RU2799422C1 - Substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3h-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid as antidotes 2,4- d in sunflower - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to new synthetic, chemical biologically active substances used to protect sunflower plants from the phytotoxic effect of the herbicide 2,4-dichlorophenoxyacetic acid. Substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid of formula (1-3) are proposed:

where (1) - R = _С2Н5, Ar = 2-thienyl; (2) - R\u003d CH₃, Ar\u003d 4-CH₃OC₆H₄; (3) - R = С₂Н₅, Ar = 4-CH₃OC₆H₄, which exhibit antidote activity against 2,4-dichlorophenoxyacetic acid in sunflower.

EFFECT: new substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid formulas 1-3 expand the range of biologically active substances exhibiting antidote properties have high antidote activity.

1 cl, 2 tbl, 2 ex

Description

The invention relates to new synthetic, chemical biologically active substances from a number of heterocyclic compounds used to protect sunflower plants from the phytotoxic effect of the herbicide 2,4-dichlorophenoxyacetic acid (antidote).

As you know, sunflower is an extremely sensitive crop to herbicides of the 2,4-D group, and, in cases of unintentional contact with herbicide on its crops, losses can be, depending on the dose, up to 100% [Chkanikov D.I., Sokolov M. WITH. Herbicidal action of 2,4-D and other halophenoxy acids. M.: Nauka, 1973. 95 p.].

Despite intensive research to find new antidotes to protect vegetative sunflower plants from the damaging effects of 2,4-D, it remains relevant and unresolved [Strelkov V.D., Dyadyuchenko L.V., Dmitrieva I.G. Synthesis of new herbicidal antidotes for sunflower. Krasnodar: Enlightenment-South, 2014. S. 79].

The closest analogue in structure and properties of the claimed compounds is N-(4-fluorophenyl)-3-amino-4,6-dimethylthieno[2,3- b ]pyridyl-2-carboxamide formula 4 [US Pat. No. 2277333 RF, IPC A01N 25/32 (2006.01) A01P 15/00 (2006.01)]

Compound 4 (prototype) in the field at a dose of 200 g/ha on vegetative sunflower plants exhibits an antidote effect against 2,4-D of about 23% and can be used as a sunflower protection agent. However, its antidote activity is not high enough, while the dose of 200 g/ha is high enough to cause negative environmental problems.

The technical result of the claimed invention is the expansion of the arsenal of biologically active substances obtained synthetically for their use in agriculture as antidotes.

The technical result is achieved by using substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid formulas1-3:

,

,

where 1 : R \u003d C ₂ H ₅ , Ar \u003d 2-thienyl; 2 : R = CH ₃ , Ar = 4-CH ₃ OC ₆ H ₄ ; 3 : R \u003d C ₂ H ₅ , Ar \u003d 4-CH ₃ OC ₆ H ₄ ;

exhibiting antidote activity against 2,4-dichlorophenoxyacetic acid on sunflower.

The claimed compounds are obtained by successive interaction of equimolar amounts of ArCHO aromatic aldehyde (thiophene-2-carbaldehyde or 4-methoxybenzaldehyde) with the corresponding cyanoacetic acid ester N≡C–CH ₂ –CO ₂ R and dithiomalondianilide (N,N'-diphenyldithiomalondiamide) 5 in the presence of morpholine as a catalyst in ethanol in accordance with the following scheme:

Example 1 Evaluation of Compounds 1-3 for Antidote Activity on Sunflower Seedlings

Germinated sunflower seeds with a germinal root length of 2–4 mm were placed for 1 hour in a solution of 2,4-dichlorophenoxyacetic acid (2,4-D) at a concentration of ^10–3 % in order to obtain 40–60% inhibition of hypocotyl growth. After the herbicidal action, the seedlings were washed with water and placed in solutions tested for antidote activity of substances at concentrations of 10 ^-2 , 10 ^-3 , 10 ^-4 , 10 ^-5 % (option "herbicide + antidote"). After 1 hour, the seeds were washed with water and laid out on filter paper strips (size 10×75 cm), 20 pieces each, which were rolled up and placed in glasses with 50 ml of water. Further germination of seeds was carried out in a thermostat for 3 days at a temperature of 28°C. The temperature of the solutions and wash water is 28°C.

Seeds of the “herbicide” variant (comparison standard) were kept for 1 h in a solution of 2,4-D at a concentration of ^10–3 % and for 1 h in water. The seeds of the control variant were kept in water for 2 hours. The experiment was repeated three times. In each repetition, 20 seeds were used.

