A method for electrochemically synthesizing amine compounds

Abstract

The present invention belongs to the technical field of electrochemical organic synthesis, and specifically relates to a method for electrochemically synthesizing amine compounds. The method for electrochemically synthesizing amine compounds described in the present invention, adds hydrazine compounds, hydrochloric acid and electrolytes to a solvent to form a reaction system, uses metals as anodes and cathodes, and performs constant current preparation, the current used is 8-15mA, after the reaction is completed, the reactants are post-treated to obtain amine compounds; the molar ratio of the hydrazine compounds, hydrochloric acid and electrolyte is 1:0.5-2:0.5-4. The structural formula of the hydrazine compound is Formula 1, Formula 2, Formula 3, Formula 4 or Formula 5:. The method for electrochemically synthesizing amine compounds provided by the present invention is simple to operate, does not require metal additives, has high product yield and is easy to separate.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical organic synthesis, and in particular relates to a method for electrochemically synthesizing amine compounds. Background Art

[0002] Amines and other nitrogen-containing functional groups are widely present in natural products, synthetic intermediates and fine chemicals, showing important application value. Among them, primary amines, as key chemical raw materials, are widely used in advanced materials, dye industry, pharmaceutical manufacturing, rubber additives and other fields. For example, 9,9-diphenyl-2-aminofluorene, as a synthetic intermediate, occupies an important position in the synthesis of OLED organic light-emitting materials. In addition, monoaryl-alkyl secondary amines play an important role in the production of pesticides and insecticides, and can also be used as gasoline additives and dye intermediates; and diarylamines are not only important synthetic building blocks, but also a key class of organic optoelectronic materials. Therefore, the development of efficient methods for the synthesis of amino-containing organic small molecules has always been a research hotspot in the field of synthetic chemistry.

[0003] In the synthesis of amine compounds, the synthesis of amines by breaking the N-N bond of hydrazine compounds is an important type of reaction. At present, the method of synthesizing amines from hydrazine compounds mainly relies on traditional chemical methods, such as metal reduction (including the use of zinc powder under acidic conditions and the use of Na(Li) / NH3 under strong alkaline conditions), low-valent metal salt reducing agents (such as titanium trichloride, samarium diiodide, etc.), catalytic hydrogenation (using palladium carbon, platinum dioxide, RANEY-Ni, etc.), photocatalysis (using ultraviolet light or visible light catalysis) and transition metal catalysis (such as ruthenium catalyst, rhodium catalyst, etc.). However, these methods generally have problems such as harsh reaction conditions (such as high temperature, strong acid, strong base), cumbersome reaction steps, expensive precious metal catalysts, poor compatibility of substrate functional groups, difficulty in separating by-products, and high cost of reaction equipment. These problems not only increase the reaction cost, but also do not meet the environmental protection requirements of green chemical processes.

[0004] Organic electrochemical reduction methods use clean electrons as reducing agents, can achieve the reduction of target molecules without exogenous chemical reducing agents, and can improve reaction efficiency and selectivity by means of current and voltage regulation and the use of electrocatalysts, thus becoming an efficient and green synthetic strategy. Therefore, in view of the limitations of the existing technology, it is necessary to develop a method for synthesizing amines from hydrazine compounds with a wide substrate range, high reaction efficiency and good economy, so as to meet the current demand for efficient and green synthetic strategies in the field of synthetic chemistry. Summary of the invention

[0005] The technical problem that the present invention aims to solve is to overcome the defects of the prior art and provide a method for electrochemically synthesizing amine compounds, which has the advantages of simple operation, no need for metal additives, high product yield and easy separation.

[0006] The electrochemical synthesis method of amine compounds of the present invention comprises adding a hydrazine compound, hydrochloric acid and an electrolyte into a solvent to form a reaction system, using metals as anodes and cathodes, and performing constant current preparation. The current used is 8-15 mA. After the reaction is completed, the reactants are post-treated to obtain amine compounds.

