IL45030A - Plant growth regulating compositions containing dithiane derivatives - Google Patents

Description

45030/2 o»n»s n'-in mo i1? n'Toan 7K»n'T nn m o^'son Plant growth regulating compositions containing dithiane derivatives f - The present invention relates to the use as plant-growt"^ regulators of certain 1 ,4-dithiane derivatives.

It has already "been disclosed that certain 2-halogeno-ethy1-trialky1-ammonium salts, especially (2-chlDroethyl)-trimethylammonium chloride,' display plant-growth-regulating properties (see U.S.Patent Specification 3» 156, 554). However, the action of these compounds is not always satisfactory, especially if low amounts and low concentrations are used.

It has been found that the 1 j4-dithiane derivatives of the general formula in vrhich R is straight or branched alkyl with 1 to 4 carbon atoms (which may be substituted by hydroxyl, methoxy, meth lcarbonyl, alkoxycarbonyl with 1 to 4 carbon atoms in the alkoxy moiety or halogen), alkenyl with 2 to 4 carbon atoms, alkynyl with 2 to 4 carbon atoms, cycloalkyl with 3 to 12 carbon atoms or benzyl optionally substituted by halogen, Z is hydrogen, chlorine or bromine, n is 0, 1 or 2 and Pis halide, tetrafluoroborate or alkylsulphate with 1 or 2 carbon atoms in the alkyl moiety, display strong plant-growth-regulating properties.

The present invention thus provides a plant-growth- regulatihg composition containing as active ingredient a compound of the formula (I) above in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

The present invention also provides a method of regulating the growth of plants, which comprises applying to the plants or a plant habitat a compound of the formula (I) above alone or in the form of a composition containing as active ingredient a compound of the formula (I) above in admixture with a diluent or carrier.

Surprisingly, the 1 ,4-dithiane derivatives according to the invention .display a substantially greater plant-growth-regulating action than the known compound (2-chloroethyl)-trimethyl-ammonium chloride, which ITS chemically the nearest active compound of the same type of action. The present invention thus represents a valuable enrichment of the art.

The following may be mentioned as examples of the active compounds of the formula (I) which can be used according to the invention: 1-methylsulphonia-4-thiacyelohexane metho-sulphate, 1 -ethylsulphonia-4-thiacyclohexane ethosulphate , 1 -propylsulphonia-4-thiacyclohexane bromide, 1 -benzylsulphonia-4-thiacyclohexane chloride, 1 -methylsulphonia-3-chloro-4-thia-cyclohexane methosulphate, 1 -methylsulphonia-4-thiacyclo- hexane-4-S-oxide methosulphate , 1 -methylsulphonia-4-thia-cyclohexane-4-S-dioxide methosulphate , 1 -cyclopentylsulphonia-4-thiacyclohexane iodide, 1 -ethylsulphonia-4-thiacyclohexane tetrafluoborate, 1 -( β-hydroxyethyl)-sulphonia-4-thiacyclo-hexane chloride, 1-(p-chloroethyl)-sulphonia-4-thiacyclo-hexane chloride, 1 -vinylsulphonia-4-thiacyclohexane chloride, 1 -allylsulphonia-4-thiacyclohexane chloride , 1 -propargyl-sulphonia-4-thiacyclohexane bromide and 1-(2' ,4-dichloro-benzyl)-sulphonia-4-thiacyclohexane chloride.

A number of the compounds which can be used according to the invention are known (see Berichte JL9_, 696-702 (1886); Berichte 67., 1142-1144 (1954); and J.Org.Ghem.H., 704-718 (1946)). Their use for regulating plant growth has hitherto not yet been described.

Some of the compounds accordirig to the invention are new and can be prepared in a simple manner in accordance with known processes. They are obtained, for example, when (a) 1,4-dithiane of the formula V_ (ID is reacted with a compound of the general formula R' - X (III), in which R' has the same meaning as R in formula I or is the trieth loxonium ion, and X is halogen, alkylsulphate or tetrafluoborate, between 0°C and 130°C or when (b) a dithiane salt obtainable according to process (a), of the general formula in which B. has the above-mentioned meaning, and Y ® represents halide, alkylsulphate or tetrafluo- borate, is reaoted either with an equimolar amount or with an excess of an oxidising agent, such as 30$ strength hydrogen peroxide solution, optionally in the presence of a solvent, for example glacial acetic acid, at temperatures between 0°C and 40°C, or when (c) a dithiane derivative, obtainable according to process (b), of the general formula in which R and Y ® have the above-mentioned meanings, is reacted with a halogenating agent, such as thionyl chloride, optionally in the presence of a solvent, for example chloroform, at temperatures between 0°C and 130°C.

