3,255,075 United States Patent Office Patented June 7, 1966 1. 2 ethylene thioethers and long chain quaternary ammonium 3,255,075 chloride compounds. METHANETHOL CONTAINING NEMATOCEDES Max J. Fielding, Wilmington, Del, assignor to E. I. du Surface-active dispersing agents such as sodium lignin Pont de Nemours and Company, Wilmington, Del, a sulfonates, low viscosity methyl cellulose and polymerized corporation of Delaware sodium salts of alkyl naphthalene sulfonic acids are also No Drawing. Filed Mar. 29, 1963, Ser. No. 269,143 suitable in the nematocidal compositions of this invention. 3 Claims. (Cl. 167-22) Among the more preferred surfactants are the anionic and non-ionic types. Among the anionic surface-active This invention relates to nematocidal compositions and agents, preferred ones are alkali metal or amine salts of methods. 10 alkyl benzene sulfonic acids, such as dodecylbenzene More specifically, this invention refers to a method of sulfonic acid, sodium lauryl sulfate, alkyl naphthalene sul killing plant pathogenic nematodes by applying to said fonates, sodium N-methyl-N-oleoyltaurate, oleic acid ester. nematodes a mercapto-terminated thiomethylene com of sodium isethionate, dioctyl sodium sulfosuccinate and pound. sodium dodecyldiphenyloxide disulfonate. Among the Plant nematodes are found in virtually all soils in which 5 non-ionic compounds, preferred members are alkyl phen plants will grow. Consequently, every major crop is a oxy poly(ethyleneoxy)ethanols such as nonyl phenol ad potential victim of this pest. The annual toll on crops ducts with ethylene oxide; also preferred are trimethyl in the United States is well over several hundred million nonyl polyethylene glycol ethers, polyethylene oxide ad dollars. A practical commercial chemical is needed to ducts of fatty and rosin acids, long chain alkyl mercaptan stop this unnecessary loss. However, in order to be com 20 adducts with ethylene oxide and polyethylene oxide ad mercially practicable a chemical must be non-toxic to ducts with sorbitan fatty acid esters. animals and plants and kill a broad spectrum of nematodes In general, less than 10% by weight of the surface at low rates. active agent will be used in compositions of this invention I have discovered that the following compounds qualify and ordinarily the amount of surface-active agents will as effective commercial nematocides: 25 range from 0.5 to 5% by weight. Nematocidal compositions of this invention can also Methanedithiol, contain finely divided inert diluents, such as talcs, natural Thiodi(methanethiol), clays, including attapulgite clay and kaolinite clay, pyro Methylenedithiobis(methanethiol), and phyllite, diatomaceous earths, synthetic fine silicas, cal Thiodimethylenedithiobis(methanethiol). 30 cium silicate, carbonates, calcium phosphates, lime, and Although all of the above compounds kill nematodes, such flours as walnut shell, wheat, redwood, soybean and particularly outstanding results are obtained from thiodi cottonseed flour. (methanethiol), methylenedithiobis(methanethiol) and The amount of the finely divided inert solid diluent thiodimethylenedithiobis(methanethiol). can vary widely but will generally range from 1 to 50% The most highly preferred compound because of its out by weight of the nematocidal composition. Compositions standing activity at low rates is thiodi(methanethiol). of from 2 to 30% active ingredient are preferred. The Acceptable nematocidal treatments are obtained from particle size can vary considerably but will ordinarily be a mixture of two or more of all the above compounds. somewhat under 50 microns in the finished formulation. A preferred formulation contains from about 10 to 50% PREPARATION 40 by weight of a mercapto-terminated thiomethylene, a total Methanedithiol is prepared in the manner described by of 45 to 89% by weight of solid diluents and 1 to 5% Cairns et al., J. Am. Chem. Soc., 74, 3982 (1952). by weight of one or more surfactants. Thiodimethanethiol is formed along with methanedithiol Although the compounds used in this invention are in the reaction between hydrogen