NL7908590A - Pesticidal triazadienes and formamidine - deriv - Google Patents

Abstract

Pesticidal (acaricidal and aphicidal) cpds comprise (A) triazadienes: of the formula shown, where X and y, identical or different, are Ph tolyl or substd phenyl where the substituents are; 2,3-Me2; 2,4-Me2; 2,6-Me2; 2,4,6-Me3; 2,4,5-Me3; 2,3,4-Me3; 2-Me-4-halo; 2-halo-4-Me; 2-halo-4,6-Me2; 2,4-dihalo -6-Me; 2-Me-H-OMe. so long as (a) when identical, X and Y are not Ph, tolyl or 2-Me-4-halophenyl and (b) when different 1 at least is 2,3- or 2-4-Me2, 2,4,6- or 2,3,4-Me3; 2-Me-4-halo- or 2-halo-4-Me-phenyl; (B) N-2,4-dimethylphenyl-N'-methylformamidine which is also an intermediate to the prefd. cpd. 1,5-di-(2,4-dimethylphenyl)-3-methyl-1,3,5-triazapenta-1,4-diene. The cpds are prepd by essentially known methods.

Description

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Reg.No. 112.142 / JKr / JvdB 1 *

Boots Pure Drug Company Limited, Nottingham, Great Britain.

Process for the preparation of an acaricidal and insecticidal composition and of the N-arylformamidine to be used therewith.

This invention relates to a process for the preparation of an acaricidal composition in which an N-arylformamide (a compound according to formula 1) is mixed with a carrier and possibly other auxiliary substances.

Such a method is known from French patent specification 1,568,957, in which a large number of substituted formamidines are described; these are compounds in which W may be hydrogen, methyl, dimethyl, chlorine, dichloro, nitro and ethoxy and either R 1 alkyl having at least 4 carbon atoms and R 2 is hydrogen or R 1 and R 2 are both alkyl. All of these compounds are said in the first paragraph to be acaricidal, herbicidal, and vermifuge. There is no actual explanation of all these applications.

It has now been found that the compound of formula 1, wherein 15 W is 2,4-dimethyl, R 1 is methyl and R 2 is hydrogen, so the compound according to L 2 of formula 2 is a very effective acaricide, and also against spider mites and aphids works. In particular, it has a strong effect on larvae and pregnant females of the infamous bovine tick Boophilus microplus, and of the red spider mite (including Tetranychus urticae). Effective dosages are between 0.05 and 100 kg / ha, usually between 0.1 and 10 kg / ha. According to the invention, the compound of formula 2, or a salt thereof, is therefore used for the preparation of an acaricidal composition.

It should be noted that British Patent 964,640 discloses a large group of N-arylamidines, the aryl group of which may be optionally substituted phenyl; they are said to have pesticidal properties, including activity against acarides.

British Patent 1,039,930 describes a group of N- (4-chloro-2-methylphenyl) formamidines which are reported to be effective against mites, as well as spider mites, but which have no effect on insects. In British Patent 7908590 2 * «.

1,140,965 discloses a group of N- (4-halo-2-methylphenyl) formamidines which are reported to have activity against the acaride Boophilus microplus.

The acaricidal activity of this compound has been compared to that of several other N-arylformamidines.

(a) Ovarian larval activity against Tetranychus urticae (column A)

Discs of French bean leaves with a diameter of 2 cm were cut so that the leaf stalk, which was kept in contact with water during the entire test, was preserved. Apart from the operations during the test, the leaf disks were kept at 18 ° C and 75% relative humidity throughout the test. Nine adult females of Tetranychus urticae were placed on a leaf blade and left for 24 hours, after which 30-50 eggs were laid on the leaf blade.

The correct number of eggs was recorded (x) and the blade was sprayed with an aqueous solution or dispersion of the test compound until almost dripped from it. After 10 days, the number of live larvae (y) on the leaf blade was counted, and the mortality was calculated:

Mortality = 100 - 100 - x

The experiment was started with a concentration of 1000 mg / liter of test compound performed. If this concentration gave a mortality above 50%, further tests with lower concentrations were carried out, so that the LD, -q could be approximately determined. The test was done in triplicate for each concentration. The LD values obtained (in mg / l test compound in the aqueous spray preparations) are shown in column A

of Table B. * \ (b) Activity against adult Tetranychus urticae (column B)

As in study (a) above, leaf-30 slices of string beans were used. 15 adult Tetranychus urticae mites were placed on a leaf disc and then sprayed with an aqueous solution or dispersion of the test compound until almost dripping from it. Mortality was determined after 72 hours.

The LD ^ Q values were determined as under (a), with an initial concentration of 1000 mg / l, and in triplicate. These are in column B of table B.

7908590 3 (c) Activity against Boophilus microplus larvae, (columns C and C ')

Trial (i)

Glass tubes measuring 5 x 2.5 cm and open on both sides were lined internally with pieces of filter paper measuring 4.2 x 4.8 cm. The paper was treated with 0.15 ml of an acetone solution of the test compound and then dried. Boophilus microplus larvae were introduced into each tube and sealed with fine sieve mesh. Mortality was recorded after 72 hours and the assay was performed in duplicate.

