JPS58188805A - Stabilized mixtures of carbamate insecticides and synthetic prethroids - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to insecticidal mixtures of carbamate compounds and synthetic pyrethroids, and more particularly to preventing racemization of pyrethroids to a form with lower insecticidal activity than before. It concerns the improvement of such mixtures by the addition of certain stabilizers for the purpose of the invention.

Carbamate compounds and synthetic pyrethroids are well known for the control of agricultural pests such as insects and mites. Although these insecticides are active in themselves, their activity is often selective and is higher against some phyla of pests than against others. Thus, formulating together rice carbamate compounds such as methomyl and synthetic pyrethroids provides mixtures that are more advantageously active against a wider range of pests. Such mixtures are shown, for example, in German patent DT 280S050, published on August 10, 1978.

Synthetic pyrethroids usually have one or more asymmetric carbon atoms and therefore exist in two or more stereoisomeric forms. Not all stereoisomers of a particular pyrethroid have the same degree of insecticidal activity, and a pair of theastereoisomers across a particular isomer is usually more active than a racemic mixture of all isomers. It is well known that

However, when some synthetic pyrethroids are split or partially split into their isomers with greater insecticidal activity, they undergo racemization under certain conditions and reconstitute into a less active form. The racemization of deltamethrin, a synthetic pyrethroid, has been found to return to J, Ag, Food Cha.
m, vol. 25, p. 1385 (1977). Racemization of pyrethroids, especially deltamethrin, often occurs when they are formulated with carbamate compounds, and it appears that it is probably caused or promoted by impurities in the carbamate. The overall insecticidal activity of the mixture is thereby unacceptably reduced;
This negates the benefits that would otherwise have been obtained from these 211 insecticide combinations. Accordingly, improved mixtures were desired in which the broad activity of the mixture was retained.

One aspect of the present invention is that the improvement is based on the weight of carbamate from 1 to 1.
20t1i% a) Formula - [wherein Rs and R4 are independently C1-C4 alkyl,
phenyl or phenyl substituted with at least one halogeno, lower alkyl, lower alkoxy or nitro, or R8 and R4 together represent C
1-C, alkyl, C1-C4 alkeni, where Y is halogeno, lower alkyl, lower alkyl, or nitro, n is 0-2, and 0-71]. , b) isocyanates of the formula %, where Y is halogen, lower alkyl, lower alkoxy or nitro, and n is from 0 to 2; C) formaldehyde; d) ninhydrin; #) fluorescamine, or f) a carbamate insecticide and a split nine-part partially split formula [wherein: R is H or cyano; R1Vi is optionally substituted alkylcyclozolobyl, alkylcyclozolobyl or arylalkyl; R8 is Hl or F; and X is C or N. An improved insecticide mixture of synthetic pyrethroids is provided.

The present invention provides, in part, that certain compounds act surprisingly as stabilizers in mixtures of carbamate insecticides and synthetic pyrethroids of lfi or higher insecticidal properties and The present invention is based on the discovery that pyrethroids that have been divided into pyrethroids prevent or substantially retard disemization of the pyrethroids when combined with carbamate compounds. Impurities in the carbamates, which are present during manufacture or formed during storage, often result in racemization of the more insecticidal isomer or diastereomer pair of the pyrethroids to a less active form. It is speculated.

The pyrethroids with which the present invention is concerned have at least one asymmetric carbon atom and have the general formula [wherein R is H or cyano and R1 is optionally substituted alkylcyclozorobyl] , alkylcyclozolobyl or arylalkyl, R1 is H or F, and X is C or N.

When R1 represents optionally substituted alkylcyclozolopyl or alkylcyclozorobyl,
Preferred compounds are those where R1 is (
1) Rc and Rb (l-j each hydrogen or optionally 3
represents an alkyl group having from 1 to 6 carbon atoms optionally substituted with up to 4 halogeno atoms, preferably F, C1 or Br, and (2) Re optionally represents up to 4 helokene atoms. represents an alkyl group having 1 to 6 carbon atoms which may be completely substituted with , or an alkenyl group having 2 to 6 carbon atoms which may be optionally substituted with up to 4 halo yy atoms.