sulfide and formalde normally liquids, it is possible to formulate them into hyde and may be separated by distillation. Methylenedi dusts for direct application or into wettable powders which thiolbis(methanethiol) and thiodimethylenedithiobis are applied in a slurry. In the case of wettable powders, (methanethiol) are prepared by the process described in surfactants and diluents are usually both present in the Saegebarth, U.S. Patent 3,056,841. nematocidal composition. COMPOSITION It is sometimes also advantageous to formulate the 50 nematocidal compound of this invention as granules or Compositions of this invention comprise one or more pellets, for example by applying the active ingredient to of the compounds described above together with one or preformed clay granules, such as granular attapulgite, or more surface-active agents. to granular vermiculite. Usually, such granules will con The surface-active agents used in this invention can be tain 1 to 10% by weight of the active ingredient, although a wetting, dispersing or an emulsifying agent which will for special uses as much as 15 to 20% by weight can be assist dispersion of the compound. Surface-active agents applied. or surfactants can include such anionic, cationic and non Emulsifiable oil solutions can be employed with one ionic agents as have heretofore been generally employed or more of the mercapto-terminated thiomethylenes used in plant control compositions of similar type. Suitable in this invention. In these nematocidal compositions, the surface-active agents are set out, for example, in Searle 60 surface-active agent and the oil form a liquid which can U.S. Patent 2,426,417; Todd U.S. Patent 2,655,417; Jones be conveniently poured and measured. Such solutions can U.S. Patent 2,412,510; or Leniher U.S. Patent 2,139,276. be mixed with water at the point of application to form A detailed list of such agents is set forth in "Detergents an emulsion containing the nematocide and the solvent. and Emulsifiers-Up to Date' (1962) by John W. Mc Such compositions have the advantage that the oil will Cutcheon, Inc., and Bulletin E-607 of the Bureau of En 65 often act as a foam inhibitor and thus reduce the tendency tomology and Plant Quarantine of the U.S. Department of for large amounts of surfactants to form objectionable Agriculture. foam. The oil used such as toluene, kerosene, stoddard Suitable surface-active agents for use in compositions of solvent, xylene, alkylated naphthalene, diesel oil and the the present invention are: polyethylene glycol fatty esters. like should be preferably water immiscible and be of a and fatty alkylol amide condensates, alkyl aryl Sulfonates, 70 type in which the active agent will be soluble in the fatty alcohol sulfates, dialkyl esters of sodium sulfosuc amounts used in particular formulations. Other solvents, cinate, fatty acid esters of sodium isethionate, polyoxy such as chlorinated hydrocarbons like tetrachloroethylene, 3,255,075 3 4. ketones like cyclohexanones, celloSolves, N,N-dialkyl Methyl mercury nitrile; amides, carbitols, and the like can also be used, either Tetrachloroquinone; and alone or in admixture with the hydrocarbon Solvents N-trichloromethylthiophthalimide. shown above. The above fungicides are added to compositions con In the above emulsifiable oil concentrates, the mer taining a mercapto-terminated thiomethylene at the rate capto-terminated thiomethylenes will be present in of 1 to 400 pounds to each 20 pounds of a compound amounts ranging from 5 to 80% by weight, 10 to 35% within the scope of this invention. Illustrative of fungi by weight being a preferred range. Precise concentrations cides used at low rates with the mercapto-terminated thio of active agent, of course, will depend on the intended use methylenes are the above-described organo mercurials. of the composition. When mixed with water at the O Illustrative of fungicides used at high rates with the mer point of application the oil concentrate will be diluted so capto-terminated thiomethylenes are thiuram sulfides and that in the final spray emulsion the active agent will be