KR800001507B1 - Process for preparing 1,2,o thiadiazol-5-yl-ureas - Google Patents

Abstract

1,2,3-Thiadiazol-5-yl-urea(I; R1 = H, C1-5 alkyl ; R2 = C1-5 alkyl; R3 = substituted or nonsubstituted pyridyl or pyrimidyl; R4 = C1-5 alkyl, aryl; X = O, S), useful as plant growth controlling agent, was prepd. by reaction of compd. (IV), obtained from reaction of compd. (II) and chloroformic ester (III) in the presence of acid binding agent, with amine (V). The reaction of isocyanate or carbamoylchloride, obtained from reaction of compd.(II) and phosgen in the presence of acid binding agent, with amine(V) gave also compd.(I).

Description

Method for preparing 1,2,3-thiadiazol-5-yl-urea

The present invention relates to a method for preparing 1,2,3-thiadiazole-5-ylurea, which is the following structural formula (I) having a growth control action and a leaf grazing action of a plant.

Wherein R ₁ is hydrogen or a C ₁ -C ₅ alkyl moiety and R ₂ is hydrogen or optionally hydrogen with one or more substituents or a C ₁ -C ₅ alkyl residue with sulfur in between and R ₃ is at least And optionally substituted heterocycle hydrocarbon residue containing one nitrogen atom.

In particular, maleic acid hydrazide (German Patent Specification No. 815,192) is used as a growth inhibitor, but its action does not have a satisfactory effect in a small amount. Also for this purpose a substituted carbamoylamino-1,2,3-thiadiazole is submitted. (Germany Publication No. 2,214,632) Nevertheless, this preparation can cause loss (withering) in plants.

Also already known as plant defoliants are tri-n-butylthiophosphate. (US Pat. No. 2,965,467) However, this active substance is always unsatisfactory in its action, especially in those who use it, which continues to have an unpleasant odor. Thus, the main focus of the present invention is to create a new formulation which is better in terms of growth control and plant deciduous action than the conventional formulation and which is less troublesome to handle.

This problem is solved through a formulation characterized by containing at least one compound of formula (I) according to the invention.

The compounds according to the invention in particular regulate the growth of vegetables, which is often a necessary need for useful plants. In addition, the compound according to the present invention has advantages such as, for example, deciduous action of plants, promoting germination, and shortening of branch axes.

The amount used for the desired plant control action is 0.05-5 kg / ha of active substance, which is achieved by foliar treatment.

In some cases, it may fall short of or exceed this category. The type and method of growth regulation are independent of each other depending on treatment time, plant type and concentration.

The compounds according to the invention can be achieved by various methods on various plant parts such as seeds, roots, stems, leaves, flowers and fruits. Again, plants can be sprayed before or after germination, or after or after germination. The way in which total growth inhibition occurs, including bushes, can be rather disturbing to the weed family.

Although lethal amounts of the compounds according to the invention may be used, only the amounts of the compounds according to the invention which can act as described above can be foreseen in accordance with the invention. Thus, the natural growth control action of the compounds according to the present invention results in morphological changes that can be identified by Shiveh observation in practice. Changes of this kind can be seen in the size, shape, color or any other part of the plant treated.

Moderate effects are natural. This effect is achieved by causing changes in plant hormone status.

For some plants, this growth retardation reduces the main stem or roots and causes more branches to the side, reducing or eliminating growth to the top.

This approach leads to many useful purposes. In many types of plants, such as potatoes, sugar cane, beets, grapes, melons, fruit trees and vegetables, they inhibit the growth of the grain to increase the carbohydrate storage of the plants in the harvest season.

In fruit and plant cultivation, it hinders plant growth, shortening the stature and making the branches flourish, making them easily accessible and easily harvested. Depending on the circumstances, vertical growth disturbances are desired in the grass because the vertical growth of the poles can be hindered to increase the time difference.

Deciduous action is an action particularly caused by the compounds according to the invention. It is well known to experts that defoliation is not a herbicide, and leaves are not herbicides, because leaves remain attached to dead plants and can harm productive plants. The deciduous action, which makes the harvest easier and the net yield increase, can mean that the original deciduous action is lost. Therefore, the plant must be alive while the leaves are falling apart. This impedes the growth of young leaves and makes it possible to further promote the growth of productive parts of the plant. All of these problems have been solved in an excellent way by the compounds according to the invention and thus far exceed the technical aspects.

