JPS61145155A - Dibenzylurea compound and preparation thereof - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (X is halogen, CF3, alkyl or alkoxy). EXAMPLE:1-(alpha,alpha-Dimethylbenzyl)-3-(2'-chlorobenzyl)urea. USE:A herbicide exhibiting remarkably high effect in the growth inhibiting test of the root and the stalk of bulrush. PREPARATION:The compound of formula I can be prepared by reacting a benzylamine of formula II with benzylisocyanate of formula III. The reaction is carried out in the absence of solvent or in an organic solvent (e.g. benzene) at room temperature -50 deg.C for 1-5hr under agitation or without agitation. As an alternative method, the objective compound can be produced by the reaction of the benzyl-isocyanate of formula IV with the benzylamine of formula V.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to dibenzylurea compounds represented by the general formula (wherein X represents a halogen atom, a trifluoromethyl group, an alkyl group, or an alkoxyl group) and their Regarding the manufacturing method.

[Prior Art] The compound of the present invention represented by the general formula (1) is structurally similar to the known compounds shown in Table 1.

The compounds shown in Table 1 above are known as raw materials for herbicides or other agricultural chemicals, but according to experiments conducted by the present inventors, their herbicidal activity is not practical as shown in the test examples below. is not something to be satisfied with.

"Problems to be Solved by the Invention" The present invention provides a novel dibenzylurea compound with high herbicidal activity and a method for producing the same.

[Means for Solving the Problems] The present inventors synthesized various 1,1-dibenzylurea compounds and examined their herbicidal activity, and found that the α,α-dimethylbenzyl group had no substituent, and the benzyl group The compound of general formula (1), which has a substituent at the ortho position of It was discovered that it has a dramatically high herbicidal activity, and the present invention was completed.

The herbicidal activity of the compound of general formula (1) is determined by the elongation inhibiting ability of the compound A listed in Table 1 on the roots and stems and leaves of firefly, as shown in Test Example 1 (ED for firefly, ?) below. They are about 7 to 125 times and about 6 to 20 times, respectively, and about 150 to 2,600 times and about 140 to 500 times, respectively, compared to that of the compound.

Although it is not clear why the compound of general formula (1) has dramatically higher herbicidal activity than the known compounds shown in Table 1 above, it is It is presumed that this is because the steric shape of the compound of general formula (1) having a relatively bulky substituent at the ortho position of the benzyl group has become well compatible.

In the general formula (1), when X is a halogen atom, halogen atoms such as chlorine, bromine, iodine and fluorine are used, but when it is a fluorine atom, the herbicidal effect is somewhat inferior compared to other halogen atoms. There is. Also, the general formula (1
), where X is an alkyl group.

Alternatively, in the case of an alkoxyl group, an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, or a hexyl group, is preferably used as the alkyl group.

The compound of the present invention represented by the general formula (1) can be synthesized by reacting an isocyanate and an amine as shown in the following formula.

(I) (wherein, X has the same meaning as above) or (I
I) (In the formula, X has the same meaning as above.) These reactions are carried out without a solvent or in benzene, toluene, xylene, acetone, or tetrahydrofuran.

After the completion of the reaction, the reaction is performed by stirring or standing for 1 to 5 hours at room temperature to 50°C in an organic solvent such as dioxane, dichloromethane, chloroform, carbon tetrachloride, pyridine, dimethylformamide, methanol, or ethanol. The compound is separated and obtained from the reaction mixture according to conventional methods.

Table 2 shows examples of the compounds of the present invention represented by general formula (1). The compound numbers in Table 2 are commonly used in the following Examples and Test Examples.

Example 1 Next, the method for producing the benzyl urea compound of the present invention will be explained by giving examples, but the present invention is not limited to these examples.In the examples, parts indicate parts by weight. (α,α-dimethylbenzyl)-3-(2'-chlorobenzyl)urea [compound number l] α,
α-Dimethylbenzyl isocyanate 18.1 g and 2
- Add 14.2 g of chlorobenzylamine, and add 2 g of chlorobenzylamine at room temperature.
I left it for a while. The precipitated crystals were recrystallized with ethanol,
28.5 g of colorless crystals with a melting point of 185-188°C were obtained.

This product was confirmed to be the title compound by 'HNMR.

叉121ヱ1-(α,α-dimethylbenzyl)-3-(2′-bromobenzyl)urea [Compound No. 2] In an Erlenmeyer flask, add α,
18.1 g of α-dimethylbenzyl isocyanate and 2-
21.2 g of bromobenzylamine was added and left to stand at room temperature for 2 hours. The precipitated crystals were filtered and had a melting point of 181-183.
38.1 g of colorless crystals were obtained.

This product was confirmed to be the title compound by HNMR.

1-(α,α-dimethylbenzyl)-3-(2-trifluorobenzyl)urea [Compound No. 4] In an Erlenmeyer flask, add 13.5 g of α,α-dimethylbenzylamine and 2
22.1 g of trifluorobenzylisocyanate) was added thereto, and the mixture was left to stand at room temperature for 4 hours. The precipitated crystals were recrystallized with ethanol to give colorless crystals with a melting point of 177-178°C.
I got g.

