DE2236339A1 - Alpha-cyano-hydrazones preparation - with pre and post-emergence herbici-dal activity - Google Patents

Abstract

Hydrazones of the formula NC-CR=N-NR1-CX-NR2R3 (where R is 2-12C alkyl, alkenyl or alkynyl, 1-8C haloalkyl, cyanoalkyl or hydroxyalkyl, opt. subst. mono-, bi- or polycyclic aryl, or opt. subst. hererocyclyl; R1 is H or alkyl; R2 and R3 are H, alkyl or opt. subst. aryl and R2 can also be an alkyl residue subst. by a group -NR3-CX-NR1-N=CR-CN and X is O or S), are prepd. by reacting cpds. of the formula NC-CR=NR4 (where R4 is R or aryl) with a cpd. of the formula H2N-NR1-CX-NR2R3 in the presence of an inert org. solvent and of an acid at 0-150 pref. 20-100 degrees C.

Description

Process for the preparation of Q <-cyanohydrazones The present Invention relates to a chemically peculiar process for the production of new d-cyano hydrazones, which can be used as herbicides.

It has already become known that α-cyanohydrazones are obtained if benzoyl cyanides are used in accordance with. (a) with hydrazine derivatives (cf. German Offenlegungsschrift 1 768 574): RI = optionally substituted phenyl.

However, this method has the disadvantage that it is generally only suitable for the synthesis of those d-cyano hydrazones in which RI stands for an aromatic Rest stands. The corresponding α-cyanohydrazones in which RI stands for an aliphatic Remainder is not accessible according to the above scheme (a) because they are used as starting materials required acyl cyanides of aliphatic carboxylic acids under the reaction conditions usually split off hydrogen cyanide (see Chemical Reports 88, 117-130 (1955)).

An exception in this regard is acetyl cyanide, which is by reaction with hydrazine derivatives into the corresponding d-cyano hydrazones leaves (see Chemical Reports 93, 2209-2216 (1960)). This reaction acts However, it is a special case because it is not based on other aliphatic acyl cyanides such as pivaloyl cyanide transferable.

It has now been found that the new i-cyano hydrazones of the general formula in which R stands for alkyl, alkenyl, alkynyl, each with 2 to 12 carbon atoms, also for haloalkyl, cyanoalkyl, nitroalkyl, hydroxyalkyl, each with 1 to 8 carbon atoms, and also for optionally substituted mono-, bi- or poly-cyclic alkyl , Aralkyl or an optionally substituted heterocyclic radical, R1 is hydrogen or alkyl, R2 and R3 can be identical or different and are hydrogen, alkyl or optionally substituted aryl and R2 is additionally one through substituted alkyl radical and X stands for oxygen or sulfur, can be obtained in a simple manner in good yields and in excellent purity if one o <-imino-nitrile'dr general formula in which R has the meaning given above and R4 represents the same radicals as R and additionally represents aryl, with hydrazine derivatives of the general formula in which R1, R2, R3 and X have the meaning given above, is reacted in the presence of an organic solvent and in the presence of an acid at temperatures between 0 and 150.degree.

It can be described as extremely surprising that after the Process a (-Cyanohydrazones of the formula (I) according to the invention in very good yields and excellent purity can be obtained because of the state of the art Technology had to expect that α-iminonitriles of the formula (II) also with hydrazine derivatives react like corresponding acyl cyanides of aliphatic carboxylic acids, namely under Elimination of hydrogen cyanide (see Chemical Reports 88, 117-130 (1955)). Indeed however, the α-iminonitriles do not lose the nitrile group in this reaction, but instead form the α-cyanohydrazones with substitution of the imino group Formula (II).

The method according to the invention has a number of advantages. For example, it is not only suitable for the production of some special oc-cyanohydrazones, but can be applied very broadly. It should also be emphasized that the implementation is remarkably easy to carry out and without disruptive side reactions with high Yields expires. A possible cyclization of the invention in some cases o-Cyanhydrazones to the corresponding 5-imino-1,2,4-triazine derivatives is not to be feared, since the production takes place under acidic conditions (cf. German Offenlegungsschrift 2 003 144).

