SE407505B - USE OF CERTAIN DICYCLOHEXYLPHENYLTENE COMPOUNDS FOR CONTROLING MUSHROOMS AND MILLS - Google Patents

Description

'_731s22ç-s 2 7 selective, when applied to the plants, in that when the organism attacking the plant is to be controlled, killed or often the plant itself is severely damaged. Chemical Abstraots, vol. 72, 1970, describes the synthesis of various non-aerobic compounds, but does not disclose the use of these compounds for controlling fungi and mites. U.S. Pat. No. 3,702,360 discloses, for example, triphenyltin hydroxide which is intended for use against parasitic insects on pets.

The action of diocylohexylphenyltin hydroxide used in the present invention and triphenyltin hydroxide of U.S. Pat. No. 3,702,560 as fungicides have been determined and compared. The compounds are used in the control of bean powdery mildew.

The amount of powdery mildew present on the plants 7 days after treatment with a dispersion containing 20 ppm of each compound was observed on two leaves of each of three plants used in the test of the two compounds. The three plants, which were sprayed with dicyclohexylphenyltin hydroxide, showed an average rating of 8.5 (out of 10 as the highest possible). The three plants, which were sprayed with a dispersion of triphenyltin hydroxide, showed an average rating of 5.0.

Dicyclohexylphenyltin hydroxide was significantly more effective at lower concentrations than triphenyltin hydroxide in controlling At the concentrations of 250, 50 and 12.5 ppm were grade- Mot apple cider. the rings for dicyclohexylphenyltin hydroxide 9.9, 9.9 and 9.1, respectively.

The corresponding grades for triphenyltin hydroxide were 10.0, 9, H and 6.0.

The acute oral toxicity (LD50) of triphenyltin hydroxide administered to male rats (albino dishes) was reported to be 171 mg / kg body weight (M J Marks, Jr., Ph D Thesis, Duquesne University, 1971).

Similarly, toxicity studies of dicyclohexylphenyltin hydroxide were found to be 326.7 mg / kg body weight, indicating that this compound is almost half as toxic as triphenyltin hydroxide.

The present dicyclohexylphenyltin compounds, wherein X represents bromine, can be advantageously prepared by reacting a suitable diocylohexyldiphenyltin compound with bromine. It is a well-known type of reaction and has been described in the chemical literature for the preparation of a number of other triorganic tin derivatives.

Tetraorganotin compound, which can be used to prepare the corresponding triorganotin bromide, has the general formula: Advantageously, the tetraorganotin compound 1 is dissolved in an appropriate solvent or a mixture of solvents, which is gradually added with a solution of bromine. Suitable solvents include alcohols having between 1 and 8 carbon atoms and liquid halogenated hydrocarbons; A compound which is liquid at the reaction temperature and does not react with the bromine or tetraorganotin compound can be used as a solvent for the tetraorganotin compound. The temperature of the reaction mixture is kept below room temperature, preferably between -30 and 25 ° C during the addition of bromine to control the degree of hydrocarbon cleavage and to maximize the yield of the desired product. The reaction is assumed to proceed according to the following scheme: The resulting dicyclohexylphenyltin bromide can be easily converted to other derivatives, such as the present hydroxide. This is done by reacting the compound with an aqueous solution of alkali metal hydroxide.

The reaction conditions, such as preferred solvents, temperatures and reaction times in the preparation of the derivatives, which are summarized in the previous table, are known and therefore do not require a detailed description. A detailed treatment of this substance can be found in an article by R K Ingham et al, which article can be found in Chemical Reviews, October 1960, p H59-539.

Dicyclohexylphenyltin compounds are effective in controlling undesirable mites and fungi without appreciably damaging the plants to which the compounds are applied. A single application of these compounds can provide permanent or extensive control of fungi and mites for a considerable period of time, and the duration of this period depends to some extent on mechanical and biological factors, including weather, but sometimes as long as several months. . w ...

... L -___ »i-: wU-.sal fl v-l, ..._.....». V .._....., -> H0 "can also be incorporated for the control of mites. , 7z1s22e + s U In the preparation of compositions for application to plants, the tin compound is often supplemented or modified by combination with one or more commonly used pesticidal additives as well as organic solvents, water or other liquid carriers, surfactant dispersants or finely divided solid carriers. the concentration of the compound in these compositions, the compositions may be used either directly for the control of the organism or in the form of concentrates, which are later diluted with one or more additional inert carriers for the preparation of the final treatment compositions. concentrate, the dicyclohexylphenyltin compound may be present in a concentration of from about 5% to about 98% by weight Attractive agents and the like Other biologically active agents which are chemically compatible with horizontal pewter compounds, can also be used.

