PL235893B1 - Phosphonium ionic liquids with n-alkyltriphenylphosphonium cation and (4-chloro-2-methylphenoxy)acetate or (2,4-dichlorophenoxy)acetate anion, method for obtaining them and application as herbicides - Google Patents

Abstract

The subject of the application are phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and (4-chloro-2-methylphenoxy)acetate or (2,4-dichlorophenoxy)acetate anion, of the formula 2, in which A- is the anion (4-chloro-2- methylphenoxy)acetic acid (MCPA) of the general formula 3 or (2,4-dichlorophenoxy)acetic acid (2,4-D) of the general formula 4 and R is an alkyl chain with 4, 6, 8 or 10 carbon atoms. The application also includes a method for their preparation, which consists in adding the potassium salt of (2,4-dichlorophenoxy)acetic acid or (4-chloro-2-methylphenoxy)acetic acid to the n-alkyltriphenylphosphonium bromide of the general formula 1, in molar ratio of quaternary salt to phosphonium bromide 1:1, the reactions being carried out at a temperature of 25 to 60°C, preferably 30°C, in methanol, then the solvent is evaporated and acetone or a mixture of acetone-methanol (10:1) is added ), and the precipitated by-product is filtered off, then the solvents are evaporated from the filtrate, the resulting product is dried at a temperature of 55 to 75°C, preferably 70°C. The application also concerns the use of phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and (4-chloro-2-methylphenoxy)acetate or (2,4-dichlorophenoxy)acetate anion as herbicides.

Description

The subject of the invention is phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and an (4-chloro-2-methylphenoxy) acetate or (2,4-dichlorophenoxy) acetate anion, a method of their preparation and use as herbicides.

Ionic liquids (ILs) are compounds with an ionic structure which have a melting point below 100 ° C. They consist of an organic cation and an anion, which can belong to both the group of organic and inorganic compounds. Due to the presence of a positive charge at different atoms, ILs are divided into ammonium, phosphonium, oxonium and sulfonium.

Phosphonium ionic liquids belong to the group of substances whose basic compound is phosphate PH3 (potassium phosphine, phosphine) - used, for example, as an insecticide. Phosphonium salts, similarly to ammonium salts, have a quaternary atom in their structure. Presented by Anna Cieniecka-Rosłonkiewicz in Green Chem., 2005, 7, 855-862, they prove that some alkyltrihexylphosphonium ionic liquids show very good antistatic and bactericidal properties. The team of Kevin J. Fraser and Douglas R. MacFarlane (Aust. J. Chem. 2009, 62, 309-321) presented in their work a summary of the current knowledge on phosphonium ionic liquids. In the article, they present a significant group of the compound with their applications and basic parameters. They suggest that phosphonium salts can serve as electrolytes in lithium-ion batteries, photovoltaic cells and supercapacitors. They are also used as corrosion inhibitors and solvents in organic syntheses. Due to the increasing expectations of consumers, new applications of phosphonium ionic liquids are sought.

(4-chloro-2-methylphenoxy) acetic acid (MCPA) and (2,4-dichlorophenoxy) acetic acid (2,4-D) - phenoxy carboxylic acid derivatives - are selective herbicides with systemic action from the group of growth regulators. They penetrate the plants through the leaves and are quickly moved mainly to the growth tips. In dicotyledonous plants sensitive to them, they first deform leaves and stems and inhibit growth. These symptoms become apparent only a few hours after the application of these herbicides. Chlorosis and necrosis develop slowly. Monocotyledonous plants are very tolerant to these herbicides. (4-chloro-2-methylphenoxy) acetic acid and (2,4-dichlorophenoxy) acetic acid are used to control dicotyledonous weeds (smoke beetle, white quinoa, common grasshopper, bundles, vetch, self-seeding rapeseed and other species) in cultivation cereals, seed grasses, orchards, lawns.

