JPS6058884B2 - herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a herbicide, and more particularly to a useful herbicide containing an N-substituted benzyl-trichlorophenylacetamide derivative as an active ingredient.

Conventionally, 2,3,6-trichlorph, enyl acetate amide (Japanese Patent Publication No. 38-20148) and the like have been known as herbicides, but their herbicidal efficacy was not sufficient and they caused great damage to rice and the like. The inventors found that this type of acetate amide derivative was sufficient.

As a result of intensive research to develop a compound J that has significant herbicidal efficacy and high selectivity, an amide compound obtained by the reaction of a specific N-substituted benzylamine and trichlorophenylacetic acid is extremely useful. I discovered that
The present invention has now been completed. That is, the present invention relates to the general formula (wherein R represents hydrogen or an alkyl group, and x represents a halogen, a haloalkyl group, an alkyl group, or an alkoxy group).

The present invention provides a herbicide containing an N-monosubstituted benzyl-trichlorophenylacetamide derivative represented by the following formula as an active ingredient. The trichlorophenyl group in this general formula (1) includes 2,3,5-trichlorophenyl group, 3,4,5-trichlorophenyl group, etc.
-3,6-trichlorophenyl group has particularly excellent herbicidal activity.

X in general formula (1) represents a halogen, a haloalkyl group, an alkyl group, or an alkoxy group.

It is preferable that X be substituted at the m-position or the o-position, and those substituted at the p-position are not preferable because of poor activity. Furthermore, those in which two or more Xs are substituted are not preferred from the viewpoint of herbicidal activity and phytotoxicity. The halogen is preferably chlorine or bromine, the haloalkyl group is preferably trifluoromethyl, and the alkyl group is preferably one having 1 to 4 carbon atoms, such as a methyl group or an ethyl group.

Moreover, as the alkoxy group, those having 1 to 4 carbon atoms such as methoxy group and ethoxy group are preferable. R in the general formula (1) represents hydrogen or an alkyl group, and the alkyl group preferably has 1 to 4 carbon atoms, such as a methyl group or an ethyl group.

The novel N-monosubstituted benzyl-trichlorophenylacetamide derivative represented by general formula (1) can be produced by various methods.

For example, thionyl chloride is added to trichlorphenyl acetic acid and heated under reflux for 1 to 5 hours to obtain trichlorophenyl acetic acid.
Acid chloride was obtained, which was then reacted with a predetermined substituted benzylamine and triethylamine in an ether solvent at room temperature for 0.5 to 3 hours, and then cooled to room temperature to react with a predetermined substituted benzylamine and triethylamine.
% aqueous hydrochloric acid solution is added and the solvent is distilled off. After the solvent is distilled off, the Z crystals are usually crystallized, so the Z crystals are separated and dried. If they do not crystallize, the above N Monosubstituted benzyl-trichlorophenylacetamide derivatives can be prepared. The herbicide of the present invention highly selectively kills weeds after germination in the presence of light.

In other words, in soil treatment under flooded conditions,
1. Kikashigusa, Japanese chickweed, Japanese chickweed, Japanese cypress, etc.
In addition to showing excellent weeding effects on annual weeds, it also shows some effect on perennial weeds such as Urikawa and Kurogai, but has almost no chemical damage to transplanted paddy rice. When using the herbicide of the present invention, the compound as an active ingredient is usually mixed with a liquid carrier such as an organic solvent or a solid carrier such as fine mineral powder, and the mixture is prepared in the form of a wettable powder, emulsion, powder, granule, etc. Formulated into a formulation. A surfactant may be added to impart emulsifying properties, dispersibility, spreading properties, etc. during formulation. In addition, it can be mixed with other herbicides, growth regulators, insecticides, fungicides and other agricultural chemicals, fertilizers, etc., if necessary. As described above, the herbicide of the present invention is extremely useful as a highly selective herbicide with high herbicidal activity and no phytotoxicity to crops, and can be widely used. Next, the present invention will be explained in more detail with reference to Synthesis Examples and Examples. Synthesis Example 1 2,3,6-trichlorophenylacetic acid 0.8g (3.3
4 mmol) was added with 2.0 V (16.8 mmol) of thionyl chloride, and the mixture was refluxed for 4 hours.

