Process for the photocatalytic oxidation amination for the preparation of amides having more than 11 carbon atoms

Abstract

The present application relates to the technical field of amide preparation, and discloses a method for preparing amides with more than 11 carbon atoms by photocatalytic oxidation and amination. The method comprises the following steps: under the action of a photocatalyst and an additive, a nitrogen source and an alkane or a derivative thereof are reacted in a solvent under light irradiation, and after post-treatment, a cyclic amide or a chain amide is obtained; wherein the photocatalyst comprises a photoactive carbazole compound; the additive comprises an acidic substance and an alkaline substance; and the alkane is selected from one or more of substituted or unsubstituted cyclic alkanes with more than 11 carbon atoms and substituted or unsubstituted chain alkanes with more than 11 carbon atoms. In the method, the alkane or the derivative thereof with more than 11 carbon atoms on the ring is directly broken and rearranged to synthesize a lactam and a chain amide by catalysis of the photocatalyst, the reaction condition of the method is mild, and the generation of tar and coke when a high-pressure mercury lamp and a ultraviolet lamp are used is avoided.

Description

Technical Field

[0001] This invention relates to the field of amide preparation technology, specifically to a method for preparing amides with more than 11 carbon atoms by photocatalytic oxidation ammoniation. Background Technology

[0002] Amides are one of the most important structural units in organic and biochemistry, with wide applications in medicine, pesticides, and materials. Amides include chain amides and lactams. Lactams are important polymerizing monomers, especially aziridine-2-one. Lactam polymerization produces polyamides, which are mainly used in synthetic fibers. Their most prominent advantage is their superior abrasion resistance compared to all other fibers—10 times more abrasion resistant than cotton and 20 times more resistant than wool. Adding a small amount of polyamide fiber to blended fabrics can significantly improve their abrasion resistance; when stretched to 3-6%, their elastic recovery rate can reach 100%; they can withstand tens of thousands of flexes without breaking.

[0003] Macrocyclic lactam polymers, such as Nylon 12, possess advantages such as low water absorption, low density, friction resistance, low wear, fuel resistance, and good weather resistance, exhibiting excellent overall performance. They are primarily used in automotive manufacturing, 3D printing, oil and gas extraction, electronics, and medical technology. They are particularly widely used in automotive fluid delivery lines, including fuel lines, clutch lines, vacuum brake booster lines, air brake lines, battery coolant lines, and the connectors for these lines. Due to their safety and reliability, they are excellent lightweight materials for automobiles.

[0004] Nylon 12 is typically produced using butadiene as a raw material, with processes including oxidative oxime oxidation, photonitrosation, and the Sonia process, among which oxidative oxime oxidation is the mainstream method. The oxidative oxime oxidation process for producing Nylon 12 involves seven steps: trimerization, catalytic hydrogenation, oxidation, ketation, oxime oxidation, Beckmann rearrangement, and ring-opening polymerization. The entire process requires the use of highly toxic and corrosive raw materials such as benzene and fuming sulfuric acid, and the ring-opening polymerization temperature needs to be 270–300°C, making the production process difficult to control.

[0005] Currently, most monomers of nylon 12 are prepared using the cyclododecanone-hydroxylamine method. The two key steps of the cyclododecanone-hydroxylamine method are oxime reaction (synthesis of cyclododecanone oxime from cyclododecanone) and Beckmann rearrangement (synthesis of azacyclotridecane-2-one from cyclododecanone oxime). In 2012, J. Ritz et al. mentioned in Ullmann's Encyclopedia of Industrial Chemistry, in their article "Caprolactam," that cyclohexane can be oxidized to cyclohexanone, followed by oxime reaction and Beckmann rearrangement to obtain the target product, caprolactam. The crucial steps are the latter two: oxime reaction (synthesis of ketoxime from cyclododecanone) and Beckmann rearrangement (synthesis of azacyclotridecane-2-one from ketoxime). The key technology in the photonitrosation method of cyclododecanone is the synthesis of cyclododecanone oxime, and the subsequent amidation is still achieved using the Beckmann rearrangement.

[0006] The conversion of nitrosamine dimers, which inevitably occur during photonitrosation, presents a challenge, affecting the yield of cyclododecanone oximes and subsequent rearrangements. Furthermore, the photonitrosation step is particularly expensive, as the mercury or sodium lamps used are fragile and have short lifespans. They also require substantial and therefore expensive cooling and power supplies (given their high power consumption). Moreover, the nitrosation reagents (mainly nitrosyl chlorides and trichloronitromethane-containing chlorinated reagents) produce 5%-10% chlorinated derivatives, forming chlorooxime hydrochlorides, which reduce the rearrangement yield in the subsequent Beckmann rearrangement. The presence of hydrochloric acid in the reaction necessitates particularly expensive safety materials and equipment, and the use of easily decomposable nitrosyl chlorides makes scale-up difficult, resulting in a very low market share. Finally, the reaction generates a large amount of tar as a byproduct, leading to low product conversion rates. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of expensive raw materials, complicated preparation steps, and harsh reaction conditions in the existing technology, and to provide a method for preparing amides with more than 11 carbon atoms by photocatalytic oxidation and amination. The method of this invention has low raw material prices, simple steps, easy operation, mild reaction conditions, and high yield.

[0008] To achieve the above objectives, the present invention provides a method for photocatalytic oxidative ammoniation to prepare amides with more than 11 carbon atoms. The method comprises: reacting a nitrogen source with an alkane or its derivative in a solvent under light irradiation and in the presence of a photocatalyst and additives, followed by post-treatment to obtain a cyclic amide or a chain amide; wherein the photocatalyst comprises a photoactive carbazole compound; the additives comprise acidic and basic substances; and the alkane is selected from one or more of substituted or unsubstituted cycloalkanes with more than 11 carbon atoms and substituted or unsubstituted chain alkanes with more than 11 carbon atoms.

[0009] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0010] The method provided by this invention uses a photocatalyst to directly break and rearrange the C-C bonds of alkanes or their derivatives with more than 11 carbon atoms to synthesize amides. This method uses inexpensive raw materials, is simple to operate, is easy to operate, has mild reaction conditions, and has a high yield. Detailed Implementation

[0011] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0012] This invention provides a method for photocatalytic oxidative ammoniation to prepare amides with more than 11 carbon atoms. The method includes: reacting a nitrogen source with an alkane or its derivative in a solvent under light irradiation and in the presence of a photocatalyst and additives, followed by post-treatment to obtain a cyclic amide or a chain amide; wherein the photocatalyst includes a photoactive carbazole compound; the additives include acidic and basic substances; and the alkane is selected from one or more of substituted or unsubstituted cycloalkanes with more than 11 carbon atoms and substituted or unsubstituted chain alkanes with more than 11 carbon atoms.

