CN116102417A

CN116102417A - Method for preparing alcohol ether carboxylic acid by catalytic oxidation

Info

Publication number: CN116102417A
Application number: CN202111328665.1A
Authority: CN
Inventors: 李少林; 孙玺; 黄家辉
Original assignee: Guangzhou Miqi Chemical Co ltd
Current assignee: Guangzhou Miqi Chemical Co ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2023-05-12

Abstract

The invention relates to the technical field of organic synthesis, in particular to a method for preparing alcohol ether carboxylic acid by catalytic oxidation. According to the invention, the supported ruthenium catalyst is used together with organic cocatalysts such as 1, 10-phenanthroline and the like, so that alcohol ether is catalyzed and oxidized to prepare alcohol ether carboxylic acid, and oxygen-containing gas can be adopted as an oxidant, so that the use of low-selectivity, toxic and harmful oxidants such as hexavalent inorganic chromium reagents and the like is avoided, and the catalyst is more environment-friendly; the residue of toxic reagents in the alcohol ether carboxylic acid which has high viscosity and is easy to wrap the reaction raw materials is avoided, so that the prepared alcohol ether carboxylic acid is safer and milder, and the application scene of the alcohol ether carboxylic acid is effectively expanded; in addition, the oxidation reaction can be carried out under the condition of 50-130 ℃, the reaction condition is milder, the purity of the alcohol ether carboxylic acid product is improved, the energy consumption is lower, the production cost is effectively reduced, and the selectivity and the conversion rate are higher than those of the traditional method for preparing the alcohol ether carboxylic acid by catalytic oxidation under the milder reaction condition.

Description

Method for preparing alcohol ether carboxylic acid by catalytic oxidation

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a method for preparing alcohol ether carboxylic acid by catalytic oxidation.

Background

The sodium salt of alcohol ether carboxylic acid is a novel multifunctional anionic surfactant which is safe and nontoxic, and has good detergency, wettability, emulsifying property, dispersibility and calcium soap dispersing power. The general structural formula is as follows: r- (OCH) ₂ CH ₂ ) _n OCH ₂ COONa, very similar to soap, but with the built-in EO chain, it combines the characteristics of anionic and nonionic surfactants, can be used under a wide range of pH conditions, and has excellent solubilizing ability, suitable for formulation of functional transparent products.

At present, the method for industrially producing alcohol ether carboxylate is mainly a chloroacetic acid method, but because the viscosity of the alcohol ether carboxylic acid is higher, the chloroacetic acid in the alcohol ether carboxylic acid is difficult to clean, and the produced alcohol ether carboxylic acid has irritation to skin and is difficult to obtain wider application, so that the product quality is improved and the alcohol ether carboxylic acid is more widely applied if the catalytic oxidation method can be realized. Early, the preparation of alcohol ether carboxylic acid by catalytic oxidation requires reaction at high temperature (150-270 ℃), the reaction conditions are harsh, and a noble metal catalyst is needed; with the development of the field, the reaction temperature for preparing alcohol ether carboxylic acid is reduced, noble metal is still needed to be used as a catalyst, the catalyst dosage is high, and the cost is high; therefore, a series of supported catalysts are developed for preparing the alcohol ether carboxylic acid, but the supported catalysts have low catalytic efficiency, or the treatment process is not environment-friendly, or the reusability is poor, so that the preparation cost of the alcohol ether carboxylic acid is difficult to be really and effectively reduced, and the large-scale industrialized production is realized. In addition, in the traditional technology, hexavalent inorganic chromium is often used as an oxidant, so that the conversion rate is low, the selectivity is poor, and a large amount of toxic wastewater containing heavy metals can be generated after the reaction, so that the environmental pollution is caused.

Disclosure of Invention

Based on the above, it is necessary to provide a method for preparing alcohol ether carboxylic acid by catalytic oxidation, which has the advantages of mild reaction conditions, low cost, high catalytic efficiency, good reaction selectivity and no pollution.

In one aspect of the present invention, there is provided a process for preparing an alcohol ether carboxylic acid by catalytic oxidation comprising the steps of:

mixing alcohol ether, a supported ruthenium catalyst and an organic cocatalyst with a first solvent to prepare a first mixed solution; introducing oxidizing gas into the first mixed solution, and reacting at 50-130 ℃ to prepare the alcohol ether carboxylic acid;

wherein the organic cocatalyst is one or more of 1, 10-phenanthroline, urea, hexamethylenetetramine, tetramethyl ethylenediamine, ethylenediamine and dichloro naphthoquinone;

in the oxidizing gas, the volume percentage of oxygen is 5-100%, and the rest is filling gas, wherein the filling gas is nitrogen and/or inert gas.