This product was confirmed to be the title compound by 'HNMR.

1-(α,α-dimethylbenzyl)-3-(2'-methylbenzyl)urea [Compound No. 5] In an Erlenmeyer flask, add α,
13.5 g of α-dimethylbenzylamine and 16.2 g of 2-methylbenzyl isocyanate were added, and the
I left it for a while. The precipitated solid was filtered and recrystallized with ethanol to obtain 28.9 g of colorless crystals with a melting point of 145-148°C.

This product was confirmed to be the title compound by 'HNMR.

1 Cliff 1''1-(α,α-dimethylbenzyl)-3-(2'-methoxybenzyl)urea [Compound No. 6] In a 1001 four-hole flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. α,α-dimethylbenzylisocyanate)
18.1g was added and dissolved with 201g of acetone. A solution prepared by dissolving 13.7 g of 2-methoxybenzylamine in acetone 201 was added dropwise from the dropping funnel over about 30 minutes while stirring while maintaining the temperature at 30°C. After that, the mixture was stirred for 1 hour to complete the reaction. After the reaction was completed, the acetone was distilled off, and the precipitated solid was recrystallized with ethanol.
25.3 g of colorless crystals having a temperature of 43 to 144°C were obtained.

This product was confirmed to be the title compound by 'HNMH.

Next, the herbicidal activity of the dibenzylurea compound of the present invention will be explained by giving examples.

m 90% inhibition concentration of firefly root and stem leaf extension (
ED9. ) Germinated firefly seeds 5 ([, the concentration of the active ingredient is 0, .
The present preparation of each test compound (60 parts of each test compound, 25 parts of diatomaceous matter, 10 parts of talc, and 5 parts of sodium alkylbenzenesulfonate were mixed and ground) was diluted with water so as to have a concentration of 001 to toopp. Add 5ml of liquid. Each vial was placed in a light incubator (25 parts at 2°C) and grown for 14 days. The lengths of the stems, leaves and roots of the firefly were then measured. A concentration that suppressed the length to 1/10 was found and was defined as a concentration that inhibited 90% of stem and root elongation.

The results are shown in Table 3,
chlorobenzyl) urea CH3 *3 1-(α,α-dimethylbenzyl)-3-(3-
Bromobenzyl) urea CH.

11'' Flooded soil treatment test A 115,000 are Wagner pot was filled with paddy soil, seeds of firefly and Cyperus japonica were mixed into the soil surface layer, two tubers of Cyperus japonica were transplanted, and the soil was flooded to a depth of 3 cm. . Each test compound was made into a 60% hydrating powder in the same manner as in Test Example 1, and after growing in a greenhouse for 50 days,
The herbicidal effect was evaluated and the results are shown in Table 4.

The herbicidal effect was evaluated according to the following criteria. 5
Complete control 480% control 360% control 240% control 1 20% control 0 No effect Table 4 *1 Same meaning as Test Example 1 above.

*2 1-(α,α-dimethylbenzyl)-3-(4'
-Methylphenyl)urea H3 Sanyo 1'' Paddy field test In a paddy field, seeds of firefly and Cyperus japonica and tubers of Cyperus japonica were mixed into the soil surface layer, and paddy rice seedlings at the 3-leaf stage were further transplanted at appropriate intervals. It was flooded to a depth of 3 cm. 7% granules of each test compound (7 parts of each test compound, 63 parts of bentonite).

After mixing and pulverizing 23 parts of talc and 3 parts of dialkyl sulfosuccinate, kneading with an appropriate amount of water was added and granulated using a granulator in the usual manner) 70 g, 140 g, and 21
0 g (active ingredient amount) equivalent to 710 are was sprayed 3 and 10 days after transplanting paddy rice.

After growing for 30 days after treatment, the herbicidal effect and paddy rice damage were evaluated, and the results are shown in Table 5.

In addition, the herbicidal effect was evaluated using the same criteria as in Test Example 2, and paddy rice phytotoxicity was evaluated using the following criteria.

one -Harmless ± Minor harm ＋　　　　　　　　Short book 〇　　　　　　　　　　　〇 ＋　　　　　　　　　　　　 ×　　　　　　　Withering Table 5 It has the same meaning as Test Example 2 above.

Claims (3)

[Claims] (1) Dibenzyl urea compound represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents a halogen atom, trifluoromethyl group, alkyl group, or alkoxyl group.) (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X represents a halogen atom, trifluoromethyl group, alkyl group, or alkoxyl group.) Benzylamine and the formula ▲ Numerical formula, chemical formula, There are tables, etc. ▼ General formula characterized by reacting benzyl isocyanate represented by ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X has the same meaning as above.) Dibenzylurea compound represented by manufacturing method. (3) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents a halogen atom, trifluoromethyl group, alkyl group, or alkoxyl group.) Benzyl isocyanate and the formula ▲ Numerical formula, chemical formula, There are tables etc. ▼ General formula characterized by reacting benzylamine represented by ▲ There are mathematical formulas, chemical formulas, tables etc. ▼ (In the formula, X has the same meaning as above.) manufacturing method.