Examples of these types of compounds are:

• (4-chloro-2-methylphenoxy) butyltriphenylphosphonium acetate, • (4-chloro-2-methylphenoxy) triphenylhexylphosphonium acetate, • (4-chloro-2-methylphenoxy) triphenyloctylphosphonium acetate, • (4-chloro-2-methylphenoxy) acetate decyltriphenylphosphonium, • (2,4-dichlorophenoxy) butyltriphenylphosphonium acetate, • triphenylhexylphosphonium (2,4-dichlorophenoxy) acetate, • triphenyloctylphosphonium (2,4-dichlorophenoxy) acetate, • decyltriphenylphosphonium (2,4-dichlorophenoxy) acetate.

The essence of the invention is phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and an (4-chloro-2-methylphenoxy) acetate or (4-chloro-2-methylphenoxy) acetate anion, of the formula 2, in which A ^- is an anion (4-chloro 2-methylphenoxy) acetic (MCPA) of general formula 3 or (2,4-dichiorophenoxy) acetic (2,4-D) of general formula 4 and R is an alkyl chain with 4, 6, 8 or 10 carbon atoms.

The method of their preparation consists in adding the potassium salt of (2,4-dichlorophenoxy) acetic acids or (4-chloro-2-methylphenoxy) acetic acids to the n-alkyltriphenylphosphonium bromide of general formula 1, in the molar ratio of the quaternary salt to phosphonium bromide 1: 1, the reactions are carried out at a temperature of 25 to 60 ° C, preferably 30 ° C, in methanol, then the solvent is evaporated and acetone or acetone-methanol mixture (10: 1) is added, and the precipitated product the by-product is filtered off, the solvents of the filtrate are evaporated off, the resulting product is dried at a temperature of 55 to 75 ° C, preferably 70 ° C.

The use of phosphonium ionic liquids with n-alkyltriphenylphosphonium cation and (4-chloro-2-methylphenoxy) acetate or (4-chloro-2-methylphenoxy) acetate anion as herbicides.

It is preferred that the phosphonium ionic liquids are used in pure form.

PL 235 893 B1

It is also preferred that the phosphonium ionic liquids are used in the form of an aqueous ethanol solution with a concentration of at least 0.05%.

Thanks to the solution used in the invention, the following technical and economic effects were obtained:

• new ionic liquids containing a single charge cation have been synthesized, • the developed methods of synthesis allow to achieve a high efficiency of at least 80%, • the synthesized salts at standard temperature are highly viscous liquids, which makes them classified as ionic liquids, • the obtained compounds are highly soluble in many organic solvents, including methanol and DMSO, but they are not soluble in water, • the synthesized compounds have an undetermined vapor pressure above their surface, • the obtained ionic liquids are characterized by thermal stability in a wide range of temperatures, • the obtained new substances are characterized by activity herbicides, these are herbicides, • ionic liquids.

The following examples illustrate the invention:

P r z k ł a d I

Method for the preparation of butyltriphenylphosphonium (4-chloro-2-methylphenoxy) acetate

5.98 g (0.015 mol) of butyltriphenylphosphonium bromide were dissolved in a round bottom flask containing 45 cm ^{3 of} methanol. Then a stoichiometric amount of potassium (4-chloro-2-methylphenoxy) acetate was added and stirred at 25 ° C. The solvent was then evaporated and 45 cm ^{3 of} acetone were added. The separated inorganic salt was then filtered off, and the solvent from the filtrate was evaporated in a vacuum evaporator, and the main product was dried in a vacuum oven at 70 ° C. The reaction yield was 90%.

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

¹ H NMR (Methanol-d4) δ ppm = 0.95 (s, 3H); 1.59 (m, 4H); 2.23 (s. 5H); 4.37 (s. 2H); 6.72 (m, 1H); 7.01 (m, 1H); 7.07 (m, 1H); 7.77 (m, 15H).

¹³ C NMR (Methanol-d4) δ ppm = 13.69; 16.48; 24.65; 24.86; 25.49; 68.95; 113.53; 120.48 [3C]; 125.78; 127.10; 130.12; 131.04; 131.41 [6C]; 134.66 [6C]; 136.21 [3C]; 157.14; 178.24.