The optimum concentration of the tin compound to be used as a toxicant in a composition for application to the organism directly or at the site of the organism or to the food of the organism may vary, provided that the organism comes into contact with an effective amount. of the toxicant. The actual weight of the compound, which constitutes an effective dose, depends primarily on the susceptibility of a particular organism to the tin compound. Good control of powdery mildew on beans is obtained with liquid compositions or powdering compositions, which contain 0.000H percent or less of the weight of the toxic agent in the preparation applied to the plant. Compositions containing as much as 90% of the weight of the toxicant can sometimes be used in the treatment of mite-infested environments.

In the preparation of powder compositions, the dicyclohexylphenyltin compound can be mixed with many commonly used finely divided solids, such as bleaching earth, attapulgite, bentonite, pyrophyllite, vermiculiu, aiatomacêjora, fam, lime, gypsum, rämjöi and the like. via such methods, the atomized carrier is mixed or ground with the toxic agent or the carrier is wetted with a dispersion of the toxic agent in a volatile liquid. Depending on the proportions of the constituents, these compositions can be used in the form of concentrates and then diluted with additional solid of the indicated kind, thereby obtaining the desired amount of active ingredient in a finely divided composition suitable for controlling the fungi and mites. Such concentrated powder compositions may also be incorporated into intimate mixtures with surfactant dispersants, such as ionic and nonionic emulsifiers or dispersants to form spray concentrates. Such concentrates can be readily dispersed in liquid carriers to form spray compositions or liquid preparations which contain the toxic agent in the desired amount. The choice of surfactant and the amount used thereof is determined by the ability of the agent to facilitate the dispersion of the concentrate in the liquid carrier to form the desired liquid composition. Suitable liquid carriers include water, methanol, ethanol, isopropanol, methyl ethyl ketone, acetone, methylene chloride, chlorobenzene, toluene, xylene and petroleum distillate. Among the preferred petroleum distillates may be mentioned those which boil completely below 205 ° C at atmospheric pressure and have a flash point sleeping about 27 ° C.

Alternatively, the dicyclohexylphenyltin compound can be dissolved in a suitable organic liquid, immiscible with water, and a surfactant dispersant to form emulsifiable concentrates, which can be further diluted with water and oil to form spray mixtures in the form of emulsions of oil. In such compositions, the carrier comprises an aqueous emulsion, i.e., a mixture of water-immiscible solvent, emulsifier and water. Suitable dispersants which can be used in these compositions are oil-soluble and include condensation products of alkylene oxides with phenols and organic and inorganic acids, polyoxyethylene derivatives of sorbitan esters, alkylaryl sulfonates, complex ether alcohols, mahogany soaps and the like. Suitable organic liquids that can be used in the compositions include petroleum distillate, hexanol, liquid halogenated hydrocarbons and synthetic organic oils.

The surfactant dispersants are commonly used in liquid dispersions and aqueous emulsions in amounts from about 1 to about 20% by weight of the combined weight of the dispersant and the active toxicant.

According to the present invention, the dicyclohexylphenyltin compound or a composition containing the compound may be applied directly to the undesired organism when mites are controlled, or the compound or composition containing the compound may be applied to the site of the organisms or feed in any suitable manner. ex. by hand-powered powdering or spraying devices or simply by mixing the compound or composition with the food ingested by the mites. Application on the foliage of the plants can conveniently be carried out with machine-driven powdering devices! 50 Duo 7316226-5 6 sprayers, boom spreaders and spray powder devices. When the compositions are used in this way, they should not contain any major amounts of phytotoxic diluents. For large scale applications, the powders or sprays can be applied from aircraft. The following examples illustrate embodiments of the present invention.

* Example 1. This example shows the preparation of dicyclohexylphenyltin bromide.

A solution containing 171.9 g (0.5 mol) of diphenyltin dichloride and 500 ml of tpluen was added portionwise over 1.25 hours to 1 liter of a mixture containing 1.5 moles of cyclohexylmagnesium chloride and tetrahydrofuran as diluent. The reaction vessel was equipped with a mechanically driven stirrer, water-cooled reflux condenser, addition funnel, thermometer and inlet for nitrogen. The temperature of the reaction mixture was gradually increased to 6,100 during the addition, after which a 250 ml portion of toluene was added.

