An imine compound and a method for preparing the same

Abstract

The present application relates to an imine compound and a preparation method thereof, and belongs to the technical field of imine compounds. The preparation method comprises the following steps: reacting an aldehyde compound, an amine compound and a cesium-containing inorganic salt in an alcohol solvent to obtain an imine compound. The preparation method uses the cesium-containing inorganic salt to regulate the aldehyde compound and the amine compound to prepare the imine compound as a substrate of a luminescent material. On the one hand, the cesium-containing inorganic salt regulates the acid-base property of the reaction environment in the solvent, and it is not necessary to introduce strong acid and strong base used in the traditional method into the reaction system. On the other hand, the cesium ion can activate the carbonyl group and the amino group of the substrate, and the separation yield of the imine compound can be improved by using the cesium-containing inorganic salt.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of imine compounds, and particularly relates to an imine compound and a preparation method thereof. BACKGROUND

[0002] It is a major task of green chemistry to synthesize fine chemicals in an environmentally friendly and atom-economic manner. Imine is an important class of nitrogen-containing organic compounds, and the active C=N bond thereof is often used to synthesize high-value-added agricultural chemicals, biochemical reagents, drugs and intermediates of polymers. On the other hand, aromatic imine-based thermally activated delayed fluorescence materials can be applied to high-efficiency organic light-emitting diodes, and aromatic imine compounds have excellent photoelectric properties and strong electricity absorption capacity, and have potential application value in the synthesis field of aromatic light-emitting materials.

[0003] Traditional synthesis methods of imine usually need to use strong acidic or basic conditions to promote the reaction. Among them, strong acids such as sulfuric acid and phosphoric acid are usually used as catalysts under acidic conditions to promote the condensation reaction of aldehyde or ketone and amine. Under alkaline conditions, strong alkaline hydroxides such as sodium hydroxide and potassium hydroxide are needed to promote the condensation reaction of aldehyde or ketone and amine. In the reaction process, since the condensation reaction needs to consume water, a dehydrating agent needs to be used to absorb the water produced in the reaction. Commonly used dehydrating agents include thionyl chloride, sodium hydroxide, potassium hydroxide and the like. These dehydrating agents need to be used with caution because they are all corrosive and toxic. In addition, these dehydrating agents are also relatively expensive, which will increase the synthesis cost. Therefore, in recent years, researchers have also explored the use of new dehydrating agents such as inorganic salts and ionic liquids to reduce synthesis cost and improve reaction efficiency (for example, 5.0 equivalents of Ti(OEt)4, or 0.1 equivalents of Yb(OTf)3, or 2.0 equivalents of KF, or 2.0 equivalents of CuSO4 are introduced into the reaction system).

[0004] In 1988, Jennings group reported the dehydration of aromatic aldehydes with aromatic phosphoramide and sulfonamide in the presence of Lewis acid TiCl4 to form the corresponding imines (Tetrahedron Lett., 1988, 29, 3725-3728.). In 1990, J. Sisko group reported a method for the preparation of sulfonimidates by condensation of N-sulfinylbenzenesulfonamides with aldehydes. This method is suitable for a wide range of substrates and can be used to prepare imines of macromolecules (J. Org. Chem., 1990, 55, 393-395.). In 2009, A. Baiker et al. used gold and other noble metal supported catalysts to catalyze the oxidative dehydrogenation of amines to prepare compounds with imine structure under the condition of oxygen or air, but the reaction conditions are harsh and it is difficult to meet the requirements of industrial application (J. Mol. Catal. A: Chem., 2009, 309, 57-62.). In 2013, M. Belén Cid group reported a general method for the synthesis of imines from aldehydes and amines under mild conditions. This method is widely applicable, and amines, sulfinamides and sulfonamides can react with aldehydes, only requiring catalytic amount of tetrahydro-pyrrole to obtain imines with high yield (J. Am. Chem. Soc., 2014, 136, 1082-1089; Org. Synth., 2017, 94, 346.). In 2015, Jonathan Reeves et al. of Boehringer Ingelheim Pharmaceuticals found a new reagent B(OCH2CF3)3 for the preparation of imines. It can condense amides or amines with carbonyl compounds to prepare various imines such as N-sulfinyl, N-tosyl, N-(dimethylamine) sulfonyl, N-diphenylphosphinoyl, N-(α-methylbenzyl) and N-(4-methoxyphenyl) aldehyde imine under mild conditions. The reaction operation is simple, no special post-treatment is required, and it is easy to separate (Org. Lett., 2015, 17, 2442-2445.). After the above literature research, it is of great significance to find a cheap, clean and efficient catalyst system to realize the synthesis of imine compounds under mild conditions. SUMMARY