³¹ P NMR (CDCb) δ ppm = 25.13

Elemental analysis for CHN for C31H32ClO3P (Mmol = 519.02 g / mol): calculated values (%): C = 71.74; H = 6.21; N = 5.97; measured values: C = 71.41; H = 6.39; N = 5.99.

P r z x l a d II

Method for the preparation of triphenylhexylphosphonium (4-chloro-2-methylphenoxy) acetate

To a reactor equipped with a magnetic stirrer was added 150 cm ^{3 of} methanol and 21.35 g (0.050 mol) of trifenyloheksylofosfoniowego. After the bromide had dissolved, 0.050 mol of potassium (4-chloro-2-methylphenoxy) acetate was added. The reaction was carried out at 35 ° C with constant stirring. The solvent was evaporated and 150 cm ³ of acetone. The separated inorganic salt was then filtered off. The solvent of the filtrate was evaporated, and the main product was then dried in a vacuum oven at 75 ° C. The reaction yield was 99%.

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

¹ H NMR (CDCl 3) δ ppm = 0.82 (s, 3H); 1.24 (m, 4H); 1.60 (m, 4H); 2.15 (s, 3H); 3.50 (m, 2H); 4.38 (s. 2H); 6.72 (m, 1H); 6.84 (m, 1H); 6.97 (m, 1H); 7.74 (m, 15H).

¹³ C NMR (CDCl 3) δ ppm = 13.64; 16.17; 21.97; 22.24; 22.49; 29.96; 30.90; 68.62; 112.89; 117.43 [3C]; 123.55; 125.72; 128.28; 129.49; 130.40 [6C]; 133.19 [6C]; 134.92 [3C]; 156.17; 172.91.

³¹ P NMR (CDCl3) δ ppm = 24.58.

Elemental CHP analysis for C33H36ClO3P (Mmoi = 547.07 g / mol): calculated values (%): C = 72.45; H = 6.63; P = 5.66; measured values: C = 72.25; H = 6.33; P = 5.36.

PL 235 893 B1

P r x l a d III

Method for the preparation of triphenyloctylphosphonium (4-chloro-2-methylphenoxy) acetate

60 cm ³ of methanol was dissolved 9.10 g (0.020 mol) of trifenylooktylofosfoniowego. Then a stoichiometric amount of potassium (4-chloro-2-methylphenoxy) acetate was added. The exchange reaction was performed at 40 ° C with constant stirring. The solvent was evaporated followed by addition of 60 cm ³ of acetone. The liberated potassium bromide was filtered off while hot under vacuum, and then the solvent was evaporated again. The residual solvent was evaporated in a vacuum oven at 65 ° C. The reaction yield was 95%.

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

1 H NMR (CDCl 3) δ ppm = 0.83 (s, 3H); 1.20 (m, 10H); 1.63 (m, 2H); 2.55 (s, 3H); 3.69 (s. 2H); 4.36 (s. 2H); 6.78 (m, 1H); 7.11 (m, 1H); 7.15 (m, 1H); 7.73 (m, 15H).

¹³ C NMR (CDCl 3) δ ppm = 13.75; 16.48; 22.24; 22.30; 22.90; 28.53; 28.57; 31.36; 68.95; 113.53; 118.55 [3C]; 125.78; 127.10; 130.12; 130.20 [6C]; 131.04; 133.40 [6C]; 134.81 [3C]; 157.14; 178.24. ³¹ P NMR (CDCl3) δ ppm = 23.25

Elemental analysis of CHN for C35H40ClO3P (Mmol = 575.13 g / mol): calculated values (%): C = 73.09; H = 7.01; P = 5.39; measured values: C = 73.49; H = 7.39; P = 5.69.

P r x l a d IV

Method for the preparation of decyltriphenylphosphonium (4-chloro-2-methylphenoxy) acetate

In the reactor were mixed 180 ^cm3 of methanol and 28.98 g (0.060 mol) of decylotrifenylofosfoniowego. After dissolution, a stoichiometric amount of potassium (4-chloro-2-methylphenoxy) acetate was added. The reaction was carried out at 30 ° C with constant stirring. The solvent was then evaporated, and then 180 cm ^{3 of} an aceto n-methanol mixture (10: 1) was added. The precipitated potassium bromide was removed by suction filtration. The solvent mixture was further evaporated. The residual solvent was then evaporated by vacuum drying at 55 ° C. The reaction yield was 87%.