The compounds of the formula (III) required as starting materials in the case of process (a) are known. The follow chloride, benzyl chloride, 4-chlorobenzyl chloride, 2,4-di-chlorobenzyl chloride, chloroacetone , chloroacetic acid and its esters, chloromethyl ether, chloromethylnaphthalene , dimethyl sulphate, diethyl sulphate and triethyloxonium tetrafluoborate.

Solvents used in carrying out the process (a) are preferably lower alcohols, for example methanol, chlorinated hydrocarbons, such as methylene chloride and chloroform, and also dimethylformamide , acetonitrile , acetone, dioxane or water.

In the preparation of the compounds by process (a), the reaction products are either obtained directly in a crystalline form after completion of the reaction or can, after completion of the reaction, be separated out in an oily state by addition of a solvent in which they are insoluble. The crystalline products are isolated, after prior concentration of the reaction mixture, by simple filtration. An additional purification can be achieved by reprecipitation. If the reaction products are obtained as oils, they are isolated by first separating the phases and then purifying the oil by treatment with active charcoal in aqueous or alcoholic solution.

In the compounds which can be prepared according to process (a) it is possible, if represents chloride, bromide or iodide, to exchange the anion by reaction with silver salts.

In the reaction according to process (b), working up is effected by concentrating the reaction mixture under reduced pressure. The reaction products are hereupon obtained as crystalline solids.

In the preparation by process (c) of the compounds to be used according to the invention, the reaction products are into the crystalline state by subsequent digestion with a polar solvent, for example acetone, and are obtained in the pure form by filtration.

The active compounds used according to the invention affect the physiological metabolism of plant growth and can therefore be used as plant-growth regulators.

The diverse effects of the active compounds depend essentially on the point in time at which they are used, relative to the stage of development of the seed or of the plant, and on the concentrations used.

Plant-growth regulators are used for various purposes which are related to the stage of development of the plant.

The growth of the plants can be greatly inhibited by means of the compounds according to the invention. Such inhibition of vegetative growth plays an important role in cereals since this can reduce or completely prevent falling-over. At the same time, the compounds according to the invention achieve a strengthening of the stalk.

In the ease of many crop plants, inhibition of the vegetative growth permits denser planting of the crop so that an increased yield relative to soil area can be achieved. A further mechanism of increasing the yield by means of growth inhibitors is based on the fact that the nutrients benefit blossoming and fruiting to an increased extent whilst vegetative growth is restricted.

However, a promotion of vegetative growth can also be achieved with the compounds to be used according to the invention. This is of great value where it is the vegetative parts of the plants which are harvested. However, promotion promotion of generative growth so that, for example, more fruit or larger fruit is formed.

Further, the active compounds can be used according to the invention to accelerate or retard the ripening of fruit and to improve the colour of fruit. It is also possible to concentrate the ripening of the fruit within a shorter time. The desired effects can be achieved by varying the concentrations of the active compounds employed and by applying them at different times during the development of the plant.

The active compounds to be used according to the present invention can be converted into the usual formulations, such as solutions, emulsions, suspensions, powders, pastes and granulates. These may be produced in known manner, for example by mixing the active compounds with extenders, that is, liquid or solid or liquefied gaseous diluents or carriers, optionally with the use of surface-active agents, that is, emulsifying agents and/or dispersing agents and/or foam-forming agents. In the case of the use of water as an extender, organic solvents can, for example, also be used as auxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatic hydrocarbons, such as xylenes, toluene, benzene or alkyl naphthalenes, chlorinated aromatic or aliphatic hydrocarbons, such as chlorobenzenes , chloroethylenes or methylene chloride, aliphati'c hydrocarbons, such as cyclohexane or paraffins, for example mineral oil fractions, alcohols, such as butanol or glycol as well as their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl iso-butyl ketone or cyclohexanone, or strongly polar solvents, Γ-·> By liquefied gaseous diluents or carriers are meant liquids which would be gaseous at normal temperatures and pressures, for example aerosol propellants, such as halo- genated hydrocarbons, for example freon. 5 As solid diluents or carriers, there are preferably used ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, or ground synthetic minerals, such as highly-dispersed silicic aeid, alumina or silicates. 10 Preferred examples of emulsifying and foam-forming agents include non-ionic and anionic emulsifiers, such as polyoxy- ethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example alkylarylpolyglycol ethers, alkyl sulphonates, alkyl sulphates and aryl sulphonates as well -jcj as albumin hydrolyzation products; and preferred examples of dispersing agents include lignin sulphite waste liquors and methyl cellulose.

The active compounds according to the invention can be present in the formulations as a mixture with other active 20 compounds.

The formulations in general contain from 0.1 to 95 per cent by weight of active compound, preferably from 0.5 to 90 per cent.