[0005] To solve the above technical problems, the present application provides an imine compound and a preparation method thereof, which can be applied to the field of synthesis of aromatic light-emitting materials. Under the action of cesium-containing inorganic salt, the substrate can be efficiently converted into a compound with imine structure at room temperature. The method has simple reaction steps and separation and purification operation, conforms to the principle of atomic economy, and the raw materials are cheap and easy to obtain, which is suitable for the efficient synthesis of imine compounds with various structures. And there is no report on the synthesis of imines using cesium-containing inorganic salt as an additive.

[0006] The first object of the present application is to provide a preparation method of an imine compound, comprising the following steps: reacting an aldehyde compound, an amine compound and a cesium-containing inorganic salt in an alcohol solvent to obtain the imine compound.

[0007] In one embodiment of the present application, the aldehyde compound has the following structural formula:

[0008]

[0009] wherein R1, R2 and R3 are independently selected from hydrogen, hydroxyl, halogen, nitro, N,N-dimethyl, ester, sulfonic acid, C1-C4 alkoxy, substituted or unsubstituted C1-C6 alkyl; the substituted group is halogen;

[0010] R4 is selected from furanyl;

[0011] R5 and R6 are independently selected from hydrogen, hydroxyl, halogen, nitro, N,N-dimethyl, ester, sulfonic acid, C1-C4 alkoxy, substituted or unsubstituted C1-C6 alkyl; the substituted group is halogen.

[0012] Further, R1, R2 and R3 are independently selected from hydrogen, hydroxyl, halogen, methoxy, substituted or unsubstituted C1-C6 alkyl; the substituted group is halogen;

[0013] R5 and R6 are independently selected from hydrogen, nitro, N,N-dimethyl, methoxy or methyl.

[0014] In one embodiment of the present application, the amine compound has the following structural formula:

[0015]

[0016] wherein R 10 , R 11 , R 12 and R 13 are independently selected from hydrogen, hydroxyl, halogen, nitro, N,N-dimethyl, ester, sulfonic acid, C1-C4 alkoxy or C1-C6 alkyl;

[0017] R 14 is selected from p-toluenesulfonyl or tert-butyl.

[0018] Further, R 10 , R 11 , R 12 and R 13 are independently selected from hydrogen, halogen or C1-C6 alkyl.

[0019] In one embodiment of the present application, the cesium-containing inorganic salt is selected from one or more of cesium fluoride (CsF), cesium chloride (CsCl), cesium bromide (CsBr), cesium sulfate (Cs2SO4), cesium carbonate (Cs2CO3), and cesium formate (CsOOCH).

[0020] Further, the cesium-containing inorganic salt is selected from cesium chloride (CsCl).

[0021] In one embodiment of the present application, the alcohol solvent is selected from one or more of methanol (MeOH), ethanol (EtOH), isopropanol (iPrOH), and tert-butanol (tBuOH).

[0022] Further, the alcohol solvent is selected from ethanol (EtOH).

[0023] In one embodiment of the present application, the molar ratio of the aldehyde compound and the amine compound is 1:1-1:2.

[0024] Further, the molar ratio of the aldehyde compound and the amine compound is 1:1.

[0025] In one embodiment of the present application, the molar ratio of the cesium-containing inorganic salt and the aldehyde compound is 5:1-1:10.

[0026] Further, the molar ratio of the cesium-containing inorganic salt and the aldehyde compound is 1:1.

[0027] In one embodiment of the present application, the temperature of the reaction is 20-40°C, and the time is 18-30 hours.

[0028] Further, the temperature of the reaction is 25°C, and the time is 24 hours.

[0029] In one embodiment of the present application, after the reaction is completed, the step of separating the imine compound from the reaction solution by using a sand core funnel is further included.

[0030] In one embodiment of the present application, the separation yield of the preparation method is 69.0%-90.0%.

