IL45926A

IL45926A - Thiadiazole phosphates and thiophosphates process for preparing them and pesticidal compositions

Info

Publication number: IL45926A
Application number: IL45926A
Authority: IL
Original assignee: Roussel Uclaf
Priority date: 1973-10-26
Filing date: 1974-10-24
Publication date: 1977-08-31
Also published as: HU171036B; ZA746781B; SU607531A3; NL7413912A; DD118225A5; GB1434699A; CA1024151A; BR7408951A; IE41208B1; BE821420A; DD123475A5; IL45926A0; PH12199A; FR2249092B1; AR210251A1; JPS5071677A; LU71167A1; FR2249092A1; IE41208L; CH594691A5

Abstract

1434699 Pesticidal phosphorus-containing thiadiazole derivatives ROUSSEL-UCLAF 24 Oct 1974 [26 Oct 1973] 46856/74 Headings C2P and C2C Novel compounds of Formula I where R is C 1-3 alkyl, X is O or S, X is -O-, -S-, -NH- or -NC 1-3 alkyl-, n is 1 to 4 and R<SP>1</SP> is H, CN, alkoxycarbonyl, C 1-3 alkoxy, C 2-4 alkenyl, phenyl or phenyl substituted by 1 or 2 halogen atoms, C 1-3 alkyl radicals and/or C 1-3 alkoxy radicals; may be prepared by reacting a compound of Formula II with a compound of Formula III where Hal is halogen. The starting materials of Formula II are prepared by ring closure of a compound of Formula IV where A is CN or alkoxycarbonyl and M is H or alkali metal, ring closure being carried out by oxidation where A is CN and by reaction with ammonia in the presence of an alkali metal hypohalite where A is alkoxycarbonyl. Intermediates of Formula IV are prepared as follows: (a) S - p - chlorobenzyl - S - potassium - N - cyanodiethioimidocarbonate by reacting dipotassium N-cyano-dithioimidocarbonate with p - chlorobenzyl chloride; (b) N,N - dimethyl - N<SP>1</SP>- ethoxycarbonyl-thiourea by reacting dimethylamine with ethoxycarbonyl isothiocyanate; (c) O - p - chlorobenzyl - S - potassium - N - cyanothioimidocarbonate by reacting sodium hydride with p-chlorobenzyl alcohol and carbon disulphide to give S-sodium-O-p-chlorobenzyl-dithiocarbonate, methylating this to give S-methyl-O- p-chlorobenzyl-dithiocarbonate and reacting this with cyanamide and potassium methylate; (d) O - n - butyl - S - sodium - N - cyano - dithiocarbonate as in (c) via S-potassium-O-n-butyldithiocarbonate and S - methyl - O - n - butyldithiocarbonate; (e) O - methyl - S - potassium- N-cyanothioimidocarbonate by reacting dimethylthiocarbonate with cyanamide and potassium methylate; and (f) O-n-propyl-S-sodium-N- cyano - thioimidocarbonate as in (c) via S- potassium - O - n - propyl - dithiocarbonate and S-methyl-O-n-propyl-dithiocarbonate. The compounds of Formula I have insecticidal and nematocidal properties and may be used as the active ingredients in conventional pesticidal compositions. [GB1434699A]

Description

45926/2 NEW THIADIAZOLE PHOSPHATES AND THIOPHOSPHATES, PROCESS FOR PREPARING THEM, AND PESTICIDAL COMPOSITIONS mmsm omn.-T? -p*?nn D-* m cno3Oi3i"»m D">D9D13 ^πίρ-η ιι 45926/2 The present invention has as its subject the new thiadiazole derivatives of formula I: in which R is an alkyl radical having from 1 to 3 carbon atoms, W 1s an oxygen or sulphur atom, X 1s an oxygen or sulphur atom or a nitrogen atom bearing an alkyl radical having from 1 to 3 carbon atoms, n 1s an integer which can vary from 1 to 4, R* represents a hydrogen atom,*a- cyano-group, an alkenyl radical having from 2 to 4 carbon atoms or a phenyl radical which may be unsubstituted or monosubstituted by a halogen atom, an alkyl or alkyl oxy radical having from 1 to 3 carbon atoms or di substituted by halogen atoms or by alkyl or alkyloxy radicals having from 1 to 3 carbon atoms.

When R 1s an alkyl radical, it can be a propyl, isopropyl or preferably ethyl or methyl radical.

When X represents a nitrogen atom, this latter bears a propyl, isopropyl, ethyl radical or preferably a methyl radical. isopropyloxy,½othoxy or preferably ethoxy-,- When R' is an alkenyl radical, it can be: 2-methyl 1-propenyl, l-methyl 1-propenyl, 2-methyl 2-propenyl, l-methyl 2-propenyl, Ι-butenyl,· 2-butenyl, 3-butenyl, allyl, isopropenyl, 2-methyl vinyl or preferably vinyl.

