DE2856750A1 - 4-Amino-3-methylthio-6-cyclopropyl-1,2,4-triazin-5-one derivs. - useful as selective herbicides - Google Patents

Abstract

Triazine derivs. of formula (I) are new. In (I) R is i-Pr, n-Pr or Et. (I) are prepd. by reaction of (II) with H2NNHCSNHNH2 (III) in presence of acid followed by methylation. Cpds. (I) are herbicides with very similar activity to corresp. cpd. where R = Me (DT 2732797). They can be used for selective pre-emergence control of grasses and broad-leaved weeds, e.g. in soya crops, or as desiccants and defoliants, e.g. for cotton or potatoes.

Description

Herbicidally active 1,2,4-triazin-5-one derivatives

The subject of the main patent ... ... ... (P 27 32 797.5) is a new triazinone derivative of the formula which influences plant growth and, in particular, has excellent herbicidal properties.

It is mainly used for weed control, but can also be due to its beneficial drying and peeling effectiveness as a harvesting aid used in crops such as cotton or potatoes.

It has now been found that the corresponding l-propyl and l-Ethylcyclopropylderivate an identical or very similar effect as the compound according to the main patent.

These compounds are also new and correspond to the general formula in which R stands for an i-propyl, n-propyl or ethyl radical.

The production can also be carried out according to one described by Dornow et'al Procedure (Ber. 97, 2173-79, (1964)). According to this procedure, an alkyl or Arylglyoxylic acid with thiocarbohydrazide to give a 6-aryl or alkyl substituted one 4-Amino-3-thiono-1.2.4-triazin-5-one condensed and then to the 3-methyl mercapto derivative reacted by means of a methylating agent. Methyl iodide, Methyl bromide or dimethyl sulfate can be used in a basic medium. When transferring However, this reaction to the preparation of the compounds according to the invention must from a tert. -Alkylamide of the corresponding glyoxylic acid can be assumed.

The reaction can be represented by the following reaction equation, where R1 stands for a tert-alkyl radical with 4 to 18 carbon atoms, in particular for the t-butyl, t-amyl or t-octyl radical: The reactions are preferably carried out in polar solvents, such as methanol, ethanol, dimethylformamide, dimethyl sulfomide, water or mixtures thereof, at temperatures between OOC and the boiling point of the solvent or mixtures.

The reactions of the thiocarbohydrazide with the tert. -Alkylamides the (1-alkyl-cyclopropyl) -glyoxylic acids are carried out in the presence of an acid, preferably Sulfuric acid or hydrochloric acid in an amount at least equal to that of the equivalents Amide amount corresponds.

The methylation is preferably carried out in a manner known per se Methyl iodide or methyl bromide.

The (l-alkyl-cyclopropyl) -glyoxylic acid-tert-alkylamides can be used for Example by condensation of the 1-alkyl-cyclopropancarboxylic acid cyanide with a tert.

Alcohol or an alkene can be obtained in an acidic medium. This implementation takes place in principle under the conditions of the so-called "Ritter" reaction or

Graf-Ritter reaction (JACS 70, 4045 (1948); JACS 1 °, 4048 (1948).). As a solvent, in particular glacial acetic acid or dichloromethane or ether, for Example dibutyl ether can be used.

The acyl cyanides in turn are derived from the corresponding acyl halides available. For example, you can use the German patent application procedure P. 27 o8 183.0 by reaction with CuCN at temperatures between 50 and 1800C in one Mixture of about 1 to 10 equivalents of an inert carboxylic acid nitrile per mole of acid halide and about 0.5 to 20 equivalents of an inert organic solvent, for example Dioxane. According to the German patent application P 27 08 182.

but this production can also be done in such a way that a mixture from about 0.1 to 5 equivalents of an alkali metal leyanide and about 0.05 to 2 equivalents of a copper (I) salt per mole of acid halide used and also in the presence an inert carboxylic acid nitrile works.

The 1,2,4-triazin-5-one derivatives of the formula I according to the invention influence plant growth and particularly show excellent herbicidal properties.

They are mainly used to control weeds, but can also be due to their beneficial drying and defoliation effectiveness as a harvesting aid be used in crops such as cotton or potatoes.

When fighting monocotyledon and dicotyledon weeds show the active ingredients of the formula I have an outstanding herbicidal action even at low application rates on unwanted vegetation with significant protection of a number of useful plant crops and therein are surprisingly structurally similar known 1,2,4-triazin-5-one derivatives think. Weed species that are difficult to control are also recorded.

The triazinones according to the invention have very good properties against gramineae, such as millet or millet-like plants, black foxtail (Alopecurus sp.).

