CN112479894A - Method for realizing N-alkylation by using alcohols as carbon source under photocatalysis - Google Patents

Method for realizing N-alkylation by using alcohols as carbon source under photocatalysis Download PDF

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CN112479894A
CN112479894A CN202011398950.6A CN202011398950A CN112479894A CN 112479894 A CN112479894 A CN 112479894A CN 202011398950 A CN202011398950 A CN 202011398950A CN 112479894 A CN112479894 A CN 112479894A
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丁玉强
江杰
杜立永
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Jiangnan University
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    • C07C209/00Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/04Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups
    • C07C209/14Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups by substitution of hydroxy groups or of etherified or esterified hydroxy groups
    • C07C209/16Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups by substitution of hydroxy groups or of etherified or esterified hydroxy groups with formation of amino groups bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings
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    • C07C213/08Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions not involving the formation of amino groups, hydroxy groups or etherified or esterified hydroxy groups
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Abstract

The invention discloses a method for realizing N-alkylation by using alcohols as a carbon source under photocatalysis, belonging to the technical field of catalytic synthesis. The method comprises the steps of placing alcohols, substrate raw materials and a catalyst in a reaction device, carrying out ultraviolet and/or visible light irradiation in an inert atmosphere, carrying out solid-liquid separation to remove the catalyst after the irradiation is finished, and carrying out extraction, distillation and purification to obtain an N-alkylated product, wherein the substrate raw materials comprise any one of amine compounds, aromatic nitro compounds or aromatic nitrile compounds, the alcohols comprise any one or more of soluble primary alcohols, and the catalyst is metal oxide/titanium dioxide or metal sulfide/titanium dioxide. The method is simple and easy to operate, can be used for high-efficiency photocatalytic one-pot multi-step hydrogenation N-alkylation reaction, and has the advantages of mild reaction conditions, high chemical selectivity of N-alkylamine, good catalyst stability and easy recycling.

Description

Method for realizing N-alkylation by using alcohols as carbon source under photocatalysis
Technical Field
The invention relates to a method for alkylating amines, in particular to a method for realizing N-alkylation by using alcohols as a carbon source under photocatalysis, belonging to the technical field of catalytic synthesis.
Background
N-methylamine is widely used as a drug, dye, detergent and synthetic intermediate. Thus, N-methylation of amines is an essential method for the synthesis of N-methylamines. The most reliable conventional method for N-methylation of amines with heteroaromatic functional groups is the Eschweiler-Clarke reaction, which, however, requires a thermal reaction with toxic formaldehyde in the presence of a reducing agent. Another important route to organic synthesis involves reacting N-containing reagents with alkylating agents such as methyl halide, dimethyl sulfate, dimethyl carbonate and dimethyl sulfoxide. However, these methylating agents (the actual alkylation) are themselves harmful to the environment and the production of stoichiometric amounts of inorganic salts during the reaction can also be harmful to the environment. In addition, the N-methylation of amines with carbon dioxide and molecular hydrogen requires high temperatures or pressures.
In recent years, Watanabe and Grigg have reported the use of alcohols for the N-alkylation of amines, and this type of process has received increasing attention due to the inherent high atom economy of the hydrogen self-transfer process and the use of water as the only by-product. Prior research has developed a variety of homogeneous catalysts, including ruthenium, iridium, silver, and palladium complexes, as well as some heterogeneous catalysts doped with noble Metal Nanoparticles (MNPs), for N-alkylation reactions. Homogeneous systems tend to be difficult to reuse and require the presence of a promoter, and in addition, most homogeneous systems require high temperatures or use of strong bases to carry out the reaction. At present, Wheatley et al established a Cu-Au hybrid photocatalytic system for rapid N-alkylation reactions, in which Au/TiO2Catalysts for CH3OH dehydrogenation, Cu/TiO2The catalyst is used for imine reduction. Li ZHaohui reports that Pd-Au @ MIL-100(Fe) catalyzes the N-alkylation reaction between an amine and an alcohol. The study by Shiraishi et al is also tabulatedIt is clear that the amount and particle size of Pd NPs has a large influence on the N-alkylation activity.