Trial (ii)

The compounds, which showed high activity in test (i), were further investigated. Using a Tatters-i5 field spray tower, 1 ml of an aqueous solution or dispersion of the test compound was uniformly sprayed onto 20-30 larvae. After drying, the larvae were transferred to a covered Petri dish and mortality recorded after 48 hours. Duplo determinations were made at various concentrations up to 250 mg / l of test compound and from the results the LDf values were calculated. The results of tests (i) and (ii) were classified in four degrees: 1 degree: In test (i) more than 50% mortality after contact with the formamidine from an acetone solution with 50 mg / l and an LDf of 125 mg / l in experiment (ii).

25 26 degree; In experiment (i) more than 50 Z mortality after contact with the formamidine from an acetone solution with 50 mg / l and an LDf greater than 125 mg / l in experiment (ii).

a

3 degree: In test (i) more than 50 Z mortality after contact with the formamidine from an acetone solution 500 mg / 1 and less than 50 Z mortality after contact with the formamidine from an acetone solution with 50 mg / 1.

4th degree: In test (i) less than 50 Z mortality after contact with the formamidine from an acetone solution with 500 mg / l.

The 3rd degree compounds are considered to have little activity against Boophilus microplus larvae; 4 degree joints as ineffective. These degrees are found in column C and the Praise values obtained in experiment (ii) are in column C 'of table B

7908590 _ * .............. '______ _____ ______. ..........

4 mentioned. The 3 and 4 degree compounds were not tested in Test (ii).

(D) Activity against pregnant females of Boophilus microplus (column D)) 10 pregnant ticks of Boophilus microplus were immersed in an aqueous solution or dispersion of the test compound for 3 minutes. They were then allowed to drain for 2 minutes, dried on filter paper, and immobilized by placing them on their back on adhesive tape. The ticks were kept at 25 ° C for 6 days, after which the number of ticks were counted that had not laid a single egg. The test was first performed at a concentration of 500 mg / liter of the test compound. If more than 50% of the ticks had not laid any eggs at this concentration, further tests were carried out with different concentrations below this 500 mg / l so that the rough EDQ could be determined. The determinations were made in duplicate. The ED values obtained, in mg of compound to be tested per liter of aqueous immersion preparation, are shown in column D of Table B. A dash in this column indicates that no test x-ash has been made with that compound.

All of the tests (a) to (d) 20 described above were carried out in a strictly comparable manner, including with aqueous spray or immersion preparations not containing any test compound. In test (c) (i), that meant contact with filter paper in which no acaricide had been applied.

Table B

Acaricidal activities of compounds of formula 1

Connection Activity

W NRjS2 ABC C 'D

2.4- (CH3> 2+ NHCH3 3 120 1 60 110 2.4- (CH3) 2 NHC2H5> 1000 420 4 -> 500 30 2.4- (CH3) 2 ++ NHC ^ Hg> 1000> 1000 4 -> 500 2.4- (CH0) „++ NHC..IL., 130> 1000 3% 13 4-Cl-2-CH3XX NHCH3 58 120 2 250> 500 4-Cl-2-CH3 NHC2H5 320> 1000 4 -> 500 4-Cl-2-CH3SK NHC3H7 380> 1000 4 -> 500 35 4-Cl-2-CH3Si NHC4H9 (sec.)> 1000> 1000 4 -> 500 4-C1-2-CH3sk NHC ^ Hg (iso) > 1000 620 4.> 500 7908590

Continued from table

W NRjR2 A B C C ’D

4-Ci-2-CH3 Δ ** N (CH3) 2 17 230 2 230> 500 5 4-Cl-2-CH3 ** N (C2H5) 2 78> 10 ° ° 4 “> 5 ° ° 5 HXN ( CH3) 2> 1000> 1000 4 4-och3 sn (ch3) 2> 1000> 1000 4 4-C1S Ν (0Η3) 2> 1000> 1000-4--4-Br SN (CH3) 2> 1000> 1000 4 -> 500 3-CF3 s N (CH3) 2> 1000> 1000 4 10 3,4-Cl2 KN (CH3) 2> 1000> 1000 4 3-CH3 XN (CH3) 2> 1000> 1000 4 3- Cl-4-CH3 SN (CH3) 2> 1000> 1000 3 3-C1 XN (CH3) 2 500 1000 3 3.4- (GH3) 2 x N (CH3) 2> 1000> 1000 4 15 4-CH- XN ( CH „)„> 1000> 1000 4 4 9 3 2 3.4- Cl2 x piperidino> 1000> 1000 4 - - 3.4 ~ C12 K morpholino> 1000> 1000 4 - - 4- C1 nhch3> 1000> 1000 4 - - 4-Br NHCH3> 250 ++> 1000 4 20 3-CF3 NHCH3> 1000> 1000 4 3.4- Cl2 NHCH3> 250 (3)> 1000 4 - - 4-C, Hn NHCH-> 3000> 1000 4 4 9 3 H NHCH3> 1000> 1000 4 4-N02 NHCH3> 1000> 1000 4 25 4-CN-2-CH3 NHCH3> 1000> 1000 4 4-N02 ~ 2-CH3 NHCH3> 1000> 1000 4 - -: 2.4.6- Cl3 NHCH3> 1000> 1000 3 2.4.6- Cl3 N (CH3) 2> 1000> 1000 3 -> 500 2 y 4,6-Me3 N (CH3) 2> 3000> 1000 4 -> 500 30 + formamide xne according to this invention; ++ specifically mentioned in French patent 1,568,957 x specifically mentioned in British patent 964,640 xx specifically mentioned in British patent 1,039,930 35 D chlorphenamidine, a commercially available acaricidal (3) concentration above 250 ppm could not be used due to phytotoxicity.

