RU2356892C1 - N1-(3-fluorophenyl)-2-(4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanil)-acetamide as antidote of 2,4-d on sunflower - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: description is given of N1-(3-fluorophenyl)-2-(4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanil)-acetamide with formula I

which is an antidote of 2,4-D on sunflower.

EFFECT: wide range of biologically active substances, obtained through synthetic methods, for use in agriculture as antidotes of 2,4-D.

1 tbl, 3 ex

Description

The invention relates to a new synthetic chemical biologically active substance from a number of heterocyclic compounds of the formula 1:

protecting sunflower plants from the phytotoxic effect of the herbicide of 2,4-dichlororfenoxyacetic acid (antidote).

As you know, sunflower is an extremely sensitive crop to 2,4-D group herbicides, and in cases of unintentional hit of a herbicide on its crops, losses can be up to 100% depending on the dose [D.I. Chkanikov, M.S.Sokolov. The herbicidal effect of 2,4-D and other halo phenoxy acids. - M .: Nauka, 1973].

Until now, the protection of vegetative sunflower plants from the damaging effects of 2,4-D remains relevant and unresolved.

The closest analogue in structure and properties of the claimed compound is N1- (3-trifluorophenyl) -2- (6-methyl-4-methoxymethyl-3-cyano-2-pyridylsulfanyl) acetamide of the formula 2 ["2-thioalkylpyridines and thieno [2, 3-b] pyridines - antidotes of the hormone-acting herbicide of 2,4-dichlorophenoxyacetic acid ", US Pat. RF №2232762 of 07.20.2004, application No. 2003105092/04 of 02.19.2003]:

Compound 2 (prototype) in a laboratory experiment on sunflower seedlings shows an antidote effect to 2,4-D in the range of 25-51% depending on the concentration.

The disadvantage of antidote 2 is that its activity has been studied only in laboratory experiments. Due to the influence of numerous natural factors, the level of antidote activity in the field experiment can differ significantly from that obtained in the laboratory experiment.

The objective of the present invention is to expand the arsenal of biologically active substances obtained synthetically, for use in agriculture as antidotes.

This is achieved by using N1- (3-fluorophenyl) -2- (4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanyl) acetamide 1 on damaged vegetative sunflower plants.

Moreover, the claimed compound is obtained by a known method - the interaction of 4,6-dimethyl-5-chloro-3-cyano-2 (1H) -pyridinethione with N- (3-fluorophenyl) -2-chloroacetamide in a solution of DMF. [Weigand Hilgetag. Experimental methods in organic chemistry. - M .: Chemistry. 1969. p. 328].

The initial 4,6-dimethyl-5-chloro-3-cyano-2 (1H) -pyridinethione was also synthesized by a known method - the reaction of 4,6-dimethyl-2-chloro-nicotinonitrile with thiourea ["Composition anti-acneique contenant en tant que compose actif un derive diisothiazolo [5,4-b] pyridine one-3 ", Patent 2555450 Franse, Applic. 11/34/83; publ. 05/31/85, RJ Chem. - 1986].

The invention is illustrated by the following examples.

Example 1. N1- (3-fluorophenyl) -2- (4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanyl) acetamide (compound 1).

A solution of 0.41 g (7.3 mmol) of KOH is added to a suspension of 1.45 g (7.3 mmol) of 4,6-dimethyl-5-chloro-3-cyano-2 (1H) -pyridinethione in 25 ml of DMF in a minimum amount of water and mix until the precipitate is completely dissolved. Then a solution of 1.37 g (7.3 mmol) of N- (3-fluorophenyl) -2-chloroacetamide in 10 ml of DMF is added to the reaction mixture and stirred at room temperature for 40 minutes, the reaction mixture is diluted with water twice and the precipitate formed is filtered off, dried . After recrystallization from ethanol, 1.25 g (72%) of the desired product 1 are obtained in the form of crystals with a melting point of 217-218 ° C.

Found,%: C 54.65; H 3.82; N, 12.34. C ₁₆ H ₁₃ CIFN ₃ OS.

Calculated,%: C 54.94; H 3.75; N, 12.01.

¹ H NMR spectrum, δ, ppm (group): 2.53 (s, 3H, 4-CH ₃ Ru); 2.55 (s, 3H, 6-CH ₃ Ru); 4.19 (s, 2H, SCH ₂ ); 6.88 ... 7.5 8 (m, 4H, Ar); 10.55 (br s, 1H, NH).

Example 2. N1- (3-trifluorophenyl) -2- (6-methyl-4-methoxymethyl-3-cyano-2-pyridylsulfanyl) acetamide (compound 2).

To a suspension of 1.94 g (10 mmol) of 6-methyl-4-methoxymethyl-3-cyano-2 (1H) -pyridinethione in 20 ml of DMF, a solution of 0.56 g (10 mmol) of KOH in a minimum amount of water is added and stirred until the precipitate is completely dissolved. Then, a solution of 3.38 g (10 mmol) of N- (3-trifluoromethyl) -2-chloroacetamide in 10 ml of DMF is added to the reaction mixture and stirred at room temperature for 30 minutes, the reaction mixture is diluted with water twice and the precipitate formed is filtered off and dried. After recrystallization from ethanol, 3.40 g (93%) of the desired product 2 are obtained in the form of crystals with a melting point of 171-172 ° C.

Found,%: C 54.48; H 3.91; N, 10.44. C ₁₈ H ₁₈ F ₃ N ₃ O ₂ S.

Calculated,%: C 54.68; H 4.08; N, 10.63.

¹ H NMR spectrum, δ, ppm (group): 2.55 (s, 3H, CH ₃ Ph); 3.45 (s, 3H, OCH ₃ Ru); 4.12 (s, 2H, SCH ₂ ); 4.55 (s, 2H, OCH ₃ ); 7.12 (s, 1H, 5-N Ru); 7.28 ... 7.96 (m, 4H, Ar); 10.27 (br s, 1H, NH).

Example 3. Evaluation of compounds 1-2 for antidote activity on sunflower plants in a field experiment.

Evaluation of the antidote activity of the claimed compound 1 and prototype (compound 2) was carried out on the experimental field of VNIIBZR. The tests were carried out according to the following procedure.

In the field, sunflower plants of the VNIIMK 8883 cultivar were treated with 2,4-dichlorophenoxyacetic acid butyl ether at a dose of 18 g / ha in a 10-16 leaf phase and after 1 day an antidote solution was applied at a dose of 200 g / ha with a flow rate of 500 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 , five repetition.

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:

A _x - antidote effect,%;

A - crop in the variant antidote + herbicide;

E - crop in the standard version (herbicide).

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

The test results are presented in the table.

Table Antidote activity of N1- (3-fluorophenyl) -2- (4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanyl) acetamide (compound 1) and prototype (compound 2) in relation to 2,4-D on sunflower Antidote Dose of antidote, g / ha Experience Options 2,4-D (herbicide) 2,4-D + antidote Productivity c / ha Productivity c / ha Antidote activity c / ha % Compound 1 200 15,2 21.7 6.5 43 * Compound 2 (prototype) 200 15,2 18,4 3.2 21 The control - 29.0 - - -

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

Thus, the use of the inventive N1- (3-fluorophenyl) -2- (4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanyl) acetamide as an antidote allows for an antidote effect of 43% against 21% in prototype, as well as expand the range of well-known antidotes.

Claims (1)

N1- (3-fluorophenyl) -2- (4,6-dimethyl-5-chloro-3-cyano-2-pyridylsulfanyl) -acetamide of the formula 1:

exhibiting antidote activity against 2,4-dichloro-phenoxyacetic acid in sunflower.