Photocatalytic N-alkylation may be an effective amine functionalization process for the development of green and sustainable synthetic processes, since the reaction is usually carried out at room temperature. The photocatalytic N-alkylation process follows a dehydrogenation-reduction reaction mechanism. However, the rate of dehydrogenation and reduction limits the overall N-alkylation reaction. By accelerating two rate limiting steps in the N-alkylation reaction. TiO because of its non-toxic, abundant, moderate cost and excellent optical properties2Has attracted considerable researchers' attention in photochemical applications such as water purification, solar energy storage and environmental purification. Research has found that the pioneering mechanism of photocatalytic N-alkylation reactions indicates that aniline is depleted in the initial stages of the reaction. In the reaction of aniline with formaldehyde, the concentration of N-methyleneaniline increases and then decreases gradually. Thus, the slow reduction step hinders the overall efficiency of the photocatalytic N-alkylation reaction. In the reduction step of the photocatalytic N-alkylation reaction, protons (H)+) Active hydrogens that react with electrons to form reduced imine intermediates. H in the reaction System+Formed from the dehydrogenation step and consumed in the reduction step.
Due to TiO2The use of photoelectrons is low, so that an auxiliary catalyst is needed to provide rapid separation of hole-electron pairs and drive the reduction point of the composite catalyst to be positioned on TiO2A surface. Because a series of non-noble metal oxides provide a narrow band gap and the levels of Conduction Band (CB) and Valence Band (VB) are higher than the corresponding TiO2The level of (c). Thus, when non-noble metal oxides and TiO2When forming type II heterojunction photocatalyst, the reduction site is located in TiO2A surface. Thus, in TiO2The formation of type II heterojunction photocatalysts with supported metal oxides may be a suitable strategy for N-alkylation reactions.
Disclosure of Invention
In order to solve the problems of toxicity, harm, high cost and low conversion rate in the existing N-alkylation process, the invention provides a method for realizing N-alkylation by using alcohols as a carbon source under photocatalysisMetals and oxides thereof and TiO2The II type heterojunction photocatalyst is formed, alcohol is used as an alkylating reagent and a carbon source, N-alkylation can be efficiently realized, and in addition, water or acid can be added into a reaction system to increase the hydrogen ion concentration of the system, so that the reaction rate is accelerated. The method is simple and economical, and can synthesize the amine alkylation product with high selectivity and high conversion rate.
Specifically, the invention provides a method for realizing N-alkylation by using alcohols as a carbon source under photocatalysis, which comprises the following steps:
(1) putting alcohols, substrate raw materials and a catalyst into a reaction device, and filling inert gas into the reaction device to replace air in the device;
(2) performing ultraviolet and/or visible light irradiation;
(3) after the illumination is finished, the catalyst is removed by solid-liquid separation, and an N-alkylation product can be obtained by extraction, distillation and purification;
wherein the substrate raw material comprises any one of an amine compound, an aromatic nitro compound or an aromatic nitrile compound.
In one embodiment of the invention, the alcohol comprises any one or more primary alcohols soluble in water.
In one embodiment of the present invention, the alcohol preferably includes one or more lower alcohols such as methanol, ethanol, propanol, butanol, etc.
In one embodiment of the present invention, the amount of the alcohol added is 10 to 2000 times the molar amount of the substrate raw material.
In one embodiment of the present invention, the amine-based starting material comprises any one of a primary or secondary aromatic amine or aliphatic amine.
In one embodiment of the present invention, the aromatic nitro compound comprises any one or more of nitrobenzene, 4-methylnitrobenzene, 4-methoxynitrobenzene, 4-chloronitrobenzene, 2-methylnitrobenzene, 2-methoxynitrobenzene and 4-chloronitrobenzene.
