PL226687B1 - Protic ammonium cation ionic liquids (3-hydroxypropyl)dimethyl-ammonium and anion the herbicide and the method for their preparation - Google Patents

Description

Description of the invention

The subject of the invention is protic ammonium ionic liquids with a (2-hydroxypropyl) dimethylammonium cation and a herbicidal anion and a method of their preparation, applicable as compounds with herbicidal activity.

Ionic liquids are defined as chemical compounds having an ionic structure. The most characteristic feature that distinguishes them from ordinary salts is their melting point, which is lower than the boiling point of water. Ionic liquids are characterized by unique properties, both physical and chemical, and these parameters are strongly related to the ionic structure of these compounds. The most interesting feature of ionic liquids is that the proper selection of cation and anion allows obtaining compounds with the desired physicochemical parameters.

Ionic liquids can be divided into protic (PlLs) and aprotic (AlLs) ionic liquids. PlLs differ from AlLs in the presence of at least one hydrogen atom linked to a central nitrogen, phosphorus, oxygen or sulfur atom. Protic ionic liquids are obtained by reacting a Bronsted acid with a Bronsted base, while the pKa value of the starting reagents indicates the strength of the proton transfer.

Intensive research on ionic liquids allows us to state that they are multifunctional compounds with a very wide application in various industries, and their application possibilities are constantly expanding. One of the most interesting possibilities of using this group of compounds is their use as herbicides. Herbicidal ionic liquids (HILs), thanks to their activity towards plants, can contribute to the improvement of both the quantity and quality of crops. An important aspect is that they are non-volatile compounds and therefore will not adversely affect neighboring plants.

Commonly occurring plant protection preparations are compounds with active substances in their composition, which include, among others, (4-chloro-2-methylphenoxy) acetic acid (MCPA), (2,4-dichlorophenoxy) acetic acid (2,4-D) and also 3,6-dichloro-2-methoxybenzoic acid (DIKAMBA). Both MCPA and 2,4-D belong to the group of chlorinated phenoxycarboxylic acid derivatives and exhibit herbicidal activity against a large group of dicotyledons. These herbicides selectively and effectively affect plants, destroying them without damaging monocotyledonous plants. Thanks to this, they are successfully used in the cultivation of cereals and grasses. After the treatment, these agents easily penetrate the plants through the leaves and roots, disrupting the growth and development functions, which in turn leads to their death. The most important application values were the salts and esters of MCPA, 2,4-D and DIKAMBY, which in low doses were also used as growth regulators to reduce premature fruit fall.

The essence of the invention are protic ionic liquids with a (3-hydroxypropyl) dimethylammonium cation and a herbicidal anion, with the general formula:

where A is (4-chloro-2-methylphenoxy) acetate or (2,4-dichlorophenoxyacetate or 3,6-dichloro-2-methoxybenzoate or 3,6-dichloro-2-methoxybenzoate anion, and the method of obtaining them is that (3-hydroxypropyl) dimethylamine hydrochloride dissolves is in an aliphatic alcohol with a carbon chain length of one to four carbon atoms or a mixture thereof, preferably methanol, mixed with an alcoholic solution of (4-chloro-2-methylphenoxy) acetic acid or (2,4-dichlorophenoxy) acetic acid, or 3 , 6-dichloro-2-methoxybenzoic acid, at a concentration of at least 1%, in a molar ratio of (3-hydroxypropyl) dimethylamine to organic acid from 1: 0.9 to 1: 1.1, preferably 1: 1, at a temperature of 293 to 363K, preferably 293K, then the inorganic by-product is filtered off, then the solvent is removed from the filtrate, and the obtained product is dried.

