DE2520315A1 - Phospholanium salt compsns. - as plant growth regulators for application to plants and seeds - Google Patents

Abstract

Plant growth regulating compsns. comprise as active component one or more phospholanium salts of formula (I) (where R1,R2 are opt substd. alkyl, alkenyl, alkynyl or cycloalkyl, or aralkyl opt. substd. in the aryl ring; R3 is halogen or alkyl; n is 0, 1 or 2; A- is a non-phytotoxic anion). Compsns. are used for treatment of plants and seeds at an application rate of 0.01-50 kg/ha pref. 0.05-10 kg/ha.

Description

Agent for regulating plant growth The present invention relates to the use of some known phospholanium salts as active ingredients to regulate plant growth.

It has already become known that certain 2-haloethyltrialkylammonium halides have plant growth-regulating properties (cf. US Pat. No. 3,156,544). For example, (2-chloroethyl5-trimethylammonium chloride can be used to influence plant growth, in particular to inhibit vegetative plant growth in cereals and other crops (cf. US Pat. Nos. 3,318,910, 3,280,136, 3,264,317 and 3 270 027). However, the action of this substance is not always entirely satisfactory, especially when low amounts and concentrations are used in which R stands for optionally substituted alkyl, alkenyl, alkyl, cycloalkyl or for optionally substituted aralkyl in m aryl part, for. Gc: optionally substituted alkyl, i kenyl, alkynyl, cycloalkyl or aralkyl optionally substituted in the aryl moiety, represents halogen or alkyl, n represents integers from 0 to 2 and represents one equivalent of an anion of a non-phytotoxic acid, strong have plant growth regulating properties.

The phospholanium salts according to the invention surprisingly show a considerably higher plant growth-regulating effect than that from the prior art Technology known (2-chloroethyl) -tri methylammonium chloride, which is recognized is an effective substance of the same type of action. The substances that can be used according to the invention thus represent a valuable addition to technology.

The phospholanium salts to be used according to the invention are through the formula (I) is clearly defined. In the formula (I), R1 preferably represents straight or branched chain alkyl of 1 to 4 carbon atoms, each of these alkyl radicals one or more, identical or different, of the following substituents can carry: hydroxy; Methoxy; Methylcarbonyl; Alkoxycarbonyl of 1 to 4 carbon atoms in the alkoxy group; Halogen, especially chlorine and bromine. Furthermore, R1 is preferably for alkenyl with 2 to 4 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, in particular, however, with 3 to 7 carbon atoms, and furthermore for optionally in the aryl part by halogen, such as chlorine, substituted aralkyl with 1 to 4 carbon atoms in the alkyl part and 6 to 10 carbon atoms in the aryl part. R2 is in the formula (I) preferably for straight-chain or branched alkyl having 1 to 4 carbon atoms, each of these alkyl radicals being one or more, the same or different from k & rm have the following substituents: hydroxy; Methoxy; Methylcarbonyl; Alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy group; Halogen, in particular Chlorine and bromine. Furthermore, R¹ preferably represents alkenyl having 2 to 4 carbon atoms, Alkynyl with 2 to 4 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, in particular, however, with 3 to 7 carbon atoms, and furthermore for optionally in the aryl part by halogen, such as chlorine, substituted aralkyl with 2 to 4 carbon atoms in the alkyl part and 6 to 10 carbon atoms in the aryl part. R3 is in the formula (I) preferably for chlorine, bromine and straight-chain or branched alkyl with 1 up to 4 carbon atoms. In the formula, n preferably stands for integers of 0 to 2. A e preferably represents halide, in particular chloride, bromide and Iodide, and also for tetrafluoroborate. In addition, A 6 preferably represents alkyl sulfate, especially for methyl sulfate or ethyl sulfate.

Examples of the active ingredients which can be used according to the invention are specifically mentioned: 1,1-dimethylphospholanium chloride 1,1-dimethylphospholanium methosulfate 1, 1-diethylphospholanium bromide, 1-methyl-1-ethylphospholanium bromide, 1-methyl-1-benzylphospholanium chloride 1-methyl-1- (2-hydroxyethyl) phospholanium chloride, 1-methyl-1- (2-chloroethyl) phospholanium chloride 1-methyl-1-ethoxycarbonylmethyl-phospholanium chloride 1,1,2-trimethylphospholanium chloride 1,1,3-trimethyl-phospholanium chloride 1,1-dimethyl-3,4-dichlorophospholanium chloride.

Some of the substances that can be used according to the invention are known (cf. J. Amer. Chem. Soc. 91: 4724-4729 (1969); Ber. 94: 113-117 (1961); Acta Chem. Scand. 19: 931-934 (1965); Tetrahedron Lett. 1971 2397-2400). Their use as plant growth regulators however is new.

