RU2648419C1 - Method of vegetating sunflower plants protection against the damaging effect of 2,4-d - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention refers to agriculture. To protect the sunflower growing plants against the damaging effect of 2,4-D, they are treated with 2-(4-R¹-benzylsulfanyl)-4,6-dimethyl-5-R-nicotinonitrile of the formula:

, where 1a R=CH₃, R¹=CI; 1b R=H, R¹=CI; 1c R=CI, R¹=H; in the amount of 30 g/ha in 1 day after application of the herbicide.

EFFECT: invention increases sunflower yield.

1 cl, 1 tbl, 5 ex

Description

The invention relates to a technology for the protection of cultivated plants from the damaging effects of herbicides.

A known method of protecting vegetative crops from the damaging effects of herbicides, providing for their treatment with an antidote after using the herbicide [Pitina M.R. and others. The current level and promising areas of protection of crops from undesirable consequences of the use of herbicides // Agrochemistry, 1986, No. 4, p. 107-136].

The objective of the invention is to expand the arsenal of antidotes for sunflower from the damaging effects of 2,4-D.

The technical result of the invention is the protection of vegetative sunflower plants from the damaging effects of 2,4-D, expressed in increased yield compared to the herbicide treated with KOHtrol.

This result is achieved by the fact that in the method of protecting vegetative plants from the damaging effects of 2,4-D, which involves treating them with an antidote after using the herbicide, 2-benzylsulfanyl-4,6-dimethylnicotino-nitriles of formula 1a-c are used as an antidote:

where 1a R = CH ₃ , R ¹ = CI; 1b R = H, R ¹ = CI; 1c R = CI, R ¹ = H;

in an amount of 30 g / ha 1 day after using the herbicide.

The closest analogue in structure and properties of the claimed compound is 2- (4-bromobenzylsulfanyl) -4,6-dimethylnicotinonitrile (compound 2) [US Pat. RF №2383135. The antidote of 2,4-dichlorophenylacetic acid in sunflower. Strelkov V.D., Dyadyuchenko L.V., Isakova L.I., Morozovsky V.V. Claim 02/11/2008. Publ. 03/10/2010. Bull. No. 7]:

Compound 2 exhibits antidote anti-2,4-D properties on sunflower and, when used at a dose of 200 g / ha, provides an antidote effect of 27%.

The synthesis of antidotes was carried out by the authors according to the scheme:

The inventive compounds were obtained by alkylation of 4,6-dimethyl-3-cyano-2 (1H) -pyridinethione 3a-with benzyl bromides in a DMF solution [Weigand-Hilgetag. Experimental methods in organic chemistry. - M .: Chemistry. 1969, p. 328].

In turn, 4,6-dimethyl-3-cyano-2 (1H) -pyridinethione was synthesized by a known method — the reaction of 4,6-dimethyl-2-chloro-nicotinonitriles 4a-c with thiourea [Pat. No. 2555450 Franse. Composition anti-acneique contenant en tant que compose actif un derive diisothia-zolo [5,4-b] pyridine one-3. Claim 11/34/83; publ. 05/31/85, RJ Chem. - 1986. -120 - 150].

The invention is illustrated by the following examples.

Example 1. 2- (4-chlorobenzylsulfanyl) -4,5,6-trimethylnicotino-nitrile (compound 1a).

To a suspension of 1.2 g (6.7 mmol) of 4,5,6-trimethyl-3-cyano-2 (1H) -pyridinethione in 20 ml of DMF is added a solution of 0.38 g (6.7 mmol) of KOH in a minimum amount of water and mix until the precipitate is completely dissolved. Then, a solution of 1.38 g (6.7 mmol) of 4-chlorobenzyl bromide in 10 ml of DMF was added to the reaction mixture and stirred at room temperature for 1 h, the reaction mixture was diluted with water twice and the precipitate formed was filtered off and dried. After recrystallization from a mixture of cyclohexane: ethyl acetate = 1: 1, 2.0 g (74%) of the desired product 1a are obtained in the form of crystals with a melting point of 147-148 ° C.

Found,%: C 64.71; H 4.84; N, 9.16. C ₁₆ H ₁₅ CIN ₂ S;

Calculated,%: C 64.46; H 4.99; N, 9.25.

¹ H NMR spectrum, δ, ppm (group): 2.26 (s, 3H, 6-CH ₃ Ru); 2.30 (s, 3H, 5-CH ₃ Ru); 2.47 (s, 3H, 4-CH ₃ Ru); 4.36 (s, 2H, SCH ₂ ); 7.30 and 7.49 (two d, 4H, Ar).

Example 2. 2- (4-Chlorobenzylsulfanyl) -4,6-dimethylnicotinonitrile (compound 1b).

To a suspension of 1.2 g (7.3 mmol) of 4,6-dimethyl-3-cyano-2 (1H) -pyridinethione in 20 ml of DMF is added a solution of 0.41 g (7.3 mmol) of KOH in a minimum amount of water and stirred until the precipitate is completely dissolved. Then, a solution of 1.50 g (7.3 mmol) of 4-chlorobenzyl bromide in 10 ml of DMF is added to the reaction mixture and stirred at room temperature for 1 h, the reaction mixture is diluted with water twice and the precipitate formed is filtered off and dried. After recrystallization from a mixture of cyclohexane: ethyl acetate = 1: 1, 1.65 g (78%) of the desired product 1b are obtained in the form of crystals with a melting point of 129-130 ° C.