PL 226 687 B1

The second method of preparation is that (3-hydroxypropyl) dimethylammonium hydrochloride is dissolved in an aliphatic alcohol with a carbon chain length of one to four carbon atoms or a mixture thereof, preferably methanol, mixed with an alcoholic solution of sodium or potassium or lithium salt. , or ammonium (4-chloro-2-methylphenoxy) acetic acid, or (2,4-dichloro-phenoxy-acetic acid, or 3,6-dichloro-2-methoxybenzoic acid, at a concentration of at least 1%, on a molar ratio of (3-hydroxypropyl) hydrochloride dimethylammonium to an organic acid salt from 1: 0.9 to 1: 1.1, preferably 1: 1, at a temperature from 293 to 363K, preferably

293K, then the inorganic by-product is filtered off, then the solvent is removed from the filtrate, and the obtained product is dried.

Another method of preparation is that (3-hydroxypropyl) dimethylammonium hydrochloride is dissolved in water, mixed with an aqueous solution of sodium or potassium or lithium or ammonium salt of (4-chloro-2-methylphenoxy) acetic acid, or (2 , 4-dichlorophenoxy) acetic or 3,6-dichloro-2-methoxybenzoic, at a concentration of at least 1%, in a molar ratio of (3-hydroxypropyl) dimethylammonium hydrochloride to salt from 1: 0.9 to 1: 1.1, preferably 1: 1, at a temperature from 293 to 363K, preferably 293K, then the solvent is evaporated and the product is extracted with an anhydrous organic solvent from the group: methanol, ethanol, propanol, isopropanol, acetone, acetonitrile, ethyl acetate, chloroform, dichloromethane, toluene, the inorganic by-product is then filtered off, the solvent in the filtrate is removed and the product obtained is dried.

Thanks to the solution according to the invention, the following technical and operational effects were obtained:

• a new group of protic ammonium ionic liquids containing a herbicide anion was obtained, • the developed method of synthesis is highly efficient and pure, • under mild temperature conditions, • the obtained ionic liquids are non-volatile and non-flammable, • synthesized liquids are characterized by high thermal stability.

The following examples illustrate the preparation of protic ammonium ionic liquids with (3-hydroxypropyl) dimethylammonium cation and (4-chloro-2-methylphenoxy) acetate, (2,4-dichlorophenoxy) acetate and 3,6-dichloro-2-methoxybenzoate anions.

P r z k ł a d I

Method for producing (4-chloro-2-methylphenoxy) acetate (3-hydroxypropyl) dimethylammonium acetate

To a reactor equipped with a magnetic stirrer were introduced 0.02 mol (2.79 g) chloro ₃ hydrochloride (3-hydroxypropyl) dimethylamine dissolved in 10 cm ^{3 of} methanol and adding ₃

0.02 mol (4.77 g) of (4-chloro-2-methylphenoxy) acetic acid potassium salt dissolved in 25 cm ^{3 of} methanol.

Stirring was continued at 323K, and as a result of the anion exchange reaction, a white precipitate of potassium chloride (0.02 mol) of the by-product precipitated from methanol, and the precipitated inorganic salt was filtered off.

The methanol filtrate was concentrated under reduced pressure, dried to give the finished product in 97% yield.

The structure of the compound was confirmed by proton and carbon nuclear magnetic resonance spectra:

¹ H NMR (DMSO-d 6) δ [ppm] = 1.75 (m, 2H); 2.18 (s, 3H); 2.61 (s, 6H); 2.94 (t, J = 5.4 Hz, 2H); 3.20 (s. 1H); 3.67 (t, J = 2.7 Hz, 2H); 4.41 (s. 2H); 6.75 (d, J = 4.3 Hz, 1H); 7.11 (d, J = 4.1 Hz, 1H); 7.16 (s. 1H); 8.15 (s. 1H);

¹³ C NMR (DMSO-d6) δ [ppm] = 172.18; 155.70; 129.72; 128.17; 126.10; 123.34; 112.80; 67.10; 59.10; 56.19; 42.87; 15.96.

Elemental CHN analysis for C14H22CINO4: (M = 303.78 g / mol): calculated values (%): C = 55.30; H = 7.24; N = 4.61;

measured values (%): C = 55.35; H = 7.30; N = 4.23.

P r z x l a d II

A process for preparing (2,4-dichlorophenoxy) ethyl (3-hydroxypropyl) dimethylammonium ₃ mol (3.09 g) of (3-hydroxypropyl) dimethylamine dissolved in 12 cm ^{3 of} methyl alcohol and placed in a reaction flask equipped with a magnetic dipole.