[0013] According to the present invention, amides with more than 11 carbon atoms include lactams with more than 11 carbon atoms and chain amides with more than 11 carbon atoms.

[0014] The method of this invention uses a photocatalyst to directly break and rearrange the C-C bonds of alkanes or their derivatives with more than 11 carbon atoms on the ring to synthesize lactams and chain amides. The method has mild reaction conditions, avoids the formation of tar and coke when using high-pressure mercury lamps and ultraviolet lamps, has high reaction efficiency, is simple to operate, and can obtain lactams and chain amides from alkanes in high yield within 1 hour.

[0015] In this invention, the additive can promote the transfer of hydrogen in the reaction and promote the formation of amide.

[0016] In some embodiments of the present invention, the photoactive carbazole compound is selected from one or more compounds with the structure shown in Formula II;

[0017]

[0018] In Equation II, R 1 and R 2Ar 1 One or more substituents; R 1 and R 2 Each of the following groups can be independently represented as hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 alkyl or C 3-12 cycloalkyl; R 3 It is hydrogen, tert-butoxycarbonyl, p-toluenesulfonyl, methanesulfonyl, silyl, aryl, heteroaryl, C 1-12 alkyl or C 3-12 cycloalkyl;

[0019] R4, R5, R6, and R7 are each independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthraceneyl, phenanthryl, ester, cyano, or C. 1-12 Alkyl groups; wherein, R 4 -R 7 Adjacent groups can be independently or linked by chemical bonds to form five- or six-membered aromatic or heteroaromatic rings; dashed lines represent those that can form bonds or those that cannot. Ar 1 and Ar 2 Each is an aromatic ring or a 5-6 member heterocyclic aromatic ring.

[0020] In some embodiments of the present invention, the photoactive carbazole compound is selected from one or more compounds with structures shown in formulas IIA-IIG;

[0021]

[0022] Among them, R 1 and R 2 Ar 1 One or more substituents; R 1 and R 2 Each of the following groups can be independently represented as hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 alkyl or C 3-12 cycloalkyl; R 3 It is hydrogen, tert-butoxycarbonyl, p-toluenesulfonyl, methanesulfonyl, silyl, aryl, heteroaryl, C 1-12 alkyl or C 3-12 cycloalkyl; Ar 1 Ar 2 and Ar 3 Each ring can be independently composed of naphthalene, anthracene, phenanthrene, or heteroaromatic rings.

[0023] In formula IIA, R 4 Ar 3 One or more substituents; R5 Ar 2 One or more substituents; R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups;

[0024] In Equation IIB, R 4 R represents one or more substituents in the benzene ring. 5 Ar 2 One or more substituents; R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups;

[0025] In formula IIC, R 4 and R 5 Ar 2 One or more substituents; R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 5 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 6 and R 7 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups;

[0026] In formula IID, R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl group; R 6 and R 7 Ar 2 One or more substituents; R 6 It can be hydrogen, trihalomethyl, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 7 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthrene, cyano, or C. 1-12Alkyl groups;

[0027] In formula IIE, R 4 and R 5 Ar 2 One or more substituents; R 6 and R 7 Ar 3 One or more substituents; R 4 R 5 R 6 and R 7 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl group; R 8 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl groups;

[0028] In formula IIF, R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, ester, cyano, or C. 1-12 Alkyl group; R 5 and R 6 Ar 2 One or more substituents; R 7 and R 8 Ar 3 One or more substituents; R 5 R 6 R 7 and R 8 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups;

[0029] In formula IIG, R 4 and R 5 Ar 2 One or more substituents; R 6 and R 7 Ar 3 One or more substituents; R 8 and R 9 Ar 4 One or more substituents; R 4 R 5 R 6 R 7 R 8 and R 9Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups.

[0030] In this invention, heteroaromatic rings include, but are not limited to: pyridine, thiophene, furan, pyrrole, indole, quinoline, pyrazine, thiazole, pyrimidine, or triazole.

[0031] In some embodiments of the present invention, the photocatalyst is a compound with the structure shown in Formula IIA and / or a compound with the structure shown in Formula IIB.

[0032] In some preferred embodiments of the present invention, in formula IIA, R 1 Hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, C 1-12 Acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 2 It can be hydrogen, trihalomethyl, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 3 It can be hydrogen, Boc, Ts, Ms, silyl, aryl, heteroaryl, or C. 1-12 alkyl or C 3-10 cycloalkyl; R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 5 It can be hydrogen, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, cyano, or C. 1-12 Alkyl groups.

[0033] In some preferred embodiments of the present invention, in formula IIB, R 1 It is a dialkylamine, alkoxy, or C 1-12 Alkyl group; R 2 For hydrogen, C 1-10 alkyl, phenyl, naphthyl, anthraceneyl, or phenanthrene; R 3 It is hydrogen, tert-butoxycarbonyl, silyl, aryl, heteroaryl, or C 1-10 alkyl, R 4 It can be an ester group, cyano group, formyl group, acetyl group, trihalomethyl group, or halogen; R 5 It is phenyl, naphthyl, anthracene or C 1-12 Alkyl groups; Ar 1 and Ar 2 Each ring is independently a naphthalene ring, anthracene ring, or phenanthrene ring; Ar 3It is selected from indole, quinoline, pyrazine, thiazole, pyrimidine, or triazole.

[0034] In this invention, the photocatalyst includes, but is not limited to, one or more compounds with structures shown in Formulas II-1 to II-24:

[0035]

[0036]

[0037] In some embodiments of the present invention, the alkaline substance is selected from one or more organic bases and inorganic bases.

[0038] In some preferred embodiments of the present invention, the inorganic base is selected from one or more of ammonia, carboxylates, carbonates, bicarbonates and hydroxides.

[0039] In some preferred embodiments of the present invention, the inorganic base is selected from one or more of ammonia, lithium formate, lithium acetate, lithium propionate, sodium formate, sodium acetate, sodium propionate, potassium formate, potassium acetate, potassium propionate, cesium formate, cesium acetate, cesium propionate, sodium carbonate, sodium bicarbonate, cesium carbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, and ammonium hydroxide.

[0040] In some preferred embodiments of the present invention, the organic base is selected from one or more organic amines and organic salts; wherein the organic salt is obtained by reacting an alcohol with an alkali metal or an alkaline earth metal.

[0041] In some preferred embodiments of the present invention, the organic amine is selected from one or more of aliphatic amines, alcoholic amines, alicyclic amines, aromatic amines, naphthyl amines, and hydroxylamines.

[0042] In some preferred embodiments of the present invention, the alcohol is selected from one or more of methanol, ethanol, n-butanol, isopropanol, tert-butanol, n-pentanol, isopentanol, and hexanol.

[0043] In some preferred embodiments of the present invention, the alkali metal is selected from one or more of lithium, sodium, potassium, cesium, and francium.