The most preferred of this group of compounds are Rc and R
b is methyl, Rc is 2,2-dihalovinyl, and the halodane atom is Ct or Br.

Which compound is suitable when R1 represents an optionally substituted arylalkyl group? l'l l-1, /
<1 is R6, where Rd is an alkyl group having 1 to 6 carbon atoms, and n is 0 or ! , Ra is H or a halodan atom, and Rf is a halodan atom or an alkyl group or alkoxy group having 1 to 4 carbon atoms optionally substituted with up to 4 halodan atoms. The most preferred among this group of compounds is one in which Rd is a branched alkyl group having 3 to 4 carbon atoms, and n is 0.
, R- is H, and Rf is F or F'i,
ct.

For example, the pyrethroid deltamethrin, which is available in a completely resolved form, racemizes in the presence of the carbamate methomyl to the other isomeric form, R-pectrin;
It has been found to have about 1/6 the insecticidal activity of deltamethrin.

Deltamethrin is a (S)-α-cyano-3-phenoxy-benzyl (IR)-cis-3-(2,2-sopromovinyl)-2,2-somethylcycloglonotane rupoxylate. R-pectrin 1d(R)-α-cyano-3-phenoxybenzo-(lR)-cis-3-(
2,2-sopromovinyl)-2,2-y methylcyclopropanecarboxylate. Besides deltamethrin, other specific examples of synthetic pyrethroids with which the present invention is concerned are the insecticidal active isomers in split or partially resolved form of the following compounds: )−α
-7ano-3-phenoxybenzyl-(IA'S)-cis, trans-3-(2,2-dichlorovinyl)-2,
2-dimethyl 7-chlorozolopane-carpoquinlate (cyhermetri/)i3-(phenoxyphenyl)methyl (
±)-x, trans-3-(2,2-dichlorovinyl)-2,2-somethylcyclopronoincarpoxylate (permethrin); (R8)-α-cyano-3-phenoxypentrue (R
E)-2-<4-chlorophenyl)-3-)1-fk fk frate (fenvalerate); (RE)-α-cyano-3-phenoxybenzo-(RS)-2-(4-difluoromethoxyphenyl )-3-methylbutyrate; cyano-(4-fluoro-3-phenoxypensok)-
)f-3-(2,2-dichlorovinyl)-2,2-1
'Methylcyclopropanecarboxylate; N-(2-chloro-4-(trifluoromethyl)phenyl)-DL-valine-(±)-cyano(3-phenoxyphenyl)methyl ester 2-(2,2-dichloro 2-(1,2-nopromo-2,2-dichloroethyl)-
Ester of 3,3-N methylcyclopanecarboxylic acid with α-hydroxy-3-phenoxy-benzeneacetonitrile.

The carbamate insecticides forming part of the improved mixture of the present invention are any of those that have been advantageously used for the control of agricultural pests.

Examples include: Among the carbamate insecticides, preferred are methomyl, carbofuran, oxamyl and carbaryl. Methomyl is most preferred.

Mixtures of carbamate insecticides and the above-mentioned pyrethroids are improved according to the invention by the addition of a stabilizer of 1 to 20 Shimotsuba-pi based on the weight of the carbamate: α) Formula [ where R1 and R' are independently C1-C4 alkyl or phenyl, or R3 and R4 together are C! ~Cl alkyl,] anhydrides. Aromatic anhydrides have up to 2 /logons,
Optionally substituted with lower alkyl, lower alkoxy or nitro. Acetic anhydride, glutaric anhydride, benzoic anhydride and phthalic anhydride are preferred.

b) Formula % Formula % [wherein R" is C□ to C, alkyl or phenyl optionally substituted with W, up to two I-lognes, lower alkyl, lower alkoxy or nitro] Among the isocyanates, phenyl incyanate is preferred.