The protective (antidote) effect was determined by the increase in the length of the hypocotyl and root in the "herbicide + antidote" variant relative to the named values in the "herbicide" variant (standard) in percent.

Statistical processing of experimental data was carried out using Student's t -test at P = 0.95.

The results of the studies are shown in Table 1. As can be seen from the data in Table 1, the use of substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1, 2]dithiolo[3,4-b]pyridine-5-carboxylic acid formulas1-3sharply weakens the toxic effect of the herbicide. Connections1-3 reduced the negative effect of 2,4-D on the hypocotyls of sunflower seedlings by 34-60% when used mainly in three or more concentrations, while the compound4 (similar in structure) showed an antidote effect of 29-31%.

Compounds 1 - 3 reduced the inhibitory effect of 2,4-D on the roots of seedlings by 40-55% also when used in three or more concentrations, and the prototype showed an antidote effect at the level of 27-35%.

Table 1. Antidote activity of dithiolopyridines 1-3 and prototype 4 to 2,4-D on seedlings of sunflower variety Master.

A drug Concentration,
% Hypocotyl length Root length mm K 2,4-D,% mm K 2,4-D,% Control 0 65 115 2,4-D ^10-3 35 55 2,4-D+
connection 1 ^{10-2
10-3
10-4
10-5} 48
47
49
52 137*
134*
140*
148* 77
79
79
77 140*
143*
143*
140* 2,4-D+
compound 2 ^{10-2
10-3
10-4
10-5} 52
54
52
53 148*
154*
148*
151* 73
83
85
83 133*
151*
155*
151* 2,4-D+
compound 3 ^{10-2
10-3
10-4
10-5} 55
56
54
53 157*
160*
154*
151* 80
83
85
83 146*
151*
155*
151* 2,4-D+
connection 4 (prototype) ^{10-2
10-3
10-4
10-5} 40
45
46
45 114
128*
131*
128* 70
71
72
74 127*
129*
131*
135*

*Differences between the variants are significant at P=0.95.

Example 2 Evaluation of Compounds 1-3 and 4 for Antidote Activity on Sunflower Plants under Field Experiment Conditions

Evaluation of the antidote activity of the claimed compounds 1-3 and the prototype (compound 4 ) was carried out on the experimental field FNTsBZR. The tests were carried out according to the following procedure. Under field conditions, sunflower plants of the Master variety in the phase of 10-16 leaves were treated with an aqueous solution of 2,4-dichlorophenoxyacetic acid at a dose of 18 g/ha, and after 3 days an antidote solution was applied at a dose of 100 g/ha with a working fluid consumption rate of 300 l/ha .

Experience has the following options:

- control - untreated plants;

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

- "herbicide + antidote" - plants treated with herbicide and antidote.

The experiments were carried out on plots with an area of 2.8 m ² , repeated five times. Sunflower harvesting was carried out at the time of full ripening of seeds.

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

× 100, A _x =

× 100,

A _x – antidote effect, %;

A - crop in the "antidote + herbicide" variant;

E - crop in the "standard (herbicide)" variant.

The obtained data were statistically processed using Student's t -test. The test results are presented in table 2.

Table 2. Antidote activity of substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid 1-3 and prototype (connection4) in relation to 2,4-D on sunflower

Antidote Antidote dose, g/ha Experience options 2,4-D
(herbicide) 2,4-D + antidote yield
c/ha yield
c/ha Antidote activity c/ha % Compound 1 100 14.0 19.8 5.8 41.4* Compound 2 100 14.0 21.2 7.2 51.4* Compound 3 100 14.0 20.8 6.8 48.6* Compound 4
(prototype) 100 14.0 17.0 3.0 21.4* Control - 22.5 - - -

Differences between the variants are significant at P = 0.90.

Thus, the use of the claimed substituted esters of 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid 1- 3 as antidotes 2,4-D on sunflower allows to provide an antidote effect at the level of 41.4-51.4% against 21.4% in the prototype, as well as to expand the range of known antidotes.

Claims (7)

Substituted 6-amino-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylic acid esters of formula (1-3)

, Where (1) - R = C ₂ H ₅ , Ar = 2-thienyl; (2) - R \u003d CH ₃ , Ar \u003d 4-CH ₃ OC ₆ H ₄ ; (3) - R \u003d C ₂ H ₅ , Ar \u003d 4-CH ₃ OC ₆ H ₄ , showing an antidote effect to 2,4-dichlorophenoxyacetic acid on sunflower.