A method for preparing amide compounds by photocatalysis

Abstract

The present invention provides a method for preparing amide compounds by photocatalysis, wherein an organic solvent is used as a medium, aldehydes and nitrogen-containing heterocyclic compounds containing active hydrogen on nitrogen atoms are used as raw materials, and under the action of a photocatalyst and / or a base, reactants are stirred for reaction in an oxygen-containing atmosphere and under light conditions, and then separated to obtain amide compounds; the present invention adopts light conditions to react in an air atmosphere, at room temperature and at normal pressure, and has mild reaction conditions, simple operation, high atom economy and environmental friendliness, and is easy for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for preparing amide compounds by photocatalysis. Background Art

[0002] Amide compounds have great application value in the chemical, pharmaceutical, and agricultural industries. Amide compounds can be used as pesticides and have excellent antibacterial, insecticidal, herbicidal, and antiviral activities. Amides can be used as medicines. Amide compounds with different structures can exert different physiological activities. For example, penicillin G, as a β-lactam antibiotic, has become the first choice for treating various acute infections caused by sensitive bacteria because of its strong effects and low prices. Compounds with N-2-pyridine benzamide groups are used as glucokinase activators (GKA) for the treatment of type 2 diabetes. Monocyclic amide-linked phenol derivatives have uric acid excretion activity. Drugs can also be made into prodrugs through amidation reactions to improve the absorption, distribution, metabolism, and excretion properties of drugs in the human body, thereby improving selectivity, such as: gemcitabine prodrugs synthesized by coupling with amino acids to construct amide bonds; amide and diamide prodrugs of levodopamine are used to treat Parkinson's disease.

[0003] At present, the synthesis of amide compounds is still mainly based on the traditional method of nucleophilic substitution reaction between carboxylic acid derivatives and amines. Most of them have low atomic utilization, a lot of chemical waste, and complex post-treatment, which limits their application in industrial production. Patent CN106279013A discloses a method for catalyzing the synthesis of amides from carboxylic acids and amines using a metal oxidant as a catalyst, and removing the byproduct water by heating the reaction system. Patent CN104058983A discloses a method for synthesizing a pharmaceutical intermediate amide compound, which uses PPh3 / CBr4 / auxiliary agent as a composite catalyst and toluene as a solvent in an inert gas atmosphere to achieve the acylation reaction of inactive carboxylic acids and amines. The reaction conditions are harsh, the operation steps are cumbersome, and the catalyst used is dangerous and pollutes the environment. Patent CN113387846A discloses a method for synthesizing N-aryl amides with recyclable raw materials. It uses iodobenzene compounds and benzene compounds as substrates, first reacts with trifluoromethanesulfonic acid to generate intermediates, and then couples with nitrile to form amides. This method has low production cost, but the reaction conditions are harsh, the operation is cumbersome, and the reaction time is long. Patent CN104418762A discloses a new water-soluble iridium complex as a catalyst, a method for synthesizing aldehydes to amides in water and air. Although the catalyst used in the reaction does not contain toxic phosphine ligands, it contains precious metals, which is costly and requires high temperature for the reaction. Patent CN104418762A discloses a method for synthesizing amides by catalyzing the reaction of aldehydes and amines using a metal iridium complex catalyst. The method generates oximes by catalyzing the reaction of aldehydes and amines, and the reaction mixture needs to react at 120°C to generate amides. There are literature reports that aldehydes are used as raw materials and oxidative amination is catalyzed by transition metals and carbenes to form amides, but this method also has some limitations, such as substrate adaptability, long reaction time, and complex separation of by-products (Bode JW, Sohn S SN-heterocyclic carbene-catalyzed redox amidations of alpha-functionalizedaldehydes with amines. Journal of the American Chemical Society, 2007, 129 (45): 13798-13799.). Thermal catalytic aldehyde-amine coupling has the following problems: 1) It is difficult to separate the catalyst from the product, the post-treatment is complicated, and the loaded phosphine ligand contains serious environmental pollution; 2) Most catalytic reactions need to be carried out under relatively high reaction temperature conditions (generally above 110°C).Aldehydes can react with amines to form amides in the presence of transition metals and oxidants (tert-butyl hydroperoxide). The reaction conditions of this method are relatively mild, but an excess of tert-butyl hydroperoxide is used during the reaction, and the use of transition metal salts is not conducive to subsequent separation (Ghosh SC, Ngiam J, Seayad AM, et al. Copper-Catalyzed Oxidative Amidation of Aldehydes with Amine Salts: Synthesis of Primary, Secondary, and Tertiary Amides. Journal of Organic Chemistry, 2012, 77(18): 8007-8015). There are literature reports that aldehydes and amines can be coupled to obtain amides using phenylglyoxylic acid as a photocatalyst and diisopropyl azodicarboxylate (DIAD) in petroleum ether, but the applicability of this reaction to substrates is limited and it is not suitable for aromatic amines (Papadopoulos GN, Kokotos CG. One-Pot Amide Bond Formation from Aldehydes and Amines via a Photoorganocatalytic Activation of Aldehydes. The Journal of Organic Chemistry, 2016, 81 (16): 7023). There are also literature reports on synthesis methods such as hydration of butyronitrile, oxidative amidation of toluene, and direct amidation of alcohols, and the atom economy efficiency is continuously improved, but there are still the following problems: 1) high temperature is required, the reaction conditions are harsh, the reaction time is long, and high temperature will cause the reaction selectivity to be low and many by-products; 2) the catalyst used contains precious metals, which is costly; 3) most thermal catalytic reactions use peroxides as oxidants, which will decompose and release heat at high temperatures, which is easy to cause harmful accidents. Therefore, developing a mild, green, economical and efficient amide synthesis method has always been a difficult problem to be solved urgently. Summary of the invention

