DE2938384A1 - 3-di:methylamino-4-methyl-1,2,4-triazinone derivs. - useful as total or selective herbicides esp. against grasses - Google Patents

Abstract

derivs. of formula (I) are new: (where R1 is t-Bu, s-Bu or cyclohexyl). (I) are useful as total or selective herbicides (pre- or post-emergence); they have good activity against grasses as well as being active against broad-leaved weeds (esp. Galium spp.), and are useful for selective weed control in maize, peanut, soya, cotton, rice and cereal crops.

Description

6-sec. -Butyl -3-dimethylamino-4-methyl-1, 2,4-triazine-5-

(4H) -one, process for its preparation and its use as Herbicide The present invention relates to a new triazinone derivative, method for its manufacture and its use as a herbicide.

It has already become known that 1,2,4-triazin-5 (4H) -ones are used as weed control agents can be used.

For example, it is known that certain 3-substituted 4-alkyl-1,2,4-triazin-5 (4H) -ones can be used as herbicides (cf. DE-OS 16 70 912). The effect of these preparations however, it is not always sufficient in low doses.

It was now the new 6-sec. -Butyl-3-dimethylamino- -4-methyl-1,2,4-triazin-5 (4H) -one of the formula found.

The triazinone of the formula (I) is obtained if (a) a 6-sec-butyl-4-methyl-3-alkylthio- (or 3-aralkylthio) -triazin-5 (4H) -one of the general formula in which R represents alkyl or aralkyl, if appropriate in the presence of a diluent and if appropriate in the presence of a lower aliphatic carboxylic acid with dimethylamine, or if (b) 3-methyl-2-oxo-valeric acid of the formula in aqueous solution with a 3-amino-1,1,2-trimethylguanidinium salt of the formula in which X is Cl, Br or I, converts.

The new triazinone of the formula (I) has strong herbicidal properties on.

The novel triazinone derivative according to the invention surprisingly shows a considerably higher herbicidal effect than those previously known from the prior art 3-substituted 4-alkyl-1,2,4-triazin-5 (4H) -ones.

For example, if you use 6-sec. -Butyl-4-methyl-3-methylthio-1, 2,4-triazin-5 <4H) -one and dimethylamine as starting products, the course of the reaction according to process (a) can be represented by the following equation: If 3-ethyl-2-oxo-valeric acid and, for example, 3-amino-1,1,2-trimethyl-guanidinium hydroiodide are used as starting materials, the course of the reaction according to process (b) can be represented by the following equation: Some of the starting materials that can be used according to the invention are known or can be produced in a simple manner by known processes. Thus, the as yet unknown 6-sec-butyl-4-methyl-3-methylthio-1,2,4-triazin-5 (4H) -one (IIa) which can be used for process (a) can be used in a manner known per se by S-methylation of 6-sec-butyl-4-methyl-5-oxo-3-thioxo-1,2,4 (2H, 4H) -triazine (V) (see preparation examples). In a similar way, other 3-alkylthio- or 3-aralkylthio-triazinones, for example 3-ethylthio-, 3-propylthio, 3-benzylthio- or 3- (4-chlorobenzylthio) -triazinones can be synthesized, which in the same way as starting products are suitable for method (a).

3-r; ethyl-2-oxo-valeric acid (III) is known (cf.

sionatshefte für Chemie, Vol. 26, 483-495 (1405); Beiistein's manual the organ. Chem., 4th ed. (1921), 3d. 3, p. 690).

3-Amino-1,1,2-trimethyl-guanidinium-hydroiodide (IV, X = I) can also be prepared by a method known from the literature (cf. J. Org. Chem. 19, 1807-1817 (1954)). The corresponding hydrochloride (IV, x = Cl) and hydrobromide (IV, X = Br) can be prepared in an analogous manner.

In process (a), all inert organic diluents can be used Solvent in question. These include hydrocarbons such as toluene and xylene; chlorinated aromatic hydrocarbons such as chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene; Ethers such as tetrahydrofuran, dioxane; Alcohols such as methanol, ethanol, propanol, isopropanol; Amides like N, N-dimethylformamide, tetramethylurea or sulfoxides such as dimethyl sulfoxide.

Isopropanol is preferably used for the reaction.