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

¹ H NMR (CDCl 3) δ ppm = 0.88 (s, 3H); 1.26 (m, 12H) 1.59 (m, 4H); 2.46 (s, 3H); 3.35 (m, 2H); 5.05 (s. 2H); 6.85 (m, 1H); 7.05 (m, 1H); 7.34 (m, 1H); 7.70 (m, 15H).

¹³ C NMR (CDCl 3) δ ppm = 14.10; 16.55; 22.71; 24.75; 25.39; 29.32; 29.44; 29.66; 30.01; 30.22; 31.55; 70.95; 111.53; 117.48 [3C]; 122.78; 128.10; 129.12; 131.54; 132.4116C]; 133.66 [6C]; 136.51 [3C]; 157.54; 179.24.

³¹ P NMR (CDCl3) δ ppm = 21.27

Elemental CHP analysis for C37H44ClO3P (Mmol = 603.18 g / mol): calculated values (%): C = 73.68; H = 7.35; P = 5.14; measured values: C = 73.41; H = 7.66; P = 5.51.

P r z k ł a d V

Method for the preparation of butyltriphenylphosphonium (2,4-dichlorophenoxy) acetate

In a flask equipped with a magnetic stir bar was dissolved 17.96 g (0.045 mol) of butylotrifenylofosfoniowego in 135 cm ³ of methanol. Then a stoichiometric amount of potassium (2,4-dichlorophenoxy) acetate was added and stirred at 55 ° C. The solvent was then evaporated and 135 cm ^{3 of} acetone were added. It was then filtered under reduced pressure to separate the precipitated potassium bromide. The solvent was further evaporated and the main product was dried in a vacuum oven at 70 ° C. The reaction yield was 80%.

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

¹ H NMR (CDCl) δ ppm = 0.93 (s, 3H); 1.57 (m, 4H); 2.28 (s. 2H); 4.57 (s. 2H); 6.94 (m, 1H); 7.13 (m, 1H); 7.15 (m, 1H); 7.44 (m, 15H).

¹³ C NMR (CDCb) δ ppm = 13.51; 24.45; 24.84; 25.55; 68.35; 113.03; 120.08 [3C]; 125.08; 127.07; 130.02; 131.34; 131.51 [6C]; 134.96 [6C]; 136.91 [3C]; 157.94; 178.94.

³¹ P NMR (CDCb) δ ppm = 29.31

Elemental analysis for CHN for C30H29Cl2O3P (Mmol = 539.43 g / mol): calculated values (%); C = 66.80; H = 5.42; P = 5.74; measured values: C = 66.41; H = 5.09; N = 5.49.

PL 235 893 B1

P r x l a d VI

Method for the preparation of triphenylhexylphosphonium (2,4-dichlorophenoxy) acetate

In the reactor were mixed 300 ^cm3 of methanol and 42.70 g (0.100 mol) of trifenyloheksylofosfoniowego. After the bromide had dissolved, a stoichiometric amount of potassium (2,4-dichlorophenoxy) acetate was added and stirred at 60 ° C. The solvent was then evaporated. Further 300 cm ^{3 of} an acetone-methanol mixture (10: 1) was added to isolate a by-product. The prepared solution was cooled, filtered under reduced pressure and the solvent mixture was removed. The residual solvent was evaporated by vacuum drying at 75 ° C. The yield was 84%.

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

1 H NMR (CDClb) δ ppm = 0.87 (s, 3H); 1.29 (m, 4H) 1.60 (m, 4H); 3.46 (s, 2H); 4.82 (s. 2H); 6.89 (m, 1H); 7.15 (m, 1H); 7.31 (m, 1H); 7.80 (m, 15H).

¹³ C NMR (CDCb) δ ppm = 14.29; 23.37; 23.54; 23.59; 31.16; 32.10; 68.88; 116.02; 119.43 [3C]; 120.57; 126.55; 128.63; 130.60 [6C]; 131.48; 134.75 [6C]; 136.23 [3C]; 154.80; 174.14.