Some of the substances that can be used according to the invention are new; you can however, they can be produced in a simple manner by known methods.

They are obtained, for example, when a) a phospholane of the formula in which R1, R3 and n have the meaning given above, with a compound of the formula R4 - X (III) in which R stands for optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, optionally substituted aralkyl in the aryl part or for triethyloxonium « Ion and X is halogen, alkyl sulfate or tetrafluoroborate, optionally reacted in the presence of a solvent at temperatures between COC and 130C, or when b) a phospholanium salt of the formula obtained by process a) in which Ra 3 and n have the meaning given above, R5 stands for alkyl substituted by a hydroxy group and y stands for halide, alkyl sulfate or tetrafluoroborate, optionally in the presence of a solvent, such as

Chloroform, and optionally in the presence of a catalyst such as dimethylformamide, with a halogenating agent such as thionyl chloride, at temperatures between 0 ° C and 130C, or when c) a phospholenium salt of the formula in which R1, R2 and ye have the meaning given above, optionally in the presence of a solvent, such as, for example

Chloroform, with a halogenating agent such as chlorine, at temperatures between 0 ° C and 1300C.

Those which can be used as starting materials when carrying out process a) Phospholanes of the formula (II) are known or can be obtained as described above Represent the procedure (cf.

J. Amer. Chem. Soc. 91: 4724-29 (1969)). As examples of phospholanes of the formula (II) are mentioned in detail: 1-methyl-phospholane 1-ethyl-phospholane 1,3-dimethyl-phospholane 1-n-hexyl-phospholane 1-cyclohexyl-phospholane Those which can still be used as starting materials when carrying out process a) Compounds of the formula (III) are also known. Examples are in detail named: methyl iodide, methyl chloride, ethyl bromide, propyl chloride, allyl chloride, propargyl chloride, Benzyl chloride, chloroacetone, chloroacetic acid or its esters, chloromethyl ether, Chloromethylnaphthalene, dimethyl sulfate, diethyl sulfate and triethyloxonium tetrafluoroborate.

A) may be preferred as the solvent when carrying out the process lower alcohols such as methanol, hydrocarbons such as toluene, and cyclohexane and furthermore, dimethylformamide, acetonitrile, acetone or water can be used.

When carrying out process a), 1 mol of a phospholane is used of the formula (II), preferably 1 mol of a starting compound of the formula (III). Exceeding or falling below the specified stoichiometric ratios is possible, but does not bring any significant improvement in yield.

In the preparation of the substances which can be used according to the invention according to the Process a) the reaction products fall either directly after the reaction crystalline or they can be removed by adding a solvent in which they are insoluble, deposit in an oily state. The crystalline products are isolated after possibly prior concentration of the reaction mixture by simple suction Additional purification is possible by reprecipitation. When the reaction products are obtained as oils, the isolation is carried out by first the Phas @@ then separates @@@ the oil by treating it with activated carbon in aqueous or alcoholic Solution cleans, B {J- Lst oilfii} lrullg of method b) sets one per mole of a 'rhciSpholaniumsalzes of the formula (IV) preferably 1.1 to 1.5 Equivalents of halogenating agent and a small amount of catalyst. Exceeding or falling below the stated stischiometric ratios is possible, but does not bring any significant improvement in yield.

The isolation of the reaction products takes place when working-after Process b) by customary methods. Appropriately, one proceeds in such a way that one the reaction mixture is concentrated under reduced pressure after the reaction has ended, the remaining residue is taken up in a suitable solvent and used for cleaning treated with activated charcoal and finally the solution obtained after filtration under reduced pressure.

Those which can be used as starting materials when carrying out process c) Phospholenium salts of the formula (V) are known or can be obtained as described above Representing methods (cf.

J. Chem. Soc. 1968, 929-931). As examples of phospholenium salts of the formula (V) may be mentioned in detail: 1,1-dimethyl-3-phospholenium chloride 1, 1-diethyl-3-phospholenium chloride.

When carrying out process c), 1 mol of phospholenium salt is used of formula (V) preferably 1 equivalent of a halogenating agent. An uber- or falling below the specified stoichiometric ratios is possible, however, does not bring any significant improvement in yield.

The isolation of the reaction products takes place when working after Process c) expediently by the fact that the reaction mixture after completion The reaction is concentrated and the crystals which separate out are filtered off. An additional Cleaning is possible by falling over. When the reaction products are in the form of oils are obtained, they can be digested with a polar solvent, e.g. Acetone, converted into the crystalline state and obtained pure after suction will.