PL 226 687 B1

Thereafter, 0.03 mol (6.63 g) ₃ of (2,4-dichlorophenoxy) acetic acid dissolved in 20 cm ^{3 of} methanol was introduced into the mixture with constant stirring.

Everything was intensively stirred at the temperature of 293K, then the solvent was evaporated and the product was dried.

There was obtained (2,4-dichlorophenoxy) acetate (3-hydroxypropyl) dimethylammonium in a yield of 100%.

The structure of the compound was confirmed by proton and carbon nuclear magnetic resonance spectra:

¹ H NMR (DMSO-d 6) δ [ppm] = 1.74 (m, 2H); 2.60 (s, 6H); 2.91 (t, J = 7.8 Hz, 2H); 3.20 (s. 1H); 3.46 (t, J = 5.9 Hz, 2H); 4.48 (s. 2H); 6.93 (d, J = 4.45 Hz, 1H); 7.30 (d, J = 3.31, 1H); 7.50 (s. 1H); 7.78 (s. 1H);

¹³ C NMR (DMSO-d6) δ [ppm] = 171.15; 153.34; 129.03; 127.68; 123.77; 121.99; 114.87; 67.53; 58.18; 54.47; 42.19; 27.45.

Elemental analysis for CHN for C13H19Cl2NO4: (M = 324.20 g / mol): calculated values (%): C = 48.12; H = 5.86; N = 4.32;

measured values (%): C = 48.16; H = 5.91; N = 4.08.

P r x l a d III

Method for producing (3-hydroxypropyl) dimethylammonium 3,6-dichloro-2-methoxybenzoate

The reactor was placed 0.02 mol (2.06 g) of (3-hydroxypropyl) dimethylamine, which czono dissolving ₃ in 10 cm ³ of ethanol.

₃

Then, the dissolved 0.02 mol (4.42 g) of dichloro-2-methoxy-ksybenzoesowego in 15 cm ³ of isopropanol and the two solutions are combined. The whole was intensively stirred at the temperature of 293K.

The solvents were evaporated and the product was thoroughly dried.

(3-hydroxypropyl) dimethylammonium 3,6-dichloro-2-methoxybenzoate was obtained in a yield of 98%.

The structure of the compound was confirmed by proton and carbon nuclear magnetic resonance spectra:

¹ H NMR (DMSO-d 6) δ [ppm] = 1.82 (m, 2H); 2.72 (s, 6H); 3.04 (t, J = 2.5 Hz, 2H); 3.17 (s. 1H); 3.48 (t, J = 5.9 Hz, 2H); 3.90 (s, 3H); 7.13 (d, J = 4.36 Hz, 1H); 7.30 (d, J = 4.32 Hz, 1H); 7.55 (s. 1H);

¹³ C NMR (DMSO-d6) δ [ppm] = 167.24; 151.48; 138.61; 128.00; 127.51; 125.54; 125.43; 61.28; 58.02; 54.45; 42.02; 27.13

Elemental analysis for CHN for C13H19Cl2NO4: (M = 324.20 g / mol): calculated values (%): C = 48.12; H = 5.86; N = 4.32;

measured values (%): C = 48.16; H = 5.91; N = 4.19.