[0044] In some preferred embodiments of the present invention, the alkaline earth metal is selected from one or more of magnesium, calcium, and barium.

[0045] In some embodiments of the present invention, the aliphatic amines are selected from one or more of the primary, secondary and tertiary amines of C1 to C18.

[0046] In some preferred embodiments of the present invention, the aliphatic amines are selected from one or more of methylamine, propylamine, butylamine, dimethylamine, diethylamine, diisopropylamine, diisopropylethyl, diisobutylamine, trimethylamine, triethylamine, tributylamine, triisopropylamine, triethylenediamine (which may also be named 1,4-diazabicyclo[2.2.2]octane or abbreviated as DABCO), 1,8-diazabicyclo[5.4.0]undec-7-ene (or abbreviated as DBU), tetrabutylamine, tetramethylguanidine, and tert-butylamine.

[0047] In some embodiments of the present invention, the acidic substance is selected from at least one of acidified substances or acidified substitutes.

[0048] In some preferred embodiments of the present invention, the acid is selected from Lewis acids and / or Brønsted acids.

[0049] In some preferred embodiments of the present invention, the Lewis acid is selected from one or more of boron trifluoride, aluminum trichloride, aluminum tribromide, and ferric chloride.

[0050] In some preferred embodiments of the present invention, the Brønsted acid is selected from one or more of sulfuric acid, hydrochloric acid, acetic acid, formic acid, propionic acid, benzoic acid, substituted sulfonic acid, and trichloroacetic acid.

[0051] In some preferred embodiments of the present invention, the substituted sulfonic acid is selected from aminosulfonic acid or p-toluenesulfonic acid.

[0052] In some preferred embodiments of the present invention, the acidification substitute is selected from one or more of formyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, cyanuric chloride, trifluoromethanesulfonyl chloride, p-toluenesulfonyl chloride, formyl bromide, acetyl bromide, propionyl bromide, butyryl bromide, cyanuric bromide, trifluoromethanesulfonyl bromide, p-toluenesulfonyl bromide, and elemental iodine.

[0053] In this invention, the additive can promote the transfer of hydrogen in the reaction and promote the formation of amide.

[0054] In some embodiments of the present invention, the alkane or its derivative has the structure shown in Formula I, wherein Formula I contains at least one methylene group;

[0055]

[0056] Formula I contains at least one methylene group; R a and R b Same or different; R a H, halogen, nitro, C 11-99 alkyl, C 11-99 alkoxy, acyl, or cyano groups; R b To replace or not be replaced by C 11-99 Alkyl; Ra and R b Cyclic or non-cyclic formation is optional;

[0057] R a and R b Each can form an independent ring, or, R a and R b They are linked together in a ring by chemical bonds.

[0058] In some embodiments of the present invention, the cycloalkane is selected from one or more of cyclododecane (mp 60°C), cyclotridecane (mp 25°C), cyclotetradecane (mp 55°C), cyclopentadecanane, cyclohexadecane (mp 65°C), cycloheptadecane, cyclooctadecane, cyclononadecanane, and cycloeicosane.

[0059] In some embodiments of the present invention, the chain alkane is selected from one or more of n-dodecane, n-tridecane, n-tetradecane, n-pentadecanane, n-hexadecane, n-heptadecane, n-octadecane, and n-nonadecanane.

[0060] In some embodiments of the present invention, the nitrogen source is selected from one or more of alkyl nitrites, aryl nitrites, and alternatives to nitrites.

[0061] Preferably, the alkyl nitrite is selected from one or more esters formed from nitrite and alcohol; more preferably, it is selected from C... 1-20 The esters formed by the reaction of n-alcohols with nitrous acid and C 1-20 The ester is selected from one or more of the isomeric alcohols and nitrous acid forming esters. More preferably, the alkyl nitrite is selected from one or more of methyl nitrite, ethyl nitrite, propyl nitrite, isopropyl nitrite, isobutyl nitrite, tert-butyl nitrite, amyl nitrite, isoamyl nitrite, neopentyl nitrite, 2-methoxyethyl nitrite, and 1-methoxypropyl-2-yl nitrite.

[0062] Preferably, the aryl nitrite is selected from one or more esters formed by nitrite and phenol or substituted phenol, for example, phenolic nitrite;

[0063] Preferably, the nitrite substitute is selected from one or more of the following products: (1) products generated by the reaction of NO, O2 with alcohols and / or phenols; (2) products generated by the reaction of NO2, NO with alcohols or phenols; (3) products generated by the reaction of NaNO2 with alcohols and / or phenols; more preferably, the alcohol has the structure C 1-20 The alcohol; the phenol is phenol or one or more phenols with one or more of the ortho, meta, and para positions of the aromatic ring.

[0064] The method of the present invention can use nitrite or its substitute as a nitrogen source to catalyze the direct cleavage and rearrangement of the C-C bonds of alkanes or their derivatives to synthesize lactams or chain amides under photocatalysis.

[0065] In some embodiments of the present invention, the solvent is selected from one or more of acetonitrile, benzonitrile, dichloroethane, tetrachloroethane, N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, NMP, acetone, and toluene.

[0066] In some embodiments of the present invention, the molar ratio of the nitrogen source to the alkane or its derivative is 1:1-200, preferably 1:10-40.

[0067] In some embodiments of the present invention, the molar ratio of the photocatalyst to the nitrogen source is 1:20-200, preferably 1:20-100.

[0068] In some embodiments of the present invention, the molar ratio of the photocatalyst to the acidic substance is 1:10-100, preferably 1:10-40.

[0069] In some embodiments of the present invention, the molar ratio of the photocatalyst to the alkaline substance is 1:20-100, preferably 1:20-80.

[0070] In some embodiments of the present invention, the molar ratio of acidic substances to alkaline substances in the additive is 1:2-50, preferably 1:2-10.

[0071] In some embodiments of the present invention, the molar ratio of the nitrogen source to the solvent is 1:1-200, preferably 1:2-100.

[0072] In some embodiments of the present invention, the light is light that can be obtained from any light source.

[0073] Preferably, the light is visible light with a wavelength of 390-760 nm, more preferably 400-500 nm. Particularly preferred is 400-450 nm.

[0074] In this invention, visible light is more preferably violet to blue light with a wavelength of 400-450nm.

[0075] In some embodiments of the present invention, the reaction is carried out in a flow reactor or a batch reactor.

[0076] The reaction provided by this invention, in which the C-C bonds of alkanes or their derivatives with more than 11 carbon atoms are directly broken and rearranged by a photocatalyst to synthesize lactams or chain amides, can be carried out in a batch reactor or a flow reactor. Carrying it in a flow reactor can significantly shorten the reaction time and easily achieve the scale-up of the reaction.