[0004] The present invention provides a method for preparing amide compounds by photocatalysis, the purpose of which is to solve the technical problems of low raw material conversion rate, difficult by-product separation, long reaction time, high energy consumption and environmental pollution in the synthesis process of amide compounds.

[0005] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a method for photocatalytically preparing amide compounds, which uses an organic solvent as a medium, aldehydes and nitrogen-containing heterocyclic compounds containing active hydrogen on nitrogen atoms as raw materials, and under the action of a photocatalyst and / or a base, the reactants are stirred and reacted in an oxygen-containing atmosphere and light conditions, and then separated to obtain amide compounds; the present invention uses light conditions to react in an air atmosphere, room temperature and normal pressure, and has the advantages of high conversion rate, mild reaction conditions, easy large-scale production, simple operation process, high atom economy and environmental friendliness.

[0006] The present invention provides a method for preparing amide compounds by photocatalysis, comprising the following steps:

[0007] After mixing an aldehyde of the structure of Formula I with an organic solvent, a nitrogen-containing heterocyclic compound of the structures of Formula II to Formula X and a photocatalyst are added, and the mixture is stirred and reacted in an oxygen-containing atmosphere and under light conditions, and then separated to obtain amide compounds of the structures of Formula XI to Formula XIX; wherein,

[0008]

[0009]

[0010] The R 1 C4~C 20 Aromatic and heterocyclic aromatic groups, C1~C 10 Alkyl, C2~C 10 Olefin group;

[0011] The R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 are independently a hydrogen atom, a halogen, an alkoxy group, a C1-C 20 Alkyl, C3~C 20 Cycloalkyl, C3~C 20 Olefin group, C3~C 20 Alkyne, C3~C 20 Heterocyclic group, C5~C 12 Heteroaryl or C6~C 20 Any of the aromatic groups;

[0012] The alkyl and cycloalkyl groups are optionally monosubstituted or polysubstituted by the same or different halogen, hydroxyl, or alkoxy groups;

[0013] The n is an integer of 1-8.

[0014] Furthermore, the photocatalyst is a metal oxide; the metal oxide is one or more of Mn3O4, CuO, Ag2O, PdO, Fe3O4, Ru2O3, Ni2O3, TiO2, Au2O3, FeO, CoO, and NiO.