[0031] In one embodiment of the present application, the method specifically comprises the following steps: adding an aldehyde compound, an amine compound, and a cesium-containing inorganic salt into an alcohol solvent, reacting at 20-40°C for 18-30 hours, after the reaction is completed, the product is precipitated in the form of a solid, the precipitated solid insoluble substance is filtered by using a sand core funnel, and is repeatedly washed with petroleum ether three times, and is dried under high vacuum to obtain an imine compound.

[0032] A second object of the present application is to provide an imine compound prepared by the method.

[0033] The technical scheme of the present application has the following advantages compared with the prior art:

[0034] (1) The preparation method of the present application uses cesium-containing inorganic salt to regulate the preparation of aldehyde compounds and amine compounds to prepare imine compound substrates of luminescent materials. On the one hand, the cesium-containing inorganic salt regulates the acidity and alkalinity of the reaction environment in the solvent, without the need to introduce strong acids and strong bases used in traditional methods in the reaction system. On the other hand, the cesium ion can activate the carbonyl group and the amino group of the substrate, and the separation yield of the imine compound can be improved by using the cesium-containing inorganic salt.

[0035] (2) The preparation method of the present application uses alcohol compounds as solvents, which is green and environmentally friendly. The product can be precipitated in the alcohol solvent, which is beneficial to the separation and purification of the imine product, and has good industrialization prospects. The product has important application in industrial production, and can be used to prepare high-value-added agricultural chemicals, biochemical reagents, drugs and polymer intermediates, and more importantly, can be used in the synthesis of aromatic luminescent materials.

[0036] (3) The preparation method of the present application has relatively mild reaction conditions, and excellent conversion of the substrate can be achieved under room temperature stirring. The present application is widely applicable, and can synthesize various types of imine compounds in one step, with high product yield and easy separation. DETAILED DESCRIPTION

[0037] The present application will be further described below in conjunction with specific examples, so that those skilled in the art can better understand the present application and implement it. However, the examples are not limiting to the present application.

[0038] In the present application, unless otherwise specified, the technical and scientific terms used in the specification of the present application have the same meaning as generally understood by those skilled in the art of the present application.

[0039] In the present application, unless otherwise specified, the terms "comprising" and / or "including" used in the specification of the present application indicate the presence of the described features, whole, steps, operations, elements or components, but do not exclude the presence or addition of one or more other features, whole, steps, operations, elements, components or combinations thereof.

[0040] In the present application, unless otherwise specified, the chemical reagents used in the specification of the present application are purchased from TCI Reagent Company, Bailingwei Reagent Company, Aladdin Reagent Company and Adama Reagent Company.

[0041] In the present application, unless otherwise specified, the nuclear magnetic analyzer used in the specification of the present application is Bruker 400M.

[0042] Examples 1-6

[0043] Preparation of imine compounds using different cesium-containing inorganic salts, which specifically includes the following steps:

[0044]

[0045] Into a reaction flask, 4-hydroxybenzaldehyde 10 mmol, aniline 10 mmol, cesium-containing inorganic salt 10 mmol, ethanol 100 mL were added in sequence, and the reaction was carried out at room temperature (25 °C) for 24 h. After the reaction was completed, the insoluble solid was filtered through a sand core funnel, and washed with petroleum ether for three times. The collected solid was dried under high vacuum to obtain the final product imine 3a. The cesium-containing inorganic salt used for the preparation of imine 3a and the separation yield were weighed and calculated, as shown in Table 1:

[0046] Table 1

[0047]

[0048]

[0049] The structure of imine 3a was determined by nuclear magnetic resonance hydrogen spectrum and carbon spectrum, and the nuclear magnetic results are as follows:

[0050]

[0051] 1 H NMR (400 MHz, DMSO-d6) δ 10.21 (s, 1H), 8.47 (s, 1H), 7.83 (d, J = 8.2 Hz, 2H), 7.39 (d, J = 7.2 Hz, 2H), 7.22 (d, J = 7.4 Hz, 3H), 6.95 (d, J = 7.7 Hz, 2H).

[0052] 13 C NMR (101 MHz, DMSO-d6) δ 161.08, 160.37, 152.40, 131.12, 129.53, 127.93, 125.73, 121.29, 116.08.