The active compounds can be used as such, as their 25 formulations or as the application forms prepared therefrom, such as ready-to-use solutions, emulsions, foams, suspensions, powders, pastes and granules. They are used in the customary manner, for example by watering, spraying, atomising, scattering, dusting and the like. formulations can be varied within a fairly wide range. In general, concentrations of from 0.0005 to 2$, preferably from 0.01 to 0. $» by weight are used.

Furthermore , 0.1 to 100 kg, preferably 1 to 10 kg, of active compound are, in general, used per hectare of soil area.

The preferred period of time within which the growth regulators are used depends on the climatic and vegetative circumstances.

The present invention further provides plants the growth of which has been regulated by their being grown in areas in which immediately prior to and/or during the time of the growing a compound of the formula (I) above was applied alone or in admixture with a diluent or carrier. It will be seen that the usual methods of providing a harvested crop may be improved by the present invention.

In the test Examples which follow ,the activity as growth regulators of the compounds to be used according to the invention is illustrated, without excluding the possibility of further uses as growth regulators.

Example A Inhibition of growth/barley Solvent: 10 parts by weight of methanol Emulsifier: 2 parts by weight of polyethylene sorbitan monolaurate To prepare a suitable preparation of active compound, 1 part by weight of active compound was mixed with the stated amount of solvent and emulsifier and the mixture was made up to the desired concentration with water. the preparation of active compound until dripping wet.

After 4 weeks, the additional growth was measured and the inhibition of growth in of the additional growth of the control plants was calculated. 100$ means that growth had stopped and 0$ denotes a growth corresponding to that of the untreated plants.

The active compounds, active-compound concentrations and results can be seen from Table A which follows. a b l e A > Inhibition o growth/barley Actire compound Concentratio in ppm 0 Water (control) C1-CH2-CH2-N(CH,)3 θ 1 ,000 500 (6) G>-c¾ CI Θ 1 ,000 500 (3) 0 -:o Φ CH3 CH3S04 Θ 500 Example Β Inhibition of growth/wheat Solvent: 10 parts by weight of methanol Emulsifier: 2 parts by weight of polyethylene sorbitan monolaurate To prepare a suitable preparation of active compound, 1 part by weight of active compound was mixed with the stated amount of solvent and emulsifier and the mixture was made up to the desired concentration with water* Young wheat plants, 25-30 cm high, were sprayed with the preparation of active compound until dripping wet.

After 4 weeks, the additional growth was measured and the inhibition of growth in of the additional growth of the control plants was calculated. 100$ means that growth had stopped and 0$ denotes a growth corresponding to that of the untreated plants0 The active compounds, active-compound concentrations and results can be seen from Table B which follows: T l e B Inhibition of growth/wheat Active compound Concentration ____ _________--—----^^--««.^«^ in ppm ; Water ( control ) - C1-CH2-CH2-.N(CH3)3 CI θ 1,000 500 (known) (1 ) ^- LcH, CH,S0^ Θ 1 ,000 500 (5) 0H_S04 θ 500 Example C Promotion of growth/beans Solvent: 10 parts by weight of methanol Emulsifier: 2 parts by weight of polyethylene sorbitan monolaurate To prepare a suitable preparation of active compound, 1 part by weight of active compound was mixed with the stated amount of- solvent and emulsifier and the mixture was made up to the desired concentration with water.

Young bean plants about 10 cm high were sprayed with the preparations of active compound until dripping wet.

After 14 days, the additional growth of the treated plants was determined in comparison with the untreated control plants.

The active compounds, active-compound concentrations and results can be seen from Table C which follows: T l e C Promotion of growth/beans Water (control) (3) 0=2^^-01^ CH5S04 θ 500 The preparation of the active compounds to be used according to this invention is illustrated in the following Examples.

Example 1 1,200 g (10 moles) of 1 ,4-dithiane and 1,260 g (10 moles) of dimethyl sulphate were dissolved in 5 litres of methanol and the mixture was heated for 10 hours under reflux. It was then allowed to cool to room temperature and the 1 ,4-dithiane salt which had precipitated was filtered off. The solution which remained was concentrated under reduced pressure. Hereupon, further crystals separated out, which were also isolated by filtration. 2,115 g (86* of theory) of 1-methylsulphonia-4-thiacyclohexane methosulphate of melting point 142°C were obtained.

Analysis Calculated: for C6H1404S3 29.3* 0 5.2* H 38.9* S Pound: 29.8* C 5.2* H 39.8* S Example 2 24 g (0.2 mole) of dithiane and 34 g (0.22 mole) of diethyl sulphate in 150 ml of dimethylformamide were heated to 120°C for 12 hours. After cooling, 300 ml of ether were stirred into the reaction solution and the oil which hereupon separated out was isolated. For subsequent purification, was treated with active charcoal and filtered. On con-trating the filtrate under reduced pressure, 45 g (73* of theory) of 1-ethylsulphonia-4-thiacyclohexane ethosulphate dihydrate were left in the form of a viscous oil.