In some embodiments, the method further comprises the step of heating the first mixed liquor to a temperature of 50 ℃ to 130 ℃ before introducing the oxidizing gas into the first mixed liquor.

In some embodiments, the alcohol ether has the following structure:

wherein R is a linear or branched alkyl group having 4 to 18 carbon atoms, and n is an integer ranging from 0 to 7.

In some embodiments, the method of preparing the supported ruthenium catalyst comprises the steps of:

mixing ruthenium chloride with a second solvent to prepare a second mixed solution; dropping the second mixed liquid on a carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure or vacuum environment, and drying at 40-100 ℃; placing the dried catalyst precursor in hydrogen or inert gas, and roasting at 280-450 ℃ to prepare the supported ruthenium catalyst;

wherein the carrier is one or more of silicon dioxide, activated carbon, aluminum oxide and molecular sieve, and the mass ratio of ruthenium element in ruthenium chloride to the carrier is 1 (2-12).

In some embodiments, the step of preparing the second mixed liquor further comprises: and sequentially adding a surfactant and a reducing agent into the mixed product of ruthenium chloride and the second solvent.

In some embodiments, the surfactant is one or more of polyvinylpyrrolidone, tetrabutylammonium bromide, tetraoctylammonium bromide, and tetraethylammonium bromide.

In some embodiments, the reducing agent is one or more of lithium aluminum hydride, sodium borohydride, potassium borohydride, and elemental iodine.

In some embodiments, the ratio of the amount of the ruthenium chloride to the amount of the surfactant in the second mixed solution is 1 (0.01 to 1).

In some embodiments, the ratio of the amount of ruthenium chloride to the amount of the reducing agent in the second mixed solution is 1 (0.5 to 7).

In some embodiments, the second solvent is one or more of water, diethyl ether, acetone, toluene, acetonitrile, methanol, ethanol, and dimethyl sulfoxide.

In some embodiments, the concentration of ruthenium chloride in the second mixed solution is 0.5g/mL to 1.8g/mL.

In some embodiments, the first solvent is one or more of 1, 4-dioxane, tetrahydrofuran, dichloroethane, chloroform, carbon tetrachloride, ethyl acetate, toluene, and xylene.

In some embodiments, the organic promoter is used in an amount of 0.1% to 3% of the total mass of the reaction mass, which is the alcohol ether, the supported ruthenium catalyst, and the organic promoter.

In some embodiments, the mass ratio of the supported ruthenium catalyst to the alcohol ether is 1 (20-800).

In some embodiments, the mass ratio of the first solvent to the alcohol ether is (0.2-3): 1.

In some embodiments, the reaction time is 12h to 36h.

In another aspect of the invention, there is also provided an alcohol ether carboxylic acid, prepared by the method described above.

The supported ruthenium catalyst is matched with organic cocatalysts such as 1, 10-phenanthroline, urea, hexamethylenetetramine, tetramethyl ethylenediamine, dichloro naphthoquinone and the like for use, alcohol ether is catalyzed and oxidized to prepare alcohol ether carboxylic acid, oxygen-containing gas can be used as an oxidant, and the use of low-selectivity, toxic and harmful oxidants such as hexavalent inorganic chromium reagents and the like is avoided, so that the catalyst is more environment-friendly; the residue of toxic reagents in the alcohol ether carboxylic acid which has high viscosity and is easy to wrap the reaction raw materials is avoided, so that the prepared alcohol ether carboxylic acid is safer and milder, and the application scene of the alcohol ether carboxylic acid is effectively expanded; in addition, the oxidation reaction can be carried out under the condition of 50-130 ℃, compared with the traditional reaction temperature of 150-270 ℃, the reaction condition is milder, the purity of the alcohol ether carboxylic acid product is improved, the occurrence of side reaction is avoided, meanwhile, the energy consumption is lower, the production cost is effectively reduced, and in addition, under the milder reaction condition, the selectivity and the conversion rate are higher than those of the traditional method for preparing the alcohol ether carboxylic acid by catalytic oxidation.

Detailed Description

In order that the invention may be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments that are illustrated in the appended drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. In the description of the present invention, the meaning of "several" means at least one, such as one, two, etc., unless specifically defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" and/or "as used herein includes any and all combinations of one or more of the associated listed items.

