DE1210622B - Means for selective weed control - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

AOIn

German class: 451-19/02

Number: 1210 622

File number: F 43945IV a / 45 ί

Filing date: September 10, 1964

Opening day: February 10, 1966

The present invention relates to the use of some known thioacyl-3,4-dichloroanilides as selective herbicides.

It has already become known to use acyl-3,4-dichloroanilide as herbicides (cf. German Auslegeschrifts 1 005 784 and 1 039 779). The 3,4-dichloroanilide of propionic acid has a large Gained importance as a selective herbicide in rice.

It has been found that the thioacylanilides of the formula

(D

in which R stands for an alkyl radical with 2 to 3 carbon atoms, have strong selective herbicidal properties.

Surprisingly, the thioacyldichloroanilides to be used according to the invention have a considerable amount higher herbicidal effect than the already known acyl-3,4-dichloroanilide.

The higher herbicidal action of the active ingredients according to the invention is therefore particularly surprising because the thiopropionic acid-S ^ -dichloranilide in studies on the inhibition of the Hill reaction only V300 to Van »the inhibitory effect of propionic acid-3,4-dichloroanilide (Plant Physiology, 36, p. 796 [1961]). Inhibition of the Hill reaction is the basis of the mechanism of action of many herbicides, which is why the inhibitory capacity of a compound in the Hill reaction is widely regarded as a measure of its herbicidal potency will.

Substances to be used according to the invention may be mentioned: thiopropionic acid-S ^ -dichloranilide, thiobutyric acid-3,4-dichloroanilide and thioisobutyric acid 3,4-dichloroanilide.

Of the substances to be used according to the invention, only 3,4-dichloroanilide is thiopropionic acid known. The other compounds can be prepared in a simple manner by methods known per se getting produced. Many processes are suitable for their production. So you can z. B. manufactured are made from fatty acid 3,4-dichloroanilides and phosphorus pentasulfide (cf. Ber., 11, p. 339), from 3,4-dichloroaniline and aliphatic thionic acid esters (cf. Zentralblatt, 1927 I, p. 1301), from fatty acid 3,4-dichloroanilide chlorides and hydrogen sulfide (cf. Ber., 10, p. 2134), from fatty acid 3,4-dichloroanilide agents for selective weed control

Applicant:

Paint factories Bayer Aktiengesellschaft,

Leverkusen

Named as inventor:

Dr. Helmuth Hack, Opladen;

Dr. Ludwig Eue, Cologne-Stammheim;

Dr. Werner Meiser, Wuppertal-Elberfeld;

Dr. Richard Wegler, Leverkusen

Chlorides and thioamides (see Zentralblatt, 1925, II, p. 1153) and from 3,4-dichloroaniline and aliphatic Aldehydes in the presence of sulfur (cf. Annalen, 431, pp. 244 to 226). Beyond that there is still further manufacturing processes.

In the following, the preparation of the compounds to be used according to the invention is described in particular advantageous method are described in more detail.

S CH ₃
NH - C - CH
CH ₃

To a Grignard solution of 108 g of activated magnesium with iodine and 615 g of isopropyl bromide in 3 1 of absolute ether is in 2 to 3 hours 678 g of 3,4-Dichlorphenylsenföl (prepared from 3,4-dichloroaniline and thiophosgene, Kp.o, ₃₁₁₆ ⁰ C) was added dropwise, the reaction proceeding evenly. The mixture is then heated to boiling for a further 2 hours. Then it is decomposed with ice and dilute sulfuric acid, the ether is separated off and distilled off. The residue is distilled with steam in order to remove odorous components. The residue is taken up in methylene chloride, separated from the water, dried and, after evaporation of the solvent, recrystallized from benzene-ligroin.

609 507/334

This gives 700 g of isothiobutyric acid-S ^ -dichloroanilide with a melting point of 66 ° C.

Cl
Cl

-C-CH ₂ -CH ₂ -CH ₃

If one works analogously to the above information with 615 g of n-propyl bromide, one obtains from benzene- Ligroin recrystallizes the thiobutyric acid-3,4-dichloroanilide with a melting point of 57 ° C same amount.

■ S

NH-C-CH ₂ -CH ₃

To a Grignard solution of 122 g of iodine-activated magnesium and 606 g of ethyl bromide in 3 liters of absolute ether, 765 g of 3,4-dichlorophenyl mustard oil are added dropwise over 2 to 3 hours, the reaction proceeding with uniform boiling. The mixture is then heated to boiling for a further 2 hours. Ice and dilute sulfuric acid are then added, and the ether is separated off and distilled off. It is worked up further as indicated above. The product is recrystallized from 800 ecm benzene with the addition of 500 ecm ligroin. Are thus obtained 700 g thiopropionic acid-3,4-dichloroanilide melting point of 73 ⁰ C.