[0053] Examples 7-9

[0054] Preparation of imine compounds using alcohol solvents, which specifically includes the following steps:

[0055]

[0056] Into a reaction flask, 4-hydroxybenzaldehyde 10 mmol, aniline 10 mmol, cesium chloride 10 mmol, alcohol solvent 100 mL were added in sequence, and reacted at room temperature (25 °C) for 24 h. After the reaction was completed, the insoluble solid precipitated was filtered through a sand core funnel and washed with petroleum ether repeatedly for three times. The collected solid was dried under high vacuum to obtain the final product imine 3a, which was weighed and the separation yield was calculated. The cesium-containing inorganic salt and the separation yield for preparing imine 3a are shown in Table 2:

[0057] Table 2

[0058] Examples Alcoholic solvents Isolated yield of imine 3a (%) Example 7 Methanol 85 Example 8 Isopropyl alcohol 79 Example 9 tert-Butanol 75

[0059] Examples 10-31

[0060] Imine compounds were prepared using different aldehyde compounds and amine compounds, which specifically included the following steps:

[0061] Into a reaction flask, aldehyde compound 10 mmol, amine compound 10 mmol, cesium chloride 10 mmol, ethanol 100 mL were added in sequence, and reacted at room temperature (25 °C) for 24 h. After the reaction was completed, the insoluble solid precipitated was filtered through a sand core funnel and washed with petroleum ether repeatedly for three times. The collected solid was dried under high vacuum to obtain the final product imine 3b-3w, which was weighed and the separation yield was calculated. The aldehyde compound, amine compound, separation yield, and nuclear magnetic resonance results for preparing 3b-3w are shown as follows:

[0062] Imine 3b: (E)-N-phenyl-1-(p-tolyl)methanimine; the aldehyde compound and the amine compound were 4-methylbenzaldehyde and aniline, respectively; the separation yield was 85%.

[0063]

[0064] 1 H NMR (400 MHz, Chloroform-d) δ 8.31 (s, 1H), 7.74 (d, J = 8.0 Hz, 2H), 7.32 (dd, J = 9.9, 5.6 Hz, 2H), 7.23-7.10 (m, 5H), 2.31 (s, 3H).

[0065] 13 C NMR (101 MHz, Chloroform-d) δ 160.60, 152.42, 142.06, 133.88, 129.78, 129.41, 129.11, 126.07, 121.22, 21.90.

[0066] Imine 3c: (E)-1-(4-bromophenyl)-N-phenylmethanimine; aldehyde, amine were 4-bromobenzaldehyde and aniline, respectively; isolated yield was 82%.

[0067]

[0068] 1 H NMR (400 MHz, Chloroform-d) δ 8.34 (s, 1H), 7.72 (d, J = 8.3 Hz, 2H), 7.55 (d, J = 8.3 Hz, 2H), 7.37 (t, J = 7.6 Hz, 2H), 7.20 (dd, J = 18.8, 7.4 Hz, 3H).

[0069] 13 C NMR (101 MHz, Chloroform-d) δ 158.96, 151.62, 135.09, 132.06, 130.21, 129.28, 126.32, 125.93, 120.94.

[0070] Imine 3d: (E)-1-(4-chlorophenyl)-N-phenylmethanimine; aldehyde, amine were 4-chlorobenzaldehyde and aniline, respectively; isolated yield was 86%.

[0071]

[0072] 1 H NMR (400 MHz, Chloroform-d) δ 8.29 (s, 1H), 7.74 (d, J = 8.3 Hz, 2H), 7.33 (t, J = 7.5 Hz, 4H), 7.17 (dd, J = 16.7, 7.6 Hz, 3H).

[0073] 13 C NMR (101 MHz, Chloroform-d) δ 158.86, 151.80, 137.46, 134.88, 130.16, 129.42, 129.22, 126.44, 121.13.

[0074] Imine 3e: (E)-N-phenyl-1-(4-(trifluoromethyl)phenyl)methanimine; aldehyde, amine were 4-trifluoromethylbenzaldehyde and aniline, respectively; isolated yield was 80%.

[0075]

[0076] 1H NMR (400 MHz, Chloroform-d) δ 8.43 (s, 1H), 7.96 (d, J = 7.8 Hz, 2H), 7.67 (d, J = 7.8 Hz, 2H), 7.38 (t, J = 7.4 Hz, 2H), 7.23 (dd, J = 16.0, 7.6 Hz, 3H).