The active ingredients which can be used according to the invention intervene in the metabolism of the plants and can therefore be used as growth regulators.

1 {for the mode of action of plant growth regulators applies after previous experience that an active ingredient has one or more different types Can have effects on plants.

The effects of the substances depend essentially on the time the application, based on the development stage of the seed or the plant as well as of the amounts of active ingredient applied to the plants or their environment and of the type of application. In any case, the crop plants should be growth regulators have a positive influence in the desired manner.

Substances that regulate the growth of plants can be used, for example, to inhibit of vegetative plant growth can be used. Such an inhibition of growth is of economic interest for grasses, among other things, because it is dampened of grass growth can e.g. the frequency of grass cuttings in ornamental gardens, parks and Sports facilities or roadsides are reduced. That is also important Inhibition of the growth of herbaceous and woody plants on roadsides and in near power lines or, more generally, in areas where a strong Vegetation is undesirable.

The use of growth regulators for inhibition is also important the increase in length in cereals, because shortening the stalk increases the risk the kinking ("storage") of the plants before harvest is reduced or completely eliminated. In addition, growth regulators can strengthen the stalk in cereals cause, which also counteracts the storage.

Inhibition of vegetative growth is possible in many cultivated plants a denser planting of the culture, so that an increased yield based on the soil area can be achieved.

A broader mechanism for increasing yields is based on growth inhibitors on the fact that the nutrients benefit to a greater extent the formation of flowers and addictions come while the vegetative wax-'um is restricted.

With growth regulators, a requirement of the vegetative growth. This is of great use when the vegetative Plant parts are harvested. However, vegetative growth can be promoted also lead at the same time to a promotion of generative growth, so that e.g.

more or larger fruits come to the training.

In some cases, yield gains can also be achieved through surgery in the vegetable metabolism can be achieved without any changes in the vegetative Make growth noticeable.

Growth regulators can also change the composition of the plants in order to bring about a better quality of the harvested products. For example, it is possible to determine the sugar content in sugar beet, sugar cane, Pineapples as well as citrus fruits increase or the protein content in soy or cereals to increase.

Under the influence of growth regulators it can lead to training parthenocarpic fruits come. The sex of the flowers can also be influenced will.

With growth regulators the production or the outflow can also be controlled positive influence of secondary plant substances. An example is stimulation called the latex flow in rubber trees.

During the growth of the plant can through the use of growth regulators also the lateral branching through a chemical breaking of the apical dominance be increased. There is interest in this, for example, when propagating plants from cuttings. However, it is also possible to inhibit the growth of the side shoots, z. B. around the formation of side shoots in tobacco plants after decapitation to prevent and thus promote leaf growth.

Under the influence of growth regulators, the leaf population of Plants are controlled so that a defoliation of the plants to a desired one Time is reached. Such defoliation is of interest to mechanical To facilitate harvesting, e.g. for wine or cotton, or to facilitate transpiration at a time when the plant is to be transplanted.

The premature fall of fruit can be prevented by using growth regulators impede. However, it is also possible to drop the fruit, for example in the case of fruit - to promote chemical thinning to a certain extent. Growth regulators can also be used to control crops at the time the harvest to reduce the force required to detach the fruit, so that mechanical or manual harvesting of the plants is possible Harvesting is facilitated.

Growth regulators can also be used to accelerate or also achieve a delay in the ripeness of the crop before or after the harvest. This is of particular advantage because it allows for an optimal adaptation bring about the needs of the market. Furthermore, growth regulators can be used in some cases improve the color of the fruit.

In addition, with the help of growth regulators, a temporal Concentration of maturity can be achieved. This creates the prerequisites for this created that e.g. with tobacco, tomatoes or coffee, a complete mechanical or manual harvesting can be carried out in just one operation.

By using growth regulators, the seeds or Bud rest of the plants, i.e. the endogenous annual rhythm, can be influenced, see above that the plants, such as pineapples or ornamental plants in nurseries, at a time germinate, sprout or bloom when they are normally unwilling to do so demonstrate.

With growth regulators can also be achieved that the budding of buds or the germination of seeds is delayed, e.g.

to damage from late frosts in areas at risk of frost to avoid.

Growth regulators can also cause halophilia in crops produce. This creates the conditions for a cultivation can be carried out by plants on salty soils.

With growth regulators, frost and drought resistance can also be achieved induced in plants.

