IE47205B1 - Substituted carbamates, preparation and compositions thereof and use thereof as insecticides - Google Patents

Abstract

Substituted carbamates, preparation thereof and use thereof as insecticides, for control of pestiferous insects belonging to such orders as Lepidoptera, Coleoptera and Diptera, the carbamates having the formula: wherein R is branched or straight chain alkyl containing 1 to 3 carbon atoms or methoxymethyl; R1 is branched or straight chain alkyl containing 1 to 3 carbon atoms; An illustrative compound is dimethyl-N,N min - [[1,2-ethanediylbis [thio(methylimino) carbonyloxy]] bis (ethaneimidothioate).

Description

This invention relates to substituted carbamates, preparation thereof and use thereof as insecticides for the control of pestiferous insects.

Belgian Patent No. 848,912, granted May 21. 1977, relates 5 to insecticidal symmetrical bis-carbamoyl sulfide compounds of the following general formula: OR' R' 0 ll II RO-C-N-S·— N C -OR and R' is alkyl containing from one to four carbon atoms. Among the numerous compounds which are included in the 4720S - 3 Belgian Patent are those wherein Rg is alkyl, optionally substituted with one or more alkylthio groups, and wherein Rg is hydrogen alkyl or alkoxy. The patentee states, however, that while compounds according to the above formula wherein Rg is an alkylthioalkyl substituent and Rg is hydrogen exhibit good pesticidal activity, their mammalian toxicity is unacceptably high.

U.S. Patent 4,004,031 issued January 18. 1977, discloses insecticidal compounds of the formula: ln θ θ 10 II II CH,-C - NO—C— N--S — N-C—0 N = C CH, I II I R-S CHg CHg S —R wherein R is an alkyl group of one to five carbons.

U.S. Patent 3,576,834 issued April 27. 1971, relates to 15 insecticidal compounds having the structure: f Ri—C = NO— C-N ί \ R4-Q -R, , such as methomyl. - 4 This invention relates to compounds of Formula 1, their preparation, to insecticidal compositions containing them and to the method of using said compounds as insecticides 0 I 1 R-C = NOCH— S — R,— S— NCON = C—R I I ί I ,,, R^ CH3 CH3 SR] wherein R is a branched or straight chain alkyl group of 1 - 3 carbon atoms of CH^OCHg; R^ is a branched or straight chain alkyl group of 1 - 3 carbon atoms: fH3 R2 is -CH2CH2-, -CH2CH- or -CH2CH2ZCH2CH2-; and Z is oxygen or sulfur.

Compounds which are preferred for their high insecticidal activity are those compounds of Formula 1 wherein R is methyl or ethyl; and R.| is methyl. - 5 More preferred for their higher insecticidal activity are those compounds of Formula 1 wherein: Ris methyl; R2 is -CH2CH2-; and preferably R^ is methyl.

He prefer those compounds of Formula 1 wherein R2 is -CH2CH2- or -CH2CH- .

Specifically preferred for its outstanding insecticidal activity is dimethyl N,N'[^1,2-ethanediy1 bisQhio(methy1imi no) carbony1oxy]]]bis(ethaneimidothiate).

The compounds of Formula 1 can be prepared, as shown in Equation A, by reacting preferably at least two moles of a substituted N-(ami nocarbonyloxy)-alkanimidothioic acid ester of Formula 11 with one mole of an alkane disulfenyl halide of Formula 111 in the presence of a base: 47305 Equation A R C = NOt—N—H + XS—R2-SX R3S CHg (11) (111) R—C = NOCN—S-R,— S-NCON = C-R II 2 I RjS CHg CHg SR1 (Γ wherein R, R^, and Rg are as previously defined and X is 10 halogen.

The reaction can be carried out in any organic solvent which is inert to the reactants and the reaction products, e.g. methylene chloride, dioxane, tetrahydrofuran, chloroform, 1,2-dichloroethane, acetonitrile, benzene, toluene, the xylenes, acetone or methyl ethyl ketone. Mixtures of such solvents can also be used. A base which will function as an acid acceptor can be used in synthesizing the compounds of this invention. 4730 5 - 7 The process can be carried out at a temperature of between -20° and 60°C, preferably between about -5° and 40°C.

Pressure is not critical; for convenience, atmosDheric pressure is preferred.

Preparation of the compounds of Formula 11 used as starting materials is described in U.S. Patent 3,574,736; 3,576,834 and 3,787,470.