[0007] The molar ratio of the hydrazine compound, hydrochloric acid and electrolyte is 1:0.5-2:0.5-4;

[0008] The concentrations of the hydrazine compound, hydrochloric acid and electrolyte are respectively: the concentration of the hydrazine compound is 0.033 mmol / mL, the concentration of the hydrochloric acid (HCl) is 0.017-0.067 mmol / mL, and the concentration of the electrolyte is 0.017-0.133 mmol / mL.

[0009] The structural formula of the hydrazine compound is Formula 1, Formula 2, Formula 3, Formula 4 or Formula 5:

[0010] ;

[0011] Wherein, in Formula 1, the R 1 is 4-phenyl, 4-benzyl, hydrogen, 2-phenyl, 2-benzyl, 3-methoxy-4-phenyl; in Formula 2, R 2 is phenyl, R 1 is hydrogen, 4-methoxy, 4-ethyl acetate, 3-methoxy, 3,4-dimethyl, aryl, 1-naphthyl, or R 2 is methyl, R 1 is hydrogen, 4-methoxy, 4-methyl, 4-cyano, 2-phenyl, or R 1 is hydrogen, R 2 is 2-hydroxyethyl; in Formula 3, R 1 It is methyl and phenyl.

[0012] The prepared amine compound is 4-aminobiphenyl, 4-aminodiphenylmethane, aniline, o-aminobiphenyl, o-benzylaniline, 3-methoxy-4-phenylaniline, 2-amino-9,9-dimethylfluorene, diphenylamine, 4-methoxydiphenylamine, 4-(phenylamino)ethyl benzoate, 3-methoxydiphenylamine, 3,4-dimethyldiphenylamine, iminodibenzyl, 1-naphthylaminobenzene, N-methylaniline, N-methyl-p-aminoanisole, N-methyl-p-methylaniline, N-methyl-4-cyanoaniline, N-methylbiphenyl-2-amine, 1,2,3,4-tetrahydroquinoline, N-phenylethanolamine or 9,9-diphenyl-2-aminofluorene.

[0013] The metal of the anode is one of tin sheet, zinc sheet, aluminum sheet, magnesium sheet, stainless steel sheet, iron sheet, nickel sheet and copper sheet. The area of ​​the anode inserted into the reaction solution is 1 cm 2 The metal of the cathode is one of tin, zinc, aluminum, magnesium, carbon, copper, platinum, and lead. The area of ​​the cathode inserted into the reaction solution = 1 cm 2 The thickness of the anode sheet and the cathode sheet is 0.5 mm. Preferably, the anode and the cathode are tin sheet electrodes.

[0014] The constant current reaction time is 6-8h, and the reaction temperature is 20-30°C.

[0015] When performing the constant current preparation, a single-chamber electrolytic cell without a diaphragm is used.

[0016] The solvent is one of N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and acetonitrile (MeCN).

[0017] The electrolyte is one of lithium acetate (LiOAc), tetrabutylammonium hexafluorophosphate (n-Bu4NPF6), tetrabutylammonium bromide (n-Bu4NBr), tetrabutylammonium iodide (n-Bu4NI), tetrabutyltetrafluoroboric acid (n-Bu4NBF4), tetrabutylammonium p-toluenesulfonate (n-Bu4NOTs), tetrabutylammonium acetate (n-Bu4NOAc), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), magnesium perchlorate (Mg(ClO4)2), and sodium iodide (NaI).

[0018] The post-treatment is to first quench with water, then extract with an organic reagent, then back-extract with saturated brine, dry with anhydrous sodium sulfate, distill under reduced pressure, and purify by silica gel column chromatography. The separation and purification method is to remove the extractant by rotary evaporation, and purify the residue by silica gel column chromatography.

[0019] The organic reagent is further ethyl acetate, dichloromethane or petroleum ether.

[0020] In the further silica gel column chromatography purification, ethyl acetate: petroleum ether is used in a ratio of 4:1-15:1. When performing constant current preparation, the current is 8-15 mA. Too large or too small a current will result in a reduced yield.