Application example

Research on biological activity in greenhouse conditions

The test plant was cornflower (Centaurea cyanus). The seeds were sown into pots filled with soil to an equal depth of 1 cm. After producing the cotyledons, a break was made, leaving 4 plants in each pot. After the production of 4 leaves, the plants were sprayed with the liquid containing the test compounds using a cabin sprayer equipped with a Tee Jet 1102 sprayer, moving over the plants at a constant speed of 3.1 m / s. Spray distance from the tips of the plants was 40 cm, the liquid pressure in the sprayer was 0.2 MPa and the flow rate of liquid in the counting FOR IN ₃ per 1 ha was 200 dm ^3. (4-chloro-2-methylphenoxy) acetate (3-hydroxypropyl) dimethylammonium acetate was dissolved in water in an amount corresponding to a dose of 400 g of herbicide (anion) per 1 ha. A herbicide registered in Poland containing ₃ 300 g of MCPA in the form of sodium-potassium salts in 1 dm ^{3 of the} preparation was used as a comparative measure. After spraying, the pots with plants were returned to the greenhouse at 20 ° C (± 2 ° C) and 60% air humidity. After 2 weeks, the plants were cut just in the soil and their weight was determined with an accuracy of 0.1 g, separately for each pot. The study was performed in 4 replications in a completely randomized design. On the basis of the obtained measurements, the reduction of the fresh weight of the plants was calculated compared to the control (plants not sprayed with the test compounds). The investigated new ionic liquids showed a higher biological activity in the control of cornflower by 14% compared to the standard herbicide.

Claims (4)

1. Proton ionic liquids with a (3-hydroxypropyl) dimethylammonium cation and a herbicide anion, with the general formula: CH ₃ wherein A is an anion (4-chloro-2-methylphenoxy) acetate, or (2,4-dichlorophenoxy) acetate or 3,6-dichloro-2-metoksybenzoesanowy. 2. A method of obtaining protic ionic liquids with a (3-hydroxypropyl) dimethylammonium cation and a herbicidal anion as defined in claim 1, characterized in that (3-hydroxypropyl) dimethylamine hydrochloride is dissolved in an aliphatic alcohol with a carbon chain length of one to four carbon atoms, or their mixture, preferably in methanol, is mixed with an alcoholic solution of (4-chloro-2-methylphenoxy) acetic acid or (2,4-dichlorophenoxyacetic acid or 3,6-dichloro-2-methoxybenzoic acid at a concentration of at least 1%, in a molar ratio) (3-hydroxypropyl) dimethylamine to an organic acid from 1: 0.9 to 1: 1.1, preferably 1: 1, at a temperature of 293 to 363K, preferably 293K, then the inorganic by-product is filtered off, and then the filtrate is removed from solvent and the product obtained is dried. 3. A method of obtaining protic ionic liquids with a (3-hydroxypropyl) dimethylammonium cation and a herbicidal anion as defined in claim 1, characterized in that (3-hydroxypropyl) dimethylammonium hydrochloride is dissolved in an aliphatic alcohol with a carbon chain length from one to four carbon atoms, or a mixture thereof, preferably in methanol, is mixed with an alkoxide solution of a sodium or potassium salt or a lithium or ammonium salt of (4-chloro-2-methylphenoxy) acetic acid, or (2,4-dichlorophenoxy) acetic acid or dichloro-2- methoxybenzoic acid, at a concentration of at least 1%, in the molar ratio of (3-hydroxypropyl) dimethylammonium hydrochloride to organic acid salt from 1: 0.9 to 1: 1.1, preferably 1: 1, at a temperature of 293 to 363K, preferably 293K then the inorganic by-product is filtered off, then the solvent is removed from the filtrate and the obtained product is dried. 4. Method of obtaining protic ionic liquids with (3-hydroxypropyl) dimethylammonium cation as defined in claim 1, characterized in that (3-hydroxypropyl) dimethylammonium hydrochloride is dissolved in water, mixed with an aqueous solution of sodium or potassium or lithium or ammonium salt (4-chloro-2-methylphenoxy) acetic acid, or (2,4-dichlorophenoxy) acetic acid, or dichloro-2-methoxybenzoic acid, at a concentration of at least 1%, in a molar ratio of (3-hydroxypropyl) dimethylammonium hydrochloride to salt from 1 : 0.9 to 1: 1.1, preferably 1: 1, at a temperature from 293 to 363K, preferably 293K, then the solvent is evaporated and the product is extracted with an anhydrous organic solvent from the group: methanol, ethanol, propanol, isopropanol, acetone, acetonitrile, ethyl acetate, chloroform, dichloromethane, toluene, then the inorganic by-product was filtered off, the solvent was removed from the filtrate and the obtained product was dried.