[0077] In some embodiments, the method includes: S1A, adding alkane or its derivatives, solvent, nitrogen source, photocatalyst and additives to a flow reactor under visible light irradiation at a temperature of 50-250°C, and reacting for 0.1-24 h;

[0078] In other embodiments, the method includes: S1B, adding alkane or its derivatives, solvent, nitrogen source, photocatalyst and additives to a batch reactor under visible light irradiation at a temperature of 50-250°C, and reacting for 0.1-24 h.

[0079] In some embodiments of the present invention, in a flow reactor, the method further includes:

[0080] S2. Filter the reaction solution obtained in step S1A to remove solid waste.

[0081] S3. Recrystallize the filtrate obtained in step S2 to collect the product;

[0082] S4. Continue to pump the recrystallized liquid from step S3 into the flow reactor, and repeat steps S1A, S2, S3, and S4 until the raw material alkane reacts completely to obtain the amide product.

[0083] S5. The filtrate from step S4 is concentrated and separated to obtain the amide product, and the photocatalyst is recovered at the same time.

[0084] In some embodiments of the present invention, in a batch reactor, the method further includes:

[0085] S2. Filter the reaction solution obtained in step S1B to remove solid waste.

[0086] S3. Distill the filtrate obtained in step S2 to recover the solvent, and then recrystallize it according to the different solubilities to recover the unreacted alkanes;

[0087] S4. Recrystallize the filtrate from step S3 to obtain the amide product;

[0088] S5. The filtrate from step S4 is concentrated and separated to obtain the amide product, and the photocatalyst is recovered at the same time.

[0089] This invention enables the reaction from alkanes with more than 11 carbon atoms to lactams or chain structures at low temperatures. The method uses nitrites or their substitutes (mixtures of nitric oxide, oxygen, and alcohols or phenols; mixtures of nitric oxide, nitrogen dioxide, and alcohols or phenols; or mixtures of sodium nitrite and alcohols or phenols) as the nitrogen source. Under the action of a photocatalyst and additives, the C-C bonds in alkanes are directly broken and rearranged to synthesize amides. The reaction avoids the use of nitrosating agents (mainly nitrosyl chloride, trichloronitromethane-containing chlorinated reagents), preventing the formation of chlorinated derivatives that would subsequently form chlorooxime hydrochlorides, which would reduce the rearrangement yield in the subsequent Beckmann rearrangement.

[0090] This invention allows the reaction to occur under visible light irradiation, employing an LED light source in the 400-600nm visible light range. This significantly improves heat dissipation and energy consumption, avoiding tar problems (caused by insufficient heat dissipation and excessive byproducts) during the reaction. This invention utilizes a photocatalyst to directly synthesize amides from alkanes in a one-pot, one-step process, avoiding the formation of ketoxime dimers in existing methods. This results in high reaction efficiency and significantly shortened reaction time. This invention eliminates the need for excessive tert-butanol or its derivatives, using solvents such as acetonitrile and dichloromethane. This ensures the sustainable use of raw materials and addresses the competition from alcohols during subsequent rearrangement. The use of a flow reactor further shortens the reaction time and improves reaction efficiency and yield.

[0091] In this invention, the photocatalyst, solvent, and alkanes, among other raw materials, can all be recovered and reused. Under laboratory-scale conditions, the raw materials and amide products are obtained separately by cooling and crystallizing at different temperatures due to their varying solubilities. In industrial production, the amide product is obtained through cooling crystallization, and the remaining raw materials and photocatalyst can be recycled in a flow reactor until the reaction is complete. Finally, most of the amide product is obtained through recrystallization, and the photocatalyst is then reused. The photocatalyst recovery rate is high, reaching over 99%.

[0092] The method of this invention uses inexpensive raw materials, is simple and easy to operate, operates under mild reaction conditions, and yields high results, making it a green synthesis method. Furthermore, the photocatalyst can be recovered and reused with a yield of >99% after the reaction.

[0093] The reaction of this invention can be scaled up with minimal impact on yield and reaction time, enabling large-scale preparation of lactams and chain forms.

[0094] One embodiment of the present invention provides a method for preparing lactams and chain-like substances by photocatalytic oxidation ammoniation, which specifically includes the following steps:

[0095] (1) A mixture of nitrite or its substitutes, alkanes or their derivatives, solvents, photocatalysts and additives is reacted in a flow reactor under LED illumination;

[0096] (2) Filter the reaction solution obtained in step (1) to remove solid waste;

[0097] (3) Recrystallize the filtrate obtained in step (2) to collect the product;

[0098] (4) The recrystallized liquid from step (3) is pumped back into the flow reactor;

[0099] (5) Repeat steps (1), (2), (3), and (4) above until the raw material alkane reacts completely; filter the reaction solution to remove solid waste;

[0100] (6) The filtrate from step (5) is concentrated and separated to obtain the amide product, and the photocatalyst is recovered by recrystallization.

[0101] The photocatalyst of this invention has excellent catalytic effect and high amide yield.

[0102] The method of this invention, carried out under the action of a photocatalyst and additives, achieves excellent results without the need for tert-butanol as a co-solvent. In contrast, tert-butanol is essential in existing technologies, participating in the reaction and stabilizing the generated nitric oxide radicals. Through in-depth research, the inventors of this invention have discovered that the method can proceed well without the addition of tert-butanol. Furthermore, omitting tert-butanol avoids the following drawbacks: the addition of large amounts of tert-butanol significantly impacts subsequent rearrangement (competing with the reactive intermediates), necessitating subsequent removal processes; and the reaction time is extremely long, indicating low efficiency, which is difficult to implement in industrial applications.

[0103] The reaction in this invention uses acetonitrile, dichloromethane, etc. as solvents, and the solvents can be removed by filtration and concentration in the later stages.

[0104] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited to the following description.

[0105] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents and instruments used without a specified manufacturer are all commercially available products.

[0106] Example 1

[0107] Synthesis of azacyclic tridecane-2-one:

[0108] 0.1 mol of isopropyl nitrite was pumped into a flow reactor at a constant rate over one hour. The compound with the structure shown in Formula II-1, DABCO (molar ratio 1:10), cyclododecane, DMF, and acetic acid were mixed and pumped into the flow reactor simultaneously at specific molar ratios (isopropyl nitrite:compound with the structure shown in Formula II-1 = 1:0.02; isopropyl nitrite:cyclododecane:DMF = 1:10:100; isopropyl nitrite:acetic acid = 1:0.1). The reaction was carried out under 50W LED illumination at 70°C for 0.4 h. After the reaction was complete, the reaction solution was acidified, filtered to remove solid waste, and then the filtrate was distilled to recover the solvent. The remaining filtrate was cooled and crystallized according to its solubility to obtain the final amide product. The recrystallized liquid was further recrystallized to recover the raw materials and the photocatalyst, the compound with the structure shown in Formula II-1. Finally, the target product, azacyclotridecane-2-one, was obtained with a yield of 88% and a weight of 17.4 g. The photocatalyst was recovered in a yield of more than 99%.

