FR2481070A1 - PROCESS FOR THE USE OF OXADIAZOLES SUBSTITUTED AS INSECTICIDES AGAINST IRON WIRES AND LARVES OF ALTISES AND AS INSECTICIDES AGAINST WHITE WORMS - Google Patents

Abstract

THE INVENTION IS IN THE FIELD OF PESTICIDES. IT CONCERNS A NEW METHOD FOR DESTROYING LARVAE OF INSECTS, WHICH CONSISTS OF APPLYING TO THE SOIL CONSTITUTING THE HABITAT OF THE SAID LARVES, AN EFFECTIVE QUANTITY FROM THE INSECTICIDE POINT OF VIEW OF A COMPOUND OF FORMULA: (CF DRAWING IN BOPI) IN WHICH R , R AND R ARE ALKYL GROUPS WITH 1 TO 4 CARBON ATOMS AND X, Y, Z AND V REPRESENT SULFUR OR OXYGEN. APPLICATION TO THE CONTROL AGAINST WALLWORMS, TAUPINS, TENEBRIONIDES AND ALTIZES AND AGAINST WHITE Worms.

Description

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  The present invention relates to certain oxadiazole derivatives and their use as insecticides against wireworms and larvae of flea beetles and as

  insecticides against white grubs.

  British Patent No. 1,213,707 discloses insecticidal compounds of the general formula R10

P; X2- in--

he

R2 3

  wherein X1 and X2, which may be the same or different, each represents an oxygen or sulfur atom; A represents an alkylene group; R1 represents an alkyl group, R2 represents an alkyl or alkoxy group; and R3 represents a hydrogen atom or an optionally substituted carbamoyl or amino group. As a particular example, the ninth compound at the top of Table 2 of this

  British patent is 3- (diethoxyphosphinothioylthio)

  methyl) -5-methyl-1,2,4-oxadiazole.

  Examples of the above-mentioned British patent illustrate insecticidal activity tests of some of the compounds on adult houseflies, mosquito larvae, cottontail moth larvae, aphids and watercress beetle adults,

  spider mites and caterpillars.

  U.S. Patent No. 4,028,377 discloses insecticidal compounds of the general formula

0-N OR3

R1- -CH3-S-P

  Wherein R1 is hydrogen, alkyl, benzyl or substituted phenyl, R2 is methyl or ethyl and R3 is unsubstituted C1-C7 alkyl optionally interrupted by oxygen or

C3 or C4 alkenyl group.

  Examples of the aforementioned U.S. Patent No. 4,028,377 illustrate insecticidal activity testing of some of the compounds on cotton ticks; tick larvae; mites; and root twisters in the soil. In this last test, the infested soil of the affected eellets is treated with the compounds to be tested, and then young tomato plants are planted immediately after the preparation of the soil or after

8 days waiting.

  British Patent No. 1,261,158 discloses compounds of the general formula: ## STR1 ## The first compound shown in Table I of the patent

  British Patent No. 1,261,158 cited above is 5- (diethoxy)

  phosphinothioylthiométhyl) -3-methylisoxazole. The compounds of the examples of the latter British patent have been subjected to insecticide efficacy tests on flies, mosquito larvae, moth larvae, watercress beetle, aphids, spider mites and

butterfly caterpillars.

  U.S. Patent No. 3,432,519 discloses various oxadiazoles bearing groups

  phosphate at position 5 on the oxadiazole ring.

  Example 2 reveals 3-methyl-5-chloromethyl-1,2,4-

  oxadiazole. The above-mentioned United States Patent No. 3,432,519 discloses in its example 4 that the last-named compound is used to destroy aphids,

spider mites and caterpillars.

  As described in the "Ortho Seed Treater Manual", filed in 1976, published by Chevron Chemical Company, page 27, wireworms and larvae of beetles were combated using a formulation.

  comprising a mixture of lindane (gamma isomer of

  chlorobenzene) and captan (n - (trichloromethyl) thio) -4-

  cyclohexene-1,2-dicarboximide). The present invention provides a method for destroying wireworms and / or flea beetle larvae by applying to the soil constituting the habitat of wireworms and / or flea beetle larvae an effective amount. from the insecticidal point of view, of a compound of formula: N

2> Z Y

R -C 3 C-CH 2 XP-ZR (I)

N VR3

  wherein R1, R2 and R3 are alkyl groups having 1 to 4 carbon atoms and X, Y, Z and V are sulfur or

oxygen.