The compounds according to the invention can be used alone or in admixture with one another or with other active substances. In some cases, defoliants, plant protection agents or pests and seaweed removal agents may be added to achieve the desired purpose.

To enhance the action and speed of action, organic solvents, wetting agents and oil-promoting additives such as oily substances can be added. These may reduce the use of the original active substance.

The compounds according to the invention are particularly effective in their function of oxins, α- (2-chlorophenoxy) -propionic acid, 4-chloro-phenoxyacetinic acid, 2,4-dichlorophenoxyacetinic acid, indole Aryl-3-acetinic acid, indolyl-3-butyric acid, α-naphthylacetic acid, β-naphthoxy-acetinic acid, naphthylacetamide, β-Nm-tolylphthalamine acid, gibbeline, apsinic (Abscisin) acid, tri-n-butyl-trithiophosphate, cytokinin, 2-chloroethylphosphonic acid, 2-chloro-9-hydroxyfluoro-9-carboxylic acid derivative, 2-chloroethyl-trimethylammonium chlorolide, N, N-dimethyl amino-puccinic acid, 2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine, phenyl-isopropyl carbamate, 3-chlorophenyl-isopropylcarbamate ethyl-2- ( 3-Chlorophenylcarbamoyloxy) -propionate, maleinhydrazide, 2,3-dichloroisobutyl acid, 0,0-dimethyl-dithio-thio Le formate, 1,1'-dimethyl-4,4-bi-pyrido diryum - can be combined with the use of a compound such as the dichloride, fatty acids, chlorates, nonanol.

Active substances or mixtures thereof, characterized according to the purpose, may be prepared in the form of powders, sprays, granules, solutions, emulsions or suspensions by the addition of liquid and / or solid carriers or diluents and optionally wetting agent adhesive emulsifiers and / or dispersion aids. use.

Suitable liquid carriers include water, benzene, toluene, xylenes, cyclohexanone, isopron, dimethylsulfoxide, aliphatic or aromatic hydrocarbons or minerals such as dimethylformamide.

Suitable solid carriers are minerals such as tonsil, silica gel, talc, kaolin ataclei, limestone, or vegetable materials such as flour and flour.

Surfactants include calcium ligninsulfonate, polyoxyethylene-alkylphenylether, naphthalinsulfonic acid or salts thereof, phenolsulfonic acid or salts thereof, formaldehyde concentrates, fatty alcohol holes or substituted benzenesulfonic acids or salts thereof .

The amount of active ingredient in one formulation can vary widely. For example, the formulation contains up to 10-80% (by weight) of active ingredient, 90-20% (by weight) of liquid or solid carrier, and optionally up to 20% (by weight) of surfactant.

Spraying of the formulations can be carried out according to conventional methods, for example using as a carrier enough water to spray an amount of 100-1000 l / ha. The use of the formulations in the so-called "low dose" and "ultra low dose" methods is possible as well as in so-called underspraying.

Among the other compounds of the invention, R ₁ is hydrogen or a C ₁ -C ₅ alkyl residue and R ₂ is hydrogen or a C ₁ -C ₅ alkyl residue and R ₃ is unsubstituted or one or more of C ₁ -C simultaneously or multiple times Particularly noteworthy are the pyridyl residues or pyrimidyl residues substituted with a ₄ -alkyl residue, a C ₁ -C ₄ alkoxy residue, a halogen atom, a nitrogen group or a trifluoromethyl group.

Alkyl residues are, for example, methyl, ethyl, propyl, n-butyl or n-pentyl.

Substituents for hydrocarbons that are heterocycles containing at least one nitrogen atom include, in particular, substituents for pyridyl residues or pyrimidyl residues, such as methyl, ethyl, propyl, n-butyl, methoxy, ethoxy, propoxy, chlorine. , Cancelled, nitro or trifluoromethyl groups.

So far unknown structural formula (I) compounds include the following structural formula (II): a) the following structural formula (III): In an organic solvent such as tetrahydrofuran, methylene chloride or dimethylformamide in the presence of an acid binder such as a base, the reaction is carried out at a temperature of 0 ° C.-60 ° C., especially at room temperature, and together with the amine of the following formula (IV), acetone, dimethylformamide In a solvent such as tetrahydrofuran or acetonitrile at a temperature of 50 ° -150 ° C., in particular at the boiling point of a solvent, or b) initially in the presence of an acid binder such as N, N-dimethylaniline React with phosgene while producing isocyanate or carbamoyl chloride followed by the following formula (IV) Prepared by reaction with an amine and the reaction product separated by known methods.