[0021] Preferably, the method for electrochemically synthesizing amine compounds comprises the following steps:

[0022] (1) Add 0.2 mmol of hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide to a 25 mL integrated electrolytic cell. Stir continuously with a magnetic bar at room temperature and air. Insert tin sheets as anode and cathode into the electrolytic cell. React at a constant current of 15 mA for 8 h and monitor by TLC.

[0023] (2) After the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue is purified by rapid silica gel column chromatography to obtain the reaction product. The eluent for silica gel column chromatography purification is ethyl acetate: petroleum ether = 1:4, and then the product is qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum are tested by deuterated chloroform-d dissolution.

[0024] Principle of the present invention:

[0025]

[0026] The present invention adopts an electro-reduction method, uses hydrazine and hydrochloric acid (hydrazine hydrochloride) as raw materials, and synthesizes amine compounds in one step at room temperature and pressure. The reaction does not require a metal catalyst or any metal reducing agent, and the product is easy to separate with high yield. The reaction has the following advantages: no metal additives are required, and the reaction is completed by electron transfer instead of the use of traditional chemical reducing agents. Cheap metal Sn is used as an electrode, no further modification is required, the reaction conditions are loose, the operation is simple, the integrated electrolytic cell does not require a diaphragm, the product is easy to separate, and the substrate functional group has good tolerance. It avoids the problems of complex operation, low yield, poor selectivity, strong reagent toxicity, and difficulty in industrialization due to the presence of precious metals in other synthetic methods.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The electrochemical synthesis method of amine compounds of the present invention does not require high temperature, high pressure, strong acid or strong alkaline conditions, nor does it require complicated synthesis steps. The amine compounds can be synthesized in one step at room temperature and pressure.

[0029] (2) The electrochemical synthesis method of amine compounds of the present invention is not restricted by site, can be synthesized in one step, requires little equipment investment, is easy to operate, has no background reaction in the electrochemical reaction, can be shut down at any time by current control, uses electrons as a clean and efficient reducing agent, and avoids the use of potentially toxic reducing agents.

[0030] (3) The electrochemical synthesis method of amine compounds of the present invention does not require metal additives, uses cheap metals as electrodes, does not require further modification, does not require a diaphragm in the integrated electrolytic cell, has loose reaction conditions, and is easy to operate.

[0031] (4) The electrochemical reduction method of the present invention for electrochemically synthesizing amine compounds has high selectivity and mild electroreduction reaction conditions, so the substrate functional groups have good tolerance, thus avoiding the problem of extremely poor compatibility of substrate functional groups caused by the strong reduction conditions in other synthesis methods and the difficulty in separating by-products from products. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the H NMR spectrum of the product of Example 1 of the present invention;

[0033] Figure 2 This is the NMR carbon spectrum of the product of Example 1 of the present invention;

[0034] Figure 3 This is the H NMR spectrum of the product of Example 2 of the present invention;

[0035] Figure 4 This is the NMR carbon spectrum of the product of Example 2 of the present invention;

[0036] Figure 5 This is the H NMR spectrum of the product of Example 3 of the present invention;

[0037] Figure 6 This is the NMR carbon spectrum of the product of Example 3 of the present invention;

[0038] Figure 7 This is the H NMR spectrum of the product of Example 4 of the present invention;

[0039] Figure 8 This is the NMR carbon spectrum of the product of Example 4 of the present invention;

[0040] Fig. 9 This is the H NMR spectrum of the product of Example 5 of the present invention;

[0041] Fig.10 This is the NMR carbon spectrum of the product of Example 5 of the present invention;

[0042] Fig.11 This is the H NMR spectrum of the product of Example 6 of the present invention;

[0043] Fig.12 This is the NMR carbon spectrum of the product of Example 6 of the present invention;

[0044] Fig.13 This is the H NMR spectrum of the product of Example 7 of the present invention;

[0045] Fig.14 This is the NMR carbon spectrum of the product of Example 7 of the present invention;

[0046] Fig.15 This is the H NMR spectrum of the product of Example 8 of the present invention;

[0047] Fig.16This is the NMR carbon spectrum of the product of Example 8 of the present invention;