If 2-phenylsimino-3,3-dimethylbutyronitrile and 4-methyl-semicarbazide hydrochloride are used as starting materials, the course of the reaction can be represented by the following equation: The d-iminonitriles used as starting materials are generally defined by formula (II). In this formula, R preferably represents straight-chain or branched alkyl having 2 to 8 carbon atoms, in particular having 2 to 5 carbon atoms. Furthermore, R preferably stands for straight-chain or branched alkenyl with 2 to 5 carbon atoms, in particular with 2 to 3 carbon atoms. In addition, R preferably stands for straight-chain or branched alkynyl with 3 to 6 carbon atoms, for haloalkyl with 1 to 4 carbon atoms and 1 to 3 halogen atoms, in particular chlorine or fluorine, furthermore preferably stands for cyanoalkyl, nitroalkyl or hydroxyalkyl, each with 1 to 4 carbon atoms. Furthermore, R preferably represents mono-, bi- or poly-cyclic alkyl having 3 to 10 carbon atoms substituted by alkyl with 1 to 3 carbon atoms, in particular, examples being cyclohexyl and adamantyl.

Furthermore, R preferably represents aralkyl with 6 to 10 carbon atoms.

material atoms in the aryl and 1 to 2 carbon atoms in the alkyl part.

Finally, R preferably represents optionally substituted Five-membered heterocycles containing one or more heteroatoms such as N and / or 0 in the ring included, especially for Furyl. Preferred substituents are: Halogen, alkyl having 1 to 3 carbon atoms, but especially the nitro group.

In formula (II), R4 is preferably straight-chain or branched Alkyl with 1 to 7 carbon atoms, for cycloalkyl with 5 to 8 carbon atoms or for six-membered heterocycles which have one or more heteroatoms such as N and / or 0 contained in the ring; may be mentioned by way of example: morpholinyl. In addition, R4 is preferably for aryl with 6 to 10 carbon atoms, especially for phenyl.

As examples of the α-iminonitriles which can be used according to the invention are mentioned in detail: 2-tert. -Butylimino-3,3-dimethylbutyronitrile, 2-phenylimino-3,3-dimethylbutyronitrile 2-Cyclohexylimino-3,3-dimethylbutyronitrile, 2-isopropyl-3,3-dimethylbutyronitrile 2-n-Butylimino-3,3-dimethylbutyronitri 1 2-phenylimino-3,3-dimethylvaleric acid nitrile α-phenylimino-ß-methyl-hexahydrobenzylnitrile o (-phenylimino-adamantyl-1-acetonitrile 2-phenylimino-3-methylbutyronitrile, 2-phenylimino-3-chloro-3-methylbutyronitrile 2-phenylimino-valeric acid nitrile 2-phenylimino-3,3-dichloropropionitrile, 2-cyclohexylimino-3-methylene-butyric acid nitrile N-Morpholino-imino- (5-nitro-furyl-2) acetonitrile.

The d-iminonitriles of the formula (II) used as starting materials are partially known (see Chemischeberichte 102, 1447-1448 (1969) or J.Org.Chem. 54: 4040-4046 (1969)).

Some of them are the subject of a separate protection request (cf. German patent application P 22 21 771.6 = Le A 14 286). The d-imino-nitriles can be prepared by using imide halides of the general formula in which R and R4 have the meaning given above and X stands for halogen, either (a): with metal cyanides of the formula Me (CN) n (v) in which Ne stands for an n-valent metal cation, or (b): with Reacts hydrogen cyanide or compounds which donate hydrogen cyanide in the presence of an acid-binding agent, if appropriate in the presence of an inert organic solvent and if appropriate in the presence of a catalyst.

The hydrazine derivatives also used as starting materials are generally defined by formula (III). In this formula, R1 preferably represents hydrogen or straight-chain or branched alkyl having 1 to 6 carbon atoms. R2 and R3 can be the same or different and preferably represent hydrogen, straight-chain or branched alkyl having 1 to 17 carbon atoms and also optionally substituted aryl having 6 to 10 carbon atoms. R2 also preferably stands for one through substituted alkyl radical with 2 to 3 carbon atoms.

X preferably represents 0 or S.

As examples of the hydrazine derivatives which can be used according to the invention the following may be mentioned in detail: 4-methylsemicarbazide 4-ethylsemicarbazide 4-tert.-butylsemicarbazide 4-n-butyl semicarbazide, 4-stearyl semicarbazide 1,2-ethylene-di- (4-semicarbazide) 4,4-dimethyl semicarbazide 2,4-dimethyl semicarbazide 2,4,4-trimethyl semicarbazide 4-phenyl semicarbazide 4-methylthiosemicarbazide 4-Phenylthiosemicarbazide 4,4-Dimethylthiosemicarbazide 4-Butylthiosemicarbazide the Hydrazine derivatives of the formula (III) used as starting materials are general known.