  Advantageous compounds for use in this process include those wherein R 2 and R 3 are ethyl groups, and especially those which are further defined in that Y is sulfur and Z and V are oxygen. The compound used is very advantageously a compound which is further defined by the fact that R 1 is a methyl group and X

is sulfur.

  According to another of its aspects, the invention relates to an insecticide composition against wireworms and / or larvae of flea beetles, which composition contains an insecticidally effective amount against wireworm larvae and / or larvae. flea beetles of a compound of formula I, wherein R 1, R and R are alkyl groups having 1 to 4 carbon atoms; and X, Y, Z and V represent sulfur or oxygen; and a biologically inert carrier. The compound used in this form of

  embodiment of the present invention is preferably 3-

  methyl-5- (diéthoxyphosphorothioylthiométhyl) -1,2,4-oxadiazole.

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  The term "wireworm" is used in this specification to refer to wireworm larvae and also covers "false worms". The wireworms belong to the family Elateridae and the following genera belonging to this family are genera to which the insecticidal process of the present invention is most advantageously applied: Melanotus, Ctenicera, Conoderus, Limonius, Horistonotus and Agriotes. False wireworms belong to the family Tenebrionidae. The following genera belonging to the family Tenebrionidae are genera against which the application of the insecticide

  present invention: Eleodes, Blapstinus and Embaphion.

  The term "larvae of flea beetle" is used herein for the flea beetle larvae belonging to the family Chrysomelidae. The following genera belonging to the family Chrysomelidae are genera against which the application of the insecticidal method of this invention is particularly appreciated.

  Chaetocnema, Epitrix, Phyllotreta and Systena.

  The present invention also provides a method for destroying white grubs by applying to the soil constituting the habitat of white grubs an insecticidally effective amount of a compound of formula I. Particularly advantageous compounds for use in this embodiment include those in which R 2 and R 3 are ethyl groups and especially compounds which are further defined in that Y is sulfur and Z and V are oxygen. The compound used is very advantageously a compound which is moreover

  defined in that R1 is methyl and X is sulfur.

  In another aspect, the present invention provides an insecticide composition against white grubs, comprising an insecticidally effective amount against white grubs, of a compound of formula I wherein R, R2 and R3 are alkyl having 1 to 4 carbon atoms; and X, Y, Z and V are 2,448 sulfur OR oxygen; and a biologically inert carrier. Preferably, the compound used in this form of

  embodiment of the present invention is 3-methyl-5-

  (Diethoxyphosphorothioylthiomethyl) -1,2,4-oxadiazoleo The term "white grub" is used herein for the purpose of designating larvae of scarabeids. Scarabaeids belong to the family Scarabeidae. The following genera belonging to the family Scarabeidae are genera against which the application of the insecticidal method of the present invention is particularly appreciated: Po2illia ,. Lachnostera, Premnotrypes, Costelytra, Phyllophaga, Heteronychus and Diaprepeso The compounds of this

  invention by subjecting 3-alkyl-5-chloromethyl-1,2,4-

  oxadiazoles (II) to a phosphorylation reaction.

  The 3-alkyl-5-chloromethyl-1,2,4-

  oxadiazoles (II) by condensing the corresponding alkylamidoximes

  (obtained from nitriles - see Chem Revs.

  61, 155 (1961)) with chloroacetyl chloride.