[0015] Furthermore, the organic solvent is one or more of toluene, cyclohexane, ethyl ether, xylene, dichloromethane, dichloroethane, benzene, 1,4-dioxane, tetrahydrofuran, carbon tetrachloride, acetone, petroleum ether and n-hexane.

[0016] Furthermore, the catalytic reaction is carried out in the presence or absence of a base; the base is one or more of potassium tert-butoxide, sodium tert-butyl alcohol, sodium hydride, potassium hydride, sodium methoxide, sodium ethoxide, potassium hydroxide, barium hydroxide, cesium carbonate and potassium carbonate.

[0017] Furthermore, the molar ratio of the aldehyde to the nitrogen-containing heterocyclic compound is 1:0.9 to 3.0.

[0018] Furthermore, the specific preparation process of the method comprises the following steps:

[0019] (1) adding an aldehyde, a nitrogen-containing heterocyclic compound, a photocatalyst, a base and an organic solvent into a reactor;

[0020] (2) Stirring the reaction under a light source of 15 to 100 W to obtain an amide compound.

[0021] Furthermore, the lighting conditions are specifically: using one or more of a xenon lamp, a light emitting diode, a mercury lamp, and a metal halide lamp as a light generating device for lighting.

[0022] Furthermore, the reaction temperature in step (2) is room temperature and the reaction time is 60 to 600 minutes.

[0023] The above scheme of the present invention has the following beneficial effects:

[0024] 1) The present invention uses aldehydes and nitrogen-containing heterocyclic compounds with active hydrogen on nitrogen atoms as raw materials for preparing amide compounds. The raw material sources are relatively wide and the cost is low. The reaction has high atom economy and environmental friendliness, which is conducive to large-scale production.

[0025] 2) The photocatalyst used in the present invention is transition metal oxides such as manganese tetraoxide, iron tetraoxide, nickel oxide, etc., which have high catalytic activity, low catalyst cost, and are easy to separate from the product and can be recycled, thus avoiding the generation of a large amount of waste, and the preparation process is green and environmentally friendly.

[0026] 3) The method for preparing amine compounds of the present invention adopts light conditions to replace traditional heating and high pressure conditions, and reacts in an air atmosphere, room temperature and normal pressure. The reaction conditions are mild, energy consumption is saved, costs are reduced, and environmental pollution is reduced.

[0027] 4) The present invention has good substrate applicability, mild process conditions, simple and easy operation method, and is conducive to popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is the mass spectrum of morpholine-4-phenyl-methanone in Example 1 of the present invention.

[0030] Figure 2 This is the mass spectrum of 3-phenyl-1-(pyrrole-1-)propyl-1-one in Example 2 of the present invention.

[0031] Figure 3 is the indolin-1-yl phenyl ketone in Example 3 of the present invention 1 HNMR spectrum.

[0032] Figure 4 This is the mass spectrum of 3,7-dimethyl-1-morpholine-2,6-octadien-1-one in Example 4 of the present invention.

[0033] Figure 5 is (5-methylpyridin-2-yl)(pyrrolidin-1-yl)methanone in Example 5 of the present invention 1 HNMR spectrum.

[0034] Figure 6 is the morpholine (thiophene-2-yl) ketone in Example 6 of the present invention 1 HNMR spectrum.

[0035] Figure 7 is the nitrogen cyclohexylidene-1-yl (thiophene-2-yl) ketone in Example 7 of the present invention 1 HNMR spectrum.

[0036] Figure 8 It is the mass spectrum of phenyl (4-phenylpiperazine-1-yl) ketone in Example 8 of the present invention.

[0037] Fig. 9 is the phenyl (4-phenylpiperazine-1-yl) ketone in Example 8 of the present invention1 HNMR spectrum. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0039] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0040] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0041] In view of the existing problems, the present invention provides a method for preparing amide compounds by photocatalysis.

[0042] All parts and percentages in the examples are by weight unless otherwise specified.