All diluents can be used in the process according to the invention inert polar organic solvent in question. These preferably include Alcohols such as ethanol and butanol, also dimethyl sulfoxide, or dimethylformamide Dioxane.

As acids that are added in the reaction according to the invention, Both organic and inorganic acids come into consideration. Preferably trifluoroacetic acid, trifluoromethanesulfonic acid, hydrochloric acid, sulfuric acid are used and phosphoric acid. The acid can either be in free form or in combination with a hydrazine derivative of the formula (III) can be used.

The reaction temperatures can be varied within a relatively wide range will. In general, temperatures between 0 and 150 ° C. are preferably used between 20 and 1000C.

The pressure can also be varied over a wide range. In general, normal pressure is used, but overpressures of 1.1 can also be used apply to about 10 atmospheres.

When carrying out the process according to the invention, one starts with 1 mole of starting compound of the formula (II) is about 0.5 to 2 moles, preferably however 1 mole of hydrazine derivative of formula (III). The acid is based on the Hydrazine derivative of the formula (III), in a molar ratio of about 1: 1 to about 3: 1, preferably Jedboh in a ratio of 1: 1.

Working up is carried out in the customary manner by adding the reaction mixture after the reaction has ended, a sufficient amount of water is added and the sucks off crystalline compounds of the formula (I). However, it is even possible to proceed in the isolation of the substances according to the invention in such a way that one first the reaction mixture is concentrated in vacuo, then the residue that remains takes up this solution in a water-immiscible organic solvent shaken with water, then dried and evaporated and the residue under reduced Pressure -distilled.

The products obtained in this way are mostly colorless analytical.

pure crystals.

The i-cyano hydrazones of the invention have excellent herbicides Properties and can therefore be used to control weeds.

All plants are to be understood as weeds in the broadest sense, that grow up in places where they are undesirable.

Whether the active ingredients according to the invention as total or selective herbicides Remedies work depends on the amount of active ingredient used.

The active compounds according to the invention can be used, for example, in the following plants are used: dicots, such as mustard (Sinapis), cress (Lapidium), burdock weed (Galium), chickweed (Stellaria), chamomile (Matricaria), French herb (Galinsoga), Goosefoot (Chenopodium), nettle (Urtica), ragwort (Senecio), cotton (Gossypium), Beets (Beta), carrots (Dauous), beans (Phaseoulus); Monocots, such as timothy grass (phleum), Bluegrass (Poa), wing (Festuca), Eleusine (Eleusine), Fennich (Setaria), Raygrass (Lolium), bromus (bromus) f barn millet (Echinochloa), maize (Zea), rice (Oryza), Oats (Avena), barley (Hordeum), wheat (Triticum), millet (Panicum), sugar cane (Saccharum).

The active compounds according to the invention can be used in the customary formulations such as solutions, emulsions, suspensions, powders, pastes and granules. These are produced in a known manner, e.g. 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 and / or foam-generating agents Means. In the case of using water as an extender, e.g. organic Solvents can be used as co-solvents. As a liquid solvent are essentially: aromatics, such as xylene, toluene, benzene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, Chloroethylene 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, strongly polar solvents, such as dimethylfor-aid and dimethyl sulfoxide, and water; Liquids 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 carriers: natural rock flour, such as kaolins, clays, talc, chalk, quartz, attapulgite, Montmorillonite and diatomaceous earth, and powdered synthetic rocks such as finely divided ones Silica, alumina and silicates; as an emulsifier and / or foam generator Medium: non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, Polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol ethers, alkyl sulfonates, Alkyl sulfates, aryl sulfonates and protein hydrolysates; as a dispersant: e.g. Lignin, sulphite 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 Active ingredient, preferably between 0.5 and 90 percent by weight.

The active ingredients can be used as such, in the form of their formulations or the application forms prepared therefrom, such as ready-to-use solutions, emulsions, Foams, suspensions, powders, pastes and granulates can be used. The application happens in the usual way, e.g. by dusting, spraying, spraying, pouring and scatter.