Excess thionyl chloride was distilled off under reduced pressure to obtain 0.86q of 2,3,6-trichlorophenylacetic acid chloride (yield: 10
0%) was obtained as a yellow oil. Next, this 2●3・6
- 15 ml of an ether solution containing 0.86y of trichlorophenylacetic acid chloride was mixed with 3.67 mmol of the substituted benzylamine shown in Table 1 and 0.405g (4
．． The mixture was added dropwise to 25 ml of an ether solution containing 0.01 mmol) at room temperature, and then heated under reflux for 2 hours.

After cooling the reaction solution to room temperature, 10 ml of 5% aqueous hydrochloric acid solution was added.
was added and the solvent was distilled off under reduced pressure. After distilling off the solvent, the resulting crystals were separated and dried over phosphorus pentoxide to obtain a colorless crystalline N-substituted benzyl-2,3,6-trichlorophenylacetamide derivative. The results are shown in Table 1. 1st
In the table, a is m-chlorobenzylamine, b is m-brobenzylamine, c is m-trifluoromethylbenzylamine, and d is o-
trifluoromethylbenzylamine, e is m-methylbenzylamine, f is m-methoxybenzylamine, g is m-chloro-α-methylbenzylamine, h is m-
Bromo-α-methylbenzylamine; i represents m-chloro-α-ethylbenzylamine; A. ．． B. ．． C. ．．
D. ．． E. ．． F. ．． G. ．． H and I each represent the corresponding N-monosubstituted benzyl-2,3,6-trichlorophenylacetamide derivative.

Example 1 (1) Herbicide formulation 97 parts by weight of Zeekrite (carrier), Neoperex powder (trade name, manufactured by Kao Atlas Co., Ltd., surfactant)
1.5 parts by weight and 1.5 parts by weight of Solpol 800A (trade name, manufactured by Toho Chemical Industries, Ltd., surfactant) were uniformly ground and mixed to obtain a carrier for a wettable powder.

9 parts of this wettable powder carrier and 1 part of the N-substituted benzyl-trichlorophenylacetic acid amide derivative were uniformly ground and mixed to obtain a herbicidal wettable powder.

(2) Biological test results Fill paddy soil in a 5500 are porcelain pot, sow the seeds of Japanese grasshopper, Kikashigusa, Firefly, and Cyperus japonica uniformly on the surface layer, and after submerging in water to a depth of 2CW1, the 2-leaf stage Two paddy rice seedlings (quality: Nipponbare) were transplanted.

When the weeds germinated, a predetermined amount of the diluted herbicide obtained in (1) above was uniformly dropped onto the water surface to treat the weeds, and then the pots were left in a greenhouse and watered at appropriate times.

Table 2 shows the results of investigating the herbicidal effect and phytotoxicity of paddy rice 20 days after the chemical solution treatment.

Claims (1)

[Claims] 1 Represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R represents hydrogen or an alkyl group, and X represents a halogen, haloalkyl group, alkyl group, or alkoxy group. A herbicide containing an N-substituted benzyl-trichlorophenylacetic acid amide derivative as an active ingredient. 2
The herbicide according to claim 1, which is represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (wherein R and X are the same as above). 3
3. The herbicide according to claim 1 or 2, wherein X is substituted at the m or o position. 4. Claim 1, wherein X is chlorine or bromine,
The herbicide according to item 2 or 3. 5. The herbicide according to claim 1, 2 or 3, wherein X is a trifluoromethyl group. 6. The herbicide according to claim 1, 2 or 3, wherein X is an alkyl group having 1 to 4 carbon atoms. 7. The herbicide according to claim 1, 2 or 3, wherein X is an alkoxy group having 1 to 4 carbon atoms. 8. The herbicide according to claim 1, 2, or 3, wherein R is an alkyl group having 1 to 4 carbon atoms.