Analysis Calculated: for Cgi^ gO^.2H20 3 .0* C 7.1* H 31.0* S Pound: 31.1* C 6.7* H 30.1* S Example 34 g (1 mole) of hydrogen peroxide (in the form of a 30* strength aqueous solution) were added dropwise to a solution of 246 g (1 mole) of 1 -methylsulphonia-4-thia-cyclohexane methosulphate (see Example 1 ) at 20°C. The reaction solution was left to stand for several days at room temperature and the volatile constituents were then stripped off in vacuo. 262 g (100* of theory) of 1 -methylsulphonia-4-thiacyclohexane-4-S-oxide methosulphate were obtained in the form of a solid white mass of melting point 100°C (with decomposition).

Analysis Calculated : for CgH1 24.4* C 4.5* H Pound: 24.6* C 4.8* H Example 4 68 g (2 moles) of hydrogen peroxide (in the form of a solution of 246 g (1 mole) of -methylsulphonia-4-thiaeyclo-hexane methosulphate (see Example 1 ) at 20°C. The reaction solution was left to stand for several days at room temperature and the volatile constituents were then stripped off in vacuo. 278 g (100% of theory) of 1 -methylsulphonia-4-thiacyelohexane-4-S-dioxide methosulphate were obtained thereby in the form of a solid white mass of melting point 205°C (with decomposition).

Analysis Calculated: for 25.9% .0 5.0% H Found: 26.2% C 5.1% H Example 5 31 g (0.5 mole) of 1-methylsulphonia-4-thiacyclohexane-4-S-oxide methosulphate (see Example 3) were suspended in 500 ml of chloroform, and 71.4 g (0.6 mole) of thionyl chloride were added slowly at 20°C. The suspension was then warmed to the boil and heated under reflux until the evolution of gas had ceased. It was then allowed to cool to room temperature and the oil which had separated out was isolated, freed of adhering residual solvent and digested with acetone. The white crystals thereby obtained were filtered off. 62 g (45% of theory) of 1-me hylsulphonia-3-chloro-4-thiacyclohexane methosulphate of melting point 1 6°C were isolated.

Analysis Calculated: for CgH^ClO^ 34.4% S 2.5% CI

Claims (16)

450JO/3 CLAIMS: 4

1. A plant-growth-regulating composition containing as active ingredient a 1 ,4-dithiane derivative of the general formula in which R is a straight-chain or branched alkyl with.l to 4 carbon atoms (which may be substituted by hydroxyl, methoxy, methylcarbonyl, alkoxycarbonyl with 1 to 4 carbon atoms in the alkyl moiety or halogen), alkenyl with 2 to 4 carbon atoms, alkynyl with 2 to 4 carbon atoms, cycloalkyl with 3 to 12 carbon atoms or benzyl optionally substituted by halogen; Z is hydrogen, chlorine or bromine; n is 0, 1 or 2; and A® is halide, tetrafluoroborate or alkylsulphate , in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent

2. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent. 45030/2

3. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

4. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

5. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

6. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier 45030/2

7. A plant-growth-regulating composition containing as active ingredient the compound of the formula in admixture with a solid or liquefied gaseous diluent or carrier or in admixture with a liquid diluent or carrier containing a surface-active agent.

8. A composition according to any of claims 1 to 7 containing from 0. 1 to 959» of the active compound, by weight.

9. A composition according to claim 8 containing from 0.5 to 0$ of the active compound, by weight.

10. A method of regulating the growth of plants which comprises applying to the plants or a plant habitat a compound of the formula given in any of claims 1 to 7 alone or in the form of a composition containing as active ingredient a compound of the formula given in any of claims 1 to 7 in admixture with a diluent or carrier.

11. A method according to claim 10 in which a composition is used containing from 0.0005 to 2$ of the active compound, by weight.

12. A method according to claim 11, in which a composition is used containing from 0.01 to 0. 5$ of the active compound, by weight.

13. A method according to claim 10, 11 or 12, in which the active compound is applied to an area of agriculture in an amount of 0. 1 to 1 00 kg per hectare.

14. A method according to claim 1> in which the active compound is applied to an area of agriculture in an amount of 1 to 1 0 kg per hectare. 45030/2

15. A method according to any of claims 10 to 14, in which the active compound is one of those hereinbefore mentioned in any of Examples A to C.

16. Plants, the growth of which has been regulated by their being grown in areas in which immediately prior to and/or during the time of the growing a compound of the formula given in any of claims 1 to 7 was applied alone or in admixture with a diluent or carrier. PC:dn