³¹ P NMR (CDCb) δ ppm = 28.29

Elemental CHP analysis for C32H33Cl2O3P (Mmol = 567.49 g / mol): calculated values (%): C = 67.73; H = 5.86; P = 5.46; measured values: C = 67.51; H = 5.39; P = 5.89.

Example VII

Method for the preparation of triphenyloctylphosphonium (2,4-dichorophenoxy) acetate

36.40 g (0.080) of triphenyloctylphosphonium bromide were dissolved in 240 cm ^{3 of} methanol. A stoichiometric amount of potassium (2,4-dichlorophenoxy) acetate was then added and stirred at 45 ° C. The methanol is then evaporated off. Further 240 cm ^{3 of} an acetone-methanol mixture (10: 1) was added to isolate a by-product. The prepared solution was cooled, filtered under reduced pressure and the solvent mixture was evaporated. Then the residual solvent was removed by vacuum drying at 65 ° C. The reaction yield was 82%.

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

¹ H NMR (CDCl) δ ppm = 0.83 (s, 3H); 1.20 (m, 10H); 1.63 (m, 2H); 3.69 (s. 2H); 4.36 (s. 2H); 6.78 (m, 1H); 7.11 (m, 1H); 7.15 (m, 1H); 7.73 (m, 15H).

¹³ C NMR (CDCb) δ ppm = 13.75; 22.24; 22.30; 22.90; 28.53; 28.57; 31.36; 68.95; 113.53; 118.55 [3C]; 125.78; 127.10; 130.12; 130.20 [6C]; 131.04; 133.40 [6Cj; 134.81 [3C]; 157.14; 178.24.

³¹ P NMR (CDCl) δ = 27.29 ppm

Elemental analysis of CHN for C34H37CUO3P (Mmoi = 595.54 g / mol): calculated values (%): C = 68.57; H = 6.26; P = 5.20; measured values: C = 68.91; H = 6.59; N = 2.69.

P r x l a d VIII

Method for the preparation of decyltriphenylphosphonium (2,4-dichlorophenoxy) acetate

To a reactor equipped with a magnetic stirrer was added 90 cm ^{3 of} methanol and 14.49 g (0.030 mol) of decylotrifenylofosfoniowego. After the bromide had dissolved, a stoichiometric amount of potassium (2,4-dichlorophenoxy) acetate was added. Stirred at 50 ° C. The solvent was further evaporated and then 90 cm ^{3 of} an acetone-methanol mixture (10: 1) was added. The precipitated potassium bromide was filtered off and the solvent was evaporated. Then the residual solvent is removed by vacuum drying at 70 ° C. The reaction yield was 87%.

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

¹ H NMR (CDCl) δ ppm = 0.88 (s, 3H); 1.26 (m, 12H); 1.59 (m, 4H); 3.23 (s. 2H); 4.99 (s, 2H); 7.00 (m, 1H); 7.11 (m, 1H); 7.37 (m, 1H); 7.82 (m, 15H).

¹³ C NMR (CDCl 3) δ ppm = 14.69; 22.65; 22.86; 23.49; 25.81; 26.33; 29.15; 29.33; 30.22;

31.99; 70.95; 117.53; 118.48 [3C]; 121.78; 126.10; 128.12; 131.40; 131.51 [6C]; 133.66 [6C]; 136.88 [3C]; 157.14; 178.24.

³¹ P NMR (CDClB) δ ppm = 27.09

Elemental analysis of CHN for C36H41Cl2O3P (Mmoi = 623.59 g / mol): calculated values (%): C = 69.34; H = 6.63; P = 4.97; measured values: C = 69.61; H = 6.29; P = 4.69.

PL 235 893 Β1

Application example

Determination of biological activity against weeds

The ionic liquid containing the alkyltriphenylphosphonium cation and the MCPA or 2,4-D anion was dissolved in a mixture of water and ethanol (1: 1 v / v). As reference substances, a commercial herbicide containing MCPA or 2,4-D was used, which was applied at the same dose of active substance as the synthesized ionic liquids (400 g / ha).