The general effectiveness of Triazinones is known, for example that of the compound 4-amino-6-t-butyl-3-methylthio-1.2.4-triazin-5-one. Of this the new connections differ mainly in the pre-emergence test with medium-sized ones Concentrations by being in some crops of useful plants, for example in corn, so yes, rye, barley and oats, a great deal 6 act more electively, as well as through their effectiveness against Galium aparine Application of the present compounds can in the usual formulations with equal success both after emergence (post-emergent) and especially before emergence (pre-emergent) of the plants take place. The application rates for the active compounds according to the invention can be dependent of purpose, place of use, crop, harmful plant species and population, climatic Ratios etc. fluctuate within wide limits and are surprisingly low. In The triazinone derivatives according to the present invention generally act on light soils in application rates from 0.1 kg per hectare and are preferably used in application rates used from 0.5 to 2.0 kg per hectare; in heavy humus rich and adsorptive Soils are to be used higher application rates. With application rates of 3.0 kg per hectare and the total herbicidal action of these compounds is more important than the selective action in the foreground.

The following examples illustrate the manufacturing processes for the new compounds of formula I.

The temperatures are given in degrees Celsius.

Example 1 a) Preparation of 1-ethyl-cyclopropanecarboxylic acid cyanide: 90.5 g of 1-ethyl-cyclopropanecarboxylic acid chloride are in 100 ml of acetonitrile: trichlorethylene = 1: 1 stirred with 79.3 g of CuCN at 80 ° C. for 12 hours. The cooled suspension is filtered, the filtrate was concentrated completely and the residue was distilled. You get 65 g of color 1-ethyl-cyclopropylcarboxylic acid cyanide with a KP60 mbar of 8800.

b) Preparation of (1-ethylcyclopropyl) glyoxylic acid tert. -butylamids: To a solution of 12.3 g of 1-ethylcyclopropanecarboxylic acid cyanide in 3'g of t-butanol and 13 ml of methylene chloride are added dropwise at 0 ° C-5 C within 10 minutes, 10 g of H2S04 (98 xig) a. The solution is then stirred for 4 hours at room temperature, then 2 ml of H20 are added and the mixture is stirred for a further 30 minutes. The answer is 80 ml. 2N NaOH adjusted to pH 6 and the organic phase separated. After removing the solvent is ° the residue from 50 ml of petroleum ether (bp 40 to 6500). at 50 C crystallized out. This gives 13.1 g of white crystals of pure (1-ithyl-cyclopropyl) -glyoxylic acid-tert. -butylamide with a melting point of 37.50C - 39 ° C.

c) Preparation of 3-mercapto-4-amino-6- (1-ethylcyclopropyl) -1 .2. 4-triazin-5 (4H) -ones: 9.2 g of thiocarbohydrazide hydrochloride are placed in 65 ml of H20 and with 12.7 g of (1-ethylcyclopropyl) -glyoxylic acid tert-butylamide in 65 ml of ethanol offset. The mixture is stirred at 80 ° C. for 8 hours.

Part of the product fails. The suspension is at 200C cooled, mixed with 130 ml of H2O and stirred for a further 2 hours. The precipitated crystals are filtered off and recrystallized from 50 ml CH3OH. 8 g of colored crystals are obtained, consisting of 3-mercapto-4-amino-6- (1-ethylcyclopropyl) -1.2.4-triazin-5 (4H) -one with a melting point of 1770-179 ° C.

d) Preparation of 3-methylthio-4-amino-6- (1-ethyl cyclopropyl) -1.2.4-triazin-5 (4H1-one: 6 g of 3-mercapto-4-amino-6- (1-ethylcyclopropyl) -1.2.4-triazin-5 (4H) -one are in 14.2 ml of 2n NaOH and 20 ml of H20 dissolved cold. A solution consisting of 4.8 g methyl iodide and 35 ml CH OH.

3 The solution is stirred for 3 hours at room temperature, and H 2 O is added and then extracted 3x with 50 ml of ethyl acetate. The organic phase is separated dried and totally evaporated. The residue (5.7 g). becomes from 70 ml of toluene: petroleum ether (40 ° C -650C) = 1: 1 recrystallized.

This gives 4 g of white crystals of a compound of the formula with a melting point of 9300-9500.

Example 2 a) Preparation of (1-n-propyl-cyclopropyl) -glyoxyltert-butylamide: Successively add to a mixture of 14.8 g of t-butanol and 15 ml of methylene chloride 13.7 g (0.1 mol) of (1-n-propyl-cyclopropyl) -carboxylic acid cyanide and 14.7 g of 98 goat Sulfuric acid was added dropwise at OOC to 50C. The mixture is stirred for 1 hour at OOC, lets it come to room temperature and stirs for 4 hours. Then one gives while cooling Add 20 ml of water and adjust to pH 7 with aqueous NaOH. It is extracted 3 times with Chloroform and the combined extracts washed with water are concentrated in vacuo.

