CH621045A5 - Pesticide containing, as active substance, an amidinophosphoric thioester, and the use of this composition. - Google Patents

Abstract

Novel pesticides are described which contain, as active substance, a compound of the formula I <IMAGE> in which R1 denotes hydrogen, C1-C4-alkyl or cyclopropyl, R2 denotes C3-C5-alkyl and R3 denotes methyl or ethyl These compositions are particularly suitable for controlling nematodes.

Description

       

  
 

** WARNING ** beginning of DESC field could overlap end of CLMS **.

 



  PATENT CLAIMS
1. Pesticides containing a compound of the formula I as at least one active component
EMI1.1
 R1 is hydrogen,, -C4-alkyl or cyclopropyl, R2 C3-Cs-alkyl and
R3 is methyl or ethyl, together with suitable extenders and / or distributing agents.



   2. Composition according to claim 1, wherein in the formula I R1 is hydrogen or methyl, R2 is n-propyl and R3 is ethyl.



   3. Composition according to claim 1 containing as active ingredient N- (O-ethyl-S-n-propylthiophosphoryl) acetamidine.



   4. Use of the agent according to claim 1 for combating nematodes and for preventing nematode attack.



   The present invention relates to pesticides with amidino-phosphoric acid thiolester as active ingredients, and to the use of these compositions for controlling nematodes.



   The new agents containing amidino-phosphoric acid thiol esters represent a narrowly limited group of highly effective compounds and correspond to the formula I.
EMI1.2
 wherein
R1 is hydrogen, C1-C4 alkyl or cyclopropyl,
R2 C3-Cs alkyl and
R3 is methyl or ethyl and preferred compounds are those in which R1 is hydrogen or methyl,
R2 n-propyl and
R3 are ethyl.



   The alkyl radicals indicated are, depending on the definition given for R1 and R2, methyl, ethyl, propyl, isopropyl and the isomeric butyl and amyl groups. Phosphorylated formamidines have already become known from DE-OS 2 312 738 and DE-OS 2 451 911 and US Pat. No. 3,734,980. However, their nematicidal activity is very unsatisfactory. In addition, they do not have sufficient soil stability, which is essential for use against soil pests.



   It has now been shown that the compounds of the formula I meet both of these requirements to a high degree. This is particularly surprising because directly homologous compounds show these properties only in a slightly pronounced form, ie they are unusable in practice.



   The compounds of the formula I are prepared, for example, by one of the following processes:
EMI1.3
 where X is halogen, preferably chlorine, bromine or iodine, or else a sulfate radical, Me = alkali metal or NH4 and Y is oxygen or sulfur.



   In the first method of amidating a thiophosphoric acid ester chloride, reaction temperatures of 0 to 100 C, preferably 10-45 C, are used.



   The reactions are carried out in solvents or diluents which are inert to the reactants. For example, the following are possible:
Aliphatic or aromatic or halogenated hydrocarbons and ethereal compounds such as dialkyl ethers.



  The reaction proceeds in the presence of an acid-binding agent or condensing agent. As such, e.g. B.



  tertiary amines in question (see. DE-OS 2451 911).



   The second process of transesterification of an amidino-phosphoric acid urethionoester in the temperature range from 20 to 100 ° C. in water is the necessary solvent for the hydro
Thiol salt lysis stage performed. Mixtures of water and an immiscible solvent such as hydrocarbon are also suitable. The simultaneous use of quaternary ammonium salts such as tetrabutylammonium bromide is advantageous here.



   In the second reaction step of the alkylation of the thiol salt formed, non-aqueous polar solvents such as acetonitrile or dimethylformamide are used (cf. US Pat. No. 3,896,193).



   Manufacturing instructions
20 g (0.21 mole) of acetamidine hydrochloride are dissolved in 100 ml of water. A solution of 40 g (0.2 mole) of O-ethyl-S-n-propyl-thiophosphoric acid chloride in 400 ml of methylene chloride is added in portions with vigorous stirring. Then the reaction mixture is added dropwise with a 0.4 molar NaOH solution which contains 16 g of solid



  Corresponds to NaOH. The temperature rises to about 30 ".