[0048] Fig.17 This is the H NMR spectrum of the product of Example 9 of the present invention;

[0049] Fig.18 This is the NMR carbon spectrum of the product of Example 9 of the present invention;

[0050] Fig.19 This is the H NMR spectrum of the product of Example 10 of the present invention;

[0051] Fig. 20 This is the NMR carbon spectrum of the product of Example 10 of the present invention;

[0052] Fig.21 This is the H NMR spectrum of the product of Example 11 of the present invention;

[0053] Fig. 22 This is the NMR carbon spectrum of the product of Example 11 of the present invention;

[0054] Fig.23 This is the H NMR spectrum of the product of Example 12 of the present invention;

[0055] Fig.24 This is the NMR carbon spectrum of the product of Example 12 of the present invention;

[0056] Fig.25 This is the H NMR spectrum of the product of Example 13 of the present invention;

[0057] Fig.26 This is the NMR carbon spectrum of the product of Example 13 of the present invention;

[0058] Fig. 27 This is the H NMR spectrum of the product of Example 14 of the present invention;

[0059] Fig.28 This is the NMR carbon spectrum of the product of Example 14 of the present invention;

[0060] Fig.29 This is the H NMR spectrum of the product of Example 15 of the present invention;

[0061] Fig.30 This is the NMR carbon spectrum of the product of Example 15 of the present invention;

[0062] Fig.31 This is the H NMR spectrum of the product of Example 16 of the present invention;

[0063] Fig.32 This is the NMR carbon spectrum of the product of Example 16 of the present invention;

[0064] Fig.33 This is the H NMR spectrum of the product of Example 17 of the present invention;

[0065] Fig.34 This is the NMR carbon spectrum of the product of Example 17 of the present invention;

[0066] Fig.35 This is the H NMR spectrum of the product of Example 18 of the present invention;

[0067] Fig.36 This is the NMR carbon spectrum of the product of Example 18 of the present invention;

[0068] Fig.37 This is the H NMR spectrum of the product of Example 19 of the present invention;

[0069] Fig.38 This is the NMR carbon spectrum of the product of Example 19 of the present invention;

[0070] Fig.39 This is the H NMR spectrum of the product of Example 20 of the present invention;

[0071] Fig.40 This is the NMR carbon spectrum of the product of Example 20 of the present invention;

[0072] Fig.41 This is the H NMR spectrum of the product of Example 21 of the present invention;

[0073] Fig.42 This is the NMR carbon spectrum of the product of Example 21 of the present invention;

[0074] Fig.43 This is the H NMR spectrum of the product of Example 22 of the present invention;

[0075] Fig.44 This is the NMR carbon spectrum of the product of Example 22 of the present invention. DETAILED DESCRIPTION

[0076] The present invention is further described below in conjunction with specific examples, but is not limited to the implementation schemes described in the specific examples listed in the present invention.

[0077] The raw materials used in the examples are commercially available.

[0078] Example 1

[0079] The 4-aminobiphenyl Preparation:

[0080] 0.2 mmol of biphenyl-4-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was continuously stirred with a magnetic bar, and tin sheets were inserted into the electrolytic cell as anode and cathode. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a with a yield of 87%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum were tested by deuterated chloroform-d dissolution.

[0081] like Figure 1 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.53 (d, J = 6.8 Hz, 2H), 7.42 –7.36 (m, 4H), 7.26 (t, J = 7.6 Hz, 1H), 6.74 (d, J = 8.8 Hz, 2H), 3.67 (br,2H).

[0082] like Figure 2 As shown, 13 C NMR (101 MHz, CDCl3) δ 145.8, 141.1, 131.5, 128.6, 128.0, 126.4, 126.2, 115.3.

[0083] Example 2

[0084] The 4-aminodiphenylmethane Preparation:

[0085] 0.2 mmol of 4-benzylphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.2 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was continuously stirred with a magnetic bar, and tin sheets were inserted into the electrolytic cell as anode and cathode. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2b with a yield of 80%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0086] like Figure 3 As shown, 1H NMR (400 MHz, CDCl3) δ 7.27 –7.24(m, 2H), 7.18 – 7.14 (m,3H), 6.96 (d, J = 8.4 Hz, 2H), 6.60 (d, J = 8.4 Hz, 2H), 3.86 (s, 2H), 3.47(br, 2H).