When R' is a monosubstituted phenyl radical, the substituent, which can be in the ortho, meta or preferably para position, can be an isopropyloxy, propyloxy, ethoxy, methoxy, isopropyl, propyl, ethyl, or methyl radical, or an iodine, bromine, fluorine or preferably chlorine atom.

When the radical R' is a disubstituted phenyl radical, the substituents can be independently isopropyloxy, propyloxy, ethoxy, methoxy, isopropyl, propyl, ethyl, or methyl radicals, or iodine, bromine, fluorine or preferably chlorine atoms.

The invention relates especially to the compounds of formula I, as defined above, characterised in that R represents an ethyl or methyl radical, X represents an oxygen or sulphur atom, or a nitrogen atom substituted by a methyl radical, n is a number equal to 1,2 or , R' represents a hydrogen atom, a p-chlorophenyl group, a phenyl group, a vinyl group, a p-tolyl group or an o-p-dichlorophenyl group.

The products of the invention are endowed with make insecticidal and nematocidal properties which/them suitable for use in controlling insects and nematodes.

The insecticidal properties of these products can be made evident especially by tests on Prodenia litura, Drosophiia melanogaster, Blatella germanica, Sitophilus granarius and Tribolium confusum.

The nematocidal properties can be made evident by tests on Panagrellus Silusiae and Ditylenchus Miceliophagus.

The invention also has as its subject a process for preparing the products corresponding to formula I, a process characterised in that a compound of formula IV: in which R1 , X and n have the meaning already indicated and in which A represents a cyano or alkyloxycarbonyl group and M a hydrogen or alkali metal atom, is subjected to cyclisation, in the presence of an oxidising agent when A represents a cyano group or in the presence of ammonia and an alkaline hypohalite when A represents an alkyloxycarbonyl group and then the compound of formula II: thus obtained is condensed with a compound of formula III: W (III) formulae in which R, R' , X, W and n have the same meaning as before and Y represents a halogen atom.

The oxidising agent used is preferably hydrogen peroxide, but bromine in aqueous medium or an organic peracid such as, for example, peracetic acid, monoperphthalic acid or perbenzoic acid can also be used.

The condensation of compound II with compound III can be .carried out in a solvent such as, for example, acetone or acetonitrile and in the presence of a base such as triethylamine or an alkaline carbonate.

The compounds of formula IV used at the start of the process of the invention can be prepared, when they are not known, according to one of the following methods, illustrated by Examples in the experimental portion: a) when X represents a sulphur atom, by the reaction of a compound of formula: N-A in which M and A have the aforementioned meaning, with a compound of formula: R'-(CH2)n-Z R* and n having the aforementioned meaning and Z being an electro-negative group such as, for example, a halogen atom or a R'-(CH2)n-S0^ -radical, b) when X represents an oxygen atom, by the reaction of a compound of general formula A-NHg in which A has the aforementioned meaning with a xanthic ester of formula R'-(CH9) -O-C-S-alc in which R' and n have the aforementioned ^ n If S meaning and ale represents an alkyl radical having from 1 to 3 carbon atoms, followed by the action of an alkaline alcoholate to obtain a compound of formula IV. in which R' and n have the aforementioned meaning and alc^ represents an alkyl radical having from 1 to 3 carbon atoms.

The invention also comprises insecticidal or nematocidaJ compositions containing as active material one, at least, of the compounds of formula I.

These compositions can be presented in the form of and powders, granules, suspensions, emulsions/ solutions, containing the active principle, for example in admixture with a vehicle and/or an anionic, cationic or non-ionic surface-active agent, ensuring, inter alia, uniform dispersion of the substances of the composition. The vehicl used can be a liquid such as water, alcohol, hydrocarbons or other organic solvents, a mineral, animal or vegetable oil or a powder such as talc, clays, silicates or kieselguhr.

The insecticidal liquids or powders for foliar spraying preferably contain from 10 to 80% by weight of active material.

As insecticidal composition there will be used, for example, an emulsifiable concentrate containing by weight 15% of 3-(diethoxythiophosphoryloxy)5-(p-chlorobenzylthio) 1,2, -thiadiazole, 6.4-% of Atlox -851 (oxyethylenated triglyceride combined with a sulphonate, acid index : 1.5)» 3.2% of Atlox 4-855 (oxyethylenated triglyceride combined with a sulphonate, acid index : 3) an 75.4-% of xylene.

The following Examples illustrate the invention without, however, giving it any limiting characteristic.

Example 1 : 3~(diethoxythiophosphorylox ) 5-methylthio 1,2,4-thiadiazole f^l a 3-hydroxy 5-raethylthio 1 ,2,4-thiaziazole ^ 80g of dipotassium N-cyano dithioimidocarbonate and 50.4g of dimethyl sulphate are introduced into 500 cm of water. This is allowed to react for two hours at ambient temperature, filtered, and 44 cm^ of 30% hydrogen peroxide are added, drop by drop, to the filtrate.