  After the reaction has ended, stirring is continued for about 4 hours at room temperature, the methylene chloride layer is separated off, dried over sodium sulfate and evaporated. 38 g of N- (O-ethyl-S-n-propyl-thiophosphoryl) acetamidine are obtained as a viscous oil which after a short time becomes rigid to colorless crystals, mp. 48-50 [verb. No. 2]. The recrystallization gives a colorless product, mp 55-57 ".



   The following connections are also produced in this way or according to a method specified above:
EMI2.1

EMI2.2

Compounds of the formula I act especially against nematodes of the plant pathogenic region, among which the genera Meloidogyne, Radopholus, Pratylenchus, Ditylenchus, Heterodera, Paratylenchus, Belonolaismus, Trichodorus, Longidorus are to be mentioned. The special advantage of these compounds is their systemic effect, which allows the pests to be controlled not only by soil treatment, but also by foliar application via the plant to be protected (basipetal transport).



   Means are advantageous which ensure a uniform distribution of the active substance over a 10-20 cm deep layer of soil. The method of application and the form of application depend in particular on the type of plant, the climate and the soil conditions. Since the new active ingredients are not phytotoxic and do not impair the ability to germinate, they can be used immediately before or after planting, even without observing a so-called grace period. Existing crops can also be treated with the new agents. In addition, certain plant parts such as seeds, stem pieces (sugar cane) or onions as well as roots or young plants can be treated with dispersions or solutions of the active compounds for propagation.



   In addition to excellent nematicidal activity, the compounds of the formula I also have significant insecticidal, acaricidal, ectoparasiticidal and in some cases also fungicidal and bactericidal activity.



   They can be used alone or together with suitable carriers and / or other additives.



  Suitable carriers and additives can be solid or liquid and correspond to the substances commonly used in formulation technology, e.g. B. natural or regenerated mineral substances, solvents, dispersants, wetting agents, adhesives, thickeners, binders or fertilizers. To broaden the spectrum of action, the compounds of the formula I can also be combined with other known insecticides, acaricides, nematicides and also with fungicides, herbicides, molluscicides or rodenticides.



   The content of active ingredient in commercial products is between 0.1-90%.



   For application, the compounds of the formula I can be present in the following working-up forms (the percentages by weight in brackets representing advantageous amounts of active ingredient): Solid working-up forms:
Dusts and grit (up to 10%)
Granules, coating granules, impregnation granules and homogeneous granules (1-80%); Liquid processing forms: a) active ingredient concentrates dispersible in water:
Wettable powders and pastes (25-90% in retail packaging, 0.01-15% in ready-to-use solution);
Emulsion and solution concentrates (10-50%; 0.01-15% in ready-to-use solution); b) Solutions (0.1-20%).



   The active compounds of the formula I of the present invention can be formulated, for example, as follows:
The following substances are used to produce a) 5% and b) 2% dusts: a) 5 parts of active ingredient,
95 parts talc; b) 2 parts of active ingredient,
1 part of highly disperse silica,
97 parts of talc.



   The active ingredients are mixed and ground with the carriers and can be dusted in this form for use.



  Granules:
The following substances are used to produce a 5% granulate:
5 parts of active ingredient,
0.25 parts of epoxidizable vegetable oil,
0.25 parts of cetyl polyglycol ether,
3.50 parts of polyethylene glycol,
91 parts of kaolin (grain size 0.3-0.8 mm).



   The active substance is mixed with epoxidizable vegetable oil and dissolved with 6 parts of acetone, then poly ethylene glycol and cetyl polyglycol ether are added. The solution thus obtained is sprayed onto kaolin, and the acetone is then evaporated off in vacuo. Such microgranules are advantageously used to control soil pests.