[0043] Example 1

[0044] The specific preparation process of photocatalyst Mn3O4 is as follows:

[0045] (1) dissolving manganese nitrate tetrahydrate in ethanol with stirring at a mass ratio of manganese nitrate tetrahydrate to ethanol of 1:300, then transferring to a hydrothermal reactor, reacting at 150° C. for 10 h, washing with ethanol and centrifuging to obtain a light pink solid, and drying the solid at 60° C. for 12 h to obtain a brown solid I;

[0046] (2) Solid I was calcined at 450 °C for 3 h to obtain a black Mn3O4 photocatalyst.

[0047] The photocatalyst Mn3O4 is used to catalyze the preparation of amide compounds, comprising the following steps:

[0048] Add 2.68g of benzaldehyde (content 99%) to a 250mL reaction bottle, add 100mL of toluene as a solvent, then add 2.86g of potassium tert-butyl alcohol (content 98%) in batches, add 2.23g of morpholine (content 99%), and then add 60mg of Mn3O4. Stir the reaction for 4 hours at room temperature and 15W LED light to obtain a brown mixed solution. The reaction was filtered, washed with alcohol, and the filtrate was distilled under reduced pressure to recover the solvent. The pH was then adjusted to 7 with 0.1mol / L hydrochloric acid solution, and washed with water to obtain 4.46g of off-white solid. After analysis and detection, the yield of morpholine-4-phenyl-ketone based on benzaldehyde was 92.9%. The structure of the synthetic product was characterized by high-resolution mass spectrometry, and the spectrum is shown in the figure. Figure 1As shown, the peak with a mass-to-charge ratio of 214.0840 in the spectrum is the [M+Na] ion peak, and the theoretical molecular weight [M+Na] of morpholine-4-phenyl-methanone is 214.0838, confirming that the synthesized product is the target compound morpholine-4-phenyl-methanone.

[0049] Mn3O4 photocatalyst catalytic performance stability test:

[0050] The catalyst Mn3O4 was recovered after filtration and water washing, dried at 120°C, and reused 5 times, and its catalytic effect was not significantly weakened.

[0051] Comparative Example 1

[0052] 2.6783g of benzaldehyde (content 99%) was added to a 250mL reaction bottle, 100mL of toluene was added as a solvent, and then 2.8571g of potassium tert-butyl alcohol (content 98%) was added in batches, 2.2294g of morpholine (content 99%) was added, and 2.7363g of tert-butyl hydroperoxide (content 70%) was added. The reaction was carried out at room temperature and 15W LED light for 10 hours. After analysis and detection, the target compound morpholine-4-phenyl-methanone was not obtained.

[0053] Example 2

[0054] 3.39g3-phenylpropanaldehyde (content is 99%) is added in the reaction flask of 250mL, 50mL dichloromethane is added as solvent, then sodium tert-butoxide (content is 98%) is added in two batches 2.45g in total, 1.80g tetrahydropyrrole (content is 99%) is added, 30mgAg2O (99%) is added, stirring reaction is 6 hours under normal temperature and 30WLED light, obtains light yellow brown liquid. Reaction reaction is filtered, alcohol washing, filtrate is recovered solvent through underpressure distillation, then pH is adjusted to 7 with the hydrochloric acid solution of 0.1mol / L, yellow solid 4.44g is obtained after washing and filtering. After analysis and detection, the yield of 3-phenyl-1-(pyrrole-1-) propyl-1-ketone based on phenylpropanaldehyde is 86.3%.

[0055] The structure of the synthesized product was characterized by high-resolution mass spectrometry. Figure 2 As shown, the peak with a mass-to-charge ratio of 226.1204 in the spectrum is the [M+Na] ion peak, and the theoretical molecular weight M+Na of 3-phenyl-1-(pyrrole-1-)propyl-1-one is 226.1202, confirming that the synthesized product is the target compound 3-phenyl-1-(pyrrole-1-)propyl-1-one.