In the invention, the technical characteristics described in an open mode comprise a closed technical scheme composed of the listed characteristics and also comprise an open technical scheme comprising the listed characteristics.

In the present invention, the numerical ranges are referred to as continuous, and include the minimum and maximum values of the ranges, and each value between the minimum and maximum values, unless otherwise specified. Further, when a range refers to an integer, each integer between the minimum and maximum values of the range is included. Further, when multiple range description features or characteristics are provided, the ranges may be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to include any and all subranges subsumed therein.

The temperature parameter in the present invention is not particularly limited, and may be a constant temperature treatment or a treatment within a predetermined temperature range. The constant temperature process allows the temperature to fluctuate within the accuracy of the instrument control.

The "inert gas" in the present invention refers to a rare gas such as helium (He), neon (Ne), argon (Ar), krypton (Kr) or xenon (Xe).

mixing alcohol ether, a supported ruthenium catalyst and an organic cocatalyst with a first solvent to prepare a first mixed solution; introducing oxidizing gas into the first mixed solution, and reacting at 50-130 ℃ to prepare alcohol ether carboxylic acid;

The oxidability of the zinc oxide gas can be regulated and controlled by controlling the content of oxygen in the oxidability gas, so that the zinc oxide gas can be better used for the oxidation of alcohol ethers with different structures. Alternatively, the volume percentage of oxygen may be, for example, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%.

Alternatively, the reaction temperature may be, for example, 60 ℃, 70 ℃,80 ℃,90 ℃,100 ℃, 110 ℃, 120 ℃.

In some embodiments, the method further comprises the step of heating the first mixed liquor to a temperature of 50 ℃ to 130 ℃ before introducing the oxidizing gas into the first mixed liquor. Before the oxidizing gas is introduced, the system is heated to the reaction temperature, so that other reactants can be better oxidized, and the reaction efficiency is improved.

In some embodiments, the alcohol ether has the following structure:

Alternatively, the number of carbon atoms of R may be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18.

Alternatively, n is 0, 1, 2, 3, 4, 5, 6 or 7.

In some embodiments, the method of preparing a supported ruthenium catalyst comprises the steps of:

mixing ruthenium chloride with a second solvent to prepare a second mixed solution; adding the second mixed liquid drop to the carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure or vacuum environment, and drying at 40-100 ℃; placing the dried catalyst precursor in hydrogen or inert gas, and roasting at 280-450 ℃ to prepare a supported ruthenium catalyst;

wherein the carrier is one or more of silicon dioxide, activated carbon, aluminum oxide and molecular sieve, and the mass ratio of ruthenium element in ruthenium chloride to the carrier is 1 (2-12). Alternatively, the molecular sieve may be, for example, molecular sieve MCM-41, molecular sieve silicalite-1, or the like. Alternatively, the mass ratio of ruthenium element in ruthenium chloride to carrier may be, for example, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11.

Preferably, when the carrier is silicon dioxide, the organic cocatalyst is 1, 10-phenanthroline.

In some embodiments, the vacuum environment has a vacuum level of-0.05 MPa to-0.1 MPa.

In some embodiments, the hydrogen or inert gas is at a pressure of 0.1MPa to 1MPa. Alternatively, the gas pressure of the hydrogen gas or the inert gas may be, for example, 0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa.

Alternatively, the drying temperature may be, for example, 50 ℃,60 ℃, 70 ℃,80 ℃,90 ℃. The proper drying temperature can effectively remove the water vapor in the catalyst precursor, and meanwhile, the water vapor is not volatilized too quickly, so that the structure of the catalyst precursor is influenced, and the catalytic efficiency of the catalyst is reduced.

Alternatively, the firing temperature may be, for example, 260 ℃, 270 ℃,280 ℃, 290 ℃,300 ℃, 310 ℃,320 ℃, 330 ℃, 340 ℃,350 ℃, 360 ℃, 370 ℃,380 ℃, 390 ℃,400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃,450 ℃, 460 ℃, 470 ℃, 480 ℃, 490 ℃. The proper roasting temperature can enable the catalyst to have better stability, so that the catalyst has higher catalytic efficiency, selectivity and recovery rate. Particularly, when the surfactant is introduced in the preparation process, the surfactant can volatilize in the roasting process, and the proper roasting temperature ensures that the surfactant is removed, and meanwhile, pores are not formed at an excessively high volatilization speed, so that the performance of the catalyst is not affected.