The amount of active ingredient used can fluctuate over a wide range. It essentially depends on the type of effect desired. In general the application rates are between 0.1 and 20 kg of active ingredient per hectare, preferably between 0.2 and 15 kg / ha.

The erfinaungagemäflen active ingredients can be used both in the pre and in the post-emergence procedures are used.

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 24 hours, watered with the preparation of the active compound. The amount of water per unit area is expediently kept constant. The concentration of active ingredient in the preparation does not matter, only the amount of active toffee applied per unit area is decisive. After three weeks, the degree of damage to the test plants is determined and denoted by the code numbers 0-5, which have the following meaning: O no effect 1 slight damage or growth retardation 2 significant damage or growth inhibition 3 heavy swaths and only poor development or only 50% accumulated 4 Plants partially destroyed after germination or only 25% emerged. 5 plants completely dead or not emerged. Active ingredients, expenditure and results are shown in the table below Active ingredient Application rate Echino- Cheno- Sina- Stella- Galin- Matri- kg / ha chloa podium pis ria soga caria CH3 CN 10 5 5 5 5 5 5 CH3-C - C = N-NH-CO-NH-CH3 5 5 5 5 5 5 5 CH3 2.5 5 5 5 5 5 5 Example B Post-emergence test Solvent: 5 parts by weight of acetone Emulsifier: 1 part by weight of alkylaryl polyglycule ether To produce an appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed with the stated amount of solvent, the stated amount of emulsifier is added and the concentrate is then diluted with water to the desired concentration .

Test plants which have a Height of 5-15 cm have such that the amounts of active ingredient given in the table per Area unit are applied.

The amount of water used depends on the concentration of the spray liquid between 1000 and 2000 1 / pa. After three weeks, the degree of damage to the plants and marked with the code numbers 0-5, which have the following meaning: 0 no effect 1 individual light burn marks 2 significant leaf damage 3 individual leaves and stem parts partly

dead 4 plant partially destroyed 5 plant totally dead Active ingredients, application rates and results are shown in the following table: Table of post-emergence test Active ingredient Application rate Echino- Cheno- Sina- Stella- Dau- Baum- kg / ha chloa podium pis ria cus wool CH3 CN 4 5 5 5 5 5 2 CH3-C - C = N-NH-CO-NH-CH3 2 5 5 5 5 5 2 CH3 1 4 5 5 5 5 1 Preparation examples Example 1 a) 37.2 g (0.2 mol) of 2-phenylimino-3,3-dimethylbutyronitrile and 27.8 g (0.2 mol) of 4,4-dimethylsemicarbazide hydrochloride are refluxed in 200 ml of ethanol for 1 hour.

The solution is concentrated in a rotary evaporator, taken up in methylene chloride and with Water shaken out. After drying the methylene chloride solution, the solvent becomes removed in vacuo and the residue is distilled.

28.1 g (72% of theory) of pivaloyl cyanide-4,4-dimethylsemicarbazone become obtained at Kp, 0.1 1080C. The rapidly solidifying product has a melting point from 75 - 780C.

C9H1 6N40 (molecular weight 196.25) Calc .: C: 55.08 H: 8.22 N: 28.55 Found: C: 55.6 H: 8.0 N: 28.4 The 2- Phenylimino-3,3-dimethylbutyronitrile can be prepared as follows: b) 980 g (5 mol) of N-phenylpivalimidoyl chloride, 477 g (S, 3 mol) of copper (I) cyanide and 20 g (0.25 mol) of pyridine are heated under reflux in 3 liters of methylene chloride for 12 hours. The solution is filtered and distilled. 847 g (91%) of 2-phenylimino-3,3-dimethyl-butyronitrile are obtained at a boiling point of 82.degree. The product solidifies at room temperature (melting point 48 ° -500 ° C.).

Example 2 830 g (5 mol) of 2-tert-butylimino-3,3-dimethylbutyronitrile and 625 g (5 mol) of 4-methylsemicarbazide hydrochloride are heated to 800 ° C. in 2 liters of ethanol for 3 hours. 809 g (89%) of pivaloyl cyanide-4-methylsemicarbazone with a melting point of 1440 ° C. are precipitated from the solution with 4 a of water.