In one embodiment of the present invention, the aromatic nitrile compound includes any one or more of benzonitrile, 2-methylbenzonitrile, 4-methylbenzonitrile, 3-methoxybenzonitrile, and the like.
In one embodiment of the present invention, the catalyst is a metal oxide/titanium dioxide or a metal sulfide/titanium dioxide, and the metal oxide or metal sulfide is a substance capable of forming a type II semiconductor composite structure with titanium dioxide.
In one embodiment of the invention, the metal oxide or metal sulfide has a higher conduction band and a higher valence band than the titanium dioxide; the metal oxide or metal sulfide is preferably a metal oxide or metal sulfide capable of forming a p-n heterojunction with titania.
In one embodiment of the present invention, the metal oxide is preferably one or more of copper oxide, cuprous oxide, nickel oxide, cobaltosic oxide, ferric oxide, and zinc oxide; the metal sulfide is preferably cadmium sulfide.
In one embodiment of the present invention, the titanium dioxide is preferably anatase titanium dioxide, and preferably, the titanium dioxide has a particle size of 10nm to 100 μm.
In one embodiment of the present invention, the catalyst is preferably CuO/TiO2、Cu2O/TiO2、CdS/TiO2、NiO/TiO2、Co3O4/TiO2、Fe2O3/TiO2、ZnO/TiO2Preferably Cu2O/TiO2And NiO/TiO2
In an embodiment of the present invention, the preparation method of the catalyst may be any method of preparing the catalyst by an immersion method, a coprecipitation method, a hydrothermal method, a chemical vapor deposition method, or an atomic layer deposition method.
In one embodiment of the invention, Cu is used2O/TiO2For example, the hydrothermal preparation method comprises: dissolving 54mg of copper nitrate trihydrate in 100mL of deionized water, adding 1g of hydrous titanium dioxide, ultrasonically oscillating for 30 minutes, stirring for 2 hours, and adding 150mg of glucose at the temperature of 75 DEG CThen dropwise adding 20mL of aqueous solution containing 120mg of sodium hydroxide, reacting for 0.5h at 75 ℃, filtering, and drying under vacuum and reduced pressure to obtain the required catalyst Cu2O/TiO2
In one embodiment of the present invention, the loading amount of the metal oxide or the metal sulfide in the catalyst is 0.005 to 0.5, and preferably 0.01.
In one embodiment of the invention, the amount of the catalyst is 1 to 5g/L, based on the volume of the reaction solvent.
In one embodiment of the present invention, the above reaction is carried out under an inert atmosphere, and the inert gas comprises N2Or one or two of Ar gas.
In one embodiment of the present invention, in the step (2), the ultraviolet light and/or visible light is ultraviolet light, visible light or sunlight which can excite the corresponding catalyst.
In one embodiment of the present invention, in the step (2), the light irradiation time is 6 to 10 hours.
In one embodiment of the present invention, in the step (3), the solid-liquid separation is preferably filtration or centrifugal separation.
In one embodiment of the present invention, in step (3), unreacted alcohol is removed by evaporation.
In one embodiment of the present invention, in step (1), one or both of water and an acid is further added.
In one embodiment of the present invention, when a certain amount of water is added, the hydrogen ion concentration of the system is increased, and the reaction rate of the system is greatly increased.
In one embodiment of the invention, the water is added in an amount of 5% to 50%, preferably 18% of the solvent system.
In one embodiment of the invention, the acid is a soluble inorganic acid used to increase the reaction rate.
In one embodiment of the present invention, the soluble inorganic acid includes any one of hydrochloric acid, sulfuric acid, and nitric acid.
In one embodiment of the present invention, the concentration of the soluble inorganic acid is 0.000001 to 0.0001mol/L, and when the concentration is too high, the metal oxide material is eluted.
In one embodiment of the invention, the N-alkylation reaction may be carried out under liquid phase conditions or gas phase conditions or mixed liquid/gas phase conditions.
The second purpose of the invention is to provide the application of the preparation method in the fields of organic synthesis, medicines, dyes and detergents.