[0087] like Figure 4 As shown, 13 C NMR (101 MHz, CDCl3) δ 144.4, 141.9, 131.1, 129.7, 128.8, 128.3, 125.8, 115.3, 41.0.

[0088] Example 3

[0089] The aniline Preparation:

[0090] Add 0.2mmol of phenylhydrazine, 0.2mmol of hydrochloric acid, 0.1mmol of lithium acetate, and 6mL of N,N-dimethylacetamide to a 25mL integrated electrolytic cell. Stir continuously with a magnetic bar at room temperature and air. Insert tin sheets as anode and cathode into the electrolytic cell. React at a constant current of 15mA for 8h and monitor by TLC. After the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, and dried with anhydrous sodium sulfate. The residue is distilled under reduced pressure at 45°C, and purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 5:1) to obtain product 2c with a yield of 60%. The product is then qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra are tested by deuterated chloroform-d dissolution.

[0091] like Figure 5 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.15 (t, J = 8.4 Hz, 2H), 6.75 (t,J = 7.6 Hz, 1H), 6.38 (d, J = 7.2 Hz, 2H), 3.62 (br, 2H).

[0092] like Figure 6 As shown, 13 C NMR (101 MHz, CDCl3) δ 146.3, 129.3, 118.5, 115.1.

[0093] Example 4

[0094] The o-aminobiphenyl Preparation:

[0095] 0.2 mmol of biphenyl-2-hydrazine, 0.4 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the mixture was continuously stirred with a magnetic bar, and a tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 15 mA for 8 h, and TLC tracking and monitoring was performed. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, and dried with anhydrous sodium sulfate. The mixture was distilled under reduced pressure at 45 °C, and the residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 5:1) to obtain product 2d with a yield of 75%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0096] like Figure 7 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.47 – 7.41 (m, 2H), 7.35 – 7.34(m, 1H), 7.17 – 7.11 (m, 2H), 6.82 (td, J = 7.6, 1.2 Hz, 1H), 6.76 (dd, J =8.0, 1.2 Hz, 1H) 3.74 (br, 2H).

[0097] like Figure 8 As shown, 13 C NMR (101 MHz, CDCl3) δ 143.5, 139.5, 130.4, 129.1, 128.8, 128.5, 127.6, 127.1, 118.6, 115.6.

[0098] Example 5

[0099] The o-benzylaniline Preparation:

[0100] 0.2 mmol of 2-benzylphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain the product 2e with a yield of 66%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0101] like Fig. 9 As shown, 1 H NMR (400 MHz, CDCl3) δ7.30 – 7.27 (m, 2H), 7.23 – 7.18(m, 3H), 7.11 – 7.05 (m, 2H), 6.77 (td, J = 7.2, 1.2 Hz, 1H), 6.67 (dd, J =8.0, 1.2 Hz, 1H), 3.90 (s, 2H), 3.49 (br, 2H).

[0102] like Fig.10 As shown, 13 C NMR (101 MHz, CDCl3) δ 144.7, 139.4, 130., 128.7, 128.5, 127.7, 126.3, 125.1, 118.7, 115.9, 38.1.

[0103] Example 6

[0104] The 3-methoxy-4-phenylaniline Preparation:

[0105] 0.2 mmol of 3-methoxy-4-phenylphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.8 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain the product 2f with a yield of 75%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0106] like Fig.11 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.49 – 7.47 (m, 2H), 7.35 (t, J =8.0 Hz, 2H), 7.22 – 7.26 (m, 1H), 7.10 (d, J = 8.4 Hz, 1H), 6.32 (dd, J =8.0, 2.0 Hz, 1H), 6.28 (d, J = 2.4 Hz, 1H), 3.72 (s, 3H), 3.68 (br, 2H).