The whole is then acidified using 40 cm 3 of concentrated hydrochloric acid and cooled with an ice bath. The crystals thus obtained are filtered, washed with water and dried; 36g of 3-hydroxy 5-methylthio 1,2,4-thiadiazole are thus . obtained, M.P . = 160°C. b) 5~(diethoxythiophosphoryloxy) 5-methylthio 1 ,2,4-thiadiazole A mixture of ?.6g of the product obtained previously, 9- 5g of diethylchlorothiophosphate and 7g of potassium carbonate in 0 cm of acetone is agitated for one night at ambient temperature. The reaction mixture is filtered and the filtrate is concentrated by evaporation under reduced pressure, then chromatographed on a column of silica , eluting with a benzene/ethyl acetate mixture, 9-1. 20 Ef = 0.4 D = 1.5534.

Example 2: 3-(dimethoxythiophosphoryloxy) 5-methylthio 1 ,2,4-thiadiazole Operating as. in paragraph b of Example 1 but using dimethylchlorothiophosphate, 3~(dimethoxythiophosphoryloxy) 5-methylthio 1,2,4-thiadiazole is obtained, M.Pt. = 45°0.

Example : 3~(diethoxythiophosphoryloxy) 5-ethylthio 1 ,2,4-thiadiazole a) 3-hydroxy 5-ethylthio 1,2,4-thiadiazole Operating as in paragraph a of Example 1 but using b) -(diethoxythiophosphoryloxy)5-ethylthio 1 ,2,4-thiadiazole Operating as in paragraph, b of Example 1 but using the product obtained in the paragraph above, there is obtained, after chromatography in benzene, ^-(diethoxythiophosphoryloxy) 20 5-ethylthio 1 ,2,4-thiadiazole , Rf = 0.55, n D - 1.53 5- Example 4: 3-(diethoxythiophosphoryloxy) 5-P-chlorobenzylthio 1 ,2,4-thiadiazole a) S-p-chlorobenzyl and potassium N-cyano dithioimidocarbonate A mixture of 80g of dipotassium N-cyano dithioimidocarbonate, 6 . g of p-chlorobenzyl chloride, 00 cur 3 of methanol and x 400 cm of water is agitated for five hours. The solvents are evaporated and the residue is recrystallised in ethanol.

S-p-chlorobenzyl and potassium N-cyano dithioimidocarbonate is thus obtained, M.Pt. = 250°C (decomposition). b) 3-hydroxy 5-p-chlorobenzylthio 1,2,4-thiadiazole l44g of S-p-chlorobenzyl and potassium N-cyanodithioimido-carbonate and 48 cm^ of $0% hydrogen peroxide are introduced into 1 litre of water. The mixture is heated to 65°C, and allowed to return to ambient temperature and the solution if filtered.

The filtrate is acidified with 40 cm of concentrated hydrochloric acid. The crystals obtained are filtered, washed with water and dried. 90g of 3-hydroxy 5"(p-chloro-benzylthio) 1 ,2,4-thiadiazole are thus obtained, and can be recrytallised in ethyl acetate, M.Pt. = 138°C. c) 3-(diethoxythiophosphoryloxy) 5-p-chlorobenzylthio 1 ,2,4-thiadiazole Operating as in paragraph b of Example 1, but starting with the product obtained in the preceding paragraph b, there is obtained, after chromatography in a cyclohexane/ethyl acetate mixture 9'-l, 3-(diethoxythiophosphoryloxy) 5-p-chlorobenzylthio 20 Operating as in paragraph c of Example 4 , hut using dimethylchlorothiophosphate 3~( imethoxythiophosphoryloxy) 5-p-chlorobenzylthio 1 , 2 ,4-thiadiazole is obtained, 20 Rf = 0.35 , n D = 1.605.

Example 6 ; $-(dimethoxythiophosphoryloxy) 5-dimethylamino 1, 2,4-thiadiazole a) Ν,Ν-dimethyl N-ethoxycarbonyl thiourea 180 cm^ of a 10% solution of dimethylamine in ether are added to a solution of 40g of ethoxycarbonyl isothiocyanate , in 200 cm of benzene. The temperature of the reaction mixture is maintained at 20 - 25°C and after fifteen minutes' agitation the solvent and the excess dimethylamine are evaporated. The final oil crystallises. M.Pt. = 66°C.

Rf. = 0.25 (silica/benzene 9/ethyl acetate l) . b) 3-hydroxy 5-dimethylamino 1 , 2 ,4-thiadiazole A solution containing 43g of Ν,Ν-dimethyl N'-ethoxy-carbonylthiourea, 25 cm 3 of soda lye and 2 0 cm 3 of water and a 1 M solution of sodium hypochlorite are poured simultaneously, at a temperature between 0° and 5°C into 5Ο cm of concentrated ammonia.