[0109] by nuclear magnetic resonance hydrogen spectrum ( 1 H NMR) and carbon nuclear magnetic resonance (NMR) 13 Chemical shift and coupling splitting by C NMR confirmed that the compound was aza-tridecane-2-one.

[0110] 1 H NMR(400MHz,Chloroform-d)δ5.50(s,1H),3.30(td,J=7.1,6.0,4.4Hz,2H), 2.23-2.16(m,2H),1.71-1.64(m,2H),1.56-1.48(m,2H),1.42-1.26(m,14H). 13 C NMR (101MHz, Chloroform-d) δ173.4,39.1,37.0,28.3,26.8,26.4,26.2,25.7,25.2,24.9,24.7,23.9.

[0111] Example 2

[0112] Synthesis of azacyclic tridecane-2-one:

[0113] Nitric oxide (0.1 mol), oxygen (0.05 mol), and isopropanol (0.1 mol) were rapidly pumped into a flow reactor. The compound with the structure shown in Formula II-1, DABCO (molar ratio 1:10), cyclododecane, DMF, and acetic acid were mixed at specific molar ratios (nitrogen source: compound with the structure shown in Formula II-1 = 1:0.02; nitrite: cyclododecane: DMF = 1:10:100; nitrite: acetic acid = 10:1). This mixture was simultaneously pumped into the flow reactor and reacted for 1 hour under 50W LED illumination at 20°C. After the reaction was complete, the reaction solution was acidified, filtered to remove solid waste, and then the filtrate was distilled to recover the solvent. The remaining filtrate was cooled and crystallized according to its solubility to obtain the final amide product. The recrystallized liquid was further recrystallized to recover the raw materials and the photocatalyst compound with the structure shown in Formula II-1. Finally, the target product, azahexacyclic tridecane-2-one, was obtained. The yield was 97%, 19.1 g. The photocatalyst was recovered in a yield greater than 99%. This was confirmed by proton nuclear magnetic resonance spectroscopy (NMR). 1 HNMR and carbon nuclear magnetic resonance (NMR) 13 Chemical shift and coupling splitting by C NMR confirmed that the compound was aza-tridecane-2-one.

[0114] 1 H NMR(400MHz,Chloroform-d)δ5.50(s,1H),3.30(td,J=7.1,6.0,4.4Hz,2H), 2.23-2.16(m,2H),1.71-1.64(m,2H),1.56-1.48(m,2H),1.42-1.26(m,14H). 13 C NMR (101MHz, Chloroform-d) δ173.4,39.1,37.0,28.3,26.8,26.4,26.2,25.7,25.2,24.9,24.7,23.9.

[0115] Example 3

[0116] Synthesis of azacyclic tridecane-2-one:

[0117] Nitric oxide (0.1 mol), nitrogen dioxide (0.1 mol), and isopropanol (0.2 mol) were rapidly pumped into a flow reactor. The compound with the structure shown in Formula II-1, DABCO (molar ratio 1:10), cyclododecane, and acetic acid were mixed at a specific molar ratio (nitrogen source: compound with the structure shown in Formula II-1 = 1:0.02; nitrite: cyclododecane: DMF = 1:10:100; nitrite: acetic acid = 10:1) and simultaneously pumped into the flow reactor. The reaction was carried out under 50W LED illumination at 30°C for 0.5 h. After the reaction was complete, the reaction solution was acidified, filtered to remove solid waste, and then the filtrate was distilled to recover the solvent. The remaining filtrate was cooled and crystallized according to its solubility to obtain the final amide product. The recrystallized liquid was further recrystallized to recover the raw materials and the photocatalyst compound with the structure shown in Formula II-1. Finally, the target product, azahexacyclic tridecane-2-one, was obtained with a yield of 82% and a weight of 16.1 g. The photocatalyst was recovered in a yield of more than 99%.

[0118] Example 4

[0119] Synthesis of azacyclic tridecane-2-one:

[0120] Sodium nitrite (0.1 mol) and isopropanol (0.1 mol) were rapidly pumped into a flow reactor. The compound with the structure shown in Formula II-1, DABCO (molar ratio 1:10), cyclododecane, and acetic acid were mixed at a specific molar ratio (nitrogen source: compound with the structure shown in Formula II-1 = 1:0.02; nitrite ester: cyclododecane: DMF = 1:10:100; nitrite ester: acetic acid = 10:1). This mixture was simultaneously pumped into the flow reactor and reacted at 50°C for 0.75 h under 50W LED illumination. After the reaction was complete, the reaction solution was acidified, filtered to remove solid waste, and then the filtrate was distilled to recover the solvent. The remaining filtrate was cooled and crystallized according to its solubility to obtain the final amide product. The recrystallized liquid was further recrystallized to recover the raw materials and the photocatalyst compound with the structure shown in Formula II-1. Finally, the target product, azahexacyclotetrazane-2-one, was obtained in a yield of 80%, 15.8 g. The photocatalyst was recovered in a yield of more than 99%.

[0121] Example 5

[0122] Synthesis of azacyclic tetradecane-2-one:

[0123] 0.1 mol of tert-butyl nitrite was reacted and post-treated according to the procedures and post-treatment steps in Example 1, wherein the molar ratios of various compounds were: tert-butyl nitrite: the photocatalyst compound with the structure shown in Formula II-9 = 1:0.02, the compound with the structure shown in Formula II-9: K2CO3 = 1:20; tert-butyl nitrite: cyclotridecane: DMF = 1:5:10; tert-butyl nitrite: acetic acid = 5:1; the pumping time was 1.5 h, and the reaction was carried out under 100 W LEDs illumination at 100 °C for 0.1 h; finally, the target product, azacyclotetradecane-2-one, was obtained in a yield of 87%, 18.3 g. The photocatalyst was recovered in a yield greater than 99%.

[0124] by nuclear magnetic resonance hydrogen spectrum ( 1 H NMR) and carbon nuclear magnetic resonance (NMR) 13 Chemical shift and coupling splitting by C NMR confirmed that the compound was azacyclic tetradecane-2-one.

[0125] 1 H NMR (400MHz, CDCl3):=5.57(br s,1H),3.36-3.26(m,2H),2.25-2.15(m,2H),1.76-1.61(m,2H),1.54-1.44(m,2H),1.43-1.20(m,16H). 13 C NMR (101MHz, CDCl3):=173.10,38.46,36.27,28.31,26.49,25.79,25.71,25.63,25.41,25.26,23.95,23.70,23.13.