captan. Of course, more or less of the above-listed fungi present in amounts ranging from 0.5 to 2% by weight. cides can be added to a composition of this invention de A formulation that I have found to be especially advan pending on the fungi present in the area to be protected. tageous in the application of mercapto-terminated thio 5 Compositions of this invention can additionally con methylenes to nematode infested soil is a composition tain soil insecticides such as chlordane, DDT, dieldrin, containing from about 20 to 80% by weight of mercapto endrin, aldrin, methoxychlor and others for simultaneous terminated thiomethylenes, from about 17 to 75% by application of nematocide, fungicide and insecticide to weight of one or more inert liquid diluents and from the soil. about 0.5 to 8% by weight of one or more surface-active 20 In addition compositions can contain special additives agents. such as corrosion inhibitors, pigments, antifoam agents and the like. APPLICATION The compounds used in this invention can also be ap plied, mixed or in common solution with other chemicals As a practical matter application rates of from 2 to 25 which are used in agronomic and horticultural manage 100 pounds of active mercapto-terminated thiomethylenes ment and are compatible with the compounds used in this per treated acre of soil are satisfactory for nematode invention. Such chemicals can be but are not restricted control, although higher rates can be used. The active to the classes of chemicals commonly known as plant nu mercapto-terminated thiomethylene, preferably in a Suit. trients, fertilizers, herbicides and other nematocides. able formulation as described above is applied to the Soil 30 by any conventional method such as spraying or dusting The following additional examples in which all percents by hand or mechanical equipment. . After application, the unless otherwise indicated are by weight are provided to composition is worked into the ground to a depth of about more clearly explain this invention. 4 to 8 inches. Spot shanking into an open furrow is a Example 1.-Preparation of methanedithiol and particularly advantageous method of application. 35 thiodi(methanethiol) The compounds used in this invention are also applied A rocker bomb is charged with 120 parts by weight of to nematode infested plant material, such as bulbs, tubers, paraformaldehyde and 544 parts of hydrogen sulfide. or roots of ornamental plants and nursery stock. Disin The bomb is closed and heated with agitation at 80-90° C. fection is carried out by dipping the bulb, tuber or plant for 12 hours. The bomb is cooled, excess hydrogen sul root into a solution or suspension containing 5 to 50,000 40 fide vented and the two phases separated. pp.m. of one or more active mercapto-terminated thio The upper aqueous phase is extracted with ether. The methylene compounds. ether extract and the lower organic phase are combined, An application to a locus of infestation includes the dried with magnesium sulfate and distilled through a col treatment of soil, plant material, before or after planting, umn. This distillation produces 90 parts of methane and other sites infected with adult nematodes, their eggs 45 dithiol, boiling point 43° C. at 44 mm., and 104 parts of or larvae. thiodi(methanethiol), boiling point 57 C. at 0.85 mm. The active compounds used in the invention can be The nuclear magnetic resonance spectrum of thiodi(meth advantageously mixed with soil fungicides such as anethiol) on Varian A-60 NMR Spectrometer using tetra p-Dimethylaminobenzenediazosodium sulfonate; methylsilane as an external reference shows three bands Quinone oxyaminobenzooxohydrazone; 50 at delta = -2.57, -2.70 and -2.84 p.p.m. assigned to the Tetraalkylthiuram sulfides such as tetramethylthiuram two thiol hydrogens and two bands at delta=-4.23 and monosulfide or disulfide and tetraethyl thiuram mono - 4.36 p.p.m. assigned to the four methylene hydrogens. sulfide or disulfide; It is not necessary to carry out the distillation. A use Metal salts of ethylene bisdithiocarbamic acid, e.g. ful preparation is obtained by