The reaction mixture is agitated for two hours at 0 - 5°C, then three hours at ambient temperature, and it is then concentrated by evaporation until solid.

This- solid is brought to pH 4 using concentrated hydrochloric acid. The solution thus obtained is extracted with chloroform, and the organic phase is dried over magnesium sulphate, then evaporated to dryness. The crystals obtained are washed with petroleum ether (B.Pt. 40 - 75°C) . llg of 3-hydroxy 5-dimethylamino 1,2 ,4-thiadiazole are obtained, M.Pt. = 142°C, Rf (acetone 1, CHCl^l) = 0.2. c) 3-(dimethoxythiophosphoryloxy) 5-dimethylamino 1, 2 ,4- carbonate in 10 cm of acetone is agitated for sixteen hours at ambient temperature. /p The reaction mixture is then filtered and the filtrate is concentrated by evaporation, then chromatographed on a column of silica, eluting with an ethyl acetate 6/cyclohexane 4-mixture. 3-(dimethoxythiopho6-phoryloxy)5-d.imethylamino 1,2, -thiadiazole is obtained, Ef = 0. 5-Example 7· 3-(diethoxythiophosphoryloxy)5-dimethylamino 1,2,4--thiadiazole Operating as in paragraph c of Example 6, but using .ethylchlorothiophosphate, there is obtained, after chromatography in a benzene/ethyl acetate mixture 8 - 2, 3~(diethoxythiophosphoryloxy)5-dimethylaLmino 1,2, -thiadiazole Ef = 0.55, .M.Pt. = 8°C.

Example 8: 3~(diethoxythiophosphoryloxy) 5-ethoxy 1,2,4- thiadiazole a) 3-hydroxy 5-ethoxy 1,2 , -thiadiazole 200g of 0-ethyl and potassium M-cyano thioimidocarbonate are introduced into 800 cm 3 of water. 130 cm^ of 30% hydrogen peroxide are added in portions of 10 cm . The whole is allowed to return to ambient temperature and 30 of sodium bicarbonate are then added.

The solution is washed with 500 cur 3 of ethyl acetate, then taken to pH 3 using concentrated hydrochloric acid. It is extracted with ethyl acetate and the organic phase is dried over sodium sulphate, then evaporated to dryness.

The 85g of oil thus obtained are crystallised in 200 cm of ether and the crystals are recrystallised in benzene; 28g of 3-hydroxy 5-ethoxy 1 ,2, -thiadiazole are thus obtained, M.Pt. = 98°C. hours at ambient temperature.

The reaction mixture is then filtered and the filtrate is concentrated by evaporation, then chromatographed on a column of silica, eluting with benzene (Rf. 0.3). 19g °f 3-(diethoxythiophosphoryloxy) 5-e oicj 1,2,4-thiadiazole 20 are obtained, n D = 1.503· Example : 3-(dimethoxythiophosphoryloxy) 5-ethylthio 1 ,2, -thiadiazole Operating as in paragraph b of Example 3 but using dimethylchlorothiophosphate,there is obtained, after chromatography in benzene, 3-(dimethoxythiophosphoryloxy)5- 20 ethylthio 1,2,4-thiadiazole, Rf. = 0.5, n D = 1.559.

Example 10: 3-(dimethoxyphosphoryloxy) 5-ethylthio .1,2,4-thiadiazo1e Operating as in paragraph b of Example 3» but using 0,0-dimethylchlorophosphate, the product expected is obtained.

Rf. = 0.2 (silica, cyclohexane/ethyl acetate 4 - 6).

Example 11: 3-(dimethoxyphosphoryloxy) -P-chlorobenzylthio 1 ,2,4-thiadiazole Operating as in paragraph c of Example , but using 0,0-dimethylchlorophosphate, the product expected is 20 obtained, n ^ = 1.5885.

Example 12: 5~(diethoxythiophosphoryloxy) 5-benzylthio 1 ,2,4-thiadiazole Stage A: 5-hydroxy 5-benzylthio 1,2,4-thiadiazole A mixture of 194.4g of dipotassium N-cyano dithioimido-carbonate, 150 cm of water, 1 litre of methanol and 126. g of benzylchloride are agitated for one hour at ambient temperature, and filtered, the methanol is evaporated, 2.5 litres of water are again added to the residue, then 110 cm^ of 3% hydrogen peroxide are slowly added. The whole is maintained under ° ° 80 g. of the product expected are obtained. M.Pt. = 125°C.

Stage B : 5~(diethoxythiophosphoryloxy) 5-benzyloxy 1,2,4-Whia- diazole Work is carried out as in stage b of Example 1, starting with 22.4 g of the product obtained in the previous stage and operating in acetonitrile . 10. g of the product expected are obtained. M.Pt.<5°°c- Example 15 5~(diethoxythiophosphoryloxy) 5-allythio 1,2,4-thia- diazole Stage A : 3-hydroxy 5-allylthio 1 , 2,4-thiadiazole Work is carried out in a manner similar to that described in Stage A of Example 12, starting with 195 g of potassium N-cyano dithioimidocarbonate and 77 g of allyl chloride, then oxydising with 100. cm3 of 30% hydrogen peroxide. 63 g of the product expected are obtained. M.Pt. » 84°C.