In the compounds of Formula 111, chlorine is the preferred halogen for economic reasons, and those compounds can be prepared by a suitable modification of the methods described in the >1 own'll of Heterocyclic Chemistry, Λ, 629 (1969). Alkane sulfenyl halides, such as those of Formula 111 wherein X is fluorine, bromine, or iodine, are also known and may bepreparedby the methods reviewed in '.Synthesis, 11, 561-580 (1970).

In the examples which follow, which are illustrative only, temperatures are given in degrees centigrade.

Example 1 Ethane-1,2 -bisthioacetate To a solution of 141 g of sodium methoxide in 1 1 of absolute ethanol, under a dry nitrogen atmosphere, was added 200 g of thiolacetic acid dropwise with stirring over a period of 20 minutes. Ethylene dibromide (229.2 g) - 8 was then added and the reaction heated to reflux for five hours. The reaction mixture was cooled, sodium bromide was filtered off, and the ethanol was removed under vacuum. The residue was taken up in diethyl ether, washed with water, dried over anhydrous magnesium sulfate and the crude product isolated by distillation of the diethyl ether solvent. After re-crystallization from hexane, the product ethane-1,2-bisthiolacetate, melted at 68 - 70°.

Example 2 Ethane-1,2-Disulfenyl Chloride Sulfuryl chloride (54 g) was added dropwise to a solution of 35.6 g of ethane-1,2-bisthiolacetate in 200 ml of methyl ene chloride at ambient temperature. After stirring for 45 minutes at room temperature the methylene chloride solvent and volati 1 eby-products were removed by vacuum distillation of 0°. The yellow product, ethane-1,2disulfenyl chloride, melted at 32 - 34°.

Example 3 Dimethyl N,N'£|?,2-ethanediylbis [thio(methylimino) carbonyl oxyJJJ bis (ethanimidothioate).

A solution of 6.5 g of N-(methyl ami nocarbonyloxy) ethanimidothioic acid, methyl ester, in 50 ml methylene chloride and 2.0 ml of pyridine was prepared. To that - 9 solution was added dropwise 28 gm of ethane-1,2-disul fenyl chloride, dissolved in 25 ml of methylene chloride, with stirring over a period of 10 minutes. The reaction was slightly exothermic. After stirring for about 16 hours at ambient temperature, the reaction mixture was washed with water, dried over anhydrous magnesium sulfate, and the crude product isolated by distilling off the methylene chloride solvent. After re-crystallization from ethyl alcohol followed by re-crystallization from acetonitrile, the product, dimethyl N,N1-£jj,2-ethanediylbis [thio( methyliminojcarbonyloxyjJJbis(ethanimidothiate), melted at 176 - 179°.

By reacting equivalent amounts of other compounds of Formula 11 with compounds of Formula 111 using the procedures of Examples 1, 2 and 3, the following comDOunds of Formula 1 can be prepared. - 10 Table 1 ?R1 0 II 0 SR, 1! 1 1 1 II R-C = NOC— -61—S—R2-S- - N— 1 C — ON = C-R 1 ch3 1 CH3 5 RR1R2 ——— CH3C2R5 -CH2CH2- ch3 hC3H7 -CH2CH2- ch3 -CH2CH2- ch3och2 ch3 -CH2CH2- 10C2H5 ch3 -CH2CH2-kC3H7 ch3 -CH2CH2- <-C3Hy ch3 -ch2ch2-C2H5C2H5 -CH2CH2-C2H5 i-CgHy -CHzCH2- 15 CgHg M-C3H7 -CH2CH2-m'C3H7C2H5 -ch2ch2- •£-c3H7C2H5 -ch2ch2- ch3 ch3 -CH2CH2OCH2CH2- ch3C2H5 -CH2CH20CH2CH2- 20C2H5 ch3 -CH2CH2OCH2CH2- ch3 ch3 -CH2CH2SCH20H2- Formulation Useful formulations of the compounds of Formula 1 can be prepared in conventional ways. They include dusts, granules, pellets, solutions, suspensions, emulsions, wettable powders, emulsifiable concentrates and the like. Many of these may be applied directly. Sprayable formulations can be extended in suitable media and used at spray volumes of from a few litres to several thousand litres per hectare (from a few pints to several hundred gallons per acre). High strength compositions are primarily used as intermediates for further formulation. The formulations, broadly, contain e.g. about 1% to 99% by weight of active ingredient(s) and at least one of (a) e.g. about 0% to 20% surfactant(s) and (b) e.g. about 1% to 99% solid or liquid diluent(s).

