JPS63313706A - Insecticide - Google Patents

Abstract

PURPOSE:To obtain an insecticide having strongly insecticidal effects on various insect pests, low toxicity to men and animals, further long residual activity, useful in agricultural and horticultural fields, containing a phosphoro thionoamidate compound as an active ingredient. CONSTITUTION:An insecticide containing a phosphorothionoamidate compound shown by formula I (R<1> and R<2> are lower alkyl; R<3> is 2-cyanophenyl group or 4-cyanophenyl) as an active ingredient. When used, the active ingredient can be directly applied as an insecticide and generally the active ingredient is processed into a form such as dust or solution and used. The compound shown by formula I as the active ingredient is synthesized by reacting a com pound shown by formula II with a compound shown by formula III as shown the reaction formula. O-methyl-O-(2-cyanophenyl)-N-isopropyl phosphorothiono amidate may be cited as the concrete example of the compound shown by formula I.

Description

Detailed Description of the Invention (a) Object of the Invention [Field of Industrial Application] The present invention relates to an organophosphorus insecticide containing a specific phosphorothionamidate compound as an active ingredient, and is applicable to agriculture, It is used in the horticultural industry.

[Conventional technology]

The phosphorothionamidate compound has the general formula [I1
], and in the following formula [I1], R4 and R5 are lower alkyl groups, n is an integer, and X is a nitro group, a cyano group, a halogen atom, or a carboxyalkyl group. .

Regarding the production method and uses of phosphorothionamidate compounds in which the substituent X is a nitro group, a cyano group, a halogen atom, etc., see Japanese Patent Publication No. 41-28979 and Japanese Unexamined Patent Publication No. 49-1989.
No. 93345, JP-A-60-130595, JP-A No. 4
No. 7-50378 and British Patent No. 659682, and the effectiveness as a herbicide is disclosed in JP-A-49-28979 and JP-A-49-933.
No. 45, Japanese Patent Publication No. 47-50378, Mei 41, and furthermore, in British Patent No. 659682, compounds in which χ in the general formula [I1] is a hydrogen atom or a nitro group are used as insecticides and fungicides. It has also been disclosed that it is effective.

Furthermore, a phosphorothionamidate compound in which the substituent X is a carboxyalkyl group is disclosed in Japanese Patent Publication No. 47-3
No. 8971, Japanese Patent Publication No. 50-21464, etc., and it has also been revealed that such compounds can be used as insecticides.

[Problem that the invention seeks to solve]

The present invention aims to provide an organophosphorus insecticide that has superior insecticidal performance than conventionally known phosphorothionamidate compounds.

(υ) Structure of the invention [Means for solving the problem] The present inventor has investigated the insecticidal performance of various phosphorothionamidate compounds, and has found that they have significantly higher insecticidal performance than conventional organophosphorus insecticides. The present invention was completed by discovering a specific phosphorothionamidate compound having this ability.

That is, the present invention relates to an insecticide having a granite component represented by the following general formula [I].

R”0 (In the above formula, R1 and R2 are lower alkyl groups, R
3 represents a 2-cyanophenyl group or a 4-cyanophenyl group. ) The present invention will be explained in more detail below.

○Phosphorothionamidate compound Organic group R1 of the phosphorothionamidate compound used in the present invention
and R2 is a lower alkyl group, such as a methyl group, an ethyl group, an i-propyl group, an i-butyl group, and the like.

The organic group R3 is a 2-cyanophenyl group or a 4-cyanophenyl group.

Specific compounds that can constitute the insecticide of the present invention include:
O-methyl-0-(2-cyanophenyl)-N-isobrobylphosphorothionamidate, 0-methyl-〇-(4-cyanophenyl)-N-isobutylphosphorothionamidate, 0-ethyl -〇-(2-cyanophenyl)-N-isopropylphosphorothionamidate, 0-(n-propyl)-0-(4-cyanophenyl)-N-isopropylphosphorothionamidate, etc. Can be mentioned.

○Synthesis method The above phosphorothionamidate compound is isofenphos (in the general formula [n], R4 is a 1-propyl group, R5 is an ethyl group, X is a 2-carboxy-1-propyl group, and n is 1). Compound) production method (Special Publication No. 47-38
971), it can be produced by the reaction of the following phosphorochloride compound [I] and an alkylamine [rV] (reaction formula (1)).

% Formula % [I] Compound [■] can be produced by reacting phosphorodichloride compound [V] and phenol [Vl] in the presence of sodium hydroxide and triethylamine as shown below ( Reaction formula (2)).

[I[[] Furthermore, the compound [V] is phosphorus trichloride [1000]
(2)] and alcohol [■] (Reaction formula (3)).

% formula % (3) [] A phosphorothionamidate compound represented by the general formula [IF obtained by a method such as reaction formula (1) can be purified by methods such as distillation, recrystallization, or chromatography. However, since reaction formula (1) proceeds selectively, the obtained compound (original substance) can be used as it is as an active ingredient of an insecticide.

Synthesis examples of compounds in which the organic group R1 is an i-propyl group, the organic group R2 is an ethyl group, and the organic group R3 is a 2-cyanophenyl group or a 4-cyanophenyl group in the general formula [+] are shown in Synthesis Example 1 and Synthesis Example 2 is shown below.

Synthesis Example 1 0-Cyanophenol (9.53 g, 0.08 mol) was dissolved in acetonitrile (100 ml), an aqueous solution of caustic soda (0.08 mol) was added thereto, and the mixture was further heated at 40 to 50°C. In, 1,000-onorinoic acid-〇-ethyl-N-isopropylamide chloride (16.1 g, 0
．． 08 mol) was added dropwise with vigorous stirring. The reaction was stirred at this temperature for 3 hours, and after filtering off the generated inorganic salts, the solvent of the filtrate was distilled off. The residue was dissolved in Hensen (100 ml) and washed with 1% aqueous sodium carbonate and water.

After drying the organic layer over anhydrous sodium sulfate, the organic layer was distilled off and 0-ethyl-〇-(2-cyanophenyl)-N
-isoprobil phosfluorothionamidate (21,
6 g, yield 95%) was obtained. The molecular weight of this substance is 284
(Mass Spectrometry). Note that the calculated value of the molecular weight is 284.

Synthesis Example 2 p-cyanophenol (9.53g, 0.08mol)
, caustic soda aqueous solution (0.08 mol) and thionophosphoric acid-〇-ethyl-N-isopropylamide chloride (
16.1 g, 0.08 mol) in acetonitrile (100
ml) in the same manner as in Synthesis Example 1, and then the same operation was performed to obtain 〇-ethyl-0-(4-cyanophenyl).
-N-isoprobyl phosphorothionamidate (2
2.0 g (597%) was obtained. The molecular weight of this substance is 284
(Mass Spectrometry). Note that the calculated value of the molecular weight is 284.

○ Composition and spraying method of insecticides The phosphorothionamidate compound represented by the general formula [+] can be sprayed as an insecticide itself, but it is usually possible to spray the compound itself as an insecticide. It is used as an active ingredient and processed into insecticides in the form of powders, liquids, wettable powders, emulsions, oils, granules, pastes, etc., and sprayed as is or diluted with water, mainly on areas infested with pests.

As the liquid carrier, any solvent or non-solvent that can disperse or dissolve the drug with an auxiliary agent can be used. Examples of such carriers include water, alcohol, benzene, xylene, dimethylnaphthalene, aromatic naphtha, and dimethylformamide.

In addition, commonly used adjuvants, such as spreading agents, emulsifiers, wetting agents, and fixing agents, may be mixed with the insecticide of the present invention to ensure effectiveness, and other herbicides, plant growth regulators, insecticides, etc. It can also be used in combination with acaricides, acaricides, nematicides, fungicides, etc., as well as other agricultural chemicals, fertilizers, etc.