In some embodiments, the drying time is from 12 hours to 48 hours. Alternatively, the drying time may be, for example, 24 hours, 36 hours.

In some embodiments, the firing time is 2 to 5 hours. Alternatively, the roasting time can be, for example, 2.5h, 3h, 3.5h, 4h, 4.5h.

In some embodiments, the step of preparing the second mixed liquor further comprises: and sequentially adding a surfactant and a reducing agent into the mixed product of ruthenium chloride and the second solvent. The surfactant and the reducer are added into the system, so that the stability of the catalyst can be improved, and the loss of active metals caused by carrier collapse can be avoided.

In some embodiments, the system is stirred for 10 to 48 hours after the surfactant and the reducing agent are added thereto. Alternatively, the stirring time may be, for example, 15h, 20h, 25h, 30h, 35h, 40h, 45h.

In some embodiments, the concentration of ruthenium chloride in the second mixed solution is from 0.5g/mL to 1.8g/mL. The proper concentration can lead the metal distribution in the prepared catalyst to be more uniform, thereby having higher catalytic activity. Alternatively, the concentration of ruthenium chloride may be, for example, 0.6g/mL, 0.7g/mL, 0.8g/mL, 0.9g/mL, 1.0g/mL, 1.1g/mL, 1.2g/mL, 1.3g/mL, 1.4g/mL, 1.5g/mL, 1.6g/mL, 1.7g/mL.

In some embodiments, the surfactant is one or more of polyvinylpyrrolidone, tetrabutylammonium bromide, tetraoctylammonium bromide, tetraethylammonium bromide.

In some embodiments, the reducing agent is one or more of lithium aluminum hydride, sodium borohydride, potassium borohydride, elemental iodine.

In some embodiments, the ratio of the amount of ruthenium chloride to the amount of surfactant material in the second mixture is 1 (0.01 to 1). Optionally, the ratio of the amounts of ruthenium chloride to the surfactant is 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9.

In some embodiments, the ratio of the amount of ruthenium chloride to the amount of reducing agent in the second mixture is 1:0.5-7).

In some embodiments, the organic promoter is used in an amount of 0.1% to 3% of the total mass of the reaction mass, which refers to the alcohol ether, the supported ruthenium catalyst, and the organic promoter. The organic cocatalyst can act with the generated alcohol ether carboxylic acid to help the alcohol ether carboxylic acid to be desorbed from the surface of the supported ruthenium catalyst, so that the conversion rate of reaction raw materials is improved, and the stability of the catalyst is improved, therefore, the use amount of the organic cocatalyst directly influences the reaction. Alternatively, the organic promoter is used in an amount of 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9% of the total mass of the reaction mass.

In some embodiments, the mass ratio of supported ruthenium catalyst to alcohol ether is 1 (20-800). Alternatively, the mass ratio of supported ruthenium catalyst to alcohol ether may be, for example, 1 (30-220), and may also be, for example, 1:50, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750.

In some embodiments, the mass ratio of the first solvent to the alcohol ether is (0.2-3): 1. Alternatively, the mass ratio of the first solvent to the alcohol ether may be, for example, 0.5:1, 0.8:1, 1.1:1, 1.4:1, 1.7:1, 2:1, 2.3:1, 2.6:1, 2.9:1.

In some embodiments, the reaction time is from 12 hours to 36 hours. Alternatively, the reaction time may be, for example, 16h, 20h, 24h, 28h, 32h.

In some embodiments, the post-treatment step after the end of the reaction comprises: and (3) after the reaction system is cooled to room temperature, filtering to remove solid matters, extracting and washing filtrate, and then removing organic solvent in the system.

In some embodiments, the solvent employed for extraction is one or more of 1, 4-dioxane, ethyl acetate, diethyl ether, chloroform, dichloroethane, and bromopropane.

In some embodiments, the solution employed for washing is one or more of dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid, and dilute sodium hydroxide solution.

In some embodiments, the organic solvent is removed from the system by distillation at atmospheric or reduced pressure, at a temperature of 20 ℃ to 70 ℃.

In another aspect of the invention, there is also provided an alcohol ether carboxylic acid, prepared by the method described above. Because alcohol ether carboxylic acid has higher viscosity, if chloroacetic acid method is adopted for preparation or hexavalent inorganic chromium is adopted as oxidant, corrosive or toxic and harmful chemical reagents are easy to remain in the product, which can greatly limit the application of alcohol ether carboxylic acid. The preparation method of the invention does not involve heavy metal oxidant, the preparation process is environment-friendly, and the used catalyst is easy to separate from the reaction system and reuse, so the prepared alcohol ether carboxylic acid has higher purity and wider use prospect.

