JPS6317833B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the following general formula () (However, in the formula, R is

【formula】

The present invention relates to a novel tetrahydrobenzothiazolylimidazolidine derivative represented by the formula: R ¹ represents a hydrogen atom, a methyl group, an acetyl group, a benzoyl group, or a phenoxycarbonyl group, and a herbicide containing the derivative as an active ingredient. As a result of various studies on herbicides, the present inventors discovered that the tetrahydrobenzothiazolylimidazolidinone derivative represented by the above general formula () has an excellent practical herbicidal effect,
This led to the present invention. The compound represented by the general formula () is a new compound that has not been described in this publication, and of course has no known physiological activity. These compounds have excellent herbicidal activity against broad-leaved weeds and the like in foliage treatment tests and soil treatment tests, and show particularly strong activity in foliage treatment tests. Its application range as a herbicide is paddy fields,
In addition to agricultural land such as fields and orchards, it can be used for non-agricultural land. The present invention will be explained in detail below. In the present invention, the general formula () having a herbicidal effect
The compound represented by can be synthesized from compounds represented by the following general formulas () and () (R ¹ =H) by any of the following reaction formulas A, B, or C. The compound of general formula () which is the starting material in these reactions is as shown in reaction formula (D). Phenyl-(4,5,6,7-tetrahydro-5,5-dimethyl-7-oxo-2-
It is obtained by reacting benzothiazolyl) carbamate () with dimethyl acetal of methylaminoacetaldehyde in a tightly closed reaction vessel. The reaction formula (A) for obtaining the compound of the present invention is a method in which compound () is reacted in alcohol (preferably ethanol) in the presence of a dilute inorganic acid. Reaction formula (B) is a method in which an acid chloride is reacted in the presence of an acid acceptor such as a tertiary amine in acetonitrile or using a basic solvent (eg, pyridine) as a reaction solvent. Further, reaction formula (C) is a method in which the reaction is carried out in methanol in the presence of a catalytic amount of concentrated sulfuric acid. Specific examples of the compounds represented by the general formula () according to the present invention, their physical and chemical properties, and the synthetic methods applied thereto are shown in Table 1 according to the reaction formulas A, B, or C.