Stage B : 5-(diethoxythiophosphoryloxy) 5-allylthio 1, 2,4-thiadiazole Work is carried out in a manner similar to that described in Stage B -,of Example 12, starting with 8„7g of the product obtained in the previous stage. 13 g of the 20 product expected are obtained. n » 1.5525· D Example 14. : 5-(diethoxythiophosphoryloxy) 5-P-methylbenzylthio- 1, 2,4-thiadiazole Stage A : 3~hydroxy .5~P~methylbenzylthio 1 , ,4-thiadiazole Work is carried out in a manner similar to that describe ed in Stage A in Example 12, starting with 58.2 g of potassium N-cyanodithioimidocarbonate and 42 g of p-methyl benzyl chloride, then oxyising with 35 cm3 of 30% hydrogen peroxide. 26 g of the product expected, are obtained. II.Pt. = 144°C.

Stage B : 5-(diethoxythiophosphoryloxy) 5~P-rcethylbenzylthio 1, ,4-thiadiazole 10.1 g of triethylamine . 10.5 g of the product expected are obtained. M.Pt. <= 0°C. ■ ^ Example 1 : .3-(dietboxythiophosphoryloxy) 5-p-chlorobe zyloxy 1 , , -thiadiazole Stage A: Sodium O-p-chlorobenzyl dithiocarbonate 14-2 g of p-chlorobenzyl alcohol and 1.200 cm3 of tetrahydrofuran are mixed, 5 g of sodium hydride (5o% in mineral oil) are added, over half an hour, the whole is taken to reflux for 2 hours, and filtered, and 76 g of carbonsulphide are added to the filtrate. The whole is agitated for half an hour at 20°C and evaporated to dryness. The residue is taken, up in ether, vacuum-filtered and 205 g of "the product expected are obtained. M.Pt. = 250°C.

Stage B: Methyl O-p-chlorobenzyl dithiocarbonate A mixture of 205 g of the product obtained in Stage A, 500 cm3 of benzene and 500 cm3 of methyl iodide ' are taken to reflux for 2 hours 30 minutes, filtered, and the filtrate is concentrated to dryness. 196 g of the product expected are obtained.

Stage C : O-p-chlorobenzyl and potassium N-cyano thioimido- carbonate 60 g of potassium methylate and 700 cm3 of ethanol are mixed, 3^ g of cyanamide are added and, after dissolution, 200 g of the product obtained in Stage B are added. The whole is maintained for 17 hours under agitation at 20°C, the crystals: obtained are vacuum-filtered and washed with ether and 126 g of the product expected are obtained. M.Pt. = 24 °C. Stage D: 3-hydroxy 5-P-chlorobenzyloxy 1 , 2 , --thiad iazole Work is carried out in a manner similar to that described in Stage A of Example 12, using 13 g of the product obtained in the previous stage and 6 cm3 of 30% hydrogen pero the product expected are obtained. M.Pt. = 170 C.

Stage E : 5-(diethoxythiophosphoryloxy) 5~P~chlorobenzylc^y 1 , 2,4-thiadiazole Work is carried out in a manner similar to that described in Stage D of Example 12, starting with 2.5 g of the product obtained in the previous stage and 1.3 g of the 20 product expected is obtained, n = 1.50 5.

D Example 16 : 5~(diethoxythiophosphoryloxy) 5~n-butoxy 1 , 2 ,4-thiadiazole Stage A : Potassium O-n-butyl dithiocarbonate 280 g of potassium in pellets and 2.5 litres of butanol are mixed, then, at 20-30°C, 380 g of carbon sulphide are added. The whole is maintained under agitation for 2 hours, vacuum-filtered, the precipitate is washed with butanol, then with ether and 640 g of the product expected are obtained. M.Pt.C-H2600C (decomposition) Stage B : . Methyl O-n-butyl dithiocarbonate A mixture of.190 g of the product obtained in the previous stage, 1 litre of benzene and 500 cm3 of methyl iodide is taken to reflux for 10 hours, filtered, and the filtrate is evaporated to dryness. The residue is rectified and 1 6 g of the product expected are obtained. B.Pt.Q = 74-°C. Stage C : O-n-butyl and sodium N-cyanothioimidocarbonate 42 g of cyanamide are added, at 20°C, to a solution of 55 g of sodium methylate in 360 cm3 of methanol and 360 cm3 of ethanol, then 164 g of the product, obtained in the previous stage' are added and the whole is maintained under agitation at 20°C for 17 hours. This is evaporated to dryness, the residue is washed with ether and 120 g of the product expected are obtained. MPt. = 240°C.