The reaction temperatures can in process (a) in a larger Range can be varied. In general, one works at temperatures between about 20 and about 1700 ° C, preferably between 60 and 90 ° C.

The reaction can be pressureless as well as at elevated pressures executed will.

There is a particularly advantageous embodiment of process (a) in that in the presence of at least the equimolar amount of a lower aliphatic Carboxylic acid works. Acetic acid is preferably used for this. This method makes it possible to manage with a relatively small excess of dimethylamine. At this Embodiment can increase the reaction rate by adding a catalytic Amount of an organic sulfonic acid can be increased. Preferably used for this p-toluenesulfonic acid.

When carrying out process (a) according to the invention according to this preferred process variant is set to 1 mol of the 3-alkylthio- or 3-aralkylthio-triazinone of the formula (II) expediently 1 to 2 mol of a lower aliphatic carboxylic acid, 0.01 to 0.05 mol of an organic sulfonic acid and 1 to 2 mol of dimethylamine, heated until the mercaptan has been split off and then works up. this can e.g.

done in such a way that you evaporate the residue with excess stirred aqueous mineral acid and separated off undissolved impurities. By addition an excessive amount of a base such as ammonia becomes the reaction product precipitated in high purity.

Process (b) is carried out in aqueous solution.

Appropriately, the sodium salt of 3-i4ethyl-2-sxo-valerlanic acid (III) presented in aqueous solution, and after adding the 3-amino-1,1,2-trimethylguanidinium salt (IV) the acid (III) is obtained by adding mineral acid, for example hydrochloric acid, released.

The reaction temperatures can also be used in process (b) in can be varied over a larger area.

In general, one works at temperatures between about 50 and about 100 ° C, preferably between 65 and 90 ° C.

Process (b) is in general carried out under normal pressure.

When carrying out process (b), 1 mole of one is used aqueous solution of the Na salt of 3 - ;; ethyl-2-oxo-valeric acid 1 to 1.1 mol of a 3-Amino-1,1,2-trimethyl-guanidinium salt (IV) and heated after the addition of Mineral acid, for example hydrochloric acid, until the reaction has ended. The work-up then happens in the same way as indicated for method (a).

The active ingredient according to the invention influences plant growth and can therefore be used as a defoliant, desiccant, haulm killer, sprout inhibitor and especially used as weed killers. Under weeds in In the broadest sense, all plants are to be understood that grow in places where they are are undesirable. Whether the substance according to the invention as a total or selective herbicide works depends essentially on the amount used.

The active ingredient according to the invention can be used, for example, in the following plants are used: Dicot weeds of the genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea.

Dicot cultures of the genera: Gossypium, Glycine, Beta, Daucus, Fhaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis, Brassica, Lactuca, Cucumis, Cuburbita.

Monocot weeds of the genera: Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea, DaNyloctenium, Agrostis, Alopecurus, Apera.

Monocot cultures of the genera: Oryza, Zea, Triticum, hordeum, Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus, Allium.

However, the use of the active ingredient according to the invention is by no means limited to these genera, but extends in the same way to other plants.

Depending on the concentration, the compound is suitable for Total weed control e.g. on industrial and rail systems and on paths and squares with and without tree growth. Likewise, the connection to weed control in permanent crops e.g. forest, ornamental wood, fruit, wine, citrus, nut, banana, Coffee, tea, rubber, oil paim, cocoa, berry fruit and hops plants and for selective weed control can be used in annual crops.

The active ingredient according to the invention shows in particular in addition to a very good effect against grass-like weeds also a herbicidal effect against broad-leaved ones Weeds, especially against Galium species. A selective use of the invention Active ingredient is possible, preferably in corn, peanuts, soybeans, cotton, Rice and other grains.

The active ingredient can be converted into the usual formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granulates, suspension-emulsion concentrates, active ingredient-impregnated Natural and synthetic materials, finest encapsulation in polymer materials.

These formulations are prepared in a known manner, for example by Mixing the active ingredient with extenders, i.e. liquid solvents and / or solid carriers, optionally with the use of surface-active agents, that is, emulsifiers and / or dispersants and / or foam-generating agents. If water is used as an extender, organic solvents, for example, can also be used can be used as co-solvents. The liquid solvents used are essentially in question: Aromatics such as xylene, toluene, or alkylnaphthalenes, chlorinated Aromatics or chlorinated aliphatic hydrocarbons such as chlorobenzenes and chloroethylenes or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. petroleum fractions, alcohols such as butanol or glycol as well as their Xther and esters, Ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclchexanone, are strong polar solution medium, such as dimethylformamide and dimethyl sulfoxide, and water.