The present invention will be described in further detail with reference to specific examples and comparative examples. The experimental parameters not specified in the following specific examples are preferentially referred to the guidelines given in the application document, and may also be referred to the experimental manuals in the art or other experimental methods known in the art, or to the experimental conditions recommended by the manufacturer. It is understood that the instruments and materials used in the following examples are more specific and in other embodiments may not be so limited.

Example 1

1.42g of ruthenium chloride (6.8 mmol) was weighed and dissolved in 20.0mL of acetone to prepare a ruthenium precursor solution; dropwise adding a ruthenium precursor solution onto 3.0g of a silica carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure environment, and drying at 40 ℃; placing the dried catalyst precursor in inert gas of 0.1MPa, and roasting at 280 ℃ to prepare a supported ruthenium catalyst;

mixing 10g of C12-C18 alcohol and alcohol ether obtained by polymerizing 6 ethylene oxides (purchased from optimization chemistry, the same applies below), 0.1g of the supported ruthenium catalyst, 0.1g of 1, 10-phenanthroline and 20g of 1, 4-dioxane to prepare a mixed solution; heating the mixed solution to 100 ℃, introducing air of 0.1MPa into the mixed solution, and reacting for 18h at 100 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, extraction was performed with chloroform, and the organic phase was washed with a dilute sulfuric acid detergent, followed by distillation under reduced pressure at 70 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 2

1.06g of ruthenium chloride (5.1 mmol) was weighed and dissolved in 20.0mL of water, and then 0.62g of polyvinylpyrrolidone surfactant (0.062 mmol) having an average molar mass of 10000 and 0.50g of lithium aluminum hydride reducing agent (13.2 mmol) were added to prepare a ruthenium precursor solution; dropwise adding a ruthenium precursor solution onto 3.0g of an alumina carrier to prepare a catalyst precursor; placing the catalyst precursor in a vacuum environment of-0.1 MPa, and drying at 80 ℃; placing the dried catalyst precursor in inert gas of 0.1MPa, and roasting at 350 ℃ to prepare a supported ruthenium catalyst;

mixing 8g of lauryl alcohol and alcohol ether obtained by polymerizing 5 ethylene oxide, 0.05g of the supported ruthenium catalyst, 0.05g of tetramethyl ethylenediamine and 8g of dichloroethane to prepare a mixed solution; heating the mixed solution to 80 ℃, introducing 0.1MPa of oxygen-nitrogen mixed gas containing 30% of oxygen concentration into the mixed solution, and reacting for 24 hours at 80 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, extraction was performed with ethyl acetate, and the organic phase was washed with a dilute hydrochloric acid detergent, followed by distillation under reduced pressure at 50 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 3

0.96g of ruthenium chloride (4.6 mmol) was weighed and dissolved in 20.0mL of toluene to prepare a ruthenium precursor solution; dropwise adding the ruthenium precursor solution onto 3.0g of a molecular sieve MCM-41 carrier to prepare a catalyst precursor; placing the catalyst precursor in a vacuum environment of-0.05 MPa, and drying at 60 ℃; placing the dried catalyst precursor in hydrogen with the pressure of 0.2MPa, and roasting at the temperature of 300 ℃ to prepare a supported ruthenium catalyst;

mixing alcohol ether obtained by polymerizing 10g of octanol and 9 ethylene oxides, 0.03g of the supported ruthenium catalyst, 0.03g of urea and 6g of carbon tetrachloride to prepare a mixed solution; heating the mixed solution to 120 ℃, introducing 0.1MPa of oxygen-nitrogen mixed gas containing 70% of oxygen concentration into the mixed solution, and reacting for 26 hours at 120 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, the filtrate was extracted with bromopropane, and the organic phase was washed with a dilute nitric acid detergent, followed by distillation under reduced pressure at 50 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 4