[0107] like Fig.12 As shown, 13 C NMR (101 MHz, CDCl3) δ 157.3, 147.2, 138.7, 131.5, 129.3, 127.8, 126.0, 121.1, 107.3, 98.7, 55.3.

[0108] Example 7

[0109] The 2-amino-9,9-dimethylfluorene Preparation:

[0110] 0.2 mmol of 9,9-dimethyl-9H-fluorene-2-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the mixture was continuously stirred with a magnetic bar, and a tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 15 mA for 8 h, and TLC tracking and monitoring were performed. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, and dried with anhydrous sodium sulfate. The mixture was distilled under reduced pressure at 45 °C, and the residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 5:1) to obtain 2 g of the product with a yield of 78%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0111] like Fig.13 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.57 (d, J = 8.4 Hz, 1H), 7.49 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 7.2 Hz, 1H), 7.27 (td, J = 7.6, 1.2 Hz, 1H), 7.19 (td, J = 7.2, 1.2 Hz, 1H), 6.74 (d, J = 2.0 Hz, 1H), 6.64 (dd, J =6.8, 2.0 Hz, 1H), 3.70 (br, 2H), 1.43 (s, 6H).

[0112] like Fig.14 As shown, 13 C NMR (101 MHz, CDCl3) δ 155.5, 152.7, 146.0, 139.6, 130.3, 126.8, 125.5, 122.3, 120.8, 118.6, 114.0, 109.5, 46.6, 27.3.

[0113] Example 8

[0114] The diphenylamine Preparation:

[0115] Add 0.2 mmol of N,N-diphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide to a 25 mL integrated electrolytic cell. Stir continuously with a magnetic bar at room temperature and air. Insert tin sheets as anode and cathode into the electrolytic cell. React at a constant current of 12 mA for 6 h and monitor by TLC. After the reaction is completed, quench the reaction system with water, extract with ethyl acetate, back-extract with saturated brine, and dry with anhydrous sodium sulfate. Distill under reduced pressure at 45 °C. Purify the residue by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2h with a yield of 94%. The product is qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra are tested by deuterated chloroform-d dissolution.

[0116] like Fig.15 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.25 (t, J = 7.2 Hz, 4H), 7.06 (d, J = 7.2 Hz, 4H), 6.92 (t, J = 7.6 Hz, 2H), 5.66 (br, 1H).

[0117] like Fig.16 As shown, 13 C NMR (101 MHz, CDCl3) δ 143.1, 129.3, 121.0, 117.8.

[0118] Example 9

[0119] The 4-methoxydiphenylamine Preparation:

[0120] 0.2 mmol of 4-methoxydiphenylhydrazine, 0.1 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 15:1) to obtain product 2i with a yield of 66%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum were tested by deuterated chloroform-d dissolution.

[0121] like Fig.17 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.22 – 7.18 (m, 2H), 7.06 (d, J =9.2 Hz, 2H), 6.91 – 6.81 (m, 5H), 5.48 (br, 1H), 3.79 (s, 3H).

[0122] like Fig.18 As shown, 13 C NMR (101 MHz, CDCl3) δ 155.3, 145.2, 135.8, 129.3, 122.2, 119., 115.67, 114.7, 55.6.

[0123] Example 10

[0124] The ethyl 4-(phenylamino)benzoate Preparation:

[0125] 0.2 mmol of ethyl 4-(1-phenylhydrazine)benzoate, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. The mixture was stirred continuously with a magnetic bar at room temperature and air, and a tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 12 mA for 6 h, and TLC tracking monitoring was performed. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, and dried with anhydrous sodium sulfate. The mixture was distilled under reduced pressure at 45 °C, and the residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain product 2j with a yield of 87%. The product was then qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0126] like Fig.19 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.92 (d, J = 8.8 Hz, 2H), 7.32(t, J = 7.2 Hz, 2H), 7.16 (d, J = 7.2 Hz, 2H), 7.05 (t, J = 7.2 Hz, 1H), 6.98(d, J = 8.8 Hz, 2H), 6.10 (br, 1H), 4.33 (q, J = 7.2 Hz, 2H), 1.37 (t, J =6.8 Hz, 3H).