18.5 g (87.6) (1-n-propyl-cyclopropyl) -glyoxyl-tert-butylamide are obtained as a light brown, thin oil.

b) Preparation of 4-amino-6- (1-n-propyl-cyclopropyl) ~ 3-mercapto-1.2.4-triazin-5-one A mixture of 9.5 g (0.045 mol) of the compound obtained according to a), 4.7 g of thiocarbohydrazide, 40 ml of ethanol and 40 ml of water are concentrated with 4.7 g.

Hydrochloric acid is added and the mixture is refluxed for 7 hours. After this The reaction mixture is cooled and the product which has crystallized out is filtered off with suction, with Water washed and dried.

8.0 g (78.5%) of pale yellow crystalline product are obtained, which after Purification (dissolving in aqueous solution, precipitation with dil. HCl and recrystallization from i-propanol) has a melting point of 167-168 ° C.

Analysis: OgH14N40S (226.30) Calculated: C 47.77- * H 6.24 ffi N 24.76 ffi S 14.17% found: 47.66 0.6 6.19% 24.43% 14.08 ffi c) methylation for 4-amino-6- (1-n-propyl-cyclopropyl) -3-methylthio-1.2.4-triazin-5-one 4.5 g (0.02 Mol) 4-amino-6- (1-n-propyl-cyclopropyl) 3-mercapto-1.2.4-triazin-5-one are in 40 ml of 2N NaOH dissolved and mixed with 1.08 g of methyl iodide.

The mixture is stirred at 20 ° to 250 ° C. and another 1.08 g each is added Add methyl iodide after 2 or 4 hours. After a reaction time of 8 hours and leaving to stand overnight, the resulting oil is taken with 50 ml of methylene chloride on. After drying and evaporation of the solvent 4.1 g (85 ffi of theory) remain. oily end product which is crystallized in petroleum ether / ether and has a melting point of 76-790C.

Chromatographically purified product melts at 81 - 82 ° C.

Analysis: C1oH16N40S (240.34) Calculated: C 49.98% H 6.71 * N 23.31 ffi S 13.34% found: 49.80 ffi 6.65% 23.19 ffi 13.33% Example 3 In the greenhouse immediately after sowing the test plants in seed bowls the surface of the earth with an aqueous suspension - the active ingredients, obtained from a 25% wettable powder, treated. Three different concentration series were used, accordingly 0.5, 0.25 and 0.125 kg of active ingredient per hectare. The seed trays are in the greenhouse at 22 - 250C and 50 - 70% rel. Humidity kept and the experiment after evaluated for three weeks and rated the results according to the following grading scale: 1 = Plants not germinated or dead completely; 2-8 = intermediate stages of damage; 9 =. Plants undamaged (like untreated control).

4-Amino-6- (1-ethyl-cyclopropyl) -3-methylthio1 2,4-triazin-5-one g / ha 500 250 125 Avena fatua 1 1 1 Lolium perenne 1 1 1 Alopecurus myos. 1 1 1 Bromus tectorum 1 1 1 Digitaria sanguinalis 1 1 1 Setaria italica 1 1 1 Echninochloa crus-galli 1 1 1 Sida spinosa 1 1 1 Sesbania exaltata 1 .1 1 Amarantus retroflexus 1 1 1 Sinapis alba 1 1 1 Pastinaca sativa 1 1 1 Rumex sp. 1 1 1 Chrysanthemum leuc. 1 1 1 Abutilon sp. 1 1 1 'Splanum nigrum 1 1 1 Corn 3 4 4 Soy 3 9 9 For the production of herbicidal agents is the active ingredient with suitable carriers and / or Distribution means combined. This is done in a manner known per se by intimate Mixing and grinding of the active ingredient of general formula I with suitable ones Carriers, optionally with the addition of inert to the active ingredients Dispersants or solvents.

The active ingredient can be used as dust, grit, granules, coating granules, Impregnation granules, homogeneous granules, wettable powders, pastes, Emulsions, solutions or aerosols can be used.

For the production of solid processing forms (dust, grit, Granules) the active ingredient is mixed with solid carriers. The grain size the carrier material is expediently up to approx. 0.1 mm for dust and for grit approx. 0.075 to 0.2 mm and for granulates 0.2 mm or more. The drug concentrations in the solid work-up forms are generally 0.5 to 80%. These mixtures The active ingredient can also be stabilized additives and / or nonionic anion-active and cation-active substances are added which, for example, die.Adhesive strength improve the active ingredient on plants and parts of plants (adhesives and adhesives) and / or better wettability (wetting agents) and dispersibility (dispersants) guarantee.