[0126] Example 6

[0127] Synthesis of N-decylacetamide:

[0128] Ethyl nitrite (0.1 mol) was pumped into a flow reactor at a constant rate over one hour. The compound with the structure shown in Formula II-1, DABCO (molar ratio 1:20), n-dodecane, DMF, and acetic acid were mixed and pumped into the flow reactor simultaneously at specific molar ratios (isopropyl nitrite:compound with the structure shown in Formula II-1 = 1:0.02; isopropyl nitrite:n-dodecane:DMF = 1:20:100; isopropyl nitrite:acetic acid = 20:1). The reaction was carried out under 100W LED illumination at 90°C for 2 hours. After the reaction was completed, the reaction solution was acidified, filtered to remove solid waste, and then the filtrate was distilled to recover the solvent. The remaining filtrate was cooled and crystallized according to its solubility to obtain the final amide product. The recrystallized liquid was further recrystallized to recover the raw materials and the photocatalyst compound with the structure shown in Formula II-1. Finally, the target product N-decylacetamide was obtained with a yield of 80%, 15.9 g. The photocatalyst was recovered with a yield greater than 99%.

[0129] by nuclear magnetic resonance hydrogen spectrum ( 1 H NMR) and carbon nuclear magnetic resonance (NMR) 13 Chemical shift and coupling splitting by C NMR confirmed that the compound was N-decylacetamide.

[0130] 1 H NMR (400MHz, CDCl3): δ = 5.83 (brs, 1H), 3.19 (qapp, J = 7.2Hz, 2H), 1.94 (s, 3H), 1.45 (m, 2H), 1.35-1.12 (m, 14H), 0.84 (t, J = 6.8Hz, 3H). 13 CNMR (101MHz, CDCl3): δ = 170.2, 39.8, 32.0, 29.7 (2C), 29.6, 29.4, 29.3, 27.0, 23.3, 22.7, 14.2.

[0131] Example 7

[0132] The azahexadecane-2-one was synthesized according to the method of Example 1, except that isoamyl nitrite was replaced with phenol nitrite in equimolar form, and the yield of azahexadecane-2-one was 90%.

[0133] Example 8

[0134] The azahexadecane-2-one was synthesized according to the method of Example 1, except that 2-methoxyethyl nitrite was used in equimolar substitution for tert-butyl nitrite, and the yield of azahexadecane-2-one was 88%.

[0135] Example 9

[0136] The azacyclotridecane-2-one was synthesized according to the method of Example 1, except that the ratio of isoamyl nitrite:cyclododecane:DMSO was 1:40:80, and the yield of azacyclotridecane-2-one was 90%.

[0137] Example 10

[0138] The azacyclotridecane-2-one was synthesized according to the method of Example 1, except that the ratio of isoamyl nitrite:cyclododecane:DMSO was 1:10:80, and the yield of azacyclotridecane-2-one was 96%.

[0139] Example 11

[0140] The aza-tridecane-2-one was synthesized according to the method of Example 1, except that the ratio of isoamyl nitrite:photocatalyst:DABCO was 1:0.05:0.5, and the yield of aza-tridecane-2-one was 91%.

[0141] Example 12

[0142] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-3 and CH3COOK, respectively, in a molar ratio of 1:20, and the yield of azahexadecane-2-one was 91%.

[0143] Example 13

[0144] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-3 and CH3COOK, respectively, in a molar ratio of 1:30, and the yield of azahexadecane-2-one was 85%.

[0145] Example 14

[0146] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-3 and CH3COOK, respectively, in a molar ratio of 1:60, and the yield of azahexadecane-2-one was 82%.

[0147] Example 15

[0148] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-3 and DABCO, respectively, in a molar ratio of 1:40, and the ratio of isoamyl nitrite to p-toluenesulfonyl chloride was 1:0.4. The yield of azahexadecane-2-one was 86%.

[0149] Example 16

[0150] The azahexadecane-2-one was synthesized according to the method of Example 1, except that the ratio of isoamyl nitrite to aminosulfonic acid was 1:5, and the yield of azahexadecane-2-one was 96%.

[0151] Example 17

[0152] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-3 and DABCO, respectively, in a molar ratio of 1:100, and the ratio of isoamyl nitrite to p-toluenesulfonic acid was 1:100. The yield of azahexadecane-2-one was 97%.

[0153] Example 18

[0154] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-25 and CH3COOK, respectively, in a molar ratio of 1:10, and the yield of azahexadecane-2-one was 42%.

[0155]

[0156] Example 19

[0157] Azahexadecane-2-one was synthesized according to the method of Example 1, except that the photocatalyst and the basic substance were a compound with the structure shown in Formula II-21 and CH3COOK, respectively, in a molar ratio of 1:10, and the yield of azahexadecane-2-one was 92%.

[0158] Comparative Example 1

[0159] The azahexadecane-2-one was synthesized according to the method of Example 1, except that eosin Y was used as an equimolar substitute for the compound with the structure shown in formula II-3 as a catalyst, and the yield of azahexadecane-2-one was 8%.

[0160] Comparative Example 2

[0161] The azahexadecane-2-one was synthesized according to the method of Example 1, except that Rhodamine B was used as an equimolar substitute for the compound with the structure shown in Formula II-3 as a catalyst, and the yield of azahexadecane-2-one was 6%.

[0162] Comparative Example 3

[0163] Azahexadecane-2-one was synthesized according to the method of Example 1, except that tris(2-phenylpyridine)iridium was used as a catalyst in equimolar substitution for the compound with the structure shown in formula II-3. The yield of azahexadecane-2-one was 10%.

[0164] Comparative Example 4

[0165] The azahexacyclic tridecane-2-one was synthesized according to the method of Example 1, except that 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (4CzIPN) was used instead of the compound with the structure shown in Formula II-3 as a catalyst, and the yield of azahexacyclic tridecane-2-one was 8%.

[0166] Comparative Example 5

[0167] Azahexadecane-2-one was synthesized according to the method of Example 1, except that PTH was used instead of the compound with the structure shown in Formula II-3 as a catalyst, wherein the structural formula of PTH (10-phenyl-10H-phenothiazine) is as follows. The yield of azahexadecane-2-one was 6%.

[0168]

[0169] Comparative Example 6

[0170] The azahexadecane-2-one was synthesized according to the method of Example 1, except that the acidic substance acetic acid was not added, and the yield of azahexadecane-2-one was 12%.

[0171] Comparative Example 7

[0172] The aza-tridecane-2-one was synthesized according to the method of Example 1, except that the solvent was CH3CN, and the yield of aza-tridecane-2-one was 7%.

[0173] Comparative Example 8

[0174] The azahexadecane-2-one was synthesized according to the method of Example 1, except that the basic substance DABCO was not added, and the yield of azahexadecane-2-one was 6%.

[0175] Comparative Example 9

[0176] The azahexadecane-2-one was synthesized according to the method of Example 1, except that the additives DABCO and acetic acid were not added, and the yield of azahexadecane-2-one was 3%.