The method for realizing N-alkylation by using alcohols as carbon sources under the illumination condition has the following advantages:
(1) the invention uses non-noble metal oxide to load TiO2Compared with the prior art, the method technology for forming heterogeneous solid and realizing rapid N-alkylation omits the participation of noble metals, high-temperature preparation environment and the like, greatly reduces the cost, has mild reaction conditions, high selectivity and high conversion rate, widens the N-alkylation synthesis thought, and has great significance.
(2) The invention provides a method for realizing N-alkylation under aqueous phase acidic conditions, and external H is introduced+Can improve the reduction process in the N-alkylation reaction, greatly improve the reaction rate, and has high selectivity and high conversion rate, green conditions and economy.
(3) The method has wide applicability to various substrates, can be used for preparing N-alkylamine by one-pot multi-step hydrogenation and N-alkylation of aromatic nitro compounds or aromatic nitrile compounds through photocatalysis, and has four continuous steps of dehydrogenating alcohol into aldehyde, hydrogenating the aromatic nitro compounds or aromatic nitrile compounds into amine, condensing the aldehyde and the amine into imine, and hydrogenating the imine into the N-alkylamine. The preparation method of the catalyst is simple and easy to operate, can be used for high-efficiency photocatalytic one-pot multi-step hydrogenation N-alkylation reaction, has mild reaction conditions, high chemical selectivity of N-alkylamine, good catalyst stability and easy recycling, and is more beneficial to popularization and industrialization.
Detailed Description
Calculation formula of conversion rate and yield:
conversion ═ raw material peak area-residual raw material peak area/raw material peak area (under liquid phase conditions)
Yield-actual isolated product weight/theoretical product weight.
To further illustrate the present invention, the following examples are provided to describe the method of the present invention for performing N-alkylation using alcohols as carbon source under light conditions.
Example 1
With Cu2O/TiO2The method for realizing aniline alkylation by using methanol as a carbon source as a catalyst (the loading amount is 0.01) comprises the following steps:
a50 mL photoreaction flask equipped with a stirrer was charged with 40mL of a methanol/water (water: 18% of the total volume of the reaction solvent (methanol + water)) solution and Cu as a photocatalyst2O/TiO250mg, 5mg of HCl and 0.2mmol of the substrate aniline. Then, the photoreaction flask was placed in a 365nm ultraviolet light source and stirred for 6 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distilling and crystallizing to obtain the product.
The invention adopts the II type heterojunction photocatalyst, so that all the alkylation steps can be completed on the surface of the recombination catalyst under the illumination condition. The final N-alkylation product yield was determined to be 99%, with a primary N-alkylation yield of 0.9% and a secondary N-alkylation yield of 99.1%, the results are shown in Table 1.
The reaction formula of the invention is as follows:
Figure BDA0002811834080000051
table 1 shows the data of the results when N-alkylation was carried out according to the procedure of example 1 while changing the catalyst, changing the carbon source and the substrate.
TABLE 1 results of N-alkylation reactions with different catalysts, carbon sources and substrates
Figure BDA0002811834080000052
Figure BDA0002811834080000061
Example 2
NiO/TiO composite material2(the loading amount is 0.02) is used as a catalyst, and methanol is used as a carbon source to realize aniline alkylation, and the method comprises the following steps:
a50 mL photoreaction flask with a stirrer was charged with 40mL of a methanol/water (water accounting for 18% of the total solvent volume) solution and the photocatalyst NiO/TiO250mg, 5mg of HCl and 0.2mmol of aniline. Then, the photoreaction flask was placed in a 365nm ultraviolet light source and stirred for 6 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying, evaporating to obtain a crude product, distilling, and purifying to obtain the product. (yield of N-alkylated product 99%).