isolating the lower organic Manganese, zinc, iron and sodium salts; 55 phase obtained in the condensation and topping off most Pentachloronitrobenzene; of the volatile methanedithiol. The topped portion is Dodecylguanidine acetate; recycled into a Subsequent condensation. The non-vola N-trichloromethylthio tetrahydrophthalimide (captan); tile residue is highly nematocidal and can be used in the Phenylmercury acetate; compositions and methods of this invention; it is desig 2,4-dichloro-6-(o-chloroanilino)-s-triazine 60 nated the crude reaction product of Example 1 for the N-methylmercury p-toluenesulfonanilide; purpose of this specification. Chlorophenol mercurihydroxide; Nitrophenol mercurihydroxides; Example 2.-Preparation of methylenedithiobis(methane Ethel mercury acetate; thiol) and thiodimethylenedithiobis(methanethiol) Ethyl mercury 2,3-dihydroxypropyl mercaptide; 65 A steel bomb is charged with 284 parts by weight of Methyl mercury acetate; 37% formalin solution. About 225 parts of hydrogen Methyl mercury 2,3-dihydroxypropyl mercaptide; sulfide is distilled into the bomb after it is chilled and 3,3'-ethylenebis(tetrahydro-4,6-dimethyl-2H-1,3,5-thiadi evacuated. The bomb is then sealed and heated at 60° C. azine-2-thione); for 4 hours. The reaction vessel is cooled, the excess Methyl mercury dicyandiamide; 70 hydrogen sulfide vented, and the lower organic phase of N-ethyl mercury-p-toluenesulfonanilide; the two phase reaction mixture is separated. This liquid Metal (e.g. iron, sodium, and zinc), ammonium and intermediate (220 parts) is stirred under nitrogen with amine salts of dialkyldithiocarbamic acids; 150 parts concentrated hydrochloric acid and 300 parts Tetrachloronitroanisole; water at 100° C. for 6 hours. The lower organic layer Hexachlorobenzene; 75 is separated, washed with water and dried over magnesium 8,255,075 5 6 sulfate. The largest constituent of the resulting oil is substantially free from infestation by nematodes. In an methylenedithiobis(methanethiol). A lesser constituent untreated area in the same field, beets are distorted and is thiodimethylenedithiobis(methanethiol). Thiodi(meth yields reduced. anethiol) is also present in variable amounts. This crude Example 6 mixture is satisfactory for the nematocidal compositions Percent and methods of this invention. 5 Methylenedithiobis(methanethiol) ------75 If desired, the active components of the reaction mix Nonyl phenol polyethoxy ethanol) ------10 ture can be separated by distillation. Thiodi(methane Xylene ------15 thiol) distills off first, boiling point 57 C. at 0.85 mm., The mixture is prepared in the same manner as Exam followed by methylenedithiobis(methanethiol), boiling 10 ple 5. point approximately 110° C. at 0.1 mm. This emulsifiable concentrate is diluted with sufficient . Example 3 water to drench the soil to the root zone of the plants Percent and applied to roses at a rate of 20 to 100 pounds active Thiodi(methanethiol) ------25 agent per acre. Excellent control is obtained of the Dioctyl sodium sulfosuccinate ------1. 15 dagger nematode (Xiphinema diversicaudatum) allowing Sodium lignin Sulfonate ------2 the roses to grow in a normal manner. Attapulgite clay ------45 Synthetic fine silica ------25 Example 7 These materials are thoroughly blended to prepare a Percent uniform mixture. The mixture is then ground in a micro 20 Thiodi(methanethiol) ------5 pulverizer until the particle size is substantially less than Granular attapulgite clay ------95 50 microns. The active ingredient is warmed to about 40° C. and This 25% wettable powder formulation, when dispersed is sprayed over the surface of the granular clay while in water, is applied with conventional spray equipment the mass is kept agitated and is being tumbled in order at a concentration of about 10 pounds wettable powder to 25 to obtain a uniformly impregnated dry granular product. 