The reaction mixture was heated at reflux for 1.5 hours, then cooled to room temperature when a solution containing 55 g of citric acid and 10000 ml of water was added. The organic phase was separated and dried by combining it with an amount of anhydrous magnesium sulfate, after which the liquid phase was concentrated under reduced pressure until it became cloudy. The addition of 250 ml of methanol gave a precipitate which was isolated and washed with methanol. .

The dried solid weighed 207.5 g (9U, 5 2 of theoretical yield).

The solid was found to contain 27.27% by weight of tin. The theoretical tin content of dicyclohexyldiphenyltin is 27.02%.

A solution containing 16.0 g (0.1 mol) of bromine, 50 ml of methanol and 50 ml of chloroform was added dropwise to a solution containing 3.9 g (0.1 mol) of dicyclohexyldiphenyltin, 50 ml of methanol and 110 ml of chloroform. The addition required 1.75 hours, during which the temperature of the reaction mixture was maintained at 000. Each drop of bromine was added only after the color obtained from the previous drop had disappeared. When the addition was complete, the resulting clear solution was concentrated under reduced pressure. The colorless liquid residue weighed 51.3 g and had a refractive index (NÉ5) of 1.52826. Unreacted dicyclohexyldiphenyltin precipitated on addition of 150 ml of methanol to the crude product. The solid weighed 4.0 g. The methanol was removed from the liquid phase under reduced pressure. The liquid was then treated with gaseous ammonia to precipitate dicyclohexyltin dibromide in the form of the ammonia complex, and the solid solid formed was removed. 7316226-5 T The residual liquid was concentrated under reduced pressure to give 22.2 g of a liquid which, on analysis by gas chromatography, was found to contain 96% by weight of dicycloxylphenylphenyltin bromide.

Example 2 Dicyclohexylphenyltin hydroxide was prepared by adding a solution containing 3.0 g (0.075 mol) of sodium hydroxide and 25 ml of water, to a solution containing 7,5 g of phenyl and 205 ml of methanol. After the addition was complete, the resulting mixture was heated at boiling point for an hour, after which the mixture was allowed to cool to room temperature with stirring. A portion of 200 ml of water was added to the resulting mixture, which contained a white solid precipitate. The solid was isolated, washed with deionized water until free of bromide and then dried in a circulating air oven. The product weighed 16.7 g (93.8 Z of the theoretical yield) and was found to contain 51.65% by weight of tin. The estimated tin content of the hydroxide is 31.31% - The biological activity of the dicyclohexylphenyltin derivative 1- ill @ ësne_ @ e§9§ez_§ë2_9§! dispersed in a mixture of water and acetone with a weight ratio of 90/10, which mixture contained a small amount of a nonionic surfactant. The resulting stock solution or dispersion was then diluted with a mixture of water and surfactant to give the desired concentration of the tin compound, while maintaining the concentration of the surfactant at 100 parts per million (Ppm).

Samples, which were found to be difficult to emulsify, were homogenized with a colloid mill or tissue homogenizer. 2- 9§! Ëz§e: ins-e! _Eâšeksizize§en_e! _§Isxkl9ëezxlšenzlienabxsz: eëiéfieaeessišilfsßzezeààsfiss The effectiveness of the triorganic tin compounds of the present invention as antifungal agents and mites were examined in the following sections. The test organisms used were: powdery bean mildew, apple scab and two-spotted spider mite.

The assessment system used to determine the activity of the organisms was based on a numerical scale, in which 10 was 100% of Hawaii. .w 7316226-å 8 .can (no surviving organisms) and zero was no effect, ie the plant was severely haunted by the organism. The assessment used for powdery mildew on beans and apple cider vinegar is a function of the proportion of total leaf area that is pan-fried by these fungi. ut 0 A; Powdery mildew on islands 1 L Dilute green bean plants with fully developed primary leaves were inoculated with spores from the powdery mildew fungus (erysíphe polygoni) 48 hours before application of dicyclohexylphenyltin hydroxide. The tin compound was applied in the concentrations given in the following table by placing the plants on a rotating table and spraying with preparations containing the inorganic tin compound. When the deposited spray had dried, the plants were placed in greenhouses for 28 days, and the amount of powdery mildew on the primary leaves was assessed at intervals of 7 days after spraying. Untreated plants function as control plants, which show an effect (score) of 1, 0 or less.