N-OH O N ----- O

  The 3-alkyl-5-chloromethyl-1,2,4-oxadiazoles are phosphorylated with phosphates of the general formula (III) to form the compounds (I) above. M = KNae and NH4e MbX-P This last reaction can be carried out in various solvents such as acetone, acetonitrile, ether, methanol, benzene, and the like. Preferably,

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  equimolar amounts of reactants, although a slight excess of both can be used. Each reactant can be added to the other content in the solvent; however, it is preferable to add the solid phosphate to a solution of 3-alkyl-5-chloromethyloxadiazole. The addition is carried out at temperatures in the range of 15 to 300C. When the addition of the salt is complete, the reaction temperature is raised, preferably to

reflux temperature.

  The reaction is generally complete in 1 to hours. At the end. of the reaction, the reaction mixture containing the product is filtered to remove any insoluble salts. The filtrate is then freed of the solvent

  reduced pressure by giving 3-alkyl-5- (dialkoxy)

  phosphorothioylthiomethyl) -1,2,4-oxadiazole crude. The crude substance can be purified by column chromatography (silica gel) and elution with hydrocarbons and

chlorinated hydrocarbons.

Example 1

  Processes of Preparation (a) Acetamidoxime Acetonitrile is added to a previously stirred solution of 0.55 moles of hydroxylamine hydrochloride and 0.55 moles of anhydrous sodium carbonate in 750 ml of absolute ethanol. This mixture is stirred for half an hour at room temperature and then refluxed at 55 ° -70 ° C. for 24 hours. The reaction mixture is cooled and filtered, the solid residue is suspended in hot acetone and the suspension is again filtered, the filtrates are collected and concentrated to an oil under reduced pressure. The oil is again taken up in a mixture of acetone and ether to rid the system of undissolved inorganic salts. The acetone-ether filtrate is concentrated under reduced pressure, the oil is then triturated with a mixture of ether and hexane and a white solid remains. Elemental Infrared (IR) and Nuclear Magnetic Resonance (NMR) Analysis

  indicates that it is acetamidoxime (melting point 128-

133 C).

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  (b) 3-methyl-5-chloromethyl-1,2,4-oxadiazole 14.1 g of acetamidoxime are placed in 200 ml of benzene in a three-necked round bottom flask equipped with a mechanical stirrer, a condenser and a dropping funnel charged with 23 g of chloroacetyl chloride. The benzene suspension is heated to the reflux temperature and the chloroacetyl chloride is added dropwise to the refluxing mixture. A Dean and Stark separator is added and the reflux is continued for 3 hours. The reaction mixture is cooled and 100 ml of benzene is added, the mixture is washed with three times 125 ml of water, dried over anhydrous magnesium sulphate and the solvent is removed under reduced pressure, to obtain the desired product under the form of an amber-colored liquid (identity confirmed by infrared analysis, analysis by

  nuclear magnetic resonance and elemental analysis).

  (c) 3-methyl-5- (diethoxyphosphorothioylthio)

methyl) -1,2,4-oxadiazole

  0.04 moles of 3-methyl-5-chloromethyl are dissolved

  1,2,4-oxadiazole in acetone and added in several

  portions, with stirring, 0.04 mole of O, O-diethyldithio-

  ammonium phosphate. The reaction mixture is then refluxed for 3 hours, cooled and filtered. The solvent is removed under reduced pressure and an amber oil remains which is chromatographed (on silica gel) eluting with a mixture of hexane and methylene chloride (80%). Phosphate is obtained under

  form of a virtually colorless oil.

Example 2

  Experimentation of compounds against wireworms and larvae of flea beetles

  Granules containing 10% by weight of 3-methyl-

  - (Diethoxyphosphinothioylthiomethyl) -1,2,4-oxadiazole (test compound) are distributed on the fly on the test site. The land is then treated with a disk plow so that the granules are incorporated into the soil at a depth of 10 to 12 cm. The dose used is 3.4, 2.3 and

  1.13 kg of test compound per hectare.

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  Then, sweet potatoes of the Julian variety are transplanted into the treated plots, obviously infested with wireworms (Conoderus vespertinus larvae).

  and C. auritus) and flea beetle larvae (Systena elongata).

  Four months later, sweet potatoes are harvested and the number of roots damaged and / or marked by wireworms and larvae of flea beetles is evaluated. The results

  are reproduced in the following Table I.