C) Formaldehyde.

d) Ninhydrin, which has the formula 1 0 (which can also be in the hydric form) or has the structural formula in the anhydrous form.

6) has the formula and was published on May 18, 1976.
l/-A-(Z/# imdrwb 5tr) Fluorescamine, which may be prepared as described in et al. US Pat. No. 957,826.

f) Mesityl oxide.

The most preferred of the above stabilizers are benzoic anhydride and phthalic anhydride because of their effectiveness and ease of formylation, and fluorescamine because of its effectiveness.

The improvement of the present invention, i.e. the prevention or retardation of racemization of pyrethroids, is 1% by weight based on the amount of carbamate IL.
This becomes evident when a small amount of at least 1 liter of the above-mentioned stabilizer is added to the mixture. A preferred range is 4-16% by weight stabilizer based on carbamate weight. It is to be understood that combinations of more than 21 of the above stabilizers can also be used and in that case the mold part percentages above refer to the sum of all stabilizers used in the mixture.

The amount of stabilizer used within the above range will also vary depending on the method of manufacturing the carbamate. This is particularly the case with methomyl. In general, compositions using 9-methomyl prepared in such a manner as to be crystallized from solution as shown in U.S. Pat. No. 3,855,620 are generally preferred. Relatively less stabilizer is required than compositions using methomyl made by solvent-free methods, such as methoxyl. For example, when compounding benzoic anhydride or phthalic anhydride, two suitable stabilizers, with methomyl produced by crystallization, the anhydride is present at a concentration of about 7 to 11% IP based on methomyl weight. It exists in

As noted above, the amount of stabilizer used will vary depending on the method of manufacturing the carbamate insecticide, the length of time it will be stored, and the type of stabilizer, and will therefore be an amount effective to substantially prevent racemization. It will be understood by those skilled in the art that it cannot be stated precisely. However, use of the above ranges will generally provide desirable results.

Overall, preferred mixtures of the present invention are comprised of methomyl and deltamethrin modified by the addition of 4 to 16 t% by weight of benzoic anhydride, phthalic anhydride or fluorescein anhydride, based on 1 weight of methomyl. It is a mixture. The most preferred among these is benzoic anhydride.

The insecticide mixtures to which the present invention is applied are 0.05 to 100
of, preferably from 1 to 50, and most preferably from 2 to y1i4.
It has a carbamate/pyrethroid weight ratio of 30. Improved mixed S types include water, ketones,
It can be dispersed in a variety of liquid diluents such as alcohols or aromatic solvents. Cyclohexanone, methanol and xylene are the preferred 41 liquids for this purpose. When the stabilizer is an isocyanate, the presence of water as a diluent has the potential to reduce the stabilizing effect of the inocyanate. Use should be avoided.

When dispersing improved insecticide mixtures in such organic liquids, it is often desirable to use a surfactant to maintain the dispersion.

Examples of surfactants that can be used are blends of oil-soluble sulfonates and polyoxyethylene ethers, fragrances,
Sulfonate oxides, sorbitan monolaurates, alkylaryl polyether alcohols, such as octylphenoxy-polyethoxyethanol (7"
riton X-100) and amine salts of dodecylbenzenesulfonic acid.

Useful preparations of improved calumet/pyrethroid compounds can be dyed by conventional methods.

These include granules, wettable powders, concentrated emulsions, and the like.

Many of these are applied directly to the plant site to be protected from agricultural pests. For example, the spray preparation orchid is Shimoda Pi,
It can be used in compositions such as, for example, evaporation, bulking in a suitable medium and at a spray volume of about 0.5 to 150 liters/hetatar. The formulations contain active ingredients (carbamates and pyrethroids), stabilizers, and optionally solid or liquid diluents and surfactants, as described above, in proportions by weight of the manure.