[0177] As can be seen from the above, the cyclic amide yields in Examples 1-18 of the present invention are all greater than 80%, while the cyclic amide yields in Comparative Examples 1-9 are all less than 12%. It is evident that the present invention provides a method for preparing lactams or chain amides by photocatalysis of ammoniation of carbon atoms with more than 11 or their derivatives. This method is highly efficient and can obtain lactams or chain amides in high yields.

[0178] Although commonly used photosensitizers such as ruthenium and iridium complexes, as well as common organic photocatalysts such as rhodamine B, rhodamine 6G, eosin Y, 4CzIPN, PTH, DPZ, and pyridine salts have catalytic effects, the yields are relatively poor.

[0179] The method of this invention uses inexpensive raw materials, has simple and easy-to-operate steps, mild reaction conditions, and high yield.

[0180] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing amides with more than 11 carbon atoms by photocatalytic oxidation and amination, characterized in that, The method includes: reacting a nitrogen source with an alkane or its derivative in a solvent under light irradiation and with the action of a photocatalyst and additives, followed by post-treatment to obtain a cyclic amide or a chain amide; wherein the photocatalyst includes a carbazole compound with photoactivity; the additives include acidic and basic substances; and the alkane is selected from one or more of substituted or unsubstituted cycloalkanes with more than 11 carbon atoms and substituted or unsubstituted chain alkanes with more than 11 carbon atoms.

2. The method according to claim 1, wherein, The photoactive carbazole compound is selected from one or more compounds with the structure shown in Formula II; In Equation II, R 1 and R 2 Ar 1 One or more substituents; R 1 and R 2 Each of the following groups can be independently represented as hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 alkyl or C 3-12 cycloalkyl; R 3 It is hydrogen, tert-butoxycarbonyl, p-toluenesulfonyl, methanesulfonyl, silyl, aryl, heteroaryl, C 1-12 alkyl or C 3-12 Cycloalkyl; R4, R5, R6, and R7 are each independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthraceneyl, phenanthryl, ester, cyano, or C. 1-12 Alkyl groups; wherein, R 4 -R 7 Adjacent groups can be independently or linked by chemical bonds to form five- or six-membered aromatic or heteroaromatic rings; dashed lines represent those that can form bonds or those that cannot. Ar 1 and Ar 2 Each is an aromatic ring or a 5-6 member heterocyclic aromatic ring.

3. The method according to claim 2, wherein, The photoactive carbazole compounds are selected from one or more compounds with structures shown in formulas IIA-IIG; Among them, R 1 and R 2 Ar 1 One or more substituents; R 1 and R 2 Each of the following groups can be independently represented as hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 alkyl or C 3-12 cycloalkyl; R 3 It is hydrogen, tert-butoxycarbonyl, p-toluenesulfonyl, methanesulfonyl, silyl, aryl, heteroaryl, C 1-12 alkyl or C 3-12 cycloalkyl; Ar 1 Ar 2 and Ar 3 Each ring can be independently composed of naphthalene, anthracene, phenanthrene, or heteroaromatic rings. In formula IIA, R 4 Ar 3 One or more substituents; R 5 Ar 2 One or more substituents; R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups; In Equation IIB, R 4 R represents one or more substituents in the benzene ring. 5 Ar 2 One or more substituents; R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups; In formula IIC, R 4 and R 5 Ar 2 One or more substituents; R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 5 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 6 and R 7 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups; In formula IID, R 4 and R 5 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl group; R 6 and R 7 Ar 2 One or more substituents; R 6 It can be hydrogen, trihalomethyl, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 7 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthrene, cyano, or C. 1-12 Alkyl groups; In formula IIE, R 4 and R 5 Ar 2 One or more substituents; R 6 and R 7 Ar 3 One or more substituents; R 4 R 5 R 6 and R 7 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl group; R 8 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl groups; In formula IIF, R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, ester, cyano, or C. 1-12 Alkyl group; R 5 and R 6 Ar 2 One or more substituents; R 7 and R 8 Ar 3 One or more substituents; R 5 R 6 R 7 and R 8 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups; In formula IIG, R 4 and R 5 Ar 2 One or more substituents; R 6 and R 7 Ar 3 One or more substituents; R 8 and R 9 Ar 4 One or more substituents; R 4 R 5 R 6 R 7 R 8 and R 9 Each group can be independently hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, or C. 1-12 Alkyl groups.

4. The method according to claim 3, wherein, The photocatalyst is a compound with the structure shown in Formula IIA and / or a compound with the structure shown in Formula IIB; Preferably, in formula IIA, R 1 Hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, C 1-12 Acyl, phenyl, naphthyl, anthracene, phenanthrene, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 2 It can be hydrogen, trihalomethyl, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, ester, cyano, C 1-12 alkyl or C 3-12 cycloalkyl; R 3 It can be hydrogen, Boc, Ts, Ms, silyl, aryl, heteroaryl, or C. 1-12 alkyl or C 3-10 cycloalkyl; R 4 It can be hydrogen, trihalomethyl, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthryl, ester, cyano, or C. 1-12 Alkyl group; R 5 It can be hydrogen, halogen, nitro, dialkylamine, alkoxy, acyl, phenyl, naphthyl, anthracene, phenanthrene, cyano, or C. 1-12 Alkyl groups; Preferably, in formula IIB, R 1 It is a dialkylamine, alkoxy, or C 1-12 Alkyl group; R 2 For hydrogen, C 1-10 alkyl, phenyl, naphthyl, anthraceneyl, or phenanthrene; R 3 It is hydrogen, tert-butoxycarbonyl, silyl, aryl, heteroaryl, or C 1-10 alkyl, R 4 It can be an ester group, cyano group, formyl group, acetyl group, trihalomethyl group, or halogen; R 5 It is phenyl, naphthyl, anthracene or C 1-12 Alkyl groups; Ar 1 and Ar 2 Each is independently a naphthalene ring, anthracene ring, or phenanthrene ring; Ar 3 It is selected from indole, quinoline, pyrazine, thiazole, pyrimidine, or triazole.

5. The method according to any one of claims 1-4, wherein, The alkaline substance is selected from one or more organic bases and inorganic bases; Preferably, the inorganic base is selected from one or more of ammonia, carboxylates, carbonates, bicarbonates, and hydroxides; more preferably, the inorganic base is selected from one or more of ammonia, lithium formate, lithium acetate, lithium propionate, sodium formate, sodium acetate, sodium propionate, potassium formate, potassium acetate, potassium propionate, cesium formate, cesium acetate, cesium propionate, sodium carbonate, sodium bicarbonate, cesium carbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, and ammonium hydroxide. Preferably, the organic base is selected from one or more organic amines and organic salts; wherein the organic salt is obtained by reacting an alcohol with an alkali metal or an alkaline earth metal; More preferably, the organic amine is selected from one or more of aliphatic amines, alkanolamines, alicyclic amines, aromatic amines, naphthylamines, and hydroxylamines; More preferably, the alcohol is selected from one or more of methanol, ethanol, n-butanol, isopropanol, tert-butanol, n-pentanol, isoamyl alcohol, and hexanol; More preferably, the alkali metal is selected from one or more of lithium, sodium, potassium, cesium, and francium; More preferably, the alkaline earth metal is selected from one or more of magnesium, calcium, and barium.

