active ingredients can be used as such, in the form of their formulations or those prepared therefrom by further dilution Application forms, such as ready-to-use solutions, emulsifiers, suspensions, powders, Pastes and granules are used.

The application of the layer in the usual white, e.g. by pouring, spraying, Spraying, dusting, scattering, dry pickling, moist pickling, wet pickling, slurry pickling or encrusting.

When used as 3 leaf fungicides, the drug concentrations in the forms of application can be varied in a larger area. You are in generally between 0.5 and 0.0005 percent by weight, preferably between 0.2 and 0.001.

In the treatment of seeds, amounts of active ingredient of 0.01 - 50 g per kilogram of seed, preferably 0.5 - 5 gs required.

For pod treatment, quantities of active ingredients from 1 - 1000 g per bm of soil, preferably from 10 - 200 g, required.

The substances according to the invention also have a microbistatic effect.

The many possible uses are based on the following Examples horvor: Example A: Seed dressing test / wheat stone brandy (seed-borne mycosis) Stretched for the production of a suitable dry dressing agent the active ingredient with a mixture of equal parts by weight of talc and kieselguhr to a finely powdered mixture with the desired concentration of active ingredient.

Wheat seeds are contaminated with 5 g of chlamydospores ton illetia caries per kg of seed. For dressing, the seeds are shaken with the dressing agent in a sealed glass bottle. The seeds are placed on damp clay under a Top layer of a layer of cheesecloth and 2 cm moderately moist compost soil for 10 days exposed to optimal germination conditions for the spores in the refrigerator at 10 ° C.

The germination of the spores is then determined microscopically the wheat grains, each with around 100,000 spores. The active substance is the more effective the fewer spores are germinated.

Active ingredients, active ingredient concentrations in the dressing agent The amounts of dressing agent applied and the percentage of germs in the spores are shown in the following table: Table of seed dressing test / wheat stone brandy Active ingredients, seed dressings, spore balls summary in p tration in the wall quantity Pickling agent in g / kg in% by weight of seeds unpickled - -> 10 S. CH2-NH-CS s Zn 10 1 5 CH2-NH-CS 5 (known) , CH3 CO-ON = C > CH 10 1 0t05 C-NH, Cly N 3 H a N) ON = C \ 10 1 0.05 H XC-NW-CO-O- 10 1 0.05 H3 13eisplßl B: Eaatgutbeizmittel-Test / snow mold (seed-like mycosis) To produce a suitable dry dressing agent, the active ingredient is stretched with a mixture of equal parts by weight of talc and kieselguhr to a finely powdered mixture with the desired active ingredient concentration.

For dressing, rye seeds are shaken, which are obtained by Fusarium nivale is naturally contaminated with the pickling agent in a sealed glass bottle. The seeds are placed 1 cm deep in Fruhstorfer standard soil with 2 x 100 seeds in seed boxes sown.

In climatic chambers at 10 ° C, 95 show relative humidity and diffuse The young plants develop and show within the daylight illumination the typical symptoms of snow mold for the first 3 weeks.

After this time one determines the number of fusarium plants in Percent of the total emerged plants. The active ingredient is the more effective the fewer plants are diseased.

Active ingredients, active ingredient concentrations in the dressing, amounts of dressing applied and the number of diseased plants are shown in the table below: Table of seed dressing test / snow mold Active ingredient active ingredient pickling agent number f- more focus- insarious tion in the wall quantity of plants Pickling agents in g / kg in% of in% by weight of total seeds accrued a plant Zen unpickled - - 14.6 S. CH2-NH-8-S s 30 2 9.1 10 1Q 2 8.3 CH2-NH-C11-S CO S. (known) H J \ zCH3 3 ° 2 0.0 10 2 10 2 3.2 C2H5 Preparation Examples A number of the compounds according to the invention have no defined melting point because they decompose at higher temperatures. In contrast, the infrared spectra show characteristic absorption bands in the range from 1500-1750 cm 1 and at approx. 1050 cm 1, which are similar to the alkyl benzimidazol-2-yl-carbamic acid esters known from the literature.

Example la: 2-aminobenzimidazole-1-carboxylic acid acetone oxime ester is stored at 25 ° C. for 120 days. Thereafter, the compound has completely rearranged into benzimidazol-2-yl-carbamic acid acetone oxime ester. The IR spectrum in KBr shows bands at 1035, 1065, 1585 to 1600, 1625 and 1670 cm, as well as an indicated CO absorption at 1735 cm 1. The strong carbonyl band of the starting material at 1760 cm 1 has disappeared.