Stage D : 3~hydroxy- 5~n-butyloxy 1, 2,4-thiadiazole previous stage. 200 cm3 of water and 500 nig of phenolphthaMn,' a basic pH is maintained "by adding soda, the whole is cool^ and the sodium salt of the product expected is vacuum-filtered-.

This salt is put into suspension in 100 cm3 of water, acidified with hydrochloric acid, extracted with ethylacetate and 58 g of "the product expected are obtained. M.Pt. = 62°C.

Stage E: ~(diethoxythiophosphoryloxy) 5~n-butoxy 1 , 2,4-thia- diazole Work is carried out in a manner similar to that described in Stage B of Example 12, starting with 8.8 g of the product obtained in the previous stage and 12 g of the 26 product expected are obtained, n-^ = 1.4-960.

Example 17· 3~(diethoxythiophosphoryloxy) 5~ ( 2,4-dichloro- benzylthio) 1 , 2 , 4-thiad.iazole Stage A : 3-hydroxy 5- ( 2,4-dichlorobenzylthio) 1 , 2,4-thiadiazol 69*9 g.of dipotassium N-cyanodithioimidocarbonate , 50 cm3 of water and 300 cm3 of methanol are mixed, then, at 30°C, 2 of 2,4-dichlorobenzylchloride are added, the whole is then maintained at 30°C under agitation for 30 minutes,the methanol is eliminated under reduced pressure, 900 cm3 of water are added to the residue and 0 cm3 of 30% hydrogen peroxide are slowly added. The basic pH is maintained by adding potash, the whole is maintained for 17 hours under agitation, washed with ethylacetate, acidified by adding hydrochloric acid, the precipitate is vacuum-filtered and recrystallized in toluene. 2 g of the product expected are obtained. M.Pt. = 134°C. ■ Stage B : 3-(d.iethoxythiophosphoryloxy) 5- ( 2,4-dichIo obenzyl- thio) 1 , 2,4-thia iazole Work is carried out in the manner similar to that described in' Stage B of Example-.14, starting with 9.3 g of product expected are obtained, n^ = 1.5930.

Example 18 : 3~(fliethoxythio ihosphoryloxy) 5~methoxy 1,2,4-thia diazole Stage A : 3~hydroxy 5-methoxy 1,2,4-thiadiazole 46.2 g of 0-methyl and potassium N-cyanothioimido- carbonate (obtained in a manner similar to that described in Example 15, Stage C, starting with dimethylthipcarbonate - described in BEILSTEIN - 3, 208, I 83, II 151 -) are mixed with 1 0 ml of water/ and, at 70 C» 60 cm3 of 30% hydrogen peroxide are slowly added, maintaining the pH at 8.4 - 8.6 by adding potash.

The whole is then washed with ether, acidified and the precipitate obtained is vacuum-filtered. 18 g of the product expected are obtained. M.Pt. = 146°C.

Stage B : 3~(diethoxythiophos horyloxy) 5~methoxy 1,2,4-thia- diazole Work is carried out in a manner similar to that described in Stage B of Example 1, starting with 6.6 g of the product obtained in Stage A and 10 g of 0,0-diethyl chlorothio- phosphate and 4.2 g of the product expected are obtained. ^5= I.5II4-.

Example 19· 5-(diethoxythiophosphoryloxy) 5~n~propyloxy 1 , 2,4-thiadiazoie Stage A : Potassium 0-n-propyl dithiocarbonate 280 g of potash are dissolved in 2 litres of propanol and, at 20°C, 38Ο g of carbon sulphide are added, then the whole is maintained for 2 hours under agitation. The precipitate formed is vacuum-filtered and 624 g of the product expected are obtained. MPt. = 230°C.

Stage B: Methyl 0-n-propyl dithiocarbonate 429 g of the product obtained in the previous under agitation for 17 hours, the organic phase is decanted 20 ^ I and 338 g of the product expected are obtained, n = 1.53 ρ· D B.Pt^ = 60°C.

Stage C : Q-n- ropyl and sodium N-cyano t ioimidocarbonate 51. 7 g of sodium are dissolved in 2 litres of propanol and °A.6 g of cyanamide are added, then the whole is maintained under agitation for 15 minutes and 338 g of the product prepared in Stage B are added. This is maintained under agitation for 24- hours at 35°C, under a current of inert gas. The whole is concentrated to dryness and 4-16 g of the product expected are obtained.

Stage D : 3~hydroxy 5~n~propyloxy l,2,4--thiadiazole The product obtained in Stage C is dissolved in 1 litre of water and, at 80°C, over two hours, 4-50 cm3 of 30% hydrogen peroxide are added, the pK being kept' ' alkaline by the addition of soda. This is maintained under agitation for 24- hours, then cooled, washed with ethylacetate , acidified by adding hydrochloric acid and the precipitate is vacuum-filtered, and washed with water and dried. 200 g of the product expected are obtained. M.Pt. = 92°C.