The same compound is obtained if 218 g of propionic acid-3,4-dichloroanilide are dissolved in 1.5 l of absolute benzene or xylene at 50 ° C. and a mixture of 80 g of phosphorus pentasulfide and 80 g of anhydrous sodium acetate (or 80 g of sodium bicarbonate) are added and heated to an internal temperature of 70 ° C. for ^{1 x} / _{2 hours.} It is decanted off through a suction filter and stirred again with 1.5 liters of solvent at 70 ° C. for ¹ ^ hour. It is then suctioned off. The combined solvents are extracted in four portions with a total of 2.2 l sodium hydroxide solution (200 ecm concentrated alkali and 21 water). The extracts are clarified with kieselguhr and charcoal, filtered off with suction and washed with water. The filtrate is concentrated with]; Hydrochloric acid or carbonic acid precipitated, filtered off with suction and washed well. 185 g of pure thiopropionic acid - 3,4 - dichloroanilide with a melting point of 73 ° C. are obtained directly in this way.

The thioacyl-3,4-dichloroanilides are characterized by selective herbicidal properties. You can therefore can be used with good success to control weeds in crops. So suitable she z. B. to destroy weeds in rice, potatoes and carrots.

As weeds caused by the thioacyl-3,4-dichloroanilide are destroyed and play a major role in rice, potatoes and carrots, the following are mentioned: Chicken millet (Echinochloa crus galli), chickweed (Stellaria media), goose foot (Chenopodium album), Mustard (Sinapis arvensis), French herb (Galinsoga parviflora) and nettle (Urtica urens).

Comparing the herbicidal effects of thiopropionic acid - 3,4 - dichloroanilide, thioisobutyric acid - 3,4-dichloroanilide and thiobutyric acid 3,4-dichloroanilide with the herbicides. Effects of the previously known Propionic acid-3,4-dichloroanilide and isobutyric acid-3,4-dichloroanilide, it is shown that the active ingredients according to the invention, for. B. a stronger effect on Echinochloa crus galli, an important one Rice weed, and are better tolerated by the rice plants than the previously known analogues Oxygen compounds (cf. Example 1, Table 2, and Example 2).

ίο The thiopropionic acid-3,4-dichloroanilide can, for. B. also used for weed control in potatoes and thioisobutyric acid-3,4-dichloroanilide as a selective herbicide in carrots. The active ingredients according to the invention are also used in this application superior to the previously known analog oxygen compounds.

The active compounds according to the invention can be converted into the customary formulations, such as Solutions, emulsions, suspensions, powders, pastes and granulates. These are done in a well known manner manufactured, e.g. B. by stretching the active ingredients with solvents and / or carriers, if appropriate using emulsifiers and / or dispersants, where z. B. in the case of the use of water as a diluent organic solvents can optionally be used as auxiliary solvents (cf. Agricultural Chemicals, March 1960, pp. 35 to 38). The following are the main auxiliaries:

Solvents such as aromatics (ζ. Β. Xylene, benzene), chlorinated aromatics (ζ. Β. Chlorobenzenes), paraffins (ζ. e.g. petroleum fractions), alcohols (e.g. methanol, butanol), amines and amine derivatives (e.g. ethanolamine, Dimethylformamide) and water; Carriers,

35. Like natural rock flour (e.g. kaolins, clays, Talc, chalk) and synthetic rock powder (e.g. highly dispersed silica, silicates); Emulsifiers, such as non-ionic and anionic emulsifiers (ζ. B. polyoxyethylene fatty acid esters, Polyoxyethylene - fatty alcohol - ethers, alkyl sulfonates and aryl sulfonates), and dispersants such as lignin, Sulphite liquors and methyl cellulose.

The active compounds according to the invention can be used in the formulations as a mixture with other known ones Active ingredients are present.

The formulations generally contain between 0.1 and 95 percent by weight of active ingredient, preferably between 0.5 and 90.

The active ingredients can be used as such, in the form of their formulations or the use forms prepared therefrom, such as ready-to-use solutions, emulsions, suspensions, powders, pastes and granulates can be used. The application happens in the usual way, for. B. by spraying, atomizing, dusting, pouring or scattering.

example 1
Post-emergence test

Solvent:

4 parts by weight of acetone

Emulsifier:
0.2 part by weight of benzyloxy polyglycol ether.

To produce an appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed with the specified amount of solvent, add the specified amount of emulsifier and dilute the

Then concentrate with water to the desired concentration.

Test plants which are about 5 to 15 cm in height are sprayed with the preparation of the active compound have just been dewy. After 3 weeks, the degree of damage to the plants is determined and the Identifiers 0 to 5, which have the following meaning:

0 no effect,

1 single light burn marks,

2 significant leaf damage,

3 individual leaves and stem parts partly dead,

4 plant partially destroyed,

5 plant totally dead.