TABLE I

  0 Compound Roots Roots mar- Roots - Roots of test and damaged by damage marked by worms to worms by iron wires iron larvae flea beetle larvae Test compound 1, 13 kg / ha 2.3 kg / ha 3.4 kg / ha No treatment Furadan (insecticide) 3.4 kg / ha 3.3 4.3 1.3 7.3 2.0 11.3 13.3 3 , 0, 3 4.3, 0 3.7 1.0, 0, 0 17.3, 3 2, 3, 7 0.7 2.0 (1) The experimental results represent the

  average of 3 trials and are based on examination of 25 roots.

Example 3

  Experimentation of a compound against white grubs

  Two attempts were made using the 3-

  methyl-5- (diethoxyphosphinothioylthiomethyl) -1,2,4-oxadiazole (test compound) to determine its effectiveness in controlling melolonthid larvae. In the first test, the test compound was applied directly to the insect, while in the second test, the soil was treated with the test compound, and then insects were

introduced into this soil.

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  Topical application Third-stage melolonthid larvae (Costelytra zealandica) weighing on average 100.5 mg were contacted with the indicated amount of the test compound, and the effects produced were periodically monitored. Test concentration and results

from Table II below.

TABLE II

  Dose Percentage affected Micrograms / insect 2 hours 3 days 7 days

100 100 100

1 93 79 75

0.1 7 7 7

  These results show that at the dose of 10 micro-

  grams / insect, the rate of destruction is 100% and at the dose of one microgram / insect, there is still a rate of

75% destruction.

  Soil treatment Horotin silty clay, with a moisture content of 32%, is treated with an insecticide, either lindane or the test compound, so that the soil contains an average active concentration of 14 parts per hectare. million (on a weight basis). Then, 86 mm Petri dishes are packed with a compact layer of 85 g of this treated soil. Ten freshly collected melolonthid larvae are then placed in each petri dish, which is then covered with a petri dish placed upside down to

  prevent the larvae from escaping.

  All the larvae sink into the soil in minutes. The affected larvae then return to the surface. The number of larvae remaining on the soil surface is noted at various intervals. After 24 hours of treated soil exposure, all larvae are removed and placed on untreated soil in covered petri dishes. There is again the number of larvae remaining on the soil surface. These results are reproduced on the

Table III.

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  The results in Table III demonstrate that the test compound has a high insecticidal activity

  against melolonthid larvae.

TABLE III

  Insecticide Percentage of melolonthid larvae (concentration affected 14 ppm) Number of larvae in place Number of larvae in soil redeposited on untreated treated soil

2 hours

  res 17 hours 24 hours 2 hours 24 hours Test compound 0 70 88 92 92 Lindane 94 94 94 100 100

No treatment

0 0 0 0 0 11i 2481'070

Claims (8)

  1. A method for destroying wireworms or larvae of flea beetles, characterized in that it consists in applying to the soil constituting the habitat of said larvae, an insecticidally effective amount of a compound of formula: NY R1-C3 5C-CH2Xi-zR2 4 1 N VR3   wherein R1, R2 and R3 are alkyl groups having 1 to 4 carbon atoms; and X, Y, Z and V represent sulfur or oxygen.   2. The process of claim 1   characterized in that R2 and R3 are ethyl groups.   3. Process according to claim 2, characterized in that Y is sulfur and Z and V represent oxygen.   4. Process according to claim 3, characterized in that R1 is methyl and X represents sulfur.   5. A method for destroying white grubs, characterized in that it consists in applying to the soil constituting the habitat of the white grubs an insecticidally effective amount of a compound of the formula: X 2 10 y R1-C3C-CH2X-ZR 4 I0 ' N VR3   wherein R1, R2 and R3 are alkyl groups having 1 to 4 carbon atoms and X, Y, Z and V are sulfur or oxygen. 12 2481070   6. The process of claim 5   characterized in that R2 and R3 are ethyl groups.   7. Process according to claim 6, characterized in that Y is sulfur and Z and V are oxygen. 8. Process according to claim 7, characterized in that R1 is a methyl group and X is sulfur.