The same compound is obtained if the starting product 11 Days at 75 ° C. The melting point is above 325 ° C of the preliminary product (according to German patent application P 21 40 863.9): 133.2 g (1 mol) 2-aminobenzimidazole and 138 g of powdered potassium carbonate are poured into 2.3 liters at OOC. Acetone submitted.

With thorough stirring, 135.5 g (1 mol) are added over the course of 150 minutes. Acetone oxime carbonate chloride was added dropwise as a goat solution in methylene chloride. The mixture is then stirred at OOC for 1 hour and at 14 ° C. for 1 hour. After 16 hours will be the crystals sucked off, washed with 200 ml of cold acetone and then while with treated with cold water until the washing liquid is free of chloride. Afterward the crystals are dried at 40 ° C. in a high vacuum. One receives 172 g (that is 74% of theory) 2-aminobenzimidazole-1-carboxylic acid acetone oxime ester. The melting point the compound is, recrystallized from water, above 3400C.

The IR spectrum in KBr shows the carbonyl band at 1760 cm as well as one NH band at 3425 cm-1.

Example 1b: 250 g of 2-aminobenzimidazole-1-carboxylic acid acetone oxime ester are refluxed for 6 hours in 1.5 l of warm alcohol-free chloroform which contains 5 g of pyridine. The product which crystallizes out at room temperature is filtered off with suction.

158 g of rearranged product are obtained. The IR spectrum is with the Product from Example 1a identical.

Example 1c: 404 g (3.04 mol) of 2-aminobenzimidazole, 542 g (3.15 mol) of carbonic acid acetone oxime ester, 1.5 l of toluene and 0.5 ml of pyridine are kept at 60 to 70 ° C. for 7 hours with stirring.

A visible reaction occurs after just 17 minutes.

The benzimidazol-2-yl-carbamic acid acetone oxime ester is filtered off with suction and washed with toluene and with water. 685 g are obtained (that is 97% of theory) Benzimidazol-2-yl-carbamic acid acetone oxime ester. The IR spectrum is with the product identical from Example 1 a.

Example 2a: 35 g of 2-amino-benzimidazole-1-carboxylic acid butanone oxime ester are refluxed for 2 hours in a mixture of 950 ml of dry methylene chloride and 100 ml of dibutyl ether.

It is filtered. After 18 hours, 9.5 g of the rearrangement product separate out of the solution. A second product fraction is obtained by careful concentration from 17 g.

The yield of benzimidazol-2-yl-carbamic acid butanone oxime ester is 75.5% of theory. IR spectrum in KBr: NH 3300 - 3320 cm 1; CO 1745 cml (m); characteristic Bands at 1040 cm-1, 1055 cm-1. 1525 cm1 (w), 1600 cm ~ 1 (5), 1645 cm 1 (ssb) sh 1670 cm 1. The melting point of the preparation is above 300 C. The NH band of the starting product at 3430 cm-1 and the CO band at 1755 cm-1 have disappeared.

Example 2b: 53.3 g (0.4 mol) of 2-aminobenzimidazole, 50 ml of toluene, 1 drop of pyridine, 84 g (0.42 mol) of methyl ethyl ketone oxime carbonate (boiling point 116-1220C / 0.8 Torr; obtained by reacting 2 moles of methyl ethyl ketone oxime with 1 mole of phosgene in the presence of 2 moles of pyridine in methylene chloride at 0 to 10 ° C) are kept at 70 ° C for 8 hours. The benzimidazol-2-ylcarbamic acid butanone oxime ester obtained is filtered off with suction, washed with toluene and dried. The yield is 87.3 g, the compound is identical to that obtained according to Example 2a.

Example 2c: 13.5 g (0.102 mol) of 2-aminobenzimidazole, 51 g (0.107 mol) of 2,4,6-tribromo-3-chlorophenyl carbonic acid butanone oxime ester, 50 ml of toluene, 1 drop of pyridine are brought to 80% over the course of 7 hours 0C held. The reaction mixture is then stirred at ° C. for 30 minutes with 4.5 g of sodium hydroxide in 100 ml of water. The benzimidazol-2-yl-carbamic acid butanone oxime ester obtained is filtered off with suction, washed with water and toluene and dried at 80 ° C. in a high vacuum.

Example 3: The connection is made analogously to Example 1b.