Weed seeds were sown in pots filled with a commercial substrate and placed in a greenhouse in order to provide optimal conditions for plant growth (temperature 20 ± 2 ° C, air humidity 60%). After producing the cotyledons, a break was made, leaving 4 plants in each pot. The treatment was performed in the 4 plant leaves phase (BBCH 14) with a cabin sprayer equipped with TeeJet 110/02 nozzles. The sprayer traveled over the plants at a constant speed of 3.7 m / s. The distance of the sprayer from the tops of the plants was 40 cm, the liquid pressure in the sprayer was 0.2 MPa, and the liquid output per 1 ha was 200 dm ³ .

After the treatment, the pots with plants were placed back in the greenhouse at a temperature of 20 ± 2 ° C and an air humidity of 60%. The lighting time was 16 hours a day. After 2 weeks, the effectiveness of the test compounds was assessed. Their activity is presented as a percentage scale, where 0% means no effect of the agent, and 100% - complete destruction of the plants. The study was performed in 4 repetitions in a completely randomized design. Table 1 shows the results of herbicidal activity tests - the effectiveness of winter oilseed rape control after the application of phosphonium ionic liquids with MCPA and 2,4-D anion 2 weeks after the treatment.

Table 1

Object No. Object Efficiency [%] Winter oilseed rape 1 Triphenylhexylphosphonium (4-chloro-2-methylphenoxy) acetate 27.8 2 Triphenyloctylphosphonium (4-chloro-2-methylphenoxy) acetate 57.2 3 Decyltriphenylphosphonium (4-chloro-2-methylphenoxy) acetate 80.3 4 a commercial herbicide containing MCPA 4.3 S. Butyltriphenylphosphonium 2,4-dichlorophenoxy) acetate 21.5 6 2,4-dichlorophenoxy cyanide in the decane lotriphenylphosphate 41.7 7 a commercial herbicide containing 2,4-D 9.3

All tested ionic liquids showed a higher effectiveness of action on winter oilseed rape plants compared to commercial agents. The increase in their biological activity depended on the length of the aliphatic chain in the cation. The compound (4-chloro-2-methylphenoxy) decyltriphenylphosphonium acetate was characterized by the highest efficiency of action on winter oilseed rape plants.

Claims (5)

1. Phosphonium ionic liquids with an n-alkyltriphenylphosphane cation and an (4-chloro-2-methylphenoxy) acetate or (2,4-dichlorophenoxy) acetate anion, of the formula 2, where A is an anion (4-chloro-2-methylphenoxy) acetic acid (MCPA) of general formula 3 or (2,4-dichlorophenoxy) acetic (2,4-D) of general formula 4 and R is an alkyl chain of 4, 6, 8 or 10 carbon atoms. 2. A method for the preparation of phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and an (4-chloro-2-methylphenoxy) acetate or (2,4-dichlorophenoxy) acetate anion as defined in claim 1, characterized in that n-alkyltriphenylphosphonium bromide of the general formula 1, the potassium salt of (2,4-dichlorophenoxy) acetic acids or (4-chloro-2-methylphenoxy) acetic acids is added in a molar ratio of quaternary salt to phosphorus bromide of 1: 1, the reaction being carried out at a temperature of 25 to 60 ° C, preferably 30 ° C, in methanol, then the solvent is evaporated and acetone or acetone-methanol mixture (10: 1) is added, the precipitated by-product is filtered off, then the solvents are evaporated from the filtrate, the resulting product is dried at a temperature of 55 to 75 ° C, preferably 70 ° C. 3. Use of phosphonium ionic liquids with an n-alkyltriphenylphosphonium cation and an (4-chloro-2-methylphenoxy) acetate or (2,4-dichlorophenoxy) acetate anion as defined in Claim 1. 1 as herbicides. Use according to claim 3, characterized in that the phosphonium ionic liquids are used in their pure form. Use according to claim 3, characterized in that the phosphonium ionic liquids are used in the form of a water-ethanol solution with a concentration of at least 0.05%: