JPH01121290A - Tetrahydrotriazopyridazine-3-thiox-1(2h)-one derivative and herbicide - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R is lower alkyl; R<1> is lower alkyl, phenyl, benzyl, cycloalkyl, alkoxyalkyl or alkoxycarbonylalkyl). EXAMPLE:2-[4-Chloro-2-fluoro-5-(1-ethoxycarbonylethyloxy)phenyl]-5,6,7 ,8-tetra hydro-1H-[1,2,4]triazolo[1,2-a]pyridazine-3-thiox-1(2H)-one. USE:A herbicide. PREPARATION:A compound expressed by formula II {e.g. 1,2-tetramethylene-2-[4-chloro-2-fluoro-5-(1-ethoxycarbonylethyloxy)ph enylthio carbamoyl]-1-ethoxycarbonylhydrazine} is refluxed in an inert solvent by heating or a base is added to heat the resultant mixture. The reaction is preferably carried out at 60-150 deg.C for 5min-24hr.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to tetrahydrotriazopyridazin-3-thioxo-1(2H)-one derivatives useful as herbicides and herbicides containing these as active ingredients. It is something.

(Prior art) As many herbicides have been developed and put into practical use in recent years,
For example, pentacine [3-isopropyl-2.1.3-benzothiadiazinone (4)-2,2-dioxide] has been used and has contributed to labor saving and improved productivity in agricultural work. Moreover, until now, tetrahydrotriazopyridazine-
2- as a 3-thioxo-1(2H)-one derivative
(4-chloro-2-fluoro-5-ethoxycarbonylmethoxyphenyl)-5.6,7.8-tetrahydro-
IH-(1,2.4)triazolo-(1.2-a)-pyridazin-3-thioxo-1-one (hereinafter referred to as comparative compound).

) is known to be effective as a herbicide.
9-172491).

(Problems to be Solved by the Invention) However, these conventional herbicides also have various problems in terms of effectiveness and safety in actual use. As a result of intensive research aimed at developing even better herbicides, the present inventors have discovered that the tetrahydrotriazopyridazin-3-thioxo-1(2H)-one derivative of the present invention can be used to treat weeds that grow in rice fields and fields. The present invention was completed based on the discovery that the present invention effectively controls the effects of the disease, is highly safe for major crops such as paddy rice and soybeans, and is also effective as a treatment agent for late-stage flooding.

(Technical means for solving the problems) Tetrahydrotriazopyridazine-3-thioxo-1(2H) of the present invention
-one derivatives have the general formula (wherein R represents a lower alkyl group, R1 represents a lower alkyl group, a phenyl group, a benzyl group, a cycloalkyl group,
Indicates an alkoxyalkyl group or an alkoxycarbonylalkyl group.

).

Next, Table 1 shows representative examples of the compounds of the present invention represented by general formula (1). In addition, compound numbers are referred to in the following description.

general formula The compound of the present invention can be produced by the following method.

(In the above reaction formula, R and R1 have the same meaning as above.) In this method, the compound represented by the general formula (II) is heated to reflux in an inert solvent, or a base is added and heated. It is done by doing. The reaction is carried out at 60-150℃
The temperature is 5 minutes to 24 hours. Here, as a base, sodium hydroxide, potassium hydroxide, sodium hydride,
Alkali metal hydroxides, hydrides or carbonates such as sodium carbonate and potassium carbonate, alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide and barium hydroxide, alkali metal alcoholades such as methylate, trialkyl Examples include tertiary amines such as amine and picoline. The amount used is about the same as a catalyst amount.

Inert solvents include benzene, toluene, xylene,
Aromatic hydrocarbons such as chlorobenzene, aliphatic calcined hydrogens such as n-hexane, n-hebutane, and petroleum ether, alicyclic hydrocarbons such as cyclohexane, nitriles such as acetonitrile, dichloromethane, chloroform, Chlorinated backing elements, halogenated hydrocarbons such as perchloren, ketones such as acetone and methyl ethyl ketone,
Ethers such as ethyl ether, tetrahydrofuran and dioxane, alcohols such as methyl alcohol and ethyl alcohol, esters such as ethyl acetate, N,
Amides such as N-dimethylformamide can be mentioned.

The compound of the present invention can also be produced by the following method.

(R and R1 in the above reaction formula have the same meanings as above.)
The above method is carried out by adding a base and heating in an inert solvent. The reaction is carried out at a temperature of 30 to 150°C for 5 minutes to 24 hours. As the inert solvent and base, those already mentioned can be used.

Next, the manufacturing method will be specifically explained with reference to Examples.

Example 1 2-C4-chloro-2-fluoro-5-(
1-ethoxycarbonylethyloxy)phenyl]-5
,6,7,8-tetrahydro-IH-[1,2,4]triazolo(1,2-a)pyridazine-3-thioxo-1
(2H)-one production In the reaction flask, 1,2-tetramethylene-2-[4-
Chloro-2-fluoro-5-(1-ethoxycarbonylethyloxy)phenylthiocarbamoyl]-1-ethoxycarbonylhydrazine 6.0 g (0,013 mol), toluene 100 m 11 and sodium hydroxide 0
．． 5 g was added and refluxed for 10 minutes to complete the reaction.

After the reaction was completed, the reaction solution was allowed to cool, washed with water, dried over magnesium sulfate, and then the solvent was distilled off to obtain a composition. This composition was purified by silica gel column chromatography to obtain 4.0 g of white crystals (yield 74%).

Melting point: 109-111°C.

Example 2 2-(4-chloro-2-fluoro-5-(
1-Cyclopentyloxycarbonylethyloxy)phenyl]-5.6,7.8-tetrahydro-IH-(1
,2,4) triazolo(1,2-a)pyridazine-3-
Preparation of thioxo-1(2H)-one In a reaction flask, 1
．． 2-tetramethylene-2-[4-chloro-2-fluoro-5-(1-cyclopentyloxycarbonylethyloxyraphenylthiocarbamoyl]-1-ethoxycarbonylhydrazine 100 m fl and sodium hydroxide 0.5 g and refluxed for 10 minutes to complete the reaction. After the reaction was completed, the reaction solution was allowed to cool, washed with water, dried over magnesium sulfate, and the solvent was distilled off to obtain a composition. This composition was Purification by silica gel column chromatography gave 3.2 g (yield 50%) of a pale brown glassy substance.

Example 3 2-[4-chloro-2-fluoro-5-
(1-methoxycarbonylethyloxy)phenyl]-
5,6,7.8-tetrahydro-IH-[1,2.4]
triazolo(1.2-a)pyridazine-3-thioxo-
Preparation of 1(2H)-one Into the reaction flask, 2-(4-chloro-2-fluoro-5
-hydroxyphenyl)-5.6,7.8-tetrahydro-IH-(1,2.4)I-riazolo[1,2-a]
Pyridazin-3-thioxo-1 (2H)-one 1.
4g (0.0044 mol), methyl 2-bromopropionate 0.8g (0.0048 mol), potassium carbonate 1.
0 g (0.007 mol) and 50 mρ of acetonitrile were added and refluxed for 1 hour to complete the reaction. After the reaction was completed, the reaction solution was allowed to cool, poured into water, and extracted with dichloromethane. The dichloromethane layer was dried over magnesium sulfate, and the solvent was distilled off to obtain a composition. This composition was purified by silica gel column chromatography to obtain 1.3 g (yield 73%) of a pale yellow glassy substance. Melting point 52~
55℃.

Next, the herbicide of the present invention is - tetrahydrotriazolopyridazine-3-thioxo-1 (2
H)-one derivative as an active ingredient. When using the compounds of the invention as herbicides, the compounds only
Or, it can be formulated into various forms such as wettable powders, granules, emulsions, or powders by adding carriers, surfactants, dispersants, adjuvants, etc. commonly used in the formulation of agricultural chemicals. can be used.

Carriers used in formulation include gicrite, talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, vermiculite, slaked lime, silica sand, ammonium sulfate,
Examples include solid carriers such as urea, liquid carriers such as isopropyl alcohol, xylene, cyclohexane, and methylnaphthalene.

Examples of the surfactant and dispersant include alcohol sulfate, alkylaryl sulfonate, lignin sulfonate, polyoxyethylene glycol ether, polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan monoalkylate, and the like. Examples of adjuvants include carboxymethyl cellulose, polyethylene glycol, and gum arabic.

When using this preparation, it can be applied directly or diluted to an appropriate concentration and sprayed.

Furthermore, the herbicide of the present invention can be used in combination with insecticides, fungicides, other herbicides, plant growth regulators, fertilizers, etc., as required.

Next, formulation examples of the herbicide of the present invention will be specifically explained by citing them as examples. Note that in the examples, % means weight percentage.

Example 4 10% of hydrating compound (1), 0.5% of Emulgen (registered trademark of Kao Corporation) 810, 0.5% of Demol (registered trademark of Kao Corporation) N, Kunilite (Kunimine Industries) 201 (registered trademark of Zikrite Co., Ltd.) and 69 parts of Zeekrite (registered trademark of Zikrite Co., Ltd.) CA are mixed and pulverized to obtain a wettable powder.

Example 5 30% of emulsion compound (2), 20% of cyclohexanone,
11% of polyoxyethylene alkylaryl ether
, 4% of calcium alkylbenzenesulfonate and 35% of methylnaphthalene were added, and these were thoroughly stirred to obtain an emulsion.

Example 6 Granules 5% of compound (1), 2% of sodium salt of lauryl alcohol sulfate, 2% of carboxymethylcellulose and 86% of clay are uniformly mixed and ground. 20 parts by weight of water were added to 100 parts by weight of this mixture, kneaded, processed into granules of 14 to 32 mesh using an extrusion type granulator, and then dried to form granules.

Example 7 Powder 2% of compound (2), 5% of diatomaceous earth and 93% of clay
are uniformly mixed and pulverized to obtain a powder (Effects of the Invention) The herbicide of the present invention is effective against annual weeds that occur in rice fields, such as Japanese barnyard grass, Japanese cypress, Japanese cypress, Japanese azalea, azalea, and Japanese aphrodisiac; It has excellent herbicidal effects against perennial weeds such as Cyperus japonica and other perennial weeds in a wide range of periods from the time of weed germination to the growing season at extremely low doses, and is highly safe for paddy rice. . In addition, there are various weeds that can be a problem in fields, such as broad-leaved weeds such as knotweed, Japanese apricot, whiteweed, dogweed, mustard, Japanese fir, noasagao, American hornwort, and Japanese thornweed.
It exhibits high herbicidal effects against weeds of the Cyperaceae family, such as Cyperus japonica, and weeds of the Poaceae family, such as barnyard grass, grasshopper, and foxtail grass, when applied in soil or foliage treatments. Furthermore, the herbicide of the present invention exhibits an extremely high killing effect even on weeds with advanced growth that are difficult to control with conventional herbicides. Namely.

It has the characteristic that it can control paddy field weeds such as Paddy weeds, Omodaka, Kurogai, Kusanem, Polygonum, etc. during the prime growing season when the leaves are advanced, without adversely affecting the paddy rice.

Weed control in the mid-term and beyond at Honda aims to avoid lower yields due to weed damage mainly due to nutrient competition, reduced agricultural work due to the complexity of harvesting, and even lower quality due to contamination of weed seeds with harvested products. It is also extremely important for this purpose. Conventionally, this has been done by manually removing the weeds or by treating them with a herbicide once they have fallen into the water, but the herbicide of the present invention can be treated under submerged conditions without falling into the water, which is extremely labor-saving. .

In addition, the herbicide of the present invention has excellent residual efficacy, so
It shows a stable herbicidal effect over a long period of time in the field.

It can also be used in gardens, pastures, lawns, non-agricultural lands, etc.

Next, the effects of the herbicide of the present invention will be explained with reference to test examples.

Test Example 1 Weeding effect test by pre-germination treatment in paddy fields A Wagner pot (surface fi 17-1/5000) was filled with paddy soil, and after puddling, seeds of Japanese millet, Japanese cypress, and Japanese cypress were sown, and the water depth was 3 (to). The area was flooded and paddy rice at the two-leaf stage was transplanted.

The next day, dilute the wettable powder prepared according to Example 4 with water,
It was dropped onto the water surface. After that, it is grown in a greenhouse and treated as 3.
After 0 days, the herbicidal effect and degree of phytotoxicity were investigated according to the criteria in Table 2.

The results are shown in Table 3.

The following is a margin test example 2 Weeding effect test by paddy field growing season treatment A Wagner pot (surface area 1/5000 are) was filled with paddy soil, and after puddling, two individual Urikawa tubers and two paddy rice plants at the two-leaf stage were placed in two squares. Transplanted to depth. The cells were grown for 40 days after transplantation.

When the cucumbers reached the 9th to 10th leaf stage, they were submerged in water to a depth of 3 G, and a wettable powder prepared according to Example 4 was diluted with water and dropped onto the water surface. After that, it was grown in a greenhouse and treated for 30 days.
On day 1, the herbicidal effect and degree of chemical damage were investigated according to the standards in Table 2. The results are shown in Table 4.

Test Example 3 Weeding effect test in a paddy field After plowing the paddy field, plots were divided into 1 section 4d and 10 individuals and 2
Twenty paddy rice seedlings at the leaf stage were transplanted to a depth of 2cm. After transplanting, they were grown under submerged water conditions at a depth of 31 days for 30 and 40 days, and when the black bream reached 20 to 30 cm and 40 to 60 cm,
A wettable powder prepared according to Example 4 was diluted with water and dropped onto the water surface. On day 30 of the treatment, the herbicidal effect and degree of chemical damage were investigated according to the criteria in Table 2. The results are shown in Table 5.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. represents an alkoxycarbonylalkyl group.) Tetrahydrotriazopyridazine-3-
Thioxo-1(2H)-one derivatives. (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. represents an alkoxycarbonylalkyl group.) Tetrahydrotriazopyridazine-3-
A herbicide characterized by containing a thioxo-1(2H)-one derivative as an active ingredient.