[0077] 13 C NMR (101 MHz, Chloroform-d) δ 158.68, 151.45, 139.36, 133.26, 132.94, 132.62, 132.30, 129.43, 129.10, 126.78, 125.89, 125.85, 125.81, 125.78, 125.42, 122.72, 121.09.

[0078] Imine 3f: (E)-1-(3-bromo-4-methoxyphenyl)-N-phenylmethanimine; aldehyde, amine were 3-bromo-4-methoxybenzaldehyde and aniline, respectively; isolated yield was 79%.

[0079]

[0080] 1 H NMR (400 MHz, Chloroform-d) δ 8.27 (s, 1H), 8.13 (d, J = 1.6 Hz, 1H), 7.71 (d, J = 8.5 Hz, 1H), 7.36 (t, J = 7.7 Hz, 2H), 7.19 (dd, J = 17.4, 7.8 Hz, 3H), 6.89 (d, J = 8.5 Hz, 1H), 3.88 (s, 3H).

[0081] 13 C NMR (101 MHz, Chloroform-d) δ 158.29, 158.22, 151.86, 133.33, 130.50, 129.96, 129.34, 126.12, 121.05, 112.45, 111.68, 56.54.

[0082] Imine 3g: (E)-1-phenyl-N-(p-tolyl)methanimine; aldehyde, amine were benzaldehyde and 4-methylaniline, respectively; isolated yield was 83%.

[0083]

[0084] 1H NMR (400 MHz, Chloroform-d) δ 8.33 (s, 1H), 7.91-7.72 (m, 2H), 7.48-7.22 (m, 3H), 7.10 (s, 4H), 2.27 (s, 3H).

[0085] 13 C NMR (101 MHz, Chloroform-d) δ 159.63, 149.70, 136.68, 136.00, 131.44, 130.09, 129.03, 129.00, 121.21, 21.34.

[0086] Imine 3h: (E)-1-phenyl-N-(m-tolyl)methanimine; aldehyde, amine were benzaldehyde and 3-methylaniline, respectively; isolated yield was 72%.

[0087]

[0088] 1 H NMR (400 MHz, Chloroform-d) δ 8.32 (s, 1H), 7.83 (dd, J = 6.3, 2.8 Hz, 2H), 7.38-7.30 (m, 3H), 7.20 (s, 1H), 6.99 (s, 3H), 2.30 (s, 3H).

[0089] 13 C NMR (101 MHz, Chloroform-d) δ 160.53, 152.21, 139.18, 136.47, 131.62, 129.32, 129.13, 129.04, 127.12, 121.99, 118.29, 21.73.

[0090] Imine 3i: (E)-N-(2-iodophenyl)-1-phenylmethanimine; aldehyde, amine were benzaldehyde and 2-iodoaniline, respectively; isolated yield was 82%.

[0091]

[0092] 1 H NMR (400 MHz, Chloroform-d) δ 8.18 (s, 1H), 7.96-7.76 (m, 3H), 7.41 (s, 3H), 6.96-6.77 (m, 2H).

[0093] 13C NMR (101 MHz, Chloroform-d) δ 161.00, 152.99, 139.11, 135.86, 131.90, 129.54, 129.27, 128.99, 127.27, 118.58, 95.27.

[0094] Imine 3j: (E)-N-(2-fluorophenyl)-1-phenylmethanimine; aldehyde, amine were benzaldehyde and 2-fluoroaniline, respectively; isolated yield was 69%.

[0095]

[0096] 1 H NMR (400 MHz, Chloroform-d) δ 8.49 (s, 1H), 7.95-7.86 (m, 2H), 7.46 (d, J = 7.0 Hz, 3H), 7.20-7.05 (m, 4H).

[0097] 13 C NMR (101 MHz, Chloroform-d) δ 140.17, 140.07, 136.07, 131.92, 130.31, 129.15, 128.93, 128.60, 126.91, 126.83, 124.68, 124.64, 122.13, 122.12, 116.48, 116.28.

[0098] Imine 3k: (E)-1-tolyl-N-(p-tolyl)methanimine; aldehyde, amine were 3-methylbenzaldehyde and 4-methyl aniline, respectively; isolated yield was 71%.