Stage E : 3~(diet;hoxythiophosphoryloxy) 5-n-propyl l,2,4--thia- diazole Work is carried out in a manner similar to that described in Stage B of Example 12 starting with 24- g of the product obtained in stage D and 28.3 S of 0,0-diethyl chlorothiophosphate , and 1?· 5 E °? the product expected are obtained, n26*5 = I.5OOO.

D . - .

Study of the insecticide! activity of the products of Examples 4-, 9,11, 13 and 16 A) Test on grain weevil (Sitophilus granarius) : 0. 2 μΐ-of acetonic solution of the product to be The concentrations 50 individuals per concentration are used. he test insects are kept at 20°C and checks are carried out four hours, twenty-four hours, forty-eight hours, five days and six days after, treatment.

The experimental results, obtained with the compounds of Examples 9, 11, 13 and 16 and expressed in percentage mortality, are summarised in the following Table: Test on Tribolium confusu : The test is similar to that used for Sitophilus granarius (topical application test) . Checks are carried out 5 days after treatment.

The experimental results , obtained with the compound of Example 9 and expressed in percentage mortality, are summarised in the following Table: Concentrations in 5, 000 2, 500 5OO p.p.m Percentage mortality after 24 hours 92.3 58.8 8 Percentage mortality C) Test on fruit fly ("Drosophila melanogaster) : a This test measures the activity as /vapour. It consists in placing the insects in a Petri dish, which shroud is connected by a tergal / . to a crystallizing dish of the same diameter, in which is placed the compound to be tested in acetonic solution, which is evaporated before introducing the insects. Three tests per concen tration are made and there are 25 individuals per concentration (adults, less than forty-eight hours old). The : are expressed in percentage mortality after one hour two hours, four hours, six hours, then after twenty-four hours (with reference to untreated controls).

The following Table summarises the experimental results obtained with the compounds of Examples 9,11»13 and 16.

D) Test on noctua (ingestion) : Caterpillars of Prodenia litura are used. Discs, 8 mm in diameter, cut from lettuce leaves, are introduced into closed plastic boxes. 4 μΐ of acetonic solution of the product to be tested are deposited on each leaf-disc. 15 caterpillars per treatment are used (caterpillars aged 10 days on average). The animals are left at 20°C in natural light with a relative humidity of 50%. The individuals are fed after they have-consumed the treated pellet. Checks are carried out one hour, twenty-four hours and forty-eight hours after treatment.

The experimental results obtained with the compounds of Examples 4 and 16 express percentage mortality, are summarised in the following Table: Concentration in p.p.m. of active 5OO 250 l?5 material , Products of Examples 4 16 4 16 4 16 1 hour 0 0 0 0 0 0 24 hours 80 20 60 30 60 0 48 hours 100 100 100 70* 80 30 100% mortality after 4 days of contact.

Test on cockroach (male Blatella germanica) This test. is carried out by micro-contact. Males of ger anic cockroaches receive a micro-drop of acetonic solution between the second and third pairs of legs. After treatment, "test insect;/' are kept in dim light at 20°C. Checks are carri out twenty-four hours } forty-eight hours then five days after treatment. results The experimental/obtained with the compounds of Exami ie:: Percen ge Concentration' in p.p.m. of active .mater* 4 Mo tality Product of- ■Examples /liter 2 hours After 8 hours After 5 days'" F) Test on Panagrellus Silusiae O.5 cm3 of water containing about 2,000 nematodes is deposited in a pill box". · . containing 10 cm3 of aqueous to be tested, insecticidal solution/ Mortality checks are carried out with a binocular magnifying glass 24 hours after treatment and on three repeats', each corresponding to a sample of 1 cm3 of the solution to be tested.

The experimental results obtained with the compound of Example 4 are summarised in the following Table (results expressed in percentage mortality) : G) Test n Dit7flenchus Myceliophagus This is carried out in the same manner as with Panagrellus Silusiae.

The experimental results obtained with the compound of Example 4 are summarised in the following Table (results expressed in percentage mortality): H) Test on Musca domestica : This test is carried out by topical application.

Plies receive a micro-drop of acetonic solution of the product / with ethyl ether/ to be tested on t-he dorsal thorax after having been anaesthetised/.

The insects are kept at 20°C and 5 % relative humidity. They are fed with milk or water. Checks are carried one hour, then - I) Test on Aphis fabae: A test is' carried out by contact-ingestion on a bean plant (Vicia Faba) . After spraying the solution of the product to be tested, which ensures complete wetting of the plant, infestation is carried out at the rate of 20 wingless individuals per bean plant. The. bean, plants are surrounded with gauze to prevent the flight of the aphids. A count of the living and the dead is carried out as a' fuction of time. The results are expressed in Abbott percentage efficacy (taking into account the control test) .