Tested formulations contained 100, 20 and M ppm dicyclohexylphenyltin hydroxide.

Conc. Days after first Assessment of effect (ppm) spraying (points) 1oo _ i 7 1o, o lß 10.0 21 10.0 28 '10, 0 7 10.0 lä 9.8 21 9.3 28 8.3 Ü 7 9.5 ln 5.9 21 ü, O 28 1.9 None of the tested preparations were phytotoxic to the plants. pm.

I was registered in the first control test. 7316226-5 B. Apple cider Frozen apple leaves with conidia spores were soaked in cold water for about 30 minutes, after which the liquid phase was filtered through a thin layer of thin cloth. A number of apple seedlings in the 5-leaf stage were sprayed with water, which contained the dispersed conidia spores. The plants were stored in a high humidity room [relative humidity (RH) = 100 μl at room temperature for two days, after which they were stored at a temperature of 2 ° C 33 ° C for 7 days and then in a high humidity and 2 days and finally at 2 ° 3 ° C for 10-15 days, during which time the affected leaves were harvested. The leaves were extracted with cold water to prepare a stock solution, which under a microscope at 100 times magnification showed an area containing not less than 20 conidia spores.

The plants to be examined were sprayed with a liquid preparation containing dicyclohexylphenyltin hydroxide. The preparation was prepared as described above. After the solvent had evaporated, the leaves were sprayed with the suspension of conidia spores, which was prepared as indicated in the previous paragraph. The plants were then placed in a room with high humidity (100% RH) at room temperature for two days, after which they were stored at normal humidity and a temperature of 2ü¿3 ° C until signs of apple scab could be observed on the untreated the control plant, which was indicated by brownish pathological changes on the leaves. The results from the survey are summarized in the following table.

Conc. of organotin compound Assessment of efficacy (ppm) (points) 250 9.9 50 9.9 12.5 9.1 C. Two-spotted mite Bean plants were sprayed with preparations containing a dispersed form of dicyclohexylphenyltin hydroxide in concentrations of 50 and 200 ppm. The particle size of the dispersion was between 50 and 100 Between one and three days after spraying, a number of spin mites were transferred in the pupal stage and in adult form to the upper surface of the plant leaves. The plants remained untouched at 2H33 ° C for between 12 and days after being exposed to the mites, and the proportion of dead mites in pupae form and in adult form was observed and the results long-term effect of the tin compound was examined by a new a number of adult mites and mites in the pdpp stage were placed on the leaves of the bean plants after the first observations. No additional triorganic tin compound was applied. The amount of dead mites in pupae form and in adult form was again observed between 21 and 30 days after the spin mites were first attacked, and the results were recorded in a residual control sample. É I Conc. of tin compound in spray (PDm) 200. 1 so | Initial control Residual control (A); (N) 10 (An 9.9 (N) (An 9å9 (NM 19 (Ma 9.9 (N) A = adult mites; N = pupa stage mites Although all the compounds used to determine the biological activity, consisted of triorganic tin hydroxides, other derivatives such as fluorides, chlorides, bromides, carboxylates, mercaptides, alkoxides, phenoxides, sulfides and sulfates are expected to be at least as effective in controlling fungi and mites, as it has been found that the anionic the group in the present triorganic tin compounds, which is represented by X and Y in the given general formula, has little, if any, effect on the degree of biological activity exhibited by the compound, unless the anion itself has significant biological activity)

Claims (1)

., ......_ w .._._..._.._.._._._. à -> ~ ..... ¿.a _........ _, _...__ _ n.. - .. U _, _. 'n iÉi- / me ln Use of a dicylcyclohexyphenyltin compound having the general é @ ~ Å ~ = å n ä i. 1 ¿1 varinX denotes bromine or hydroxyl for the control of fungi and mites. ø -_ - _- un_uu ------ o _-_- I Auåöáó fi PuaL1kÅï1oNsR: TyskLana 2 218 211 zcorf 7/221 us 3 591 615 (260-429.7), 3 702 360 (424-2ss> Andra Publikatnonerz . 'Chemical. Abstracts.? 2 (1-97D), ref. 100842 f. / Ïfàííf nll fl l l'I'V