[0099]

[0100] 1 H NMR (400 MHz, Chloroform-d) δ 8.37 (d, J = 2.0 Hz, 1H), 7.71 (s, 1H), 7.62 (t, J = 6.3 Hz, 1H), 7.33-7.19 (m, 2H), 7.18-7.03 (m, 4H), 2.35 (dd, J = 16.2, 3.8 Hz, 6H).

[0101] 13 C NMR (101 MHz, Chloroform-d) δ 159.85, 149.58, 138.50, 136.38, 135.75, 132.14, 129.85, 128.96, 128.69, 126.43, 120.93, 21.39, 21.11.

[0102] Imine 3l: (E)-N-(2-fluorophenyl)-1-(m-tolyl)methanimine; aldehyde, amine were 3-methylbenzaldehyde and 2-fluoroaniline, respectively; isolated yield was 88%.

[0103]

[0104] 1 H NMR (400 MHz, Chloroform-d) δ 8.46 (s, 1H), 7.77 (s, 1H), 7.66 (d, J = 6.9 Hz, 1H), 7.35 (ddd, J = 25.3, 17.3, 7.5 Hz, 2H), 7.13 (dd, J = 5.4, 2.9 Hz, 4H), 2.40 (s, 3H).

[0105] 13 C NMR (101 MHz, Chloroform-d) δ 192.75, 163.33, 163.30, 156.56, 154.09, 140.28, 140.18, 139.04, 138.70, 136.03, 135.43, 132.77, 130.15, 129.23, 129.01, 128.79, 127.36, 126.80, 126.78, 126.73, 124.65, 124.62, 122.09, 122.07, 116.45, 116.25, 21.43.

[0106] Imine 3m: (E)-1-(3-bromo-4-methoxyphenyl)-N-(2,6-diisopropylphenyl)methanimine; aldehyde, amine were 3-bromo-4-methoxybenzaldehyde and 2,5-diisopropylaniline, respectively; isolated yield was 83%.

[0107]

[0108] 1 H NMR (400 MHz, Chloroform-d) δ 8.16 (s, 1H), 8.07 (s, 1H), 7.79 (d, J = 8.5 Hz, 1H), 7.17 - 7.06 (m, 3H), 6.99 (d, J = 8.5 Hz, 1H), 3.96 (s, 3H), 2.95 (p, J = 6.8 Hz, 2H), 1.16 (d, J = 6.9 Hz, 12H).

[0109] 13C NMR (101 MHz, Chloroform-d) δ 159.76, 158.32, 149.03, 137.67, 133.07, 130.18, 129.42, 124.13, 123.03, 112.44, 111.64, 56.49, 27.94, 23.53.

[0110] Imine 3n: (E)-N-(2,6-diisopropylphenyl)-1-(3,4,5-trimethoxyphenyl)methanimine; aldehyde and amine were 3,4,5-trimethoxybenzaldehyde and 2,5-diisopropylaniline, respectively; isolated yield was 85%.

[0111]

[0112] 1 H NMR (400 MHz, Chloroform-d) δ 9.85 (s, 1H), 7.12 (s, 2H), 7.02 (d, J = 7.6 Hz, 1H), 6.78 (t, J = 7.6 Hz, 0H), 3.92 (d, J = 8.2 Hz, 9H), 3.77 (s, 1H), 2.92 (dt, J = 13.3, 6.7 Hz, 1H), 1.26 (d, J = 6.7 Hz, 6H).

[0113] 13 C NMR (101 MHz, Chloroform-d) δ 191.03, 153.59, 143.46, 140.29, 132.28, 131.69, 122.68, 118.37, 106.60, 60.92, 56.18, 27.85, 22.41.

[0114] Imine 3o: (E)-N-benzylidene-4-methylbenzenesulfonamide; aldehyde and amine were benzaldehyde and p-toluenesulfonamide, respectively; isolated yield was 84%.

[0115]

[0116] 1 H NMR (400 MHz, Chloroform-d) δ 9.03 (s, 1H), 7.90 (dd, J = 10.8, 8.3 Hz, 4H), 7.61 (t, J = 7.4 Hz, 1H), 7.48 (t, J = 7.5 Hz, 2H), 7.34 (d, J = 7.9 Hz, 2H), 2.43 (s, 3H).

[0117] 13C NMR (101 MHz, Chloroform-d) δ 170.17, 144.66, 135.15, 134.98, 132.40, 131.33, 129.85, 129.18, 128.13, 21.70.