IR spectrum in KBr: NH 3320 cm-1; CO 1740 cm-1 other bands 1060, 1530, 1605, 1642, 1675 cm-1. IR spectrum of the starting product in KBr: NH 3425 cm 1; CO 1752 cm-1.

Example 4: The connection is established analogously to Example 1c.

Mp. Approx. 242 ° C. (with decomposition). IR spectrum in KBr: NH 3330-3350 cm-1; CO 1735 cm-1 (m), other bands 1530 cm-1 (w), 1605, 1640 (sh) 1670 cm-1; 1055 (sh) 1070 cm 1.

IR spectrum of the starting product bis (cyclohexanone oxime) carbonate in CCl4: CO 1785, 1810 cm-1; C = N 1650 cm-1.

Example 5: The connection is produced analogously to Example 1b.

IR spectrum in KBr: NH 3320 cm-1, CO 1730 cm-1. other gangs 1520 cm 1 (w), 1595, 1630 eh 1655 cm-1. 1045 sh 1060 cm 1st IR spectrum of the starting product: -NH 3430 cm-1 CO 1748 cm (ss).

Example 6: The connection is produced analogously to Example 1b.

IR spectrum in KBr: NH 3330 cm-1, ao 1728 cm 1 (m), other bands 1595 cm-1, 1630 eh 1655 cm-1, 1045 eh 1055 cm 1.

IR spectrum of the starting product: NH 3425 cm-1, CO 1745 cm-1 (ss).

Example 7: The connection is made analogously to Example 1.

The melting point is above 3000C. IR spectrum in KBr: NH 3280 - 3320 cm-1, CO 1745 cm-1 (w), CH3 1375 cm-1, other bands 1595 cm-1, 1625 - 1645cm-1 sh 1665cm-1, 1045cm-1.

Subsequent product: (Example for the use of the according to Examples 1a to 1c obtained compound ale intermediate product) 23.2 g (0.1 mole) Benzimidazol-2-yl-carbamic acid acetoxime ester, 50 g toluene, 50 g methanol, 1 drop Pyridine is kept at 67 ° C. for 3 hours with stirring. The crystals will be suctioned off, washed with methanol and water. 18.5 g of methyl benzimidazol-2-yl-carbamate are obtained (known from U.S. Patent 3 010 968 and German Offenlegungsschrift 1 620 175). The band sequence in the IR spectrum of the reaction product is identical with a sample of the compound prepared according to the literature procedure.

Claims (6)

P a t e n t a n s p r ü c h e: 1 Benzimidazol-2-yl-carbamic acid ketone oxime ester of the formulas in which R and R 'stand for alkyl and alkenyl each with up to 6 carbon atoms and for phenyl, in addition one of the substituents can stand for alkylthio with up to 4 carbon atoms, furthermore R and R' together can stand for alkylene with 4 to 10 Are carbon atoms and R "is hydrogen and alkyl of up to 8 carbon atoms. 2) Process for the preparation of benzimidazol-2-ylcarbamic acid ketonoxlme8tern, characterized in that a) a 2-aminobenzimidazole-1-carboxylic acid oxime ester of the formula in which R, R 'and R "have the meaning given above, rearranged in the solid or liquid phase, or that b) a 2-aminobenzimidazole of the formula in which R "has the meaning given above, with an oxime carbonate of the formula in which R and R 'have the meaning given above, or that c) a 2-aminobenzimidazole of the formula (III) with a phenyl ketone oxime carbonate of the formula in which R and R 'have the meaning given above and X, X' and X "represent an electron-withdrawing substituent and X"'represents hydrogen, halogen, alkyl with up to 3 carbon atoms and nitro, or that one d) an o-phenylenediamine of the formula in which R ″ has the meaning given above, according to a special process (described in US Pat. No. 3,010,968 or German Offenlegungsschrift 1,812,005) with a bisacylated isothiourea of the formula in which R and R 'have the meaning given above and R "' represents alkyl, alkenyl and alkynyl with up to 6 carbon atoms each and represents benzyl, 3) Fungicidal agent, characterized by a content of benzimidazol-2-yl-carbamic acid ketone oxime esters according to claim 1. 4) Method of combating fungi, characterized in that one benzimidazol-2-yl-carbamic acid ketone oxime ester according to claim 1 on mushrooms or allows their living space to act. 5) Use of benzimidazol-2-yl-carbamic acid ketone oxime esters according to claim 1 for combating fungi. 6) Process for the production of fungicidal agents, characterized in that that benzimidazol-2-yl-carbamic acid ketone oxime ester according to claim 1 with extenders and / or surfactants mixed together.