Wherein R ₁ , R ₂ and R ₃ are as described above, X is oxygen or sulfur and R ₄ is an aryl residue such as a C ₁ -C ₅ alkyl residue or a phenyl moiety.

In the following, the preparation method of the compound according to the present invention is described above.

Example 1

1- (2-pyridyl) -3- (1,2,3-thiadiazol-5-yl) -urea (Compound No. 1)

16.5 g (0.075 moles) of 5-phenoxycarbonylamino-1,2,3-thiadiazole is suspended in 150 ml of acetone and 9.4 g (0.1 moles) of 2-amino pyridine is added. It is then heated to reflux for 3 hours. After cooling to room temperature, the pale brown crystals are dried by suction filtration. Recrystallize from ethanol.

Yield: 9.3 g (56.3%), colorless crystals.

Melting Point: 227 ° C (Decomposition)

Elemental Analysis: Calculation C43.41% H3.19% N31.67% S14.50%

Found 43.86% 3.24% 31.89% 14.20%

Starting material for the preparation of compound 1

5-phenoxycarbonylamino-1,2,3-thiadiazole

To 10.1 g (0.1 mol) of 5-amino-1,2,3-thiadiazole solution dissolved in 75 ml of tetrahydrofuran, 17.4 ml (0.1 mol) of hexamethylphosphoric acid-triamide were added. 15.7 g (0.1 mole) of chloroformic acid-phenyl ester is added dropwise while increasing the temperature to ° C. Stir at room temperature for 5 hours and then dilute with 400 ml of water. The process is suction filtered, dried and recrystallized from ethanol.

Yield: 19.5 g (88.1%)

Melting Point: 218-220 ℃ (Decomposition)

In a similar manner to the above to prepare a compound according to the invention as follows.

The compounds according to the invention are colorless odorless crystalline substances and insoluble in water or aliphatic hydrocarbons or aromatic hydrocarbons. Very well soluble in polar organic solvents such as acetone, isophorone, cyclohexanone, dimethylsulfoxide or dimethylformamide.

The following test report demonstrates the availability of the compounds according to the invention as deciduous agents.

Example 2

Soybean (Phaseolus vulgaris) after the first leaf is produced and soybean (Glycine maxima) which has the first three leaves and starts to grow in a hotbed is a compound according to the present invention 1- (2-pyridyl) -3- (1,2 , 3-thiadiazol-5-yl) -urea are treated in different amounts, ie 0.1 / 0.3 / 1 and 3 kg / ha. To this end, it is formulated as a spraying powder containing 20% of the active substance and used as a hydrating suspension so that the amount of liquid used is 500 l / ha. Growth regulation is measured by measuring the nodes 2 days after treatment.

As a result of the measurement, the percentage of growth inhibition is calculated in comparison with the untreated control plants. As shown in the following table, the desired control effect can be obtained with the compounds according to the present invention in a wide range of concentrations without deterioration of the leaves.

Example 3

Growing cotton tree with 810 leaves is treated with 0.5 kg of the active substance which is the compound according to the present invention and the same amount of the control agent. The amount of water used is 500 l / ha.

From the table it can be demonstrated that the compounds according to the invention are excellent in terms of strength of action and in some cases, speed of action.

Claims (1)

Reacting or turning the compound of formula (IV) formed by reacting the compound of formula (II) in the presence of an acid binder with the chloroformic acid ester of formula (III) in the presence of an amine of formula (V) and an organic solvent 1,2,3-thiadiazole-5 of formula (I) characterized by reacting a compound of with a phosgene and the corresponding isocyanate or carbamoyl chloride produced in the presence of an acid binder with an amine of formula (V) A method of preparing yl-urea.

Wherein R ₁ is hydrogen or alkyl having 1 to 5 carbon atoms and R ₂ is alkyl having 1 to 5 carbon atoms which may be substituted and / or interrupted by one or more heteroatoms selected from hydrogen or oxygen and sulfur atoms and R ₃ Is an unsubstituted or substituted pyridyl or pyrimidyl, R ₄ is alkyl or aryl having 1 to 5 carbon atoms and X is an oxygen or sulfur atom.