(including parts by weight) Active ingredients (classes) 10-90 5-50 1-9
5 Diluent (class) 0-90 40-95 5
-99 Surfactant (class) 1-10 0-15
0-15 Stabilizer(s) 0.1-15 0.
0.05-10 0.01-15 Of course, lower or higher amounts of active ingredient may also be present depending on the intended use and physical properties of the compound. A high proportion of surface-active to active ingredients is often desirable and is achieved by incorporation into the formulation or by mixing in a tank.

A typical solid diluent is Watkina
'Hαndbook of In5aetiet
d-nocstDiluents and Carrie
rs', 2nd edition, Trantopx (Dorlax)
d Books, Caldwmll, N.

J,). A diluent with higher absorbency is suitable for use in wettable powders. Representative liquid diluents and solvents are described by Marsden (Mαds%) in “5oLva
xts guide”, '¥2 edition, Interscience, N, Y, 195
0 years and “McCutcheon'a Datgrga
nta and Emul-aiftara Annu
al”, A11Sred Pub
L, Corp, , N, J,
Author, “Encllopedia of 5urf
ace A, tiveAgents”, Chemical Publishing.

Co, Inc., N, Y, ), 1964, displays surface activity and its recommended uses. All preparations may contain small amounts of additives to reduce foaming, corrosion, microbial growth, etc. Preferably each component should be approved by the US Environmental Conservation Agency for its intended use.

Methods for producing such compositions are well known.

Solutions are prepared by simply mixing the components.

Finely divided solid compositions are produced by mixing and commonly grinding using a thermometer or fluid energy mill. Granules may be produced by spraying the active substance onto pre-shaped granular carriers or by agglomeration methods. Reference, J.E., Broming.”
"Agglomgration", Chemieal
Enginsring, December 4th issue, 147 pages (19g?), and Ferry, Che.
mical Engineer's Handbook
, 4th edition, pp. 8-59, published by McG
raw-H4ll, N, Y, ), 1963.

In the examples below, all methomyl is
, 576.834, by crystallization from solution.

Examples 1-10 Simple mixtures of methomyl, deltamethrin, solvent and (with the exception of Example 5) stabilizer were prepared.

The mixtures were stored in a closed container at room temperature of 45° C. for 3 hours. These conditions apply to savings over a period of at least one year;
It was set up to simulate a return to life.

At the end of the three week period, the mixtures were analyzed by high pressure liquid chromatography to determine whether conversion to R-becitrin, which was not present in the initial mixture, had occurred. All mold bones are expressed as a percentage of the total mixture weight.

Examples 11-13 Mixtures of methrin, deltamethrin, solvent, surfactant, and stabilizer were prepared, stored, and analyzed in a manner similar to Examples 1-5. All weights are expressed as a percentage of the total mixture weight.

In Control Example 5, 20% of deltamethrin was racemized to R-pecitrin. To illustrate the present invention, no racemization was observed in Examples 1, 2.6, and 8, and even in the racemization examples where some racemization occurred, it was limited to a maximum value of about 7% (Example 1 and .

Example 14 Mixtures of IJ, solvent, and surfactant were prepared, stored, and analyzed in a manner similar to the previous examples. All weights are expressed as percentages of total mixture weight.

Methomyl 27.6 Deltamethrin 1.71 Surfactant
40 Phthalic anhydride 20 10 α0

Claims (1)