7908590 6

The action of N-2,4-dimethylphenyl-N'-methylformamidine and some related N-arylamidines against the louse Megoura viciae were determined as follows: Broad bean plants were grown separately in pots and when they were 3.5 cm high infected with Megoura viciae. Each plant was sprayed with an aqueous solution or dispersion of the test compound until almost dripping, and kept at 18 ° C and 75% relative humidity for 72 hours. Mortality was then determined by counting the dead and living lice. The test was started at a concentration of 1000 mg / l of test compound. If a mortality above 50% occurred at this concentration, further tests with lower concentrations were carried out, so that the LD ^ q could be calculated. Three determinations were made for each concentration. The obtained LD 2 values in mg / l of the compounds to be tested in the aqueous spray preparations are shown in Table C. Blank tests were of course also carried out under identical conditions.

Table C

Insecticidal activity against Megoura viciae Compound according to formula 1, Rj = CH ^ 20 _R1, 'LD50_ 2.4- (CH3) 2 + H 43 "' 4-Cl-2-CH3 CH3> 1000 4-C1 CH3> 1000 3-CF3 CH3 > 1000 25 3.4 ”C12 CH3 '> 1000 3-ci-4-ch3 ch3> 1000 3.4- (CH3) 2 CH3> 1000 4-C4H9 CH3> 1000 30 + formamidine of this invention.

The invention also relates to a process for the preparation of the N- (2,4-dimethylphenyl) -N'-methylformamidine of formula 2, which is carried out in a manner known per se for analogous compounds, in particular by condensation of 2,4- dimethylaniline with 35 N-methylformamide in the presence of a dehydrating agent.

The carriers and any auxiliary substances with which the compound 7908590 7 of formula 2 is mixed in the preparation of agricultural preparations may be either solid or liquid. The methods of mixing are sufficiently known per se and they lead to dusting powders, dispersible powders, solutions, emulsifiable concentrates, dispersions and emulsions, aerosols and smoking candles. The intended agricultural compositions generally can contain from 5 to 95% by weight of active substance. In addition, they may optionally contain other active substances, for example one or more fungicides, insecticides or other acaricides.

The preparations according to the invention can be applied on soil, for example on the soil around milking devices, in order to combat ticks present thereon. Preferably, however, the cattle are treated with aqueous suspensions or emulsions of so-called "immersion preparations". The active substance concentration in the aqueous liquids to be used should generally be between 0.001 and 10% by weight, usually between 0.005 and 5% by weight.

A preparation of the compound according to formula 2 is now prepared.

While stirring, 55.1 g of 2,4-dimethylaniline hydrochloride, 83.7 g of p-toluenesulfonyl chloride and 60 ml of N-methylform-20 amide were mixed together with stirring, occasionally requiring cooling of OO to adjust the temperature. between 20 and 35 C. When the exothermic reaction had subsided, the mixture was stirred for an additional 4 hours at room temperature, then poured into a mixture of ice and water, which mixture was kept alkaline with 10N NaOH and kept below 10 ° C by cooling. The solid precipitate was filtered off, washed with water to alkali-free, dried at room temperature and recrystallized from cyclohexane to yield N- (2,4-dimethylphenyl) -N, methylformamidine with m.p. 75-76 ° C was obtained.

7908590

Claims (2)

1. Process for the preparation of an acaricidal composition, in which an N-arylformamidine is mixed with a carrier and possibly other auxiliary substances, characterized in that the compound is 1-'1 1 1 1 1 ππι · - " -Γ ΓΓΓ J. thing of formula 2 or a salt thereof used. 2. Process for the preparation of an N-arylform-amidine, suitable for the process according to claim 1, or a method known per se for analogous compounds, characterized in that the compound according to formula 2 is prepared. A 7908590 v- - CH, ch> -CVN = CH "Vh 2 CH> 7908590 Limited in Hottinghan, Great Britain Boots Pore Drug Company Limited, t