Example 3
With Cu2O/TiO2(the loading amount is 0.5) is used as a catalyst, and ethanol is used as a carbon source to realize aniline alkylation, and the method comprises the following steps:
a50 mL light reaction flask with stirrer was charged with 40mL of ethanol/water solution (water accounting for 18% of the total solvent volume), photocatalyst Cu2O/TiO250mg, 5mg of HCl and 0.2mmol of p-chloronitrobenzene. Then, the light reaction flask was placed in a 480nm light source and stirred for 6 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust pH to 1-2, and rotary evaporating to remove all ethanol. Residual reactionThe aqueous mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distillation and purification to obtain the product (yield of N-alkylated product 99%).
When p-chloronitrobenzene is replaced by any one of nitrobenzene, 4-methylnitrobenzene, 4-methoxynitrobenzene, 4-chloronitrobenzene, 2-methylnitrobenzene or 2-methoxynitrobenzene, the yield of the obtained N-alkylated product is more than 95 percent.
Example 4
With Cu2O/TiO2(the loading amount is 0.1) is used as a catalyst, and methanol is used as a carbon source to realize the method for alkylating the dodecylamine, which comprises the following steps:
a50 mL light reaction flask with stirrer was charged with 40mL of a methanol/water (water 18% of the total solvent volume) solution and the photocatalyst Cu2O/TiO250mg, 5mg of HCl and 0.2mmol of dodecylamine, and the photoreaction flask was then placed in a 365nm UV light source and stirred for 6 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distilling and purifying to obtain the product (the yield of the N-alkylation product is 99 percent)
Example 5
A50 mL light reaction bottle with a stirrer is filled with 40mL methanol/water solution and a photocatalyst Cu in different proportions2O/TiO2(loading 0.01)50mg and 0.2mmol of substrate aniline. Then, the light reaction flask was placed in a 480nm light source and stirred for 10 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distilling and carrying out column chromatography to obtain the product.
Figure BDA0002811834080000081
TABLE 2 results of N-alkylation reactions carried out at different water addition ratios
Figure BDA0002811834080000082
Example 6
CdS/TiO2(the loading amount is 0.2) is used as a catalyst, and methanol is used as a carbon source to realize aniline alkylation, and the method comprises the following steps:
a50 mL photoreaction flask with stirrer was charged with 40mL of methanol/water ((water 20% of the total system of the reaction) solution, photocatalyst CdS/TiO250mg, 4mg of HCl and 0.5mmol of benzonitrile. Then, the photoreaction flask was placed in a 450nm light source and stirred for 8 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distillation and purification to obtain the product (yield of N-alkylated product 98.3%).
When p-chloronitrobenzene is replaced by any one of 2-methylbenzonitrile, 4-methylbenzonitrile and 3-methoxybenzonitrile, the yield of the obtained N-alkylated product is more than 96 percent.
Example 7
With Co3O4/TiO2(the loading amount is 0.5) is used as a catalyst, and methanol is used as a carbon source to realize aniline alkylation, and the method comprises the following steps:
a50 mL photoreaction flask equipped with a stirrer was charged with 40mL of a methanol/water solution (water 10% of the total system of the reaction), and Co as a photocatalyst3O4/TiO250 mg. 10mg of HCl and 1mmol of nitrobenzene. Then, the photoreaction flask was placed in a 450nm light source and stirred for 10 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distillation and purification to obtain the product (yield of N-alkylated product 99.2%).
When p-chloronitrobenzene is replaced by any one of 4-methylnitrobenzene, 4-methoxynitrobenzene, 4-chloronitrobenzene, 2-methylnitrobenzene, 2-methoxynitrobenzene or 4-chloronitrobenzene, the yield of the obtained N-alkylated product is more than 95 percent.
Example 8
With Cu2O/TiO2The method for realizing aniline alkylation by using methanol as a carbon source as a catalyst (the loading amount is 0.01) comprises the following steps:
a50 mL photoreaction flask equipped with a stirrer was charged with 40mL of methanol and Cu as a photocatalyst2O/TiO250mg and 0.2mmol of the substrate aniline. Then, the photoreaction flask was placed in a 365nm ultraviolet light source and stirred for 10 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all methanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporating to obtain a crude product. Distilling and crystallizing to obtain the product.