10 gallons of water at a rate between 20 to 100 pounds The granular product is applied to soil infested with active ingredient per acre to land infested with plant pathogenic nematodes at rates of 20 to 100 pounds active pathogenic nematodes. After spraying onto the surface agent per acre using a conventional fertilizer spreader. of the soil, the chemical is mixed in the soil to a depth 30 The active agent is then worked into the soil by disking. of 4 to 6 inches with a rotovator. This treatment gives substantially complete control of the When soil infested with root-knot nematode, Meloi sting nematode (Belonolaimus sp.) as shown by a dogyne, is treated in this way, cotton plants grown show nematode count 15 days after treatment. normal development free from nematode infection. Example 8 Plants grown in similar non-treated soil show stunting, Percent and reduced yields due to nematode infection. Methanedithiol ------25 Example 4 Blend of polyalcohol carboxylic esters and oil-soluble Percent Sulfonates ------6 The crude reaction product of Example 2, containing Alkylated naphthalenes ------69 methylenedithiobis(methanethiol), thiodi(meth 40 The above ingredients are blended until a completely anethio) and thiomethylenedithiobis(methane homogeneous mixture is obtained. The resulting emulsifi thiol) ------15.0 able composition is extended with water and sprayed at Sodium alkyl naphthalene Sulfonate ------2.0 the rate of 75 pounds per acre of active ingredient in 120 Partially desulfonated sodium lignin sulfonates ---- 0.5 gallons of water on a field infested with sugar beet Kaolin clay ------82.5 45 nematode (Heterodera schachtii) and the chemical is These materials are thoroughly blended in a ribbon worked into the soil to a depth of 6 inches. Sugar beets blender, and ground in a micropulverizer until the particle grown in this field are substantially free from nematode size is substantially less than 50 microns. The resulting infestation. wettable powder formulation can be diluted with water to the desired spray concentration. 50 Example 9 This formulation is suspended in water, and drenched The wettable powder of Example 3 is diluted with about the roots of boxwood plants infected with the spiral micaceous talc to obtain a dust containing 2.5 active in nematode (Helicotylenchus buxophilus) at rates of 50 to gredient: 200 pounds active agent per acre, using enough water to Percent wash the active agent down about the plant roots. Sub Powder of Example 3 ------in a won a 10 stantially all spiral nematodes are killed by this treatment, Micaceous talc ------90 allowing the boxwood plant to develop in a normal aller. The ingredients are thoroughly blended and deagglom Example 5 erated until a uniform product is obtained. The mixture Percent 60 is applied to the soil at the rate of 20 to 100 pounds of The crude reaction product of Example 1 ------30 active ingredient per acre and is disked or rototilled into Blend of poly-alcohol carboxylic esters and oil the soil to obtain mixing into the Zone of nematode Soluble Sulfonates ------6 infestation. Alkylated naphthalenes ------64 65 Example 10 The above ingredients are blended until a completely The emulsifiable formulation of Example 6 is diluted homogeneous mixture is obtained. The resulting emul with water to give an aqueous system containing 5 to 100 sifiable composition can be extended with water to the p.p.m. of the active ingredient. Narcissus bulbs infested required concentration for spraying. with the bulb and stem nematode (Dity lenchus dipsoci) The above emulsifiable concentrate is diluted with water 70 are dipped in this diluted preparation for a period of and sprayed at the rate of 60 pounds per acre of active 10 to 30 minutes. The treated bulbs planted in field soil ingredient in 120 gallons of water on a field infested with grow to produce good yields of both cut flowers and new sugar beet nematode (Heterodera schachtii) and the bulbs. Similarly infected bulbs that are not treated grow chemical is worked into the soil to a depth of 6 inches. poorly giving only small yields of both flowers and Sugar beets grown in this field develop normally and are 75 bulbs. 