C8H14N40 (molecular weight 182.23) Calc .: C: 52.73 H: 7.74 N: 30.75 Found: C: 52.8 H: 7.8 N: 30.8 The same result is obtained if instead of the 4-methylsemicarbazide hydrochloride the free base 4-methylsemicarbazide and the equimolar Amount of hydrogen chloride can be used as a gas.

In a manner analogous to the compounds of Preparation Examples 1 and 2, the following substances can be prepared: Table le Example structural formula melting point No. (in c) CH3 CN 3 CH3-C -C / 144 CH3 N-NH-CO-NH2 CH,, CN 3 CHH3 s 3 CCONH (CH2) 3 CH3 49-50 C1H3 / CN CH3 5 CH3 - C '3 5 CH, -C 94N ~ NH ~ C ° -NH-8 ~ CH3 127-128 3 CH3 CN 6 CH3- ¢ - G / 145-146 CH3 N-NH-CO-NH-C6H5 9H3 / CN 7 CH3-- <+ N-NH-CO-NH- (CH2) 16-CH3 81 3 e 195-197 8 rH3-Ç - C / -NH-CO-NH-C Table (continued) Example structural formula melting point No. (in Oc) CH CN 9 CH | 3 C / 68-69 C1H CNNCONHCH3 68-69 3. H3 CH 3 10 CH? -C- CN-NH-c-NH, 4 5 CH CN 11 CHJ-CN-NH- "- NH-CH, CH3-Ç CH3 N-NH-ff-NH-CH3 110 5 C1H3 CN 12 CH3-Ç - C 117-118 N-Ni-T} 1-C2H5 CH3 5 13 C1H3 / CN 75 CH3-CH2- - N-NH-CO-NH-CH, CH3 3 14 CH3 N HC \ -NH- 180-182 CH3 CO-NU-CH3 Table (continued) i: i »Lcl- structural formula Schme lzpurtkt No. (in oC) CN 15 CH3 CH2 CH2 C (218-219 N-NH-CO-NH-CH3 cFr 16 D; 1; CN 95-97 S N-NH-CO-NH-CH3 3 CN 17 g to -NH-CO-NH-CH3 106-187 CH2 CN 18 X Cc / 139-141 CH3 / N-NH-CO-NH-CH3 o2N »¼ \ CNCNNHCoNMCM3 228 (decomp.) 2 N-NH-CO-NH-CH3

Claims (10)

Claims 1) Process for the preparation of d-cyano-hydrazones, characterized in that oc-imino-nitrile6 of the general formula in which R stands for alkyl, alkenyl, alkenyl each with 2 to 12 carbon atoms, furthermore for haloalkyl, cyanoalkyl, nitroalkyl, hydroxyalkyl each with 1 to 8 carbon atoms, also for optionally substituted mono-, bi- or polycyclic alkyl, aralkyl or an optionally substituted heterocyclic radical and 4 R stands for the same radicals as R and also for aryl, with hydrazine derivatives of the general formula in which R1 stands for hydrogen or alkyl, R2 and R3 can be identical or different and stand for hydrogen, alkyl or optionally substituted aryl and R2 additionally stands for one through substituted alkyl radical and <<X is oxygen or sulfur, in the presence of an inert organic solvent and in the presence of an acid at temperatures between 0 ° C and 150 ° C. 2) Method according to claim 1, characterized in that the Implementation at temperatures between 20 0C and 1000C carried out. 3) Method according to claim 1, characterized in that the acid required for implementation in combination with a hydrazine derivative of the formula (III) used as its hydrazonium salt. 4) Method according to claim 1, characterized in that one is on 1 mol of starting compound of the formula (II) 0.5 to 2 mol of a hydrazine derivative of the formula (III) and - based on the hydrazine derivative - an equimolar amount of acid begins. 5) Method according to claim 1, characterized in that the Implementation of the reaction in an inert polar organic solvent. 6) d-cyano hydrazones of the formula in which R, R1, R2, R3 and X have the meaning given in claim 1. 7) Herbicidal agents, characterized by a content of «-Cyanohydrazonen according to claim 6. 8) method of controlling unwanted plant growth, thereby characterized in that one α-cyanohydrazones according to claim 6 to the undesired Plants or their habitat can act. 9) Use of i-cyano hydrazones according to claim 6 for combating of unwanted plant growth. 10) Process for the preparation of herbicidal agents, characterized in that that one d-cyanohydrazones according to claim 6 with extenders and / or surface-active Means mixed up.