The following can be used as solid carriers: e.g. 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 solid carrier materials for granulates are possible: e.g.

broken and fractionated natural rocks such as calcite, marble, Pumice, sepiolite, dolomite and synthetic granules made from inorganic and organic Flours and granules made from organic material such as sawdust, coconut shells, corn on the cob and tobacco stalks; as emulsifying and / or foam-producing agents are possible: e.g. non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, Polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol Xther, alkyl sulfonates, Alkyl sulfates, aryl sulfonates and protein hydrolysates; come as a dispersant in question: e.g. lignin sulphite waste liquors and methyl cellulose.

Adhesives such as carboxymethyl cellulose, natural and synthetic powdery, granular or latex shaped Polymers are used, such as gum arabic, polyvinyl alcohol, polyvinyl acetate.

Dyes such as inorganic pigments, e.g.

Iron oxide, titanium oxide, ferrocyan blue and organic dyes such as Alizarin, azo-metal phthalocyanine dyes and trace nutrients such as salts of Iron, manganese, boron, copper, cobalt, molybdenum and zinc can be used.

The formulations generally contain between 0.1 and 95% by weight Active ingredient, preferably between 0.5 and 90% by weight.

The active ingredient according to the invention can be used as such or in its formulations can also be used in a mixture with known herbicides for weed control, finished formulation or tank mixing is possible.

Also a mixture with other known active ingredients, such as fungicides, Insecticides, acaricides, nematicides, bird repellants, growth substances, Plant nutrients and soil structure improvers are possible.

The active ingredient can be used as such, in the form of its formulations or the use forms prepared therefrom by further dilution, such as ready-to-use Solutions, suspensions, emulsions, powders, pastes and granulates can be used. It is used in the usual way, e.g. by watering, squirting, atomizing, Dusting or scattering.

The active ingredient according to the invention can be used both before and after emergence of the plants are applied.

The application is preferably before the emergence of the plants, that is in the pre-emergence procedure. It can also be pre-sown in the ground be incorporated.

The amount of active ingredient used can fluctuate over a wide range. It essentially depends on the type of effect you want. In general the application rates are between 0.01 and 10 kg of active ingredient per hectare, preferably between 0.01 and 5 kg / ha.

Preparation examples A) 6-sec-butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one (I) - according to process (a) 1065 g (5 mol) of 6-sec-butyl-4-methyl-3-methylthio-1,2,4-triazin-5 (4H) -one, 375 g of acetic acid and 25 g of p-toluenesulfonic acid are dissolved in 3 liters of isopropanol submitted. 360 g (8 mol) of dimethylamine are passed in without cooling, refluxed for 6 hours and then another 225 g (5 mol) of dimethylamine are passed into the boiling mixture over the course of 6 hours.

At 90-100 ° C, most of the solvent is passed through initially distilled off from nitrogen at normal pressure; then remove at 20 mbar and a bath temperature of 1000C residual amounts of the solvent.

The oily residue is stirred at 0-5 ° C. with 6 liters of ice water and 460 ml of 37% hydrochloric acid, add 400 ml of chloroform and separate after a short time Stir the phases. The organic phase is discarded to the aqueous phase if you add 2 liters of 25% ammonia solution at 10-20 ° C. with stirring, this takes off The separated oil is dissolved in 400 ml of chloroform, the phases are separated and the aqueous phase is stirred Phase again with 400 ml of chloroform and distilled the evaporation residue the combined chloroform solutions in a high vacuum.

392 g (85% of theory) of the abovementioned compound (I) are obtained of bp 131 ° C / 0.15 mbar and with the refractive index nD20 = 1.5324.

D The purity, determined by gas chromatography, is 99%.