3,255,075 7 8 Example II Example 13 For the simultaneous control of root knot nematode Percent and Pythium spp. and Rhizoctonia spp., the mixture of Pentachloronitrobenzene ------10.0 Example 3 plus commercial formulations of dimethyl Thiodo(methanethiol) ------20.0 aminobenzenediazo sodium sulfonate and pentachloro 5 Sodium alkyl naphthalene sulfonate ------2.0 nitrobenzene are prepared in a tank mix. For this mix Partially desulfonated sodium lignin sulfonate ---- 0.5 ture 40 pounds of the formulation of Example 3 is mixed Kaolin clay ------67.5 with 80 gallons of water. To this is added 7/2 pounds of 70% pentachloronitrobenzene wettable powder and 10 The above ingredients are thoroughly mixed in a ribbon O blender and the mixture ground in a micropulverizer pounds of 60% p-dimethylaminobenzenediazo sodium until the particle size is substantially less than 50 microns. sulfonate. This mixture is applied as a soil spray by ap This 30% wettable powder formulation is dispersed plication to bands of soil with conventional spray equip in Water at the rate of 10 pounds wettable powder per 10 ment. The application rate is 5 pounds per acre total ac gallons of Water. This mixture is now applied as a soil tive ingredient (equivalent to 100 pounds per acre in the 15 Spray by application to bands of soil with conventional treated band). The soil is rotovated immediately there spray equipment. The application rate is 3 pounds total after to mix the chemicals thoroughly with the soil. Fol active ingredient per acre (equivalent to 60 pounds per lowing this, cotton seed is planted in the treated band. acre in the treated band). The soil is rotovated immedi The cotton seedlings which develop are protected against ately after application of the spray, thoroughly mixing the root knot nematode (Meloidogyne spp.) and the fungi 20 chemicals with the soil. Immediately thereafter cotton Pythium spp. and Rhizoctonia spp. A healthy stand of Seed is planted in the treated band. The developing cot cotton plants is obtained and at harvest time an increased ton seedlings are protected against root knot nematode yield of cotton. and the fungi Rhizoctonia spp. A healthy stand of cotton Example 12 plants is obtained and the yield of cotton at harvest time Percent 25 is increased. p-Dimethylaminobenzenediazo sodium sulfonate ---- 15 The invention claimed is: Thiodi(methanethiol) ------20 1. A method of controlling nematodes comprising ap Sodium lignin sulfonate ------2 plying to soil a nematocidally effective amount of thiodi (methanethiol). Dioctyl Sodium sulfosuccinate ------1. 30 2. A method of controlling nematodes comprising ap Synthetic fine silica ------20 plying to soil a nematocidally effective amount of methyl Attapulgite clay ------42 enedithiobis(methanethiol). The above materials are thoroughly blended to prepare 3. A method of controlling nematodes comprising ap a uniform mixture. The mixture is then ground in a plying to soil a nematocidally effective amount of thio micropulverizer until the particle size is substantially less 35 dimethylene dithiobis(methanethiol). than 50 microns. This 35% wettable powder formulation is dispersed in References Cited by the Examiner water at the rate of 10 pounds wettable powder per 10 gallons of water. This mixture is now applied as a soil UNITED STATES PATENTS spray by application to bands of soil with conventional 40 2,864,739 12/1958 Scott ------167-22 spray equipment. The application rate is 3% pounds 2,882,197 4/1959 Webb ------167-22 total active ingredient per acre (equivalent to 70 pounds 2,938,827 5/1960 Wadsworth ------167-22 per acre in the treated band). The soil is rotovated im 2,966,521 12/1960 Webb ------167-13 mediately after application of the spray, thoroughly mix 2,998,346 8/1961 Scott ------167-22 ing the chemicals with the soil. Immediately thereafter, 45 3,103,464 9/1963 Larson ------167-22 cotton seed is planted in the treated band. The cotton 3,137,615 6/1964 Ichikawa et al. ------167-22 seedlings which develop are protected against root knot nematode (Meloidogyne spp.) and the fungi Pythium spp. JULIAN S. LEVITT, Primary Examiner. resulting in a healthy stand of cotton plants and an in S.J. FRIEDMAN, Assistant Examiner. creased yield of cotton at harvest time. 50