[0118] Imine 3p: (E)-N-tert-butyl-1-phenylmethanimine; aldehyde and amine were benzaldehyde and tert-butylamine, respectively; isolated yield was 90%.

[0119]

[0120] 1 H NMR (400 MHz, Chloroform-d) δ 8.24 (s, 1H), 7.73 (dd, J = 6.8, 2.4 Hz, 2H), 7.35 (dt, J = 5.0, 2.9 Hz, 3H), 1.28 (s, 9H).

[0121] 13 C NMR (101 MHz, Chloroform-d) δ 155.14, 137.27, 130.27, 128.60, 128.03, 57.32, 29.87.

[0122] Imine 3q: (E)-1-(furan-2-yl)-N-phenylmethanimine; aldehyde and amine were furan-2- carboxaldehyde and aniline, respectively; isolated yield was 78%.

[0123]

[0124] 1 H NMR (400 MHz, Chloroform-d) δ 8.19 (s, 1H), 7.51 (s, 1H), 7.32 (t, J = 7.6 Hz, 2H), 7.21 - 7.16 (m, 3H), 6.86 (d, J = 3.2 Hz, 1H), 6.46 - 6.43 (m, 1H).

[0125] 13 C NMR (101 MHz, Chloroform-d) δ 152.07, 151.34, 147.80, 145.69, 129.24, 126.30, 121.07, 116.48, 112.27.

[0126] Imine 3r: (1E,2E)-N,3-diphenylprop-2-en-1-imine; aldehyde and amine were cinnamaldehyde and aniline, respectively; isolated yield was 79%.

[0127]

[0128] 1 H NMR (400 MHz, Chloroform-d) δ 8.26 (dd, J = 6.2, 1.8 Hz, 1H), 7.53 (d, J = 6.9 Hz, 2H), 7.38 (tt, J = 11.1, 4.9 Hz, 5H), 7.25 - 7.12 (m, 5H).

[0129] 13 C NMR (101 MHz, Chloroform-d) δ 161.81, 151.81, 144.20, 135.69, 129.75, 129.32, 129.07, 128.69, 127.64, 126.28, 121.07.

[0130] Imine 3s: (1E,2E)-3-(2-methoxyphenyl)-N-phenylprop-2-en-1-imine; aldehyde, amine were 2-methoxycinnamaldehyde and aniline, respectively; separation yield was 88%.

[0131]

[0132] 1 H NMR (400 MHz, Chloroform-d) δ 8.29 (dd, J = 9.0, 1.8 Hz, 1H), 7.65 - 7.48 (m, 2H), 7.40 (t, J = 7.9 Hz, 2H), 7.37 - 7.30 (m, 1H), 7.28 - 7.11 (m, 4H), 7.08 - 6.86 (m, 2H), 3.87 (d, J = 1.8 Hz, 3H).

[0133] 13 C NMR (101 MHz, Chloroform-d) δ 162.69, 157.58, 151.84, 139.49, 130.91, 129.20, 129.00, 127.85, 126.01, 124.49, 121.03, 120.89, 111.12, 55.50.

[0134] Imine 3t: (1E,2E)-N-phenyl-3-(p-tolyl)prop-2-en-1-imine; aldehyde, amine were 4-methylcinnamaldehyde and aniline, respectively; separation yield was 86%.

[0135]

[0136] 1H NMR (400 MHz, Chloroform-d) δ 8.21 (d, J = 6.0 Hz, 1H), 7.44 - 7.32 (m, 4H), 7.18 (t, J = 7.3 Hz, 5H), 7.07 (d, J = 5.2 Hz, 2H), 2.35 (s, 3H).

[0137] 13 C NMR (101 MHz, Chloroform-d) δ 161.85, 151.81, 144.17, 139.93, 132.87, 129.69, 129.20, 127.64, 127.51, 126.04, 120.97, 21.50.

[0138] Imine 3u: (1E,2E)-3-(4-methoxyphenyl)-N-phenylprop-2-en-1-imine; aldehyde compound, amine compound were 4-methoxycinnamaldehyde and aniline, respectively; separation yield was 83%.

[0139]

[0140] 1 H NMR (400 MHz, Chloroform-d) δ 8.20 (d, J = 8.4 Hz, 1H), 7.46 (d, J = 8.4 Hz, 2H), 7.36 (t, J = 7.6 Hz, 2H), 7.25 - 7.12 (m, 3H), 7.09 - 6.94 (m, 2H), 6.89 (d, J = 8.5 Hz, 2H), 3.79 (s, 3H).