[0056] Comparative Example 2

[0057] 2.68g of benzaldehyde (content 99%) was added to a 100mL reaction bottle, 50mL of dichloromethane was added as a solvent, and then 2.86g of potassium tert-butyl alcohol (content 98%), 1.80g of tetrahydropyrrole (content 99%) were added in batches, and then 0.10g of AgNO3 was added, and the reaction was carried out at room temperature and 30W LED light for 8 hours. After analysis and detection, the target compound phenyl-pyrrolidine-1-methanone was not obtained.

[0058] Example 3 (Fe3O4)

[0059] 2.73g benzaldehyde (content 99%) was added to a 100mL reaction bottle, 50mL benzene was added as a solvent, and then 1.00g sodium hydride (content 60%) was added twice, and appropriate shaking was added. After the bubbles disappeared, 3.01g 2,3-dihydroindole (content 99%) was added, and 40mg Fe3O4 (99%) was added. The reaction was carried out at room temperature and 100W LED light for 7 hours to obtain a light yellow liquid. The reaction was filtered, washed with alcohol, the filtrate was dried, and the pH was adjusted to 7 with 0.1mol / L hydrochloric acid solution. After washing with water, 4.63g of white solid was obtained, and the yield of indoline-1-yl phenyl ketone based on benzaldehyde was 83.1%.

[0060] The white solid was directly characterized. 1 HNMR spectrum Figure 3 As shown: δ2.50 is the solvent peak, δ: 3.03 (t, 2H), 3.85 (t, 2H), 6.41 (d, 1H), 6.59 (t, 1H), 6.82 (d, 1H), 6.94 (t, 1H), 7.07 (m, 3H), 7.37 (d, 1H), δ7.51 (d, 1H), whose chemical shift is consistent with the hydrogen on indolin-1-ylphenyl ketone.

[0061] Comparative Example 3

[0062] 2.73g benzaldehyde (content 99%) was added to a 100mL reaction bottle, 50mL benzene was added as solvent, and then 1.50g sodium ethoxide (content 60%) was added twice, and appropriate shaking was added. After the bubbles disappeared, 3.01g 2,3-dihydroindole (content 99%) was added, and then 0.10g FeCl3 (content 99%) and 0.05g piperidine alcohol oxide (TEMPO, content 98%) were added, and the reaction was carried out at room temperature and 100W LED light for 10 hours. After analysis and detection, the target compound indolin-1-yl phenyl ketone was not obtained.

[0063] Example 4 (Au2O3)

[0064] 3.84g of neral (content 99%) was added to a 250mL reaction bottle, 100mL of cyclohexane was added as solvent, 1.30g of potassium hydride (content 60%) was added in batches, 2.23g of morpholine (content 99%) was added, 50mg of Au2O3 hydrate (99%) was added, and the mixture was reacted for 5 hours at room temperature and 100W LED light to obtain a yellow liquid. The reaction was filtered, washed with alcohol, the filtrate was dried, the pH was adjusted to 7 with 0.1mol / L HCl, and 3.67g of yellow liquid was obtained after washing with water.

[0065] The structure of the synthesized product was characterized by high-resolution mass spectrometry. Figure 4 As shown, the peak with a mass-to-charge ratio of 238.0811 in the spectrum is the [M+1] ion peak, and the theoretical molecular weight M+H of 3,7-dimethyl-1-morpholine-2,6-octadien-1-one is 238.08, confirming that the synthesized product is the target compound 3,7-dimethyl-1-morpholine-2,6-octadien-1-one.

[0066] Example 5

[0067] The specific process of preparing the photocatalyst CuO in the laboratory is:

[0068] (1) According to the molar ratio of NaOH:CuCl2 being 1:5, NaOH and CuCl2 were ground in a mortar for 5 min respectively and then mixed, PEG-400 was added and ground for another 30 min, and the mixture was ultrasonically washed with distilled water for 3 times, and PEG-400 was removed with anhydrous ethanol to obtain a black powder solid I;

[0069] (2) Dry the solid I at 80°C for 3 h to obtain a CuO catalyst.