More specifically, they will contain these ingredients in the following approximate proportions: - 12 Percent by Height* Acti ve Ingredient Diluent(s) Surfactant(s) Wettable Powders 20 - 90 0 - 74 1 - 10 5 Oil suspensions, emulsions, solutions, (including emulsifiable concentrates) 5 - 50 40 - 95 0 - 15 Aqueous Suspensions 10 - 50 40 - 84 1 - 20 Dusts 1 - 25 70 - 99 0 - 5 10 Granules and Pellets 1 - 95 5 - 99 0 - 15 High Strength Compositions 90 - 99 0 - 10 0 - 2 *Active ingredient plus at least one of a Surfactant or Diluent equals 100 weight percent.

Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound. Higher ratios of surfactant to active ingredient are sometimes desirable, and are achieved by incorporation into the formulation or by tank mixing.

Typical solid diluents are described in Watkins, et al., Handbook of Insecticide Dust Diluents and Carriers, 2nd Edn., Dorland Books, Caldwell, N.J. The more absorptive - 13 diluents are preferred for wettable powders and the denser ones for dusts. Typical liquid diluents and solvents are described in Marsden, Solvents Guide, 2nd Edn., Interscience, New York, 1950. Solubility under 0.1% is preferred for suspension concentrates; solution concentrates are preferably stable against phase separation at 0°C. McCutcheon's Detergents and Emulsifiers Annual, McCutcheon Division, MC Publishing Co., Ridgewood, New Jersey, as well as Sisely and Wood, Encyclopedia of Surface Active Agents, Chemical Publ. Co., Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth, etc.

The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Patent 3,060,084). Granules and pellets may be made by spraying the active material upon preformed granular carriers or by agglomeration techniques.

See J.E. Browning, Agglomeration1' Chemical Engineering, Dec. 4, 1967, pp. 147ff. and Perry's Chemical Engineer's Handbook, 4th Edn., McGraw-Hill, N.Y., 1963, pp. 8 - 59ff.

For further information regarding the art of formulation, see for example: J.8. Buchanan, U.S. Patent 3,576,834 April 27. 1971, Col. 5, line 36 through Col. 7, line 70 and Exs. 1 - 4, 17, 106, 123 - 140.

R.R. Shaffer, U.S. Patent 3,560,616, Feb. 2, 1971, Col. 3, line 48 through Col. 7, line 26 and Exs. 3 - 9, 11 - 18.

E. Somers, Formulation, Chapter 6 in Torgeson, Fungicides, Vol. 1, Academic Press, New York, 1967.

Example 4 Wettable Powder Dimethyl N,N'-£[T,2-ethanediylbis [thi o(methylimi no)-carbonyloxy J J J bis(ethanimidothioate) dioctyl sodium sulfosuccinate sodium 1igninsulfonate low viscosity methyl cellulose 40.055 .5% .555 attapulgite 54.0% - 15 The ingredients are thoroughly blended, Dassed through an air mill, to produce an average particle size under 15 pm, reblended, and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) before packaging.

All compounds of the invention may be formulated in the same manner.

Example 5 Wettable Powder Dimethyl N,N'-[(j ,2-ethanediylbis 10 Jthio(methylimino)-carbonyloxyJ]] bis (ethanimidothioate) 50.0“/ sodium alkylnaphthalenesulfonate 2.0/ low viscosity methyl cellulose 2.0% diatomaceous earth 46.0% The ingredients areblended, coarsely hammer milled and then air milled to produce particles of active ingredient essentially all below 10 pm in diameter. The product is reblended before packaging. 47305 - 16 Example 6 Wettable Powder Dimethyl N,N'-£ [l ,2-ethanediylbis [thio(methylimino)-carbonyloxy] ]] bis (ethanimidothioate) 65.055 dodecylphenol polyethylene glycol ether 2.05! sodi um ligninsulfonate 4.0% sodi um silicoaluminate 6.055 10 montmori11onite (calcined) 23.0% The ingredients are thoroughly blended. The liquid surfactant is added by spraying upon the solid ingredients in the blender. After grinding in a hammer mill to produce particles essentially all below 100 qm, the material is reblended and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) and packaged.

Example 7 Aqueous Suspension Dimethyl N,N'[l,2-ethanediylbis [thio (methyl imino) -carbonyl oxy]]] bis(ethanimidothioate) 25.0% hydrated attapulgite 3.055 crude calcium ligninsulfonate 10.055 sodium dihydrogen phosphate 0.555 water .55! - 17 The ingredients are ground together in a ball or roller mill until the solid particles have been reduced to diameters under 10 pm.