【table】

[Table] Next, the method for synthesizing the compound of the present invention will be explained by giving specific examples. In addition, the proton assignment by NMR of the product was performed using the numbering shown in the figure below. Synthesis Example 1 1-(4,5,6,7-tetrahydro-5,5
-dimethyl-7-oxo-benzothiazole-
2-yl)-3-methyl-5-hydroxy-1,
Synthesis of 3-imidazolidin-2-one (Compound No. 1) Phenyl-(4,5,6,7-tetrahydro-
5,5-dimethyl-7-oxo-2-benzothiazolyl) carbamate (compound) 28.8g (0.09
16.3 g of dimethyl acetal of methylaminoacetaldehyde in a DMF (150 ml) suspension of
(0.136 mol) was added, and the mixture was heated and stirred for 3 hours. After evaporating DMF, the residue was dissolved in chloroform, and the chloroform solution was washed with a 10% aqueous sodium carbonate solution and then with water, dried, and then chloroform was distilled off to obtain pale yellow crystals. mp86-89℃, yield 18g, yield 60% This crystal is 2-[1-methyl-3-(4,5,
6,7-tetrahydro-5,5-dimethyl-7-
It was confirmed from the IR spectrum that it was a dimethyl acetal (compound) of oxo-2-benzothiazol-2-yl)-ureido]acetaldehyde. IR KBrcm ^-1 : νNH−3380, νNHCO−1670,
νCO−1630 18 g (0.053
mol), ethanol (112.5 ml), dilute hydrochloric acid (150 ml)
ml: 8.8% concentration), heated and refluxed for 30 minutes, and then allowed to cool to precipitate crystals. Take this,
After washing with water and warm acetone, white crystals were obtained. mp229-230°C (decomposition), yield 6g This crystal was confirmed to be Compound No. 1 from the IR spectrum and NMR spectrum. NMR (CDCl ₃ : δ, ppm) 1.15 (6H, S: 5th CH ₃ ), 2.47 (2H, S: 4
position H), 2.79 (2H, S: 6th position H), 3.01 (3H,
S: 3' position N-CH ₃ ), 3.32 to 4.05 (2H, m: 4' position H), 4.9 (1H, d, J = 2Hz: 5' position OH), 6.11
(1H, dd, J = 2Hz, 7Hz: H at 5' position) Synthesis example 2 1-(4,5,6,7-tetrahydro-5,5
-dimethyl-7-oxo-benzothiazole-
Synthesis of 2-yl)-3-methyl-5-benzoyloxy-1,3-imidazolidin-2-one (compound number 3) 1-(4,5,6,7-tetrahydro-5,5
-dimethyl-7-oxo-benzothiazole-2
-yl)-3-methyl-5-hydroxy-1,3
-imidazolidin-2-one (compound I: R ¹ =
1.7 g (0.012 mol) of benzoyl chloride was added dropwise to a solution of 3 g (0.01 mol) of H) in pyridine (60 ml) under ice cooling, and the mixture was stirred for 10 minutes. Next, the refrigerant was removed and the mixture was stirred for 2 hours, after which the reaction solution was poured into 100 ml of water, and the precipitated crystals were collected and washed with water. The crystals were recrystallized from a mixed solution of benzene-hexane to obtain white crystals. mp176-178°C, Yield 1.8g This crystal was confirmed to be Compound No. 3 from the IR spectrum and NMR spectrum. NMR (CDCl ₃ : δ, ppm) 1.1 (6H, S: 5th position CH ₃ ), 2.47 (2H, S: 4
position H), 2.75 (2H, S: 6th position H), 3.11 (3H,
S: 3' position N-CH ₃ ), 3.71 (1H, dd, J = 2Hz,
11Hz: 4′ position H), 4.12 (1H, dd, J = 7Hz, 11
Hz: 4'H), 7.41 (1H, dd, J = 2Hz, 7
Hz: 5' position H), 7.49-8.31 (5H, m, aromatic proton) Synthesis example 3 1-(4,5,6,7-tetrahydro-5,5
-dimethyl-7-oxo-2-benzothiazol-2-yl)-3-methyl-5-methoxy-
Synthesis of 1,3-imidazolidin-2-one (compound number 5) 1-(4,5,6,7-tetrahydro-5,5
-dimethyl-7-oxo-2-benzothiazol-2-yl)-3-methyl-5-hydroxy-1,
3-imidazolidin-2-one (compound I: R ¹
=H) 3 g (0.01 mol) in anhydrous methanol solution
120 ml of the solution was heated to reflux in the presence of a catalytic amount of concentrated sulfuric acid, and then allowed to cool to precipitate crystals. This was taken to obtain white crystals. mp128-130°C (decomposition), yield 2.1g This crystal was confirmed to be Compound No. 5 from the IR spectrum and NMR spectrum. NMR (CDCl ₃ : δ, ppm) 1.13 and 1.16 (6H, S: 5th position CH ₃ ), 2.47 (2H,
S: 4th place H), 2.83 (2H, S: 6th place H), 3.0
(3H, S: 3' position N-CH ₃ ), 3.5 (1H, dd, J=
2Hz, 11Hz: 4' position H), 3.59 (3H, S: 5' position O-
CH ₃ ), 3.81 (1H, dd, J = 7Hz, 11Hz: H at 4' position), 5.99 (1H, dd, J = 2Hz, 7Hz: H at 5' position) Compound of the general formula (1) according to the present invention To use it as a herbicide, it can be applied alone or diluted to an appropriate concentration with a diluent in the same way as general herbicides, and applied by methods such as spraying.If necessary, a spreading agent, It is also possible to add auxiliary agents such as wetting agents and fixing agents. Further, the compound of the general formula (1) according to the present invention is
Even when mixed with other drugs, there is no risk of decomposition or deterioration of the drug itself, and there is no risk of decomposition or deterioration of the other drug, so other physiologically active drugs, e.g.
It can also be used in combination with or mixed with fungicides, insecticides, herbicides, plant growth inhibitors, etc., or fertilizers. Next, some examples will be given, but the mixing ratio of the carrier (diluent) and auxiliary agents and the active ingredients can be varied within a wide range. Example 1 Wettable powder compound No. 1 50 parts lignin sulfonate 5 parts alkyl sulfonate 3 parts diatomaceous earth 42 parts are mixed and ground to prepare a wettable powder, which is diluted with water and used. Example 2 Emulsion Compound No. 2 25 parts xylene 65 parts polyoxyethylene alkyl allyl ether 10 parts were uniformly mixed to form an emulsion, which was diluted with water before use. Example 3 Granules Compound No. 3 8 parts bentonite 40 parts clay 45 parts lignin sulfonate 7 parts were mixed uniformly, water was added and kneaded, processed into granules using an extrusion granulator and dried to obtain granules. shall be. Next, test examples will be shown to demonstrate the effectiveness of the compounds of the present invention. Test example: Weed killing test using foliage spraying Plastic planter (180 x 580 x 150 mm)
Filled with field soil, this was used to grow barnyard grass, black-and-white grass, sycamore, purslane, white grass, goldenrod,
Japanese knotweed, Japanese knotweed, wheat, corn,
Soybean and cotton seeds were sown and grown in a greenhouse, and the wettable powder of the compound of the present invention was diluted with water to give an active ingredient concentration of 0.1% and 0.2%. The leaves were sprayed with a pressure sprayer. After 20 days of treatment, an investigation was conducted using the following herbicidal power criteria.
The growth level of the test plants at the time of spraying was as follows: barnyard grass, crabgrass, sycamore, wheat, and corn at the 2- to 3-leaf stage; purslane, silverwort, goldenrod, and knotweed at the 2- to 3-leaf stage; and ash at the 3- to 4-leaf stage. Soybeans and cotton are in their first true leaf stage.

【table】 [Brief explanation of the drawing]

The attached figures are the infrared absorption spectra of the compounds of the present invention. Figure 1 shows compound number 1, Figure 2 shows compound number 2, Figure 3 shows compound number 3, and Figure 4 shows compound number 4. , Figure 5 shows compound number 5, compound number 6
The figure shows compound number 6.

Claims (1)

[Claims] 1 Represented by the general formula [Formula] (wherein R is [Formula] or [Formula] R ¹ represents a hydrogen atom, a methyl group, an acetyl group, a benzoyl group, or a phenoxycarbonyl group) Tetrahydrobenzothiazolylimidazolidinone derivative. 2 A herbicide containing a tetrahydrobenzothiazolylimidazolidinone derivative represented by the general formula [Formula] (wherein R is [Formula] or [Formula] R ¹ is the same as above) as an active ingredient.