RU2430915C2 - 2,4-dichlorophenoxyacetic acid herbicide antidotes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemical agents for protecting sunflower seedlings and plants from damage by the 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide. N-substituted naphthyl-2-sulphonyl amides are the proposed substances which can reduce the negative effect of the 2,4-D herbicide on sunflower plants. N-substituted naphthyl-2-sulphonyl amides are applied by treating damaged sunflower seedlings and plants.

EFFECT: wide range of biologically active substances capable of reducing the damaging effect of the 2,4-D herbicide.

3 tbl, 4 ex

Description

The invention relates to the protection of seedlings and vegetative plants of sunflower from the phytotoxic effect of 2,4-D herbicides, which are proposed compounds of formula 1-2:

where 1 R = CH ₃ ;

2 R = C ₂ H ₅ .

The use of chemical means of weed control is an integral element of modern agricultural production technologies. However, they are toxic not only to weeds, but also to cultivated plants (D.I. Chkanikov, M.S. Sokolov. The herbicidal action of 2,4-D and other halo phenoxy acids. M .: Nauka, 1973).

There are cases when significant areas of sunflower, cotton, tomato and other crops were severely damaged by derivatives of 2,4-dichlorophenoxyacetic acid (2,4-D).

The foregoing determines the direction of research on the search for effective remedies (antidotes) for vegetative plants from the damaging effects of 2,4-D.

Known substances are antidotes with the ability to reduce the damaging effect of the 2,4-D herbicide on vegetative sunflower plants [A method of increasing the resistance of cultivated plants to herbicides. A.S. USSR No. 231971 dated 12.09.68, application No. 1141256 dated 14.03.67; The antidote of the hormonal action herbicides of 2,4-dichlorophenoxyacetic and 4-amino-3,5,6-trichloropicolinic acids. Pat. RF №2043021 from 09/10/95, application No. 5042089 from 05/14/92].

Antidote activity against 2,4-D is possessed by 2-p (aminobenzenesulfamido) -5-ethyl-1,3,4-thiadiazole (ethazole), adopted as a prototype (compound 3):

Etazole (compound 3) is widely used in medical practice as an antibacterial agent (VG Belikov. Pharmaceutical chemistry. M: Higher school. 1985. p.768).

The objective of the present invention is to expand the range of sunflower protection (antidotes) from the damaging effects of the herbicide 2,4-D.

This is achieved by using the 2,4-dichlorophenoxyacetic acid herbicide N-substituted naphthyl-2-sulfonylamides of the formula 1-2 as antidotes.

Moreover, the claimed compounds are obtained by a known method - the interaction of naphthalene-2-sulfochloride with methyl or ethylbenzylamine at room temperature in anhydrous benzene in the presence of triethylamine as an acceptor of hydrogen chloride [Weigand-Khilgetag. Experimental methods in organic chemistry. - M .: Chemistry. 1969. P.621].

The study of the antidote activity of the claimed compounds of N-methyl-N-benzyl-2-naphthalen-2-yl-sulfonylamide (compound 1) and N-ethyl-N-benzyl-2-naphthalene-2-yl-sulfonylamide (compound 2) was carried out in laboratory conditions on sunflower seedlings and in the field on vegetative sunflower plants.

The invention is illustrated by the following examples.

Example 1. N-ethyl-N-benzylnafil-2-sulfonylamide (compound 1).

To a solution of 2.0 g (8.8 mmol) of naphthalene-2-sulfonyl chloride in 20 ml of anhydrous benzene is added a solution of 1.19 g (8.8 mmol) of ethylbenzylamine and 0.9 g (8.8 mmol) of triethylamine in 20 ml of anhydrous benzene and stirred at room temperature for 5.5-6 hours. Next, the reaction mass is separated from the precipitate of triethylamine hydrochloride, evaporated to dryness, the residue is recrystallized from cyclohexane, obtain 2.05 g (72%) of the desired product 1 in the form of white crystals with so pl. . 87-88 ° C.

Found,%: C 69.61; H 6.02; N, 4.42. C ₁₉ H ₁₉ NO ₂ S;

Calculated,%: C 70.13; H 5.88; N, 4.30.