Example 8 Oil Suspension Dimethyl N,N1 -[ [Ϊ,2-ethanediy 1 bis [thio(methylimino)-carbonyloxy] j] bis(ethanimidothioate) 25.0% polyoxyethylene sorbitol hexaoleate 5.0% highly aliphatic hydrocarbon oil 70.0% The ingredients are ground together in a sand mill until the solid particles have been reduced to under about 5 pm. The resulting thick suspension may be applied directly, but preferably after being extended with oils or emulsified in water.

Example 9 Granule wettable powder of Example 4 10.0% attapulgite granules 90.0% (U.S.S. No. 20 - 40; 0.84 - 0.42 mm) A slurry of wettable powder containing 50% solids is sprayed on the surface of attapulgite granules in a doublecone blender. The granules are dried and packaged. - 18 47 au ο Example 10 Extruded Pellet Dimethyl Ν,Ν'-[l,2-ethanediyIbis (thio(methylimino)-carbonyloxy] j ] bis(ethanimidothioate) 25.0% anhydrous sodium sulfate 10.0% crude calcium ligninsulfonate 5.0% sodium alkylnaphthalenesulfonate 1.0% calcium/magnesium bentonite 59.02 The ingredients are blended, hammer-milled and then moistened v/ith about 12% water. The mixture is extruded as cylinders about 5 mm diameter which are cut to produce pellets about 3 mm long. These may be crushed to pass a U.S.S. No. 20 sieve (0.84 mm opening). The granules held on a U.S.S. No. 40 sieve (0.42 mm opening) may be packaged for use and the fines recycled.

Example 11 High Strength Concentrate Dimethyl N,N'-[ Q,2-ethanediylbis [thio (me thyl imi no)-carb onyl oxyjjj bis(ethanimi dothi oate) 98.5% silica aerogel 0.5% synthetic amorphous fine silica 1.02 - 19 47205 The ingredients are blended and ground ina hammer mill to produce a high-strength concentrate essentially all passing a U.S.S. No. 50 sieve (0.3 mm opening). This material may then be formulated in a variety of ways.

Example 12 Dust high-strength concentrate, Example 11 25.4% pyrophyllite, powdered 74.6% The ingredients are thoroughly blended and packaged for use.

Example 13 Emulsifiable concentrate Dimethyl N, N1 £ [j, 2-e th an e di y 1 b i s [thi o (methy 1 i mi no)-carbonyl oxy] ] ] bis (ethanimidothioate) 20.0% chlorobenzene 74.0% sorbitan monostearate and polyoxyethylene condensates thereof 6.0% The ingredients were combined and stirred to produce a solution which can be emulsified in water for application 47305 Example 14 Emulsifiable Concentrate Dimethyl N,N' ,2-ethanediylbis [thio (me thyl imi no)-carb onyl oxyj J J bis(ethanimidothioate) blend of oil-soluble sulfonates and polyoxyethylene ethers xylenes .0% .0% 80.0% The ingredients are combined and stirred with gentle 10 warming to speed solution. A fine screen filter is included in packaging operation to ensure the absence of any extraneous undissolved material in the product.

Use The compounds of this invention are useful for control of 15 insects which are detrimental to agriculture.

As demonstrated in Examples 16 to 18 below, improved residual insecticidal properties as well as decreased phytotoxicity are obtained with a formulation containing a compound of Formula 1. - 21 47205 The compounds readily control pestiferous insects belonging to such orders as Lepidoptera, Coleoptera, and Diptera. More specifically, insects controlled by the compounds of this invention include but are not limited to: cotton bollworm (Heliothis sea), tobacco budworm (Heiiothis vires cens }, southern armyworm (Spodoptera eridania), beet armyworm (Spodoptera exigua), soybean looper (B; eudoplus ia ineludere ), Mexican bean beetle (Epilachna varives tis ), and the house fly (Mus ca domes tic a).

The insects are controlled by applying the compound to the locus of infestation, to the area to be protected, or to the pests themselves. For the control of insects in agriculture crops, a compound of Formula 1 is generally applied to the foliage or other plant parts which are infested or which are to be protected. Effective amounts to be applied depend upon the species to be controlled, its life stage, its size and location, the amount of rainfall, the time of year, moisture, temperature, type of application, and other variables. In general, 0.1 to 10 kg/ha may be required for insect control in agriculture with rates of .2 to 4 kg/ha usually being sufficient in many situations. In large-scale field operations, rates in the range of 1/4 to 2 kg/has are generally used. 4-7 20 5 - 22 The compounds of this invention will generally be used in formulation with a carrier that commonly will contain oil or water. Applications may be made with concentrated or dilute suspensions of the insecticide in the carrier.