[0070] Preparation of amide compounds using homemade photocatalyst CuO:

[0071] 3.05g5-methylpyridine-2-carboxaldehyde (content of 99%) was added to a 100mL reaction bottle, 50mL of n-hexane was added as a solvent, and then 1.50g of sodium methoxide (content of 60%), 1.80g of tetrahydropyrrole (content of 99%) were added in batches, and 40mg of homemade CuO was added, and the reaction was carried out for 10 hours at room temperature and 30WLED light conditions. The reaction was filtered, washed with alcohol, the filtrate was spin-dried, and the pH was adjusted to 7 with 0.1mol / L hydrochloric acid solution. After washing with water, 4.33g of white solid was obtained, and the yield of (5-methylpyridine-2-yl) (pyrrolidine-1-yl) ketone based on 5-methylpyridine-2-carboxaldehyde was 91.4%.

[0072] The structure of the synthesized product was characterized by nuclear magnetic resonance spectroscopy. 1 HNMR spectrum Figure 5As shown: the solvent peak is at δ7.26, δ: 1.82 (m, 4H), 2.50 (s, 3H), 3.58 (m, 4H), 7.11 (d, 1H), 7.48 (d, 1H), 7.57 (d, 1H), and its chemical shift is consistent with the hydrogen on (5-methylpyridin-2-yl)(pyrrolidin-1-yl)methanone.

[0073] Example 6

[0074] 2.83g thiophene-2-carboxaldehyde (content of 99%) was added to a 250mL reaction bottle, 100mL toluene was added as a solvent, and then 2.86g potassium tert-butyl alcohol (content of 98%) was added in batches, 2.23g morpholine (content of 99%) was added, and 50mg PdO (content of 99%) was added, and the reaction was carried out for 6 hours at room temperature and 30W LED light conditions. The reaction was filtered, washed with alcohol, the filtrate was spin-dried, and the pH was adjusted to 7 with 0.1mol / L hydrochloric acid solution. After washing with water, 4.57g of yellow solid was obtained, and the yield of morpholine (thiophene-2-yl) ketone based on thiophene-2-carboxaldehyde was 92.7%.

[0075] The structure of the synthesized product was characterized by nuclear magnetic resonance spectroscopy. 1 HNMR spectrum Figure 6 As shown: the solvent peak is at δ2.50, δ: 3.63 (m, 8H), 7.13 (t, 1H), 7.43 (d, 1H), 7.77 (d, 1H), and its chemical shift is consistent with the hydrogen on morpholino(thiophene-2-yl)methanone.

[0076] Example 7

[0077] 2.83g thiophene-2-carboxaldehyde (content of 99%) was added to a 250mL reaction bottle, 100mL toluene was added as a solvent, and then 2.86g potassium tert-butyl alcohol (content of 98%) was added in batches, 2.5043g cycloheximide (content of 99%) was added, and 50mg Co3O4 (content of 99%) was added, and the reaction was carried out for 6 hours at room temperature and under the conditions of 30W LED light. The reaction was filtered and washed with alcohol, and the filtrate was dissolved in 20mL water after being spin-dried, and the pH was adjusted to 7 with 0.1mol / L hydrochloric acid solution, and 4.67g yellow liquid was obtained after washing with water, and the yield of nitrogen cyclohexylidene-1-yl (thiophene-2-yl) ketone based on thiophene-2-carboxaldehyde was 89.3%.

[0078] The structure of the synthesized product was characterized by nuclear magnetic resonance spectroscopy. 1 HNMR spectrum Figure 7As shown: the solvent peak is at δ2.50, δ: 1.53 (m, 4H), 1.71 (m, 4H), 3.55 (m, 4H), 7.12 (t, 1H), 7.40 (d, 1H), 7.72 (d, 1H), and its chemical shift is consistent with the hydrogen of nitrogen cyclohexylidene-1-yl (thiophene-2-yl)methanone.