Active ingredients, active ingredient concentrations and results are shown in the following tables:

Table 1 (post-emergence test)

Active ingredient Active ingredient
concentration
in ° / o Stellaria Cheno-
podium Sinapis Gael-
so Urtica Carrots potatoes O
. Ii Cl - / S - NH - C - C ₂ H ₅
Cl
(known) 0.8
0.4
0.2
0.1 5
5
5
4th Ui Ui Ui Ui Ul U) U) U) U) U) U) U) 5
5
5
4th 5
5
4 to 5
4th 4th
3
Ibis 2
0 S.
Ν Cl - / V - NH - C - C ₂ H ₅
Cl 0.8
0.4
0.2
0.1 U) U) Ul Ul Ul ul ul ul U) U) U) U) Ul ul ul ul U) ul ul ul 5
4th
3
2 1
0
0
0 O CH ₃ Cl - / V- NH - C - (
α ⁽
(known) 0.8
0.4
0.2
0.1 U) ul ul ul 5
5
5
5 5
5
5
5 5
5
5
4th 5
5
5
4th 5
4th
4th
2 3
3
2
1 :H
: h ₃ S CH ₃ 0.8
0.4
0.2
0.1 5
5
5
4th Ul U) Ul Ul 5
5
5
4th Ul ul ul ul 5
5
5
4th Obisl
0
0
0 3 to 4
3
2
1 Cl - <f ^ - NH - C - (
α ⁽ :H
: h ₃

Table 2 (post-emergence test)

Echinochloa crus galli (chicken millet) and Oryza sativa (rice) were made in three different varieties Development stages (characterized by the number of leaves) used as test plants

Active ingredient Active ingredient
concentration 2 to 3 millet
Number of leaves 6 to 7 2 to 3 rice
Number of leaves 6 to 7 in% 4 to 5 4 to 5 O
Μ 5
5
4 to 5 3 to 4
2 to 3
Ibis 2 2
Ibis 2
0 Ibis 2
1
0 Cl - / V - NH - C - C ₂ H ₅
Cl 0.4
0.2
0.1 Tf Tf Tf Ibis 2
1
0 (known)

continuation

Active ingredient (known) Active ingredient
concentration 2 to 3 millet
Number of leaves
4 to 5 6 to 7 2 to 3 rice
Number of leaves
4 to 5 6 to 7 S.
Μ S CH ₃
Η • Cl - ^ \ _)> - NH - C - C ₂ H ₅ .
Cl Cl - \ _ y ~ NH - C - (
α ⁽ 0.4
0.2
0.1 Ui Ui Ui 5
5
4 to 5 5
4th
3 to 4 2
1
0 1
1
0 1
Obisl
0 O CH ₃
Il :H
IiH ₃ Cl- ^ V-NH-C - ( 0.4
0.2
0.1 5
5
4th 4 to 5
4th
4th 4th
3
2 2 to 3
2
1 2
1
Obisl 2
1
1 :H
: h3 0.4
0.2
0.1 5
5
4 to 5 5
4 to 5
4th 4 to 5
4th
3 O H- K) 1
0
0 1
0
0

Example 2

In the field test, rice plots (Oryza sativa) of 10 m ² which had been heavily weeded with Echinochloa crus galli (chicken millet) were sprayed with the application rates of the active compound preparations mentioned in Example 1 given in the table. The spraying was carried out when both the Echinochloa herbs and the rice plants had developed two to three leaves. In each plot, the echinochloa plants were grown and weighed ^{on 1 m 2 7 weeks after the treatment.} 3 weeks after the treatment, no damage could be seen on rice.

Active ingredient control C. :—( Cl S CH ₃ S. Application rate
kg / ha Echinochlo
Number of plants a crus galli
Weight in kg O
Ν . Cl- ^ ~ V-NH- C C1 ^ ~ J ^ NH —C - (
α ■ ⁽ Cl ~ ^ (~ \ - NH - C - CH ₂ - CH ₂ - CH ₃ 246 18.5 Cl - <\ ^ -NH-CC ₂ H ₅ I. Ζ2Ή.5 :H
: h ₃ Cl Cl 3.3
5.0 63
56 5.2
4.7 (known) 3.3
5.0 14th
10 1.1
0.8 3.3
5.0 • 62
■ 34 5.4
3.8 3.3
5.0 14th
28 1.2
3.0

Claims (1)

Claim: 10 Agent for selective weed control, characterized by a content of Thioacyl-S ^ -dichloranilides of the formula Cl NH-C-R Cl in which R stands for an alkyl radical with 2 to 3 carbon atoms. 507/334 2.66 ® Bundesdruckerei Berlin