The results obtained are as follows: J) Test on house fly larvae ( usca domestica) : This test is carried out by contact-ingestion. It consists in depositing 2 ml of acetonic solution at different concentrations of the compound to be tested on 1 g of bran, placed and, after having "been well mixed, it is contaminated with 20 house fly larvae aged from three to four days.

There are three tests per concentration. The larvae are kept at 20°C and 30% relative humidity. Checks are carried out forty-eight hours and eight days after treatment.

The experimental results obtained, expressed in percentage mortality, are summarised in the following Table:

Claims

WHAT IS CLAIMED IS :

1. The thiadiazole deri vatives of formula I : in which R is an al kyl radical having from 1 to 3 carbon atoms , W is an oxygen or sulphur atom, X is an oxygen or sulphur atom a nitrogen atom bearing- an al kyl radical having from 1 to 3 carbon atoms , n is an integer which can vary from 1 to 4, R' represents a hydrogen atom, a. cyano gro p, an al kenyl radical having from 2 to 4 carbon atoms or a phenyl radical capable of being unsubsti tuted, or monosubstituted by a halogen atom, an alkyl or al kyl oxy radical having from 1 to 3 carbon atoms or disubstituted by halogen atoms or by al kyl or alkyloxy radicals having from 1 to 3 carbon atoms .

2. The compounds of formula I , as defined i n claim 1 , in which R represents an ethyl or a methyl radi cal , X represents an oxygen or sulphur atom or nitrogen atom substi tuted by a methyl radical , n is a number equal to 1 or 2, R1 represents a hydrogen atom, a p-chl orophenyl group, a phenyl group, a vinyl group, a p-tolyl group or an ο,ρ-dichlorophenyl group.

3. 3-(diethoxythiophosphoryloxy) 5-methylthio 1 ,2,4-thiadiazole.

4. 3-(dimethoxythiophosphoryl oxy) 5 -ma th I t h o 1 ,2,4-thiadiazole.

5. 3-(diethoxythiophosphoryloxy) 5-ethyl thio 1 ,2,4-thiadiazole.

6. 3-(diethoxythiophosphoryloxy) 5-p-chl orbenzyl thio 1 ,2,4-thiadi azole.

7. - 3~(dimethoxythiophosr>horyloxy) 5-P"~chlorobenzylthio I, 2, 4-thiadiazole .

8. 3~(dimethoxythiophosphoryloxy) 5~diKe"th lamino 1,2,4-thiadiazole.

9. 3~(diethoxythiophosphoryloxy) 5-dimethylamino 1,2,4-thiadiazole.

10. 3_(diethoxythiophosphoryloxy) 5-ethoxy 1,2,4-thiadiazole.

11. II. 3-(dimethoxythiophosphoryloxy) 5-ethylthio 1 , 2,4-thiadiazole

12. 3-(dimethoxyph0sphoryloxy) 5-ethylthio 1,2,4-thiadiazole.

13. 3-(dime hoxyphosphoryloxy) 5_P_chlorobenzylthio 1,2,4-thiadiazole .

14. 3-(diethoxythiophosphoryloxy) 5~benzylthio 1 ,2,4-thiadiazole

15. 3-(diethoxythiophosphoryloxy) 5~allyl"thio 1,2,4-thiadiazole.

16. 3-(diethoxythiophosphoryloxy) 5~P~^e"thyl'benzylthio 1,2,4-thiadiazole.

17. 1 . 3-(diethoxythiophosphoryloxy) 5-p-chlorobenzyloxy 1,2,4-thiadiazole.

18. 3-(diethoxythiophosphoryloxy) 5-n-butoxy 1,2,4-thiadiazole.

19. 3-(diethoxythiophosphoryloxy) 5-(2,4-dic2ilorobenzylthio) 1,2,4-thiadiazole.

20. 3"(diethoxythiophosphoryloxy) 5_^ethox 1,2,4-thiadiazole.

21. 3~(diethoxythiophosphoryloxy) 5-n-propyloxy 1,2,4-thiadiazole.

22. A -process for preparing the compounds as defined in claim 1, characterised in that a compound of formula IV: in which R' X and n have the meaning already indicated and in -carbonyl which A represents a cyano or alkyloxy/group and M a hydrogen or alkali , metal atom, is 'subjected to cyclisation, in the or in the presence of ammonia and an alkaline hypohalite when A represents an alkyloxycarbonyl group and then the compound of formula II: (II) thus obtained is condensed with a compound of formula III : /OR Y-P ^OR - V/ (III) formulae in which R, R1 , X, W and n have the same meaning as before and Y represents a halogen atom.

23. · Insecticidal or nematocidal compositions, containing as active material one, at least, of the compounds as defined in claim 1.

24. '24. Insecticidal or nematocSdal compositions , containing as active material one, at least, of the compounds as defined in claim 2.

25. Insecticidal or nematocidal compositions containing as active material one, at least,- of the compounds as defined by any one of claims 3 to 21. P. O. Box 33116 , Tel-Aviv Attorneys for Applicant