6. The method according to claim 5, wherein, The aliphatic amines are selected from one or more of the primary, secondary, and tertiary amines from C1 to C18; Preferably, the aliphatic amine is selected from one or more of methylamine, propylamine, butylamine, dimethylamine, diethylamine, diisopropylamine, diisopropylethyl, diisobutylamine, trimethylamine, triethylamine, tributylamine, triisopropylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, tetrabutylamine, tetramethylguanidine, and tert-butylamine.

7. The method according to any one of claims 1-6, wherein, The acidic substance is selected from at least one of acid compounds or acid substitutes; Preferably, the acid is selected from Lewis acids and / or Brønsted acids; more preferably, the Lewis acid is selected from one or more of boron trifluoride, aluminum trichloride, aluminum tribromide, and ferric chloride; even more preferably, the Brønsted acid is selected from one or more of sulfuric acid, hydrochloric acid, acetic acid, formic acid, propionic acid, benzoic acid, substituted sulfonic acid, and trichloroacetic acid; even more preferably, the substituted sulfonic acid is selected from aminosulfonic acid or p-toluenesulfonic acid. Preferably, the acidification substitute is selected from one or more of formyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, cyanuric chloride, trifluoromethanesulfonyl chloride, p-toluenesulfonyl chloride, formyl bromide, acetyl bromide, propionyl bromide, butyryl bromide, cyanuric bromide, trifluoromethanesulfonyl bromide, p-toluenesulfonyl bromide, and elemental iodine.

8. The method according to any one of claims 1-7, wherein, The alkanes or their derivatives with more than one carbon atom have the structure shown in Formula I. Formula I contains at least one methylene group; R a and R b Same or different; R a H, halogen, nitro, C 11-99 alkyl, C 11-99 alkoxy, acyl, or cyano groups; R b To replace or not be replaced by C 11-99 Alkyl; R a and R b Cyclic or non-cyclic formation is optional; R a and R b Each can form an independent ring, or, R a and R b They are linked together in a ring by chemical bonds.

9. The method according to any one of claims 1-8, wherein the cycloalkane is selected from one or more of cyclododecane, cyclotridecane, cyclotetradecane, cyclopentadecane, cyclohexadecane, cycloheptadecane, cyclooctadecane, cyclononadecane, and cycloeicosane; And / or, the chain alkane is selected from one or more of n-dodecane, n-tridecane, n-tetradecane, n-pentadecanane, n-hexadecane, n-heptadecane, n-octadecane, and n-nonadecanane.

10. The method according to any one of claims 1-9, wherein, The nitrogen source is selected from one or more of alkyl nitrites, aryl nitrites, and substituted nitrites; Preferably, the alkyl nitrite is selected from one or more esters formed from nitrite and alcohol; more preferably, it is selected from C... 1-20 The esters formed by the reaction of n-alcohols with nitrous acid and C 1-20 The ester is selected from one or more of the isomeric alcohols and nitrous acid to form esters; more preferably, the alkyl nitrous ester is selected from one or more of methyl nitrite, ethyl nitrite, propyl nitrite, isopropyl nitrite, isobutyl nitrite, tert-butyl nitrite, pentyl nitrite, isoamyl nitrite, neopentyl nitrite, 2-methoxyethyl nitrite, and 1-methoxypropyl-2-yl nitrite. Preferably, the aryl nitrite is selected from one or more esters formed by nitrite and phenol or substituted phenol; Preferably, the nitrite substitute is selected from one or more of the following products: (1) products generated by the reaction of NO, O2 with alcohols and / or phenols; (2) products generated by the reaction of NO2, NO with alcohols or phenols; (3) products generated by the reaction of NaNO2 with alcohols and / or phenols; more preferably, the alcohol has the structure C 1-20 The alcohol; the phenol is phenol or one or more phenols with one or more of the ortho, meta, and para positions of the aromatic ring.

11. The method according to any one of claims 1-10, wherein, The solvent is selected from one or more of acetonitrile, benzonitrile, dichloroethane, tetrachloroethane, N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, NMP, acetone, and toluene.

12. The method according to any one of claims 1-11, wherein, The molar ratio of the nitrogen source to the alkane or its derivative is 1:1-200, preferably 1:10-40; And / or, the molar ratio of the photocatalyst to the nitrogen source is 1:20-200, preferably 1:20-100; And / or, the molar ratio of the photocatalyst to the acidic substance is 1:10-100, preferably 1:10-40; And / or, the molar ratio of the photocatalyst to the alkaline substance is 1:20-100, preferably 1:20-80; And / or, in the additive, the molar ratio of acidic substances to alkaline substances is 1:2-50, preferably 1:2-10; And / or, the molar ratio of the nitrogen source to the solvent is 1:1-200, preferably 1:2-100.

13. The method according to any one of claims 1-12, wherein, The light mentioned is light that can be obtained from any light source; Preferably, the light is visible light with a wavelength of 390-760nm, more preferably 400-500nm.

14. The method according to any one of claims 1-13, wherein, The reaction is carried out in a flow reactor or a batch reactor; Preferably, the method includes: S1A, adding alkane or its derivatives, solvent, nitrogen source, photocatalyst and additives to a flow reactor under visible light irradiation at a temperature of 50-250°C, and reacting for 0.1-24 hours; Alternatively, the method may include: S1B, adding alkane or its derivatives, solvent, nitrogen source, photocatalyst and additives to a batch reactor under visible light irradiation at a temperature of 50-250°C, and reacting for 0.1-24 h.

15. The method according to claim 14, wherein, In a flow reactor, the method further includes: S2. Filter the reaction solution obtained in step S1A to remove solid waste. S3. Recrystallize the filtrate obtained in step S2 to collect the product; S4. Continue to pump the recrystallized liquid from step S3 into the flow reactor, and repeat steps S1A, S2, S3, and S4 until the raw material alkane reacts completely to obtain the amide product. S5. The filtrate from step S4 is concentrated and separated to obtain the amide product, and the photocatalyst is recovered at the same time.

16. The method of claim 14, wherein, In a batch reactor, the method further includes: S2. Filter the reaction solution obtained in step S1B to remove solid waste. S3. Distill the filtrate obtained in step S2 to recover the solvent, and then recrystallize it according to the different solubilities to recover the unreacted alkanes; S4. Recrystallize the filtrate from step S3 to obtain the amide product; S5. The filtrate from step S4 is concentrated and separated to obtain the amide product, and the photocatalyst is recovered at the same time.

Images