RU2783115C1 - 3-BENZYL-2,5-BIS(4-METHOXYPHENYL)-7-THIOXO-2,3,5,6,7,8-HEXAHYDROPYRIMIDO[4,5-d]PYRIMIDIN-4(1H)-ON AS AN ANTIDOTE 2,4-D ON SUNFLOWER - Google Patents

Abstract

FIELD: chemical biologically active substances.

SUBSTANCE: invention relates to new synthetic, chemical biologically active substances from a number of heterocyclic compounds. 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidine-4(1H )-on:

.

EFFECT: compound 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidin-4(1H)-on provides extensions arsenal of biologically active substances obtained synthetically, used to protect sunflower plants from the phytotoxic effect of the herbicide 2,4-dichlorophenoxyacetic acid.

1 cl, 2 tbl, 2 ex

Description

The invention relates to new synthetic, 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 (antidotes).

As you know, sunflower is an extremely sensitive crop to hormonal 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 .FROM. Herbicidal action of 2,4-D and other halophenoxy acids, M.: Nauka, 1973, 95 p.].

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

The closest analogue in structure and properties of the claimed compound is 3-amino-2-[N-(4-fluorophenyl)carbamido]-4,6-dimethylthieno[2,3-b]pyridine of formula 1 [US Pat. No. 2277333 RF, IPC A01N 25/32 (2006.01) A01P 15/00 (2006.01)]

Compound 1 (prototype) in the field at a dose of 200 g/ha on vegetative sunflower plants exhibits an antidote effect against 2,4-D at the level of 22-24% and can be used as a means of sunflower protection. However, its antidote activity is not high enough, while the dose of 200 g/ha is high enough and can 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.

This is achieved by using 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidin-4(1H)-one formula 2:

exhibiting antidote activity against 2,4-dichloro-phenoxyacetic acid on sunflower seedlings in laboratory conditions and in a field small-plot experiment on vegetative sunflower plants.

To create compound 2, a procedure was chosen in which 4-methoxybenzaldehyde was reacted with N-(benzyl)cyanoacetamide 3 in the presence of catalytic amounts of morpholine in ethanol on heating; the resulting product, having the structure of substituted acrylamide 4, was reacted without isolation with thiourea in the presence of sodium ethoxide in ethanol. After 48 hours, the reaction mass was treated with water and 10% acetic acid until neutral, the precipitated crystals were separated and recrystallized from ethanol. The product yield was 70%. Based on the combination of spectral methods of analysis, it was found that the structure of the synthesized compound corresponds to the structure of the compound 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido claimed as an antidote [4,5-d]pyrimidin-4(1Н)-one 2 (Scheme 1):

Example 1 Evaluation of Compound 2 for Antidote Activity on Sunflower Seedlings

Germinated sunflower seeds of the Master variety 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 % (herbicide + antidote option). 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 (reference standard) were kept for 1 hour in a solution of 2,4-D at a concentration of 10 ^-3 % and for 1 hour 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 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6, 7,8-hexahydropyrimido[4,5-d]pyrimidin-4(1H)-one 2 sharply weakens the toxic effect of the herbicide. Compound 2 reduced the negative effect of 2,4-D on the hypocotyls of sunflower seedlings by 23-42% when used mainly in three or more concentrations, while compound 2 (analogue in structure) showed an antidote effect of 5-29%.

Compound 2 reduced the inhibitory effect of 2,4-D on the roots of seedlings by 47-52% also when used in three or more concentrations, compound 2 (prototype) showed an antidote effect at the level of 20-21%.

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

The evaluation of the antidote activity of the claimed compounds 2 and the prototype (compound 1) was carried out on the experimental field of the FNTsBZR in 2021. The tests were carried out according to the following procedure. Under field conditions, sunflower plants of the Master variety in the most sensitive 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:

And _x - antidote effect,%;

A - crop in the variant antidote + herbicide;

E - crop in the version of the standard (herbicide).

The obtained data were statistically processed using Student's t-test.

The test results are presented in table 2.

Differences between the variants are significant at Р=0.90

Thus, the use of the claimed 3-benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidine-4(1H) -it as an antidote 2,4-D on sunflower allows you to provide a protective effect at the level of 63% versus 25% for the prototype, as well as to expand the range of known antidotes.

Claims (3)

3-Benzyl-2,5-bis(4-methoxyphenyl)-7-thioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]pyrimidin-4(1H)-one

, showing antidote effect to 2,4-dichlorophenoxyacetic acid on sunflower.