[0127] like Fig. 20 As shown, 13C NMR (101 MHz, CDCl3) δ 166.6, 148.0, 141.0, 131.5, 129.5, 123.0, 121.5, 120.3, 114.6, 60.5, 14.5.

[0128] Embodiment 11

[0129] The 3-methoxydiphenylamine Preparation:

[0130] 0.2 mmol of 3-methoxydiphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the mixture was continuously stirred with a magnetic bar, and a tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 12 mA for 6 h, and TLC tracking and monitoring was performed. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2k with a yield of 92%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0131] like Fig.21 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.28 – 7.24 (m, 2H), 7.16 (t, J =8.0 Hz, 1H), 7.09 – 7.07 (m, 2H), 6.93 (t, J = 7.2 Hz, 1H), 6.65 – 6.63 (m,2H), 6.49 – 6.46 (m, 1H), 5.69 (br, 1H), 3.76 (s, 3H).

[0132] like Fig. 22 As shown, 13 C NMR (101 MHz, CDCl3) δ 160.7, 144.6, 142.8, 130.1, 129.3, 121.2, 118.3, 110.2, 106.1, 103.3, 55.2.

[0133] Example 12

[0134] The 3,4-dimethyldiphenylamine Preparation:

[0135] 0.2 mmol of 3,4-dimethyldiphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was continuously stirred with a magnetic bar, and tin sheets were inserted into the electrolytic cell as anode and cathode. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2l with a yield of 93%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d dissolution test was carried out for hydrogen and carbon spectra.

[0136] like Fig.23 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.25 – 7.21 (m, 2H), 7.04 – 7.00(m, 3H), 6.89 – 6.84 (m, 3H), 5.55 (br, 1H), 2.22 (s, 3H), 2.21 (s, 3H).

[0137] like Fig.24 As shown, 13 C NMR (101 MHz, CDCl3) δ 144.1, 140.6, 137.6, 130.4, 129.7, 129.3, 120.4, 120.2, 116.9, 116.3, 20.0, 19.0.

[0138] Example 13

[0139] The iminodibenzyl Preparation:

[0140] 0.2 mmol of 3,4-dimethyldiphenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2m with a yield of 90%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0141] like Fig.25 As shown,1 H NMR (400 MHz, CDCl3) δ 7.08 – 7.02 (m, 4H), 6.76 (td, J= 7.2, 1.2 Hz, 2H), 6.71 (dd, J = 8.0, 1.2 Hz, 2H), 5.96 (br, 1H), 3.07 (s,4H).

[0142] like Fig.26 As shown, 13 C NMR (101 MHz, CDCl3) δ 142.5, 130.7, 128.7, 126.9, 119.5, 118.0, 35.0.

[0143] Embodiment 14

[0144] The 1-naphthylaminobenzene Preparation:

[0145] 0.2 mmol of 1-(1-naphthyl)-1-phenylhydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain product 2n with a yield of 82%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum were tested by deuterated chloroform-d dissolution.

[0146] like Fig. 27 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.99 (d,J = 9.6 Hz, 1H), 7.85 (d,J = 7.6 Hz, 1H), 7.55 (d, J = 7.6 Hz, 1H), 7.50 – 7.43 (m, 2H), 7.40 – 7.33(m, 2H), 7.26 – 7.21 (m, 2H), 6.97 (d,J = 9.6 Hz, 1H), 6.89 (t, J = 7.2 Hz,1H), 5.90 (br, 1H).

[0147] like Fig.28 As shown, 13C NMR (101 MHz, CDCl3) δ 144.8, 138.8, 134.7, 129.3, 128.5, 127.7, 126.1, 126.0, 125.7, 123.0, 121.8, 120.5, 117.4, 115.9.