Low-volume applications utilizing dispersions containing about 20% of the active ingredient may be preferred by some applicators while others may prefer dilute suspensions containing only 25 ppm in high-volume applications.

The compounds of this invention possess significant 10 advantages over prior art compounds, e.g. fewer applications are required to provide a given level of insect control due to this distinctly longer residual insecticidal action. Use of fewer applications results in greater economy to the grower and dissemination of less insecticide in the environment. An additional advantage is lower phytotoxicity to cotton.

Conventionally, the compounds will be incorporated into a formulation in a known manner with incorporation of other components such as (a) surfactants, (b) diluents, (c) additives to reduce foam or corrosion, or (d) preservatives to control microbiological growth. - 23 The compounds of this invention can be mixed with fungicides, bactericides, acaricides, nematicides, other insecticides, or other biologically active compounds in order to achieve desired results with a minimum expenditure of time, effort and material. Amounts of these biologically active materials added for each part by weight of the composition of this invention may vary from 0.05 to 25 parts by weight. Suitable agents of this type are wellknown to those skilled in the art. Some are listed below; the terms Monocide, Morestan, Folbex, Kelthane, Pentac, Furadan, Pyridin and Ambush are Trade Marks, at least in Great Britain.

Fungicides methyl 2-benzimi dazolecarbamate; tetramethyl thiuram disulfide (thiuram); n-dodecylguanidine acetate (dodine); manganese ethylenebisdithiocarbamate (maneb); 1,4-dichloro-2,5-dimethoxybenzene (chloroneb); methyl 1 -(butylcarbamoyl)-2-benzimidazolecarbamate (benomyl); N-trichioromethylthiotetrahydrophthalimide (captan); N-tri chloromethylthi ophthali mi de (folpet); Baaterioides : tribasic copper sulfate; streptomycin sulfate; - 24 Acaricides: senecioic acid, ester with 2-oec-butyl-4,6-dinitrophenol (moroci de); 6- methyl-l,3-dithiolo [4,5-b] quinoxalin-2-one (Morestan ®) 5 ethyl 4,4'-dichlorobenzilate (Folbex); 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (Kelthane); bis{pentachloro-2,4-cyclopentadien-l-yl) (Pentac); tricyclohexyl tinhydroxide (cyhexatin); Nematicides : S-methyl 1 -(dimethyl carbamoyl)-N-{methyl carbamoyloxy)thioformimidate (oxamyl); S-methyl 1-carbamoyl-N-(methylcarbaraoyloxy)thi oformimidate; N-isopropylphosphoramidic acid, 0-ethyl-0'-[4-(methylthi0)m-tolyljdiester (fenamiphos); Insecticide: methylcarbamic acid, ester with 2,3-dihydro-2,2-dimethy17- benzofuranol (Furadan); 0- (2,4,5-tri chloro-a-(chloromethyl) benzyl] phosphoric acid, 0‘,0'-dimethyl ester (tetrachlorvinphos); 0-ethyl-0-(4-nitrophenyl)phenylphosphonothioate (EPfl); octachlorocamphene (toxaphene); cyano(3-phenoxyphenyl)methyl-4-chloro-alpha-(1methylethyl)benzeneacetate (Pyridin); - 25 (3-phenoxyphenyl)methyl( + )-cis, trans-3-(2,2di chloroethenyl-2,2-dimethylcyclopropanecarboxylate (Ambush); 3-phenoxybenzyl-dl-cis, trans-chrysanthemate (phenothrin); 2-mercaptosuccinic acid, diethyl ester, S-esterwith thionophosphoric acid, dimethyl ester (malathion); phosphorothioic acid, 0,0-dimethyl, 0-p-nitrophenyl ester (methyl parathion); methylcarbamic acid, ester with α-naphthol (carbaryl); methyl N-(methyl ami nocarbonyloxy)ethaneimidothi oate (methomyl); N'-(4-chloro-o-tolyl)-N,N-dimethylformamidine (chiordimeform); 0,0-di ethyl-0-(2-isopropyl-4-methy1-6-pyrimidyl phosphorothioate (Diazinon); 0,S-dimethylacetyl phos ph orami dothioate (acephate); 0,S-dimethylphosphoramidothi oate (methami dophos).