[0079] Example 8

[0080] 2.73g benzaldehyde (content is 99%) is added to a 100mL reaction bottle, 50mL benzene is added as a solvent, then 1.01g sodium hydride (content is 60%) is added twice, and appropriate vibration is added while adding. After the bubble disappears, 4.09g N-phenylpiperazine (content is 99%) is added, and 40mg Ni2O3 (content is 99%) is added. The reaction is carried out at room temperature and under the conditions of 30WLED light for 7 hours to obtain a light yellow liquid. The reaction is filtered, washed with alcohol, and the filtrate is spin-dried, and the hydrochloric acid solution of 0.1mol / L is adjusted to pH 7. After washing with water, 4.63g of white solid is obtained, and the yield of phenyl (4-phenylpiperazine-1-yl) ketone based on benzaldehyde is 83.10%.

[0081] The white solid was directly characterized, phenyl (4-phenylpiperazine-1-yl) ketone C 17 H 18 The theoretical value of [M+H] of N2O is 267.1492, and its mass spectrum results are as follows Figure 8 As shown in the figure, 267.1490 is the [M+H] peak of phenyl (4-phenylpiperazine-1-yl) ketone. 1 HNMR spectrum Fig. 9 As shown: δ2.50 is the solvent peak, δ: 3.15 (m, 4H), 3.62 (m, 2H), 3.97 (m, 2H), 6.93 (m, 3H), 7.29 (m, 2H), 7.45 (m, 5H), whose chemical shifts are consistent with the hydrogen on phenyl (4-phenylpiperazine-1-yl)methanone, confirming that the product is the target compound phenyl (4-phenylpiperazine-1-yl)methanone.

[0082] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing amide compounds by photocatalysis, characterized in that: The method comprises the following steps: mixing an aldehyde of formula I with an organic solvent, adding a nitrogen-containing heterocyclic compound of formula II, formula III, formula VIII or formula IX and a photocatalyst, stirring and reacting in an oxygen-containing atmosphere and under light conditions, and then separating to obtain an amide compound of formula XI, formula XII, formula XVII or formula XVIII; wherein, The R 1 C4~C 20 Aromatic and heteroaromatic groups; The R 2 , R 3 , R 9 , R 10 are independently a hydrogen atom, a halogen, an alkoxy group, a C1-C 20 Alkyl, C3~C 20 Cycloalkyl, C3~C 20 Olefin group, C3~C 20 Alkyne, C3~C 20 Heterocyclic group, C5~C 12 Heteroaryl or C6~C 20 Any of the aromatic groups; The alkyl and cycloalkyl groups are optionally monosubstituted or polysubstituted by the same or different halogen, hydroxyl, or alkoxy groups; The n is an integer from 1 to 8; The photocatalyst is a metal oxide; the metal oxide is one or more of Mn3O4, CuO, Ag2O, PdO, Fe3O4, Ni2O3, Au2O3, and Co3O4; The reaction is carried out in the presence of a base; the base is one or more of potassium tert-butoxide, sodium tert-butyl alcoholate, sodium hydride, potassium hydride, and sodium methoxide.

2. The method for preparing amide by photocatalysis according to claim 1, characterized in that: The organic solvent is one or more of toluene, cyclohexane, ethyl ether, xylene, dichloromethane, dichloroethane, benzene, 1,4-dioxane, tetrahydrofuran, carbon tetrachloride, acetone, petroleum ether and n-hexane.

3. The method for preparing amide compounds by photocatalysis according to claim 1, characterized in that: The molar ratio of the aldehyde to the nitrogen-containing heterocyclic compound is 1:0.9-3.

0.

4. The method for preparing amide compounds by photocatalysis according to claim 1, characterized in that: The specific preparation process of the method comprises the following steps: (1) adding an aldehyde, a nitrogen-containing heterocyclic compound, a photocatalyst, a base and an organic solvent into a reactor; (2) Stirring the reaction under a light source of 15 to 100 W to obtain an amide compound.

5. The method for preparing amide compounds by photocatalysis according to claim 4, characterized in that: The lighting conditions are specifically: using one or more of a xenon lamp, a light emitting diode, a mercury lamp, and a metal halide lamp as a light generating device for lighting.

6. The method for preparing amide compounds by photocatalysis according to claim 5, characterized in that: The reaction temperature in step (2) is room temperature and the reaction time is 60 to 600 minutes.

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