Active ingredient concentrates dispersible in water, wettable powders (wettable powder), pastes and emulsion concentrates are agents that can be mixed with water every desired concentration can be diluted. You insist from active ingredient, carrier, optionally additives stabilizing active ingredient, surface-active substances and antifoams and optionally solvents; The active ingredient concentration in these agents is 5 - 80 *. The wettable powder (wettable powder) and pastes are obtained by mixing the active ingredient with dispersants and powdery carriers in suitable devices until they are homogeneous mixed and ground. In some cases it is advantageous to use mixtures of different Use carriers. Silicones, for example, are used as antifoam agents. in question. The active ingredient is mixed with the additives listed above, ground, sieved and happens that in wettable powders the solid fraction has a grain size of 0.02 - 0.04 and not exceeding 0.003 mm for pastes. For production of Emulsion concentrates and pastes become dispersants, organic solvents and water used.

The solvents must be practically odorless, not phytotoxic, inert to the active substance and not slightly flammable.

The agents according to the invention can also be used in the form of solutions will. For this purpose, the active ingredient of general formula I is used in suitable organic Solvents, solvent mixtures or water. The solutions are supposed to Contains active ingredient in a concentration range of 1 - 20 ffi.

Granules The following are used to produce your own 5 granules Substances used: 5 parts of active ingredient according to formula I, 0.25 part of epichlorohydrin, 0.25 Parts of cetyl polyglycol ether with 8 moles of ethylene oxide, 3 to 50 parts of polyglycol ("Carbowax" , 91 parts of kaolin (grain size 0.3-0.8 mm).

The active ingredient is mixed with epichlorohydrin and added 6 parts Dissolved acetone, then polyglycol and cetyl polyglycol ether are added. The so The solution obtained is sprayed onto kaolin and then the acetone in vacuo evaporates.

Spray powder for making a) 50 own, b) 25 above and c) 10 own wettable powder the following ingredients are used: a) 50 parts of active ingredient according to formula I 5 parts of sodium dibutylnaphthylsulphonate, 3 parts of naphthalenesulphonic acids-phenolsulphonic acids-formaldehyde condensate 3: 2: 1, 20 parts kaolin, 22 parts. Champagne chalk, b) 25 parts of the above-mentioned active ingredient 5 parts of oleylmethyltauride sodium salt, 2.5 parts of naphthalenesulfonic acid-formaldehyde condensate, 0.5 parts carboxymethyl cellulose, 5 parts neutral potassium aluminum silicate, 62 Parts of kaolin; q) 1..0 parts of the above-mentioned active ingredient 3 parts mixture of sodium salts of saturated fatty alcohol sulfates, 5 parts of naphthalenesulfonic acid-formaldehyde condensate., 82 parts of kaolin.

The specified active ingredient is applied to the appropriate carriers (Kaolin and chalk) drawn up and then mixed and ground. You get Wettable powder with excellent wettability and suspension properties. From such wettable powders By diluting with water, suspensions of any desired concentration of active substance can be created can be obtained. Such suspensions can be used to control weeds and Weed grasses are used in cotton plantings.

Paste The following substances are used to produce your own paste used: 45 parts of active ingredient according to * Formula I 5 parts of sodium aluminum silicate, .14 parts of cetyl polyglycol ether with 8 moles of ethylene oxide, 1 part of cetyl polyglycol ether with 5 moles of ethylene oxide, 2 parts of spindle oil, 10 parts of polyglycol ("Carbowax" @), 23 Share water.

The active ingredient is mixed with the additives in suitable devices intimately mixed and ground. A paste is obtained from which, by diluting it make suspensions of any desired concentration with water.

Emulsion concentrate For the production of your own 10 emulsion concentrate 10 parts of active ingredient according to formula I 15 parts of oleyl polyglycol ether with 8 mol Ethylene oxide, 75 parts of isophorone (3,5,5-trimethylcyclohex-2-en-1 -one) with one another mixed. This concentrate can be mixed with water to form emulsions at suitable concentrations be diluted. such emulsions are suitable for combating weeds in Cultivated plants such as soybeans and potatoes etc.

Claims (4)

Herbicidally active 1,2.4-triazin-5-one derivatives Patent claims 1. 1. 1.2.4-Triazin-5-one derivatives of the general formula according to the main patent (P 27 32 797.5), characterized in that R stands for an i-propyl, n-propyl or ethyl radical. 2) Herbicidal agent, characterized in that it is used as an active ingredient contains a compound according to claim 1 in addition to customary auxiliaries. 3) Use of the compounds according to claim 1 or those containing them herbicidal compositions for controlling weeds. 4) Process for the preparation of the compounds according to claim 1, characterized characterized in that the compound of the formula H2N.NH.CS.NH.NH2 is known per se Way with a (1-propyl), or (l-ethyl-cyclopropyl) -glyoxylic acid-tert.-alkylamide condensed in the acidic medium and the reaction product in a manner known per se methylated.