Example 15 The foliage only of red kidney bean plants in the two-leaf stage was sprayed to run-off with aqueous dispersions of dimethyl N,N'-£[l,2-ethanediylbis [th io(methyl imino) carbonyloxy]]]bis(ethanimidothioate) (1) at the dilutions indicated. The sprays contained Duponol L-144-WDG (sulfonated oleyl acetate surfactant) at a concentration of 1:3000. After drying, a single leaf from each treated - 26 plant was excised and placed in a covered 20 x 100 mm Petri dish containing a moistened filter paper and 10 southern armyworm (SAW) larvae approximately 13 mm in length. The test was conducted in duplicate. Insect mortality was evaluated two days later and is recorded below.

Mortality SAW Treatment Concentration (iAl) 2 day 1 0.01 100 10 0.005 100 0.0025 75 untreated control - 0 Example 16 The plants from the test described in Example 1 were 15 kept in a growth room at 77 + 2°F and 53 5% relative humidity for 7 days. At the end of that period of time, the remaining cotyledonary leaf from each bean plant was placed singly in a Petri dish with southern armyworms as previously described. Insect mortality was again read 2 days later and is set forth below: - 27 47205 Treatment % Mortality SAW Concentration (%A1) 2 days 1 0.01 100 0.005 95 5 0.0025 50 untreated control --- 0 Example 17 Cotton plants approximately 22 cm in height having 3-4 true leaves were sprayed to run-off with an aqueous dispersion of dimethyl N,N'-fβ,2-ethanediylbis [thio(methylimi no) carbonyloxy] ]]bis(ethanimidothioate) (1) at a concentration of 0.05%. The spray contained Duponol L-144-WDG at a concentration of 1:3000. Another set of plants was similarly treated with methomyl. Plant injury was evaluated 6 days after treatment and is recorded below.

Treatment Injury Rating* methomyl *Scale: 0 = no injury = plant killed slight trace

Claims (14)

1. A compound of the formula 5 RjS CHg CHg SR 1 wherein R is branched or straight chain alkyl containing 1 to 3 carbon atoms or methoxymethyl; R-j is branched or straight chain alkyl containing 1 10 to 3 carbon atoms; R 2 is -CH 2 CH 2 -, -CH 2 CH- or -CHgCHgZCHgCHg-; and Z is 0 or S.

2. A compound of claim 1 wherein R is methyl or ethyl 15 and R-j is methyl.

3. A compound of claim 1 or 2 wherein R is methyl and R 2 is -CH 2 CH 2 ~. - 29 A compound of claim 1 wherein Rg I s -CHgCH., or CH. -ch 2 ch~.

4. 5. A compound of claim 1 which is dimethyl-N,N 1 -[[l ,25 eth ane d iyl bis[thi o (methyl imi no) carbo nyl oxy] J J bis (ethaneimidothioate) having the formula: CHg—C = N— 0 — C — N—S —CHgCHg— S-N—- C — 0—N = C—CHg CHgS CHg CH. SCHg 10

5. 6, A composition suitable for control of pestiferous insects comprising an effective amount of an insecticidal compound and at least one of (a) an inert diluent and (b) a surfactant characterised in that said insecticidal compound is a compound of any of claims 1 - 4. 15

6. 7. The composition of claim 6 wherein said insecticidal compound is the compound of claim 5. - 30

7. 8. A method for control of pestiferous insects by applying to a locus of infestation, to the area to be protected or to the pests themselves, an effective amount of an insecticidal compound characterised in that said 5 insecticidal compound is a compound of any of claims 1 - 4.

8. 9. The method of claim 8 wherein said insecticidal compound is the compound of claim 5.

9. 10. A process for preparing a compound of claim 1 10 characterised in that compounds of the formulae: R-C = NO-C-NH and XS·-R,-SX I 2 SR ] CH 3 wherein 15 X is a halogen atom; and R, R^ and Rg are as defined in claim 1, are reacted in an inert organic solvent in the presence of a base.

10. 11. A compound substantially as hereinbefore described with reference to the Examples. 47 205 - 31

11. 12. A composition substantially as hereinbefore described with reference to the Examples.

12.

13. A method substantially as hereinbefore described with reference to the Examples. 5

14. A process substantially as hereinbefore described with reference to the Examples. Dated the 30th day of June, 1978. CRUICKSHANK & CO. Agents for the Applicants, Youghal House, 13 Trinity Street, Dublin, 2.