¹ H NMR spectrum, δ, ppm (group): 2.63 (s, 3H, N-CH ₃ ); 4.42 (s, 2H, CH ₂ ); 7.01 ... 8.20 (m, 12H, Ar).

Example 2. N-methyl-N-benzylnafil-2-sulfonylamide (compound 2).

To a solution of 2.0 g (8.8 mmol) of naphthalene-2-sulfonyl chloride in 20 ml of anhydrous benzene is added a solution of 1.06 g (8.8 mmol) of ethylbenzylamine and 0.9 g (8.8 mmol) of triethylamine in 20 ml of anhydrous benzene and stirred at room temperature for 5.5-6 hours. Next, the reaction mass is separated from the precipitate of triethylamine hydrochloride, evaporated to dryness, the residue is recrystallized from cyclohexane, obtain 2.03 g (74%) of the desired product 2 in the form of white crystals with so pl. . 94-895 ° C.

Found,%: C 69.66; H 5.41; N, 4.58. C ₁₈ H ₁₇ NO ₂ S;

Calculated,%: C 69.43; H 5.50; N, 4.50.

¹ H NMR spectrum, δ, ppm (group): 1.09 (t, 3H, CH ₂ CH ₃ , J = 7.2 Hz); 3.24 (q, 2H, CH ₂ CH ₃ , J = 7.2 Hz); 4.54 (s, 2H, CH ₂ ); 6.94 ... 8.14 (m, 12H, Ar).

Example 3. Evaluation of compounds 1-3 for antidote activity on seedlings of sunflower in a laboratory experiment.

Germinated sunflower seeds were exposed to 2,4-D and an antidote (variant herbicide + antidote). Some seeds were treated only with herbicide (reference standard). Untreated seeds served as control. Further seed germination was carried out at t = 28 ° C for 3 days. After 3 days, the length of the hypocotyl and the root of the sunflower seedlings were measured.

Antidote activity was evaluated by increasing the length of the root and hypocotyl of the seedlings in the herbicide + antidote variant as compared with the herbicidal variant (reference).

The data obtained are statistically processed using t-student test.

The test results are presented in tables 1, 2.

Example 4. Evaluation of compounds 1-3 for antidote activity on sunflower plants in a field experiment.

On the experimental field of VNIIBZR on sunflower plants, the antidote activity of compounds 1-2 and the prototype was evaluated (compound 3).

Sunflower plants of the Master variety in the 10-16 leaf phase were treated with 2,4-dichlorophenoxyacetic acid butyl ether at a dose of 12 g / ha and after one day an antidote was applied at a dose of 200 g / ha at a flow rate of 500 l / ha.

In the experiment, the following options were provided:

- herbicide + antidote - plants treated with a herbicide and after 1 day an antidote;

- herbicide (standard) - plants treated with a herbicide;

- control - untreated plants.

The experiments were carried out on plots with an area of 3 m ² , five repetition.

Harvesting of sunflower was carried out at the time of complete ripening of seeds. The antidote effect was determined by increasing the yield of sunflower seeds in the herbicide + antidote variant relative to the herbicidal variant, which was taken as the standard and was calculated by the formula:

,

,

where A _x - antidote effect,%;

A - crop of sunflower seeds in the variant herbicide + antidote, kg / ha;

E - harvest of sunflower seeds in the variant herbicide (standard), t / ha.

Statistical processing of experimental data was performed using Student's t-test at a probability level of P = 0.90. The test results are presented in table 3.

As can be seen from tables 1, 2, the claimed compounds weakened the toxicity of 2,4-D for hypocotyls of sunflower seedlings by 17-58% (prototype 4-29%), for the roots of seedlings - 25-70% (prototype 10-25 %).

The use of the inventive N-substituted naphthyl-2-sulfonylamides in the field reduces the effect of 2,4-D for sunflower by 39-45%, providing an increase in the yield of sunflower seeds in comparison with a standard of 4.2-5.0 c / ha; the prototype reduces the negative effect of 2,4-D on sunflower by 23%, the increase in seed yield was 2.6 c / ha

Claims (1)

The antidotes of the sunflower 2,4-dichlorophenoxyacetic acid herbicide, which are N-substituted naphthyl-2-sulfonylamides of the formula 1-2:

where 1 R = CH ₃ ;
2 R = C ₂ H ₅ .