[Claims] 1. 1 to 20% by weight based on the weight of the carbamate of α) formula [wherein R'' and R4 are independently C, alkyl, phenyl or at least one af is phenyl substituted with nitro, lower alkyl, lower alkoxy or nitro, or R3 and R4 together represent C!
~CS alkyl, C2-C4 alkenyl, where Y
b) anhydrides of the formula %, where C) formaldehyde, d) ninhydrin, #) fluorescamine, or f) mesityl oxide. a carbamate insecticide and a split or partially split formula [wherein R is H or cyano and R1 is optionally substituted], comprising the addition of a stabilizer selected from the group improved insecticide mixtures of synthetic pyrethroids, wherein R1 is H or F and 1X is C or N. The improved mixture of claim 1, wherein 2-R is cyanide and the carbamate insecticide is methomyl, oxamyl, carbaryl or carbofuran. & R is cyano, and the stabilizer is of the formula [wherein R''
and R4 are independently C1-C4 alkyl, phenyl or phenyl substituted with at least 41 halogen, lower alkyl, lower alkoxymodi or nitro, or Bs and R4 together are C1-C4 C1 alkyl, C1-C4 alkeni, where Y is halogen, lower alkyl, lower alkoxy or nitro; n is 0-2; and n is 0-1. , an improved mixture according to claim 1. 4. The improved mixture of claim 3, wherein the stabilizer is benzoic anhydride, phthalic anhydride, glutaric anhydride, or acetic anhydride. & Claim 4, wherein the stabilizer is benzoic anhydride.
Improved mixtures as described in Section. 6, R is cyano, and the stabilizer is 2RI-N=C
= 0, where Y is no-logne, lower alkyl, lower alkoxy, or nitro, and n is 0 to 2. blend. 7. The improved mixture of claim 1, wherein R is cyano and the stabilizer is formaldehyde, ninhydrin, or fluorescamine. & R is cyanide and the stabilizer is fluorescamine, in Claims at Clause Il! Improved mixtures loaded with lT'. Claim 3.4. wherein the pyrethroid is deltamethrin and the carbamate insecticide is methomyl. ! S, 6, 7. or an improved mixture as described in order 8. 10. The improved mixture of claim 9 comprising adding from 1 to 20 parts of stabilizer based on the weight of methomyl. 11. The improved mixture according to claim 9, which consists of adding 4 to 16 parts of stabilizer based on the weight of methomyl. 12. The improved compound of claim 9, wherein the weight ratio of methomyl to pyrethroid is about 1-50. lλ Surfactant, diluent! /! 9. A commercial composition comprising a combination thereof and a pesticidal effective amount of the improved mixture according to claim 1. 14. The composition of claim 13, comprising the improved mixture of claim 2, a surfactant, a diluent or a combination thereof, and a pesticidally effective amount of the improved mixture of claim 2. thing. 15. The composition according to claim 13, comprising the improved mixture according to claim 3, of a surfactant, a diluent or a combination thereof, and a pesticidally effective amount. thing. 16. Agricultural composition according to claim 13i, consisting of a surfactant, a diluent or a combination thereof, and a pesticidal effective amount of the improved mixture according to claim 4. thing. 17. Agricultural composition according to claim 13, comprising the improved mixture according to claim 5, a surfactant, a diluent or a combination thereof, and a pesticidally effective amount of the improved mixture according to claim 5. . 1 & an agricultural composition according to claim 133, comprising the improved mixture of claim 6 of a surfactant, a diluent or a combination thereof, and a pesticidally effective amount. 1s, a surfactant, a diluent or a combination thereof, and a pesticidal effective amount of the improved mixture of claim 7. . 20, a surfactant, a diluent or a combination thereof, and a pesticidal effective amount of the improved mixture of claim 8. thing. 21, a surfactant, a diluent or a combination thereof, and an insecticidal effective amount of the improved mixture as claimed in claim 9; Composition for use. 2z A method for controlling agricultural pests, which comprises applying an insecticidal effective amount of the improved mixture according to claim 1 to the site to be protected. 2λ A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 2 to the site to be protected. 24. A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 3 to the place to be protected. ! A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 4 to the area to be protected. 26. A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 5 to the site to be protected. ! ! 7. 23. A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 6 to the site to be protected. 2. A method for controlling agricultural pests according to claim NL22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 7 to the site to be protected. 29. A method for controlling agricultural pests according to claim 22, which comprises applying an insecticidal effective amount of the improved mixture according to claim 8 to the site to be protected.