B) starting materials a) 6-sec-butyl-4-methyl-5-oxo-3-thioxo-tetrahydro-1,2,4 (2H, 4H) -triazine (V) 525 g (5 mol) of 4-methyl-thiosemicarbazide are dissolved in 2 liters of water and 600 ml of 37% hydrochloric acid and a solution of 760 g (5 mol) of the sodium salt of 3-methyl-2- oxo-valeric acid in 1.5 liters of water increases rapidly. The mixture is refluxed for 10 hours, allowed to cool with stirring, filtered off with suction and washed with 2 liters of water. The moist crude product is then stirred with 1 liter of methanol at -200C, suctioned off at -200C and washed with methanol at -700C. After drying at 80 ° C., 697 g (70 ° 10 of theory) of compound (v) with a melting point of 117 ° -119 ° C. are obtained. A sample recrystallized from methanol melts at the same temperature.

b) 6-sec-butyl-4-mechyl-3-methylthio-i 2,4-triazin-5 (4H) -one (IIa) 1 ml of 3-benzyl-4-hydroxy-biphenyl-polyglycol ether as an emulsifier and 995 g (5 mol) of 6-sec.-butyl 4-methyl-5-oxo-3 are added to a solution of 202 g of NaOH in 5 liters of water -thioxo-tetrahydro-1,2,4 (2H, 4H) -t, iazine (V). 724 g (5.1 mol) of methyl iodide are added dropwise and stirring is continued until the slightly exothermic reaction has ended and a pH of 7-8 is reached. After filtering off with suction, washing with water and drying at 300 ° C. in vacuo, 907 g (85% of theory) of compound (IIa) with a melting point of 45 ° -500 ° C. are obtained. The crude product is sufficiently pure for further implementation. A sample recrystallized from pentane melts at 54 - 5500.

Example A Pre-emergence test Solvent: 5 parts by weight of acetone Emulsifier: 1 part by weight of alkylaryl polyglycol ether Active ingredient preparation is mixed 1 part by weight of active ingredient with the specified Amount of solvent, add the specified amount of emulsifier and dilute the concentrate with water to the desired concentration.

Seeds of the test plants are sown in normal soil and after Doused with the active ingredient preparation for 24 hours.

The amount of water per unit area is expediently kept constant. The concentration of the active substance in the preparation does not matter, it is decisive is only the amount of active ingredient applied per unit area. After three weeks it will the degree of damage to the plants is rated in% damage compared to development the untreated control. It means: 0 fi s no effect (like untreated Control) 100% = total destruction In this test, the active ingredient (I) shows a excellent effect.

Example B Post-emergence test Solvent: 5 parts by weight acetone Emulsifier: 1 part by weight of alkylaryl polyglycol ether Active ingredient preparation is mixed 1 part by weight of active ingredient with the specified Amount of solvent, add the specified amount of emulsifier and dilute the concentrate with water to the desired concentration.

Test plants which have a Height of 5-15 cm so that the respectively desired amount of active ingredient per unit area is applied. The concentration of the spray liquor is chosen so that in 2000 1 water / ha, the amount of active ingredient wiped in each case is applied. After three weeks the degree of damage to the plants is rated in% damage compared to Development of the untreated control. The following mean: 0 X = no effect (like untreated Control) 100% = total destruction In this test too, the active ingredient (I) shows an excellent effect.

Claims (6)

Claims (X 6- sec. -Butyl-3-dimethylamino-4-methyl-1 2,4-triazin-5 (4H) -one of the formula 2) Process for the preparation of 6- sec-butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one (I), characterized in that (a) a 6- sec. -Butyl-4-methyl-3-alkylthio- (or 3-aralkylthio) -triazin-5 (4H) -one of the general formula in which R represents alkyl or aralkyl, if appropriate in the presence of a diluent and if appropriate in the presence of a lower aliphatic carboxylic acid, reacted with dimethylamine, or (b) 3-14ethyl-9-oxo-vaieric acid of the formula in aqueous solution with a 3-amino-1,1,2-trimethylguanidinium salt of the formula in which X is Cl, Br or I, converts. 3) Herbicidal agents, characterized by a content of 6- sec. -Butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one according to claim 1. 4) method of controlling unwanted plant growth, thereby characterized in that 6-sec-butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one act according to claim 1 on the undesired plants or their habitat leaves. 5) using 6- zue c. sec-butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one according to claim 1 for controlling plant growth. 6) Process for the preparation of herbicidal agents, characterized in that that 6- sec. -Butyl-3-dimethylamino-4-methyl-1,2,4-triazin-5 (4H) -one according to claim 1 mixed with extenders and / or surfactants.