1.17g of ruthenium chloride (5.6 mmol) was weighed and dissolved in 20.0mL of dimethyl sulfoxide, and then 1.23g of tetrabutylammonium bromide surfactant (3.8 mol) and 0.96g of elemental iodine reducing agent (3.8 mmol) were added to prepare a ruthenium precursor solution; dropwise adding the ruthenium precursor solution onto 3.0g of active carbon carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure environment, and drying at 100 ℃; placing the dried catalyst precursor in inert gas of 0.1MPa, and roasting at 400 ℃ to prepare a supported ruthenium catalyst;

mixing 30g of stearyl alcohol and alcohol ether obtained by polymerizing 7 ethylene oxide, 0.10g of the supported ruthenium catalyst, 0.83g of tetramethyl ethylenediamine and 15g of carbon tetrachloride to prepare a mixed solution; heating the mixed solution to 110 ℃, introducing air of 0.1MPa into the mixed solution, and reacting for 24 hours at 110 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, extraction was performed with diethyl ether, and the organic phase was washed with a dilute sodium hydroxide detergent, followed by distillation under reduced pressure at 30 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 5

1.62g of ruthenium chloride (7.8 mmol) was weighed and dissolved in 20.0mL of methanol, and then 2.06g of tetraethylammonium bromide surfactant (6.4 mmol) and 1.87g of sodium borohydride reducing agent (49.4 mmol) were added to prepare a ruthenium precursor solution; dropwise adding the ruthenium precursor solution onto 3.0g of a molecular sieve silicalite-1 carrier to prepare a catalyst precursor; placing the catalyst precursor in a vacuum environment of-0.1 MPa, and drying at 90 ℃; placing the dried catalyst precursor in hydrogen with the pressure of 0.1MPa, and roasting at the temperature of 450 ℃ to prepare a supported ruthenium catalyst;

mixing 50g of lauryl alcohol and alcohol ether obtained by polymerizing 6 ethylene oxide, 0.20g of the supported ruthenium catalyst, 1.3g of hexamethylenetetramine and 33.3g of toluene to prepare a mixed solution; heating the mixed solution to 90 ℃, introducing oxygen and nitrogen mixed gas with the oxygen concentration of 50% at 0.1MPa into the mixed solution, and reacting for 24 hours at 90 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, extraction was performed with dichloroethane, and the organic phase was washed with a dilute hydrochloric acid detergent, followed by distillation under reduced pressure at 60 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 6

0.59g of ruthenium chloride (2.8 mmol) was weighed and dissolved in 20.0mL of diethyl ether to prepare a ruthenium precursor solution; dropwise adding the ruthenium precursor solution onto 3.0g of active carbon carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure environment, and drying at 100 ℃; placing the dried catalyst precursor in inert gas of 0.1MPa, and roasting at 450 ℃ to prepare a supported ruthenium catalyst;

mixing alcohol ether obtained by polymerizing 25g of lauryl alcohol and 10 ethylene oxides, 0.17g of the supported ruthenium catalyst, 0.3g of dichloro naphthoquinone and 20.8g of xylene to prepare a mixed solution; heating the mixed solution to 130 ℃, introducing 0.1MPa of mixed gas of oxygen and nitrogen with the oxygen concentration of 50%, and reacting for 24 hours at 120 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, the organic phase was washed with 1, 4-dioxane, and then distilled under reduced pressure at 50℃to remove the organic solvent, thereby obtaining an alcohol ether carboxylic acid product.

Example 7

1.38g of ruthenium chloride (6.7 mmol) was weighed and dissolved in 20.0mL of ethanol, and then 0.99g of tetraoctylammonium bromide surfactant (1.8 mmol) and 1.03g of potassium borohydride reducing agent (19.1 mmol) were added to prepare a ruthenium precursor solution; dropwise adding a ruthenium precursor solution onto 3.0g of a silica carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure environment, and drying at 50 ℃; placing the dried catalyst precursor in hydrogen with the pressure of 0.1MPa, and roasting at 380 ℃ to prepare a supported ruthenium catalyst;

mixing 100g of octyl alcohol and alcohol ether obtained by polymerizing 3 ethylene oxide, 0.50g of the supported ruthenium catalyst, 2.6g of 1, 10-phenanthroline and 80g of ethyl acetate to prepare a mixed solution; heating the mixed solution to 120 ℃, introducing air of 0.1MPa into the mixed solution, and reacting for 36h at 120 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, the filtrate was extracted with bromopropane, and the organic phase was washed with a dilute sodium hydroxide detergent, followed by distillation under reduced pressure at 70 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 8