  Spray powder:
The following constituents are used to prepare a) 70%, b) 40%, c) and d) 25%, e) 10% wettable powder: a) 70 parts of active ingredient,
5 parts of sodium dibutylnaphthyl sulfone at,
3 parts of naphthalenesulfonic acid-phenolsulfonic acids-
Formaldehyde condensate 3: 2: 1,
10 parts of kaolin,
12 parts of champagne chalk; b) 40 parts of active ingredient,
5 parts of sodium lignosulfonic acid,
1 part of dibutylnaphthalenesulfonic acid sodium salt,
54 parts of silica;

   c) 25 parts of active ingredient,
4.5 parts of calcium lignin sulfonate,
1.9 parts champagne chalk / hydroxyethyl cellulose
Mixture (1: 1),
1.5 parts of sodium dibutyl naphthalenesulfonate,
19.5 parts of silica,
19.5 parts of champagne chalk,
28.1 parts kaolin; d) 25 parts of active ingredient,
2.5 parts of isooctylphenoxy-polyoxyethylene-ethanol,
1.7 parts champagne chalk / hydroxyethyl cellulose
Mixture (1: 1),
8.3 parts of sodium aluminum silicate,
16.5 parts of diatomaceous earth,
46 parts of kaolin; e) 10 parts of active ingredient,
3 parts mixture of the sodium salts of saturated fat alcohol sulfates,
5 parts of naphthalenesulfonic acid / formaldehyde condensate,
82 parts of kaolin.



   The active ingredients are intimately mixed with the additives in suitable mixers and ground on appropriate mills and rollers. This gives wettable powders of excellent wettability and suspension, which can be diluted with water to form suspensions of any desired concentration and used for soil and leaf application.



  Emulsifiable concentrates:
The following substances are used to produce a 25% emulsifiable concentrate:
25 parts of active ingredient,
2.5 parts of epoxidized vegetable oil,
10 parts of an alkylarylsulfonate / fatty alcohol polyglycol ether mixture,
5 parts of dimethylformamide,
57.5 parts xylene.

 

   Emulsions of any desired concentration can be prepared from such concentrates by dilution with water.



   example 1
Testing the nematicidal activity
For testing against soil nematodes, the active substance is given in a concentration of 10 and 2.5 ppm in soil or sand infected by root-gall nematodes (Meloidogyne incognita) and mixed intimately. Immediately afterwards, tomato seedlings and tobacco seedlings are planted in the so prepared soil.



   To assess the nematicidal activity, the galls present at the roots are counted 28 days after planting.



   Compounds of formula I showed a good activity against Meloidogyne incognita in the above test, as can be seen from the mean values of three parallel tests. The following clef was used:
0 = 0- 5% infestation
1 = 5-25% infestation
2 = 25-80% infestation
3 = over 80% infestation (ineffective)
The compounds of the formula I showed consistently full activity (grade 0) at an active substance concentration of 10 ppm, almost complete activity at 2.5 ppm with an infection reduction to 0-25% (grades 0 or 1). Among others, compounds No. 1, 2, 4, 8,
12, 13 and 14 are also fully effective in this concentration (grade 0).



   Immediately structural homologous connections such as
EMI4.1
   130-135 C (known from US Pat. No. 3,734,980) semicrystalline showed no nematicidal activity even at high dosages of 25 and 50 ppm.



   Example 2
Acaricidal effects
Bean plants (Phaseolus vulgaris) were covered with an infested leaf piece from a mass cultivation of Tetranychus urticae 12 hours before the test. The overflowed moving stages were sprayed with the emulsified test preparations from a chromatography atomizer so that the spray liquor did not run off. After 2 to 7 days at 250 C in the greenhouse, larvae, adults and eggs were evaluated under the binocular for living and dead individuals.

 

  Compounds of formula I showed a high efficiency against adults and larvae of Tetranychus urticae.



   Example 3
Systemic insecticidal activity: Aphis fabae
In order to determine the systemic effect, rooted bean plants (Vicia faba) were placed in a 0.01% strength aqueous active ingredient solution (obtained from a 10% strength emulsifiable concentrate). After 24 hours, aphids (Aphis fabae) were placed on the aerial plant parts.



  The animals were protected from contact and gas effects by a special device. The test was carried out at 24 C and 70% relative humidity.



   Compounds Nos. 2, 3 and 8 transported in the sap flow of the plant completely killed the aphids.


    

Claims (4)

PATENT CLAIMS 1. Pesticides containing a compound of the formula I as at least one active component EMI1.1  R1 is hydrogen, C4-alkyl or cyclopropyl, R2 C3-Cs-alkyl and R3 is methyl or ethyl, together with suitable extenders and / or distributing agents.  2. Composition according to claim 1, wherein in the formula I R1 is hydrogen or methyl, R2 is n-propyl and R3 is ethyl.  3. Composition according to claim 1 containing as active ingredient N- (O-ethyl-S-n-propylthiophosphoryl) acetamidine.  4. Use of the agent according to claim 1 for combating nematodes and for preventing nematode attack.  The present invention relates to pesticides containing amidino-phosphoric acid thiolester as active ingredients, and to the use of these compositions for controlling nematodes.  The new agents containing amidino-phosphoric acid thiol esters represent a narrowly limited group of highly effective compounds and correspond to the formula I. EMI1.2  wherein R1 is hydrogen, C1-C4 alkyl or cyclopropyl, R2 C3-Cs alkyl and R3 is methyl or ethyl and preferred compounds are those in which R1 is hydrogen or methyl, R2 n-propyl and R3 are ethyl.  The alkyl radicals indicated are, depending on the definition given for R1 and R2, methyl, ethyl, propyl, isopropyl and the isomeric butyl and amyl groups. Phosphorylated formamidines have already become known from DE-OS 2 312 738 and DE-OS 2 451 911 and US Pat. No. 3,734,980. However, their nematicidal activity is very unsatisfactory. In addition, they do not have sufficient soil stability, which is essential for use against soil pests.  It has now been shown that the compounds of the formula I meet both of these requirements to a high degree. This is particularly surprising because directly homologous compounds show these properties only in a slightly pronounced form, ie they are unusable in practice.  The compounds of the formula I are prepared, for example, by one of the following processes: EMI1.3  where X is halogen, preferably chlorine, bromine or iodine, or a sulfate radical, Me = alkali metal or NH4 and Y is oxygen or sulfur.  In the first method of amidating a thiophosphoric acid ester chloride, reaction temperatures of 0 to 100 C, preferably 10-45 C, are used.  The reactions are carried out in solvents or diluents which are inert to the reactants. For example, the following are possible: Aliphatic or aromatic or halogenated hydrocarbons and ethereal compounds such as dialkyl ethers. The reaction proceeds in the presence of an acid-binding agent or condensing agent. As such, e.g. B. tertiary amines in question (see. DE-OS 2451 911).  The 2nd method of transesterification of an amidino-phosphoric acid urethionoester is in the temperature range from 20 to 100 "C in water as a necessary solvent of the hydro Thiol salt lysis stage performed. Mixtures of water and an immiscible solvent such as hydrocarbon are also suitable. The simultaneous use of quaternary ammonium salts such as tetrabutylammonium bromide is advantageous here.    In the second reaction step of the alkylation of the thiol salt formed, non-aqueous polar solvents such as acetonitrile or dimethylformamide are used (cf. US Pat. No. 3,896,193).  Manufacturing instructions 20 g (0.21 mole) of acetamidine hydrochloride are dissolved in 100 ml of water. A solution of 40 g (0.2 mol) of O-ethyl-S-n-propyl-thiophosphoric acid chloride in 400 ml of methylene chloride is added in portions with vigorous stirring. Then the reaction mixture is added dropwise with a 0.4 molar NaOH solution which contains 16 g of solid ** WARNING ** End of CLMS field could overlap beginning of DESC **.