Insecticide powders and wettable powders containing the compound of the present invention as an active ingredient;
An example of a method for preparing emulsions and the like is as follows.

The powder is obtained by mixing and pulverizing 5% of the compound of the present invention (1% (the same applies hereinafter)) and 95% of a mixture of talc and clay.

The hydrating agent is 30% of the compound of the present invention, 65% of a mixture of gicrite and clay, and 3% of sodium alkylhenzenesulfonate.
, by mixing and grinding 2% dinaphthylmethane disulfonic acid sodium.

The emulsion contains 30% of the compound of the present invention, 65% of Kijirole, and 5% of an emulsifier (for example, Tsurupol: trade name, manufactured by Toho Chemical Industry ■).
It is obtained by mixing and stirring.

[Effect]

It is desirable that chemicals that are inherently toxic be sprayed as little as possible within the range that allows the desired pest control effect to be obtained, and the compounds of the present invention exhibit insecticidal effects against a wide variety of pest insects in small amounts. Therefore, it is very preferable.

Examples of pests to which the compounds of the present invention can be applied are as follows.

(a) Coleoptera: Anomala cuprea, Anomala rufocuprea, Popi-11ia japonica, and Echinocnemus sq. uame
us), rice weevil (Lissorhoptru
s ory-zophilus), Oulema oryzae, and adzuki bean weevil (C
allosobruchus chinensis) etc.

(G)) Diptera Onion fly (Ilemya antiqua)
, Musca domestica, Hylemya platur-a, Dacus cucurbitae, etc.

The insecticide of the present invention, like conventional organophosphorus insecticides, produces an oxidized product corresponding to its active poisonous substance, oxone.
Unlike conventional organophosphorus insecticides, the oxidized product has an extremely low cholinesterase inhibitory effect.

In addition to having a strong insecticidal effect against various pests, the compound of the present invention has other features such as low toxicity to humans and animals, and long residual efficacy.

These properties make it an excellent insecticide, making it extremely useful for exterminating various harmful insects.

〔Example〕

Next, the content of the present invention will be specifically explained with reference to Examples.
The present invention should not be limited to this only.

The effectiveness of the compounds as insecticides against two types of pests is shown in Table 1 as Examples 1 and 2 and Comparative Examples 1 to 3 for the compounds of the present invention and conventional compounds, respectively. Further, a test to examine the effectiveness against two types of pests was conducted using the method shown below.

■. The compound to be tested for effectiveness against the adzuki bean weevil was made into an acetone solution, solutions at various concentration levels were prepared, and the acetone was allowed to evaporate naturally after being placed in a test tube.
A total of 920 Azukijiram were placed in the tank, and the lead rate after 48 hours was examined. A regression line of the lead ratio is determined by the method of B115s, and L D s. (50% lethal dose) was calculated.

(2) The compound to be evaluated for effectiveness against house flies was made into an acetone solution, solutions at various concentration levels were prepared, and applied locally to the abdominal dorsal plate of house flies using a microsyringe, and the predominance rate was determined after 24 hours. LD by the same method as . I asked for

The above test results are shown in Table 1, and it can be seen from the results that the insecticidal effect of the compound of the present invention is extremely large.

That is, as shown in Example 1.2 of Table 1, the compound according to the present invention is effective against both types of pests in small amounts, and is extremely excellent as an insecticide. Recognize.

On the other hand, as shown in Comparative Examples 1 to 3 in Table 1, conventional compounds were quite effective against one type of pest, but not very effective against other pests. .

(C) Effects of the Invention The insecticide of the present invention exhibits an excellent insecticidal effect that cannot be expected from conventional organophosphorus insecticides, and is extremely effective in the agricultural and horticultural industries.

Claims (1)

[Claims] 1. An insecticide containing a phosphorothionamidate compound represented by the following general formula [I] as an active ingredient. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the above formula, R^1 and R^2 represent a lower alkyl group, and R^3 represents a 2-cyanophenyl group or a 4-cyanophenyl group.)