0.86g of ruthenium chloride (4.1 mmol) was weighed and dissolved in 20.0mL of dimethyl sulfoxide to prepare a ruthenium precursor solution; dropwise adding a ruthenium precursor solution onto 3.0g of an alumina carrier to prepare a catalyst precursor; placing the catalyst precursor in a vacuum environment of-0.1 MPa, and drying at 40 ℃; placing the dried catalyst precursor in hydrogen with the pressure of 0.1MPa, and roasting at 400 ℃ to prepare a supported ruthenium catalyst;

mixing 12g of stearyl alcohol and alcohol ether obtained by polymerizing 9 ethylene oxide, 0.03g of the supported ruthenium catalyst, 0.06g of ethylenediamine and 24g of tetrahydrofuran to prepare a mixed solution; heating the mixed solution to 100 ℃, introducing air of 0.1MPa into the mixed solution, and reacting for 32h at the temperature of 100 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, extraction was performed with dichloroethane, and the organic phase was washed with a dilute nitric acid detergent, followed by distillation under reduced pressure at 60 ℃ to remove the organic solvent, to obtain an alcohol ether carboxylic acid product.

Example 9

1.73g of ruthenium chloride (8.3 mmol) was weighed and dissolved in 20.0mL of acetonitrile to prepare a ruthenium precursor solution; dropwise adding the ruthenium precursor solution onto 3.0g of a molecular sieve silicalite-1 carrier to prepare a catalyst precursor; placing the catalyst precursor in a normal pressure environment, and drying at 50 ℃; placing the dried catalyst precursor in inert gas of 0.1MPa, and roasting at 320 ℃ to prepare a supported ruthenium catalyst;

mixing 150g of octanol and alcohol ether obtained by polymerizing 7 ethylene oxide, 0.75g of the supported ruthenium catalyst, 2.8g of dichloro naphthoquinone and 93.8g of chloroform to prepare a mixed solution; heating the mixed solution to 120 ℃, introducing air of 0.1MPa into the mixed solution, and reacting for 28 hours at 120 ℃; after the reaction solution was cooled to room temperature, solid matters were removed by filtration, the filtrate was retained, the organic phase was washed with 1, 4-dioxane, and then distilled under reduced pressure at 60℃to remove the organic solvent, thereby obtaining an alcohol ether carboxylic acid product.

Example 10

Substantially the same as in example 7 was conducted except that the ruthenium precursor solution was prepared without adding a surfactant and a reducing agent.

Example 11

Substantially the same as in example 7, except that the organic cocatalyst was dichloro naphthoquinone.

Example 12

Substantially the same as in example 6, except that 68g of alcohol ether was added to polymerize lauryl alcohol and 10 ethylene oxides, and 0.83g of dichloro naphthoquinone was added (the mass ratio of the supported ruthenium catalyst to the alcohol ether, 1:400, and the co-catalyst ratio remained unchanged).

Comparative example 1

Substantially the same as in example 7, except that 1, 10-phenanthroline was not added to the mixed solution.

Comparative example 2

Substantially the same as in example 7, except that 1, 10-phenanthroline is replaced with an equivalent amount of lysine.

Comparative example 3

Substantially the same as in example 7, except that the amount of 1, 10-phenanthroline used was 5.29g (5% of the reaction mass).

Comparative example 4

Substantially the same as in example 7, except that the amount of the silica carrier used was 1.02g (ruthenium element to carrier mass ratio: 1:1.5).

The conversion of the alcohol ether feedstock in each of the example and comparative reactions was calculated to investigate the catalytic efficiency; the alcohol ether carboxylic acid ratio in the oxidation product was calculated to examine the reaction selectivity, and the results are shown in Table 1:

TABLE 1

Group of	Catalyst	Organic cocatalysts	Conversion/%	Selectivity/%
					Example 1	Ru/SiO ₂	1, 10-phenanthroline	92	97
Example 2	Ru/Al ₂ O ₃	Tetramethyl ethylenediamine	88	99
					Example 3	Ru/MCM-41	Urea	86	99
Example 4	Ru/C	Tetramethyl ethylenediamine	68	96
					Example 5	Ru/silicalite-1	Hexamethylene tetramine	90	99
Example 6	Ru/C	Dichloro naphthoquinone	78	86
					Example 7	Ru/SiO ₂	1, 10-phenanthroline	92	99
Example 8	Ru/Al ₂ O ₃	Ethylenediamine	86	95
					Example 9	Ru/silicalite-1	Dichloro naphthoquinone	68	90
Example 10	Ru/SiO ₂	1, 10-phenanthroline	90	96
					Example 11	Ru/SiO ₂	Dichloro naphthoquinone	85	96
Example 12	Ru/C	Dichloro naphthoquinone	71	93
					Comparative example 1	Ru/SiO ₂	-	62	90
Comparative example 2	Ru/SiO ₂	Lysine	58	83
					Comparative example 3	Ru/SiO ₂	1, 10-phenanthroline	88	90
Comparative example 4	Ru/SiO ₂	1, 10-phenanthroline	93	88