Found,%: C 62.54; H 4.36; N, 9.60. C ₁₅ H ₁₃ CIN ₂ S;

Calculated,%: C 62.38; H 4.54; N, 9.70.

¹ H NMR spectrum, δ, ppm (group): 2.31 (s, 3H, 6-CH ₃ Ru); 2.42 (s, 3H, 4-CH ₃ Ru); 4.35 (s, 2H, SCH ₂ ); 7.13 (s, 1H, 5-N Ru); 7.29 and 7.47 (two d, 4H, Ar).

Example 3. 2- (Benzylsulfanyl) -4,6-dimethyl-5-chloro-nicotinonitrile (compound 1c).

To a suspension of 1.99 g (10 mmol) of 4,6-dimethyl-3-cyano-2 (1H) -pyridinethione in 20 ml of DMF was added a solution of 0.56 g (10 mmol) of KOH in a minimum amount of water and stirred until complete dissolution of the precipitate. Then, a solution of 1.71 g (10 mmol) of 4-chlorobenzyl bromide in 10 ml of DMF was added to the reaction mixture and stirred at room temperature for 1 h, the reaction mixture was diluted with water twice and the precipitate formed was filtered off and dried. After recrystallization from a mixture of cyclohexane: ethyl acetate = 1: 1, 2.3 g (81%) of the expected product 1 s are obtained in the form of crystals with a melting point of 77 ° C.

Found,%: C 62.21; H 4.40; N, 9.88. C ₁₅ H ₁₃ CIN ₂ S;

Calculated,%: C 62.38; H 4.54; N, 9.70.

¹ H NMR spectrum, δ, ppm (group): 2.28 (s, 3H, 6-CH ₃ Ru); 2.52 (s, 3H, 4-CH ₃ Ru); 4.40 (s, 2H, SCH ₂ ); 7.42 ... 7.70 (m, 5H, Ar).

Example 4. 2- (4-bromobenzylsulfanyl) -4,6-dimethylnicotinonitrile (compound 2, prototype).

To a suspension of 1.2 g (7.3 mmol) of 4,6-dimethyl-3-cyano-2 (1H) -pyridinethione in 20 ml of DMF, a solution of 0.41 g (7.3 mmol) of KOH in a minimum amount of water is added and stirred until the precipitate is completely dissolved. Then, a solution of 1.82 g (7.3 mmol) of 4-bromobenzyl bromide in 10 ml of DMF is added to the reaction mixture and stirred at room temperature for 1 h, the reaction mixture is diluted with water twice and the precipitate formed is filtered off and dried. After recrystallization from a mixture of cyclohexane: ethyl acetate = 1: 1, 1.8 g (88%) of target product 1 are obtained in the form of crystals with a melting point of 152-153 ° C.

Found,%: C 53.80; H 3.81; N, 8.56. C ₁₅ H ₁₃ BrN ₂ S;

Calculated,%: C 54.06; H 3.93; N, 8.41.

¹ H NMR spectrum, δ, ppm (group): 2.38 (s, 3H, 6-CH ₃ Ru); 2.55 (s, 3H, 4-CH ₃ Ru); 4.47 (s, 2H, SCH ₂ ); 7.12 (s, 1H, 5-HPU); 7.35 ... 7.54 (m, 4H, Ar).

Example 5. Evaluation of compounds 1a-c and prototype antidote activity on sunflower plants in a field experiment

Evaluation of the antidote activity of the claimed compounds on sunflower plants was carried out on the experimental field of the All-Russian Research Institute of Plant Biological Protection. As a prototype used compound 2.

In the field, flagman sunflower plants in the 10-16 leaf phase were treated with 2,4-dichlorophenoxyacetic acid butyl ether at a dose of 18 g / ha per 40-60% of the damage to the culture and after 1 day an antidote solution was applied at a dose of 30 g / ha with a flow rate of 300 l / ha.

In the experiment, the following options are provided:

- control - untreated plants;

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

- “herbicide + antidote” - plants treated with herbicide and antidote.

The experiments were carried out on plots with an area of 2.8 m ² , four repetitions. Harvesting of sunflower seeds was carried out at the time of complete ripening of seeds.

The antidote effect was determined by the absolute value of the yield increase to the herbicidal standard and in percentage by the formula:

And _x is the antidote effect,%;

A - crop in the variant antidote + herbicide;

E - crop in the standard version (herbicide).

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

The test results are presented in the table.

* The differences between the options are significant at P = 0.90

Thus, the present invention allows to provide an antidote effect at the level of 32-44% against 19% in the prototype, which increases the yield of sunflower by 4.7-6.6 c / ha.

Claims (4)

A method for protecting vegetative sunflower plants from the damaging effects of 2,4-D, comprising treating them with an antidote after using the herbicide, characterized in that 2- (4-R ^1- benzylsulfanyl) -4,6-dimethyl-5-R is used as an antidote -nicotinonitriles of the formula 1a-c:

where 1a R = CH ₃ , R ¹ = CI; 1b R = H, R ¹ = CI; 1c R = CI, R ¹ = H; in an amount of 30 g / ha 1 day after using the herbicide.