[0141] 13 C NMR (101 MHz, Chloroform-d) δ 161.94, 160.84, 151.82, 143.90, 129.18, 129.07, 128.36, 126.39, 125.93, 120.95, 114.38, 55.36.

[0142] Imine 3v: (1E,2E)-3-(2-nitrophenyl)-N-phenylprop-2-en-1-imine; aldehyde compound, amine compound were 2-nitrocinnamaldehyde and aniline, respectively; separation yield was 70%.

[0143]

[0144] 1H NMR (400 MHz, Chloroform-d) δ 8.32 (d, J = 8.9 Hz, 1H), 8.01 (d, J = 8.1 Hz, 1H), 7.79 - 7.60 (m, 3H), 7.44 (dt, J = 38.7, 7.6 Hz, 3H), 7.23 (dd, J = 20.4, 7.4 Hz, 3H), 7.07 (dd, J = 15.8, 8.9 Hz, 1H).

[0145] 13 C NMR (101 MHz, Chloroform-d) δ 160.89, 151.26, 148.08, 138.23, 133.62, 133.26, 131.32, 129.81, 129.37, 128.59, 126.81, 125.11, 121.11.

[0146] Imine 3w: N,N-dimethyl-4-((lE,3E)-3-(phenylimino)prop-l-en-l-yl)aniline; aldehyde, amine were 4-N,N-dimethyl cinnamaldehyde and aniline, respectively; isolated yield was 86%.

[0147]

[0148] 1 H NMR (400 MHz, Chloroform-d) δ 8.21 (d, J = 8.9 Hz, 1H), 7.42 (d, J = 8.7 Hz, 2H), 7.36 (t, J = 7.8 Hz, 2H), 7.18 (t, J = 7.9 Hz, 3H), 7.06 (d, J = 15.8 Hz, 1H), 6.93 (dd, J = 15.7, 8.9 Hz, 1H), 6.67 (d, J = 8.7 Hz, 2H), 2.99 (s, 6H).

[0149] 13 C NMR (101 MHz, Chloroform-d) δ 162.55, 152.23, 151.41, 145.10, 129.24, 129.21, 125.65, 124.01, 123.68, 121.09, 112.11, 40.32.

[0150] It is apparent that the above examples are merely illustrative and not limiting on the embodiments. Based on the above description, those skilled in the art can make other different forms of changes or variations. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for producing an imine compound, characterized by, The method comprises the following steps: reacting an aldehyde compound, an amine compound and a cesium-containing inorganic salt in an alcohol solvent to obtain the imine compound; the reaction is carried out at a temperature of 20-40 DEG C for 18-30 hours. The aldehyde compound has the following structural formula: ， R1, R2 and R3 are independently selected from hydrogen, hydroxyl, halogen, nitro, sulfonic acid group, C1-C4 alkoxy, substituted or unsubstituted C1-C6 alkyl; the substituted group is halogen; R4 is selected from furanyl; R5 and R6 are independently selected from hydrogen, hydroxyl, halogen, nitro, sulfonic acid group, C1-C4 alkoxy, substituted or unsubstituted C1-C6 alkyl; the substituted group is halogen; The amine compound has the following structural formula: ， wherein R 10 , R 11 , R 12 and R 13 are independently selected from hydrogen, hydroxyl, halogen, nitro, sulfonic acid group, C1-C4alkoxy or C1-C6alkyl; R 14 selected from p-toluenesulfonyl or tert-butyl; The cesium-containing inorganic salt is cesium chloride.

2. The method for preparing the imine compound according to claim 1, characterized in that, The alcohol solvent is selected from one or more of methanol, ethanol, isopropanol and tert-butanol.

3. The method for preparing the imine compound according to claim 1, characterized in that, The molar ratio of the aldehyde compound to the amine compound is 1:1-1:

2.

4. The method for preparing the imine compound according to claim 1, characterized in that, The molar ratio of the cesium-containing inorganic salt to the aldehyde compound is 5:1-1:

10.

5. The method for preparing the imine compound according to claim 1, characterized in that, After the reaction, the imine compound is separated from the reaction solution by using a sand core funnel.

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