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 and / or foam-generating agents Means. In the case of the use of water as an extender, z. B. also 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, Chlorethylene or Methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, e.g. B. 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 dimethylformamide and dimethyl sulfoxide, as well as water; with released gaseous extenders or carriers such fluids in common, which at normal temperature and under normal pressure are gaseous, e.g. B. aerosol propellants such as dichlorodifluoromethane or trichlorofluoromethane; as solid carrier materials: natural rock flour, such as kaolins, clays, talc, Chalk, quartz, attapulgite, montmorillonite, or diatomaceous earth, and synthetic Ground rock, such as finely divided silica, aluminum oxide and silicates; as an emulsifier: nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers r, e.g. alkylaryl polyglycol ethers, alkyl sulfonates, alkyl sulfates and tirJz1su] forms; as a dispersant: e.g. Lignin, sulphite waste liquors and methyl cellulose.

Di: Active ingredients according to the invention can be mixed in the formulations with other known active ingredients, such as fungicides, insecticides, acaricides and herbicide, as well as mixed with fertilizers.

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 use forms prepared therefrom, such as ready-to-use solutions, emulsifiable Concentrates, emulsions, foams, suspensions, wettable powders, pastes, soluble powders, Dusts and granules. The application happens in the usual Way, e.g. by pouring, spraying, atomizing, scattering, dusting, foaming, Gassing, etc. It is also possible the active ingredients according to the ultra-low-volume process to apply plants or parts of plants with the active compound preparation or the To coat the active ingredient itself or the active ingredient preparation or the active ingredient inject yourself into the ground. It can also treat the seeds of the plants will.

The active ingredient concentrations can be varied over a wide range will. In general, concentrations of from 0.00005 to 2% are used, preferably from 0.0001 to 0.5%. Furthermore, 0.01 is generally used per hectare of floor area up to 50 kg, preferably 0.05 to 10 kg, of active ingredient.

For the application time, the use of the growth regulators applies is carried out in a preferred period, the exact delimitation of which is based on aligns with the climatic and vegetative conditions.

In the following examples, the activity of the invention Substances presented as growth regulators without the possibility of further application to exclude as growth regulators.

Example A Growth inhibition / wheat solvent: 10 parts by weight of methanol Emulsifier: 2 parts by weight of polyethylene sorbitan monolaurate Appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed with the specified amounts of solvent and emulsifier and fill up with water to the desired Concentration on.

Young wheat plants are treated with the preparation of the active compound in the 2-leaf stage sprayed dripping wet. After the untreated control plants have reached a height of have reached about 60 cm, the increment is measured for all plants and the Growth inhibition calculated in% of the growth of the control plants. It means 100 % the stagnation of the growth and 0% a growth corresponding to that of the untreated Control plants.

Active ingredients, active ingredient concentrations and results are shown in Table A below: Table A Growth inhibition / wheat Wilkstoff concentration inhibits growth in% in% of the control Water O (Control) Cl-CH2-CH2-N (CH) Cl e 0.05 40 3.3 (known) C9 / CHf 0.05 40 CH3 ()) CH.3 @ '~ 3 cd S049 40 CH3 At the end of the experiment, the leaf color and the stalk thickness are also assessed on all plants.

It turns out that those treated with the active ingredients according to the invention Plants in contrast to the untreated control plants and to those with the comparison substance treated plants have a strong dark green leaf color. Continue to own the plants treated with the active compounds according to the invention are significantly thicker Culms than the untreated control plants and those with the comparison substance treated plants. Precisely this observed reinforcement of the stalks is to prevent of storage is crucial.

Example B Growth inhibition / beans Solvent: 10 parts by weight of methanol Emulsifier: 2 parts by weight of polyethylene sorbitan monolaurate Appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed with the specified amounts of solvent and emulsifier and fill up with water to the desired Concentration on.

Young bean plants are at the stage at which the primary leaves are fully unfolded, sprayed to runoff with the active compound preparations. After 2 weeks the growth is measured and the growth inhibition in 96 of the growth of the control plants calculated. 100% means the growth has come to a standstill and 0 96 means growth corresponding to that of the untreated control plants.

Active ingredients, active ingredient concentrations and results are shown in Table B below: Table B Growth inhibition / beans Active ingredient concentration W * ìCi '\ tumshemmung in in%% animal control Water - O (Control) C10 H3 0.05 20 (5) 3 X9 / 3 C10 at 0.05 40 \ CH t (6 example 1 33.4 g (0.2 mol) of ethyl bromoacetate are added to a solution of 20.4 g (0.2 mol) of 1-methylphospholane in 200 ml of toluene at room temperature while stirring. The reaction mixture is then left to stand for a few hours at room temperature and the precipitate which has separated out is then filtered off with suction. In this way, 1-methyl-1-ethoxycarbonylmethyl-phospholanium bromide is obtained in the form of crystals which decompose on heating at 1220C.