The final N-alkylated product yield was determined to be 45.1%.
When the reaction time was extended to 20 hours, the final N-alkylated product yield was 86.3%.
Comparative example 1
With Cu2O/TiO2Using isopropanol as a catalyst (the loading amount is 0.01) to realize anilineA process for alkylation comprising the steps of:
a50 mL light reaction flask with stirrer was charged with 40mL isopropanol/water (water 18% of the total volume of the reaction solvent) solution and the photocatalyst Cu2O/TiO250mg, 5mg of HCl and 0.2mmol of the substrate aniline. Then, the photoreaction flask was placed in a 365nm ultraviolet light source and stirred for 6 hours.
Centrifuging the mixed solution system, adding excessive hydrochloric acid to adjust the pH value to 1-2, and performing rotary evaporation to remove all isopropanol. The remaining aqueous reaction mixture was adjusted to pH 8 using sodium carbonate solution and extracted with water and ethyl acetate (5 times 3mL each). The organic layer was washed with brine, washed with Na2SO4Drying and evaporation, the yield of N-alkylated product was finally found to be 0.
Comparative example 2
When the metal oxide chosen is not a metal oxide according to the invention, e.g. ZrO is chosen2The rest of the procedure was identical to that of example 1, the yield of product being only 13.2%.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. A method for realizing N-alkylation by using alcohols as carbon sources under photocatalysis is characterized by comprising the following steps:
(1) putting alcohols, substrate raw materials and a catalyst into a reaction device, and filling inert gas into the reaction device to replace air in the device;
(2) performing ultraviolet and/or visible light irradiation;
(3) after the illumination is finished, the catalyst is removed by solid-liquid separation, and an N-alkylation product can be obtained by extraction, distillation and purification;
the substrate raw material comprises any one of an amine compound, an aromatic nitro compound or an aromatic nitrile compound, the alcohol comprises any one or more of soluble primary alcohols, the catalyst is metal oxide/titanium dioxide or metal sulfide/titanium dioxide, and the metal oxide or metal sulfide is metal oxide or metal sulfide capable of forming a II-type semiconductor composite structure with titanium dioxide.
2. The method of claim 1, wherein the alcohol comprises one or more of methanol, ethanol, propanol, and butanol.
3. The process according to claim 1 or 2, characterized in that said amine-based raw material comprises any one of primary or secondary aromatic or aliphatic amines; the aromatic nitro compound comprises one or more of nitrobenzene, 4-methylnitrobenzene, 4-methoxynitrobenzene, 4-chloronitrobenzene, 2-methylnitrobenzene, 2-methoxynitrobenzene and 4-chloronitrobenzene; the aromatic nitrile compound comprises any one or more of benzonitrile, 2-methylbenzonitrile, 4-methylbenzonitrile and 3-methoxybenzonitrile. .
4. A method according to any one of claims 1 to 3, wherein the conduction band and the valence band of the metal oxide or metal sulfide are both higher than those of titanium dioxide.
5. The method according to any one of claims 1 to 4, wherein the metal oxide is one or more of copper oxide, cuprous oxide, nickel oxide, cobaltosic oxide, ferric oxide and zinc oxide; the metal sulfide is cadmium sulfide.
6. The method according to any one of claims 1 to 5, wherein the amount of the catalyst is 1 to 5 g/L.
7. The method according to any one of claims 1 to 6, wherein in the step (2), the light irradiation time is 6 to 10 hours.
8. The method according to any one of claims 1 to 7, wherein in step (1), one or both of water and an acid is further added.
9. The method of claim 8, wherein the water is added in an amount of 5% to 50% of the solvent system; the acid is soluble inorganic acid, including any one of hydrochloric acid, sulfuric acid and nitric acid.
10. Use of the method according to any one of claims 1 to 9 in the fields of organic synthesis, pharmaceuticals, dyes, detergents.
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