As can be seen from Table 1, the examples herein allow for the preparation of alcohol ether carboxylic acids with high conversion and high selectivity. Compared with example 7, the ruthenium precursor solution was prepared in example 10 without the addition of surfactants and reducing agents, and the stability of the catalyst was inferior to that of example 7, so that the reaction conversion and selectivity were slightly reduced, but still maintained at a higher level; in the embodiment 11, the organic cocatalyst is replaced by the dichloro naphthoquinone, and the matching property of the dichloro naphthoquinone and the silica carrier is not as good as that of 1, 10-phenanthroline, so that the conversion rate and the selectivity are not as good as those of the embodiment 7; in example 12, the alcohol ether was used in a higher amount to effectively improve the reaction selectivity, but the conversion efficiency was somewhat lowered.

The comparative example 1 does not use an organic cocatalyst, so that the reaction conversion rate is seriously reduced, and the selectivity is obviously reduced; in the comparative example 2, lysine is adopted to replace 1, 10-phenanthroline, the matching degree with a carrier is very poor, and the reaction system is interfered to a certain extent, so that the conversion rate and the selectivity are even lower than those of the comparative example 1; the use level of the organic cocatalyst in the comparative example 3 is higher, and the conversion rate and the selectivity are obviously reduced; the amount of the carrier in comparative example 4 is low, and the catalyst with a certain mass is loaded with more metal elements, so that the reaction conversion rate can be slightly improved, but the selectivity is obviously reduced.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. The scope of the invention is, therefore, indicated by the appended claims, and the description may be intended to interpret the contents of the claims.

Claims

1. A method for preparing alcohol ether carboxylic acid by catalytic oxidation, which is characterized by comprising the following steps:

wherein the organic cocatalyst is one or more of 1, 10-phenanthroline, urea, hexamethylenetetramine, tetramethyl ethylenediamine, ethylenediamine and dichloro naphthoquinone.

2. The method according to claim 1, wherein the volume percentage of oxygen in the oxidizing gas is 5-100%, and the rest is filling gas, and the filling gas is nitrogen and/or inert gas; and/or

The method further comprises the step of heating the first mixed solution to 50-130 ℃ before introducing the oxidizing gas into the first mixed solution.

3. The method of claim 1, wherein the alcohol ether has the structure:

4. The method according to claim 1, wherein the preparation method of the supported ruthenium catalyst comprises the steps of:

5. The method of claim 4, wherein the step of preparing the second mixed liquor further comprises: and sequentially adding a surfactant and a reducing agent into the mixed product of ruthenium chloride and the second solvent.

6. The method of claim 5, wherein the surfactant is one or more of polyvinylpyrrolidone, tetrabutylammonium bromide, tetraoctylammonium bromide, and tetraethylammonium bromide; and/or

The reducing agent is one or more of lithium aluminum hydride, sodium borohydride, potassium borohydride and elemental iodine; and/or

In the second mixed solution, the ratio of the amount of the ruthenium chloride to the amount of the substance of the surfactant is 1 (0.01-1); and/or

In the second mixed solution, the ratio of the amount of the ruthenium chloride to the amount of the reducing agent is 1 (0.5-7).

7. The method according to any one of claims 4 to 6, wherein the second solvent is one or more of water, diethyl ether, acetone, toluene, acetonitrile, methanol, ethanol, and dimethyl sulfoxide; and/or

In the second mixed solution, the concentration of ruthenium chloride is 0.5 g/mL-1.8 g/mL.

8. The method according to any one of claims 1 to 6, wherein the first solvent is one or more of 1, 4-dioxane, tetrahydrofuran, dichloroethane, chloroform, carbon tetrachloride, ethyl acetate, toluene and xylene; and/or

The dosage of the organic cocatalyst is 0.1% -3% of the total mass of the reaction materials, wherein the reaction materials refer to the alcohol ether, the supported ruthenium catalyst and the organic cocatalyst.

9. The method according to any one of claims 1 to 6, wherein the mass ratio of the supported ruthenium catalyst to the alcohol ether is 1 (20 to 800); and/or

The mass ratio of the first solvent to the alcohol ether is (0.2-3) 1; and/or

The reaction time is 12-36 h.

10. An alcohol ether carboxylic acid prepared by the process of any one of claims 1 to 9.