Analysis: (CgH1802PBr) Calculated: 29.8% Br Found: 29.1% Br Das Infrared spectrum shows a strong carbonyl band.

Example 2 A solution of 20.4 g (0.2 mol) of 1-methylphospholane in 200 ml of toluene is mixed with 16.1 g (0.2 mol) of 2-chloroethanol at room temperature while stirring. The reaction mixture is then allowed to stand for a few hours at room temperature and the precipitate which has separated out is then filtered off with suction. In this way, 1-methyl-1 - (2-hydroxyethyl) phospholanium chloride is obtained in the form of nygroscopic crystals with a melting point of 78-80.degree.

Analysis: (C7H160PC1) Calculated: 46.1% C; 8.9% H; Found 19.5% Cl : 45.1% C; 8.8% H; 18.8% Cl.

Example 3 In a solution of 36.5 g (0.2 mol) of l-methyl-l- (2-hydroxyethyl) phospholanium chloride in 200 ml of chloroform and a small amount of dimethylformamide, 27.3 g (0 , 23 mol) thionyl chloride was added dropwise. After the evolution of hydrogen chloride has subsided, the reaction mixture is concentrated under reduced pressure and the residue that remains is taken up in water. The resulting solution is mixed with activated charcoal and then filtered. Concentration of the filtrate under reduced pressure gives 1-methyl-1 - (2-chloroethyl) phospholanium chloride in the form of a crystal hydrate from which water is split off when heated at 700C. The remaining substance melts above 250 ° C.

Analysis: (C7H15PC12) Calculated: 35.5, Cl Found: 36.0% Cl Example 4 44.3 g (0.2 mol) of 1,1-dimethyl-3-phospholenium chloride are suspended in 250 ml of chloroform and reacted at 200 ° C. with 14.2 g (0.2 mol) of chlorine. When the reaction has ended, the reaction mixture is concentrated under reduced pressure.

In this way, 3,4-dichloro-1T1-dimethylphospholanium chloride is obtained in the form of colorless crystals with a melting point of 90 to 1000C (decomposition).

Example 5 The known 1,1-dimethyl-phospholanium bromide (see. J. Amer.

Chem. Soc. 91, 4724 (1969)) is with the help of a with chloride ions loaded anion exchanger converted into the corresponding chloride. The eluted aqueous solution is evaporated under reduced pressure. This is what you get Monohydrate of 1,1-dimethylphospholanium chloride in the form of a viscous oil.

Analysis: (C6H1 4ClP-H20) Calculated: 20.6% Cl Found: 20.0, Cl Example 6 A solution of 20.4 g (0.2 mol) of 1-methylphospholane in 200 ml of toluene is admixed with 25.3 g (0.2 mol) of benzyl chloride at room temperature while stirring. The reaction mixture is then left to stand for a few hours at room temperature and the precipitate which has separated out is then filtered off with suction. In this way, 1-methyl-1-benzyl-phospholanium chloride is obtained in the form of crystals which decompose on heating.

Analysis: (C12H18PC1) Calculated: 63.0% C; 7.9% H; 13.0% P Found: 63.2% C; 8.0% H; 13.2% P EXAMPLE 7 A solution of 102 g (1 mol) of 1-methylphospholane in 1 l of toluene is mixed with 126 g (1 mol) of dimethyl sulfate at room temperature while stirring. After the reaction mixture has stood for 10 hours, the precipitate which has separated out is filtered off with suction. In this way, 1,1-dimethylphospholanium methosulfate is obtained in the form of crystals which have a melting point of 1260.degree.

Analysis: Calculated: 36.9% C; 7.4% H; 13.6% P; 14.1% S Found: 36.6% C; 7.2% H; 12.9% P; 14.6% S.

Claims (5)

Claims 1. Agent for regulating plant growth, characterized by a content of at least one phospholanium salt of the formula in which R1 represents optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl or optionally substituted aralkyl in the aryl part, R2 represents optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl or optionally substituted aralkyl in the aryl part, R3 represents halogen or alkyl, n stands for integers from 0 to 2 and A 0 stands for one equivalent of an anion of a non-phytotoxic acid. 2. Means for inhibiting growth and for influencing the habitus of higher plants, characterized in that there is at least one phospholanium salt according to claim 1 contains. 3. A method for regulating plant growth, characterized in that that one phospholanium salts according to claim 1 on the plants or their habitat can act. 4. Use of phospholanium salts according to claim 1 for regulation of plant growth. 5. Process for the production of plant growth regulators, characterized in that phospholanium salts according to Claim 1 are mixed with extenders and / or surfactants mixed together.