[0148] Embodiment 15

[0149] The N-methylaniline Preparation:

[0150] 0.2 mmol of 1-methyl-1-phenylhydrazine, 0.1 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2o with a yield of 67%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0151] like Fig.29 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.19 (t, J = 7.6 Hz, 2H), 6.71 (t, J = 7.2 Hz, 1H), 6.61 (d, J = 7.8 Hz, 2H), 3.66 (br, 1H), 2.83 (s, 3H).

[0152] like Fig.30 As shown, 13 C NMR (101 MHz, CDCl3) δ 1494, 129.2, 117.3, 112.4, 30.8.

[0153] Example 16

[0154] The N-methyl p-aminoanisole Preparation:

[0155] 0.2 mmol of N-methyl-N-(p-methoxyphenyl)hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2p with a yield of 94%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum were tested by deuterated chloroform-d dissolution.

[0156] like Fig.31 As shown, 1 H NMR (400 MHz, CDCl3) δ 6.80 (d, J = 8.8 Hz, 2H), 6.59 (d, J = 8.8 Hz, 2H), 3.75 (s, 3H), 3.11 (br, 1H), 2.81 (s, 3H).

[0157] like Fig.32 As shown, 13 C NMR (101 MHz, CDCl3) δ 152.2, 143.6, 114.9, 113.7, 55.9, 31.7.

[0158] Embodiment 17

[0159] The N-methyl-p-methylaniline Preparation:

[0160] 0.2 mmol of 1-methyl-1-(p-tolyl)hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2q with a yield of 88%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen spectrum and carbon spectrum were tested by deuterated chloroform-d dissolution.

[0161] like Fig.33 As shown, 1H NMR (400 MHz, CDCl3) δ 7.00 (d, J = 6.4 Hz, 2H), 6.53 (d, J = 8.4 Hz, 2H), 3.51 (br, 1H), 2.79 (s, 3H), 2.24 (s, 3H).

[0162] like Fig.34 As shown, 13 C NMR (101 MHz, CDCl3) δ 147.2, 129.7, 126.5, 112.6, 31.1, 20.4.

[0163] Embodiment 18

[0164] The N-methyl-4-cyanoaniline Preparation:

[0165] 0.2 mmol of 4-(1-methylhydrazine)benzonitrile, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. The mixture was stirred continuously with a magnetic bar at room temperature and air. The tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain product 2r with a yield of 93%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0166] like Fig.35 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.43 (d, J = 8.4 Hz, 2H), 6.55 (d, J = 8.8 Hz, 2H), 4.29 (br, 1H), 2.88 (d, J = 4.4 Hz, 3H).

[0167] like Fig.36 As shown, 13 C NMR (101 MHz, CDCl3) δ 152.2, 133.7, 120.6, 111.8, 98.6, 30.0.

[0168] Embodiment 19

[0169] The N-methylbiphenyl-2-amine Preparation:

[0170] 0.2 mmol of 1-methyl-1-(2-biphenyl)hydrazine, 0.2 mmol of hydrochloric acid, 0.3 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 8 mA for 8 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 10:1) to obtain the product 2s with a yield of 75%. The product was qualitatively analyzed by nuclear magnetic resonance, and the deuterated chloroform-d was dissolved to test the hydrogen spectrum and carbon spectrum.

[0171] like Fig.37 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.45 – 7.40 (m, 4H), 7.36 – 7.31(m, 1H), 7.27 (t, J = 8.0 Hz, 1H), 7.08 (dd, J = 7.2, 1.6 Hz, 1H), 6.77 (t, J= 7.2 Hz, 1H), 6.69 (d, J = 8.0 Hz, 1H), 3.95 (br, 1H), 2.79 (s, 3H).

[0172] like Fig.38 As shown, 13 C NMR (101 MHz, CDCl3) δ 146.1, 139.5, 130.0, 129.4, 128.8, 128.7, 127.6, 127.2, 116.8, 109.8, 30.7.

[0173] Embodiment 20

[0174] The 1,2,3,4-tetrahydroquinoline Preparation:

[0175] Add 0.2mmol of 1-amino-1,2,3,4-tetrahydroquinoline, 0.2mmol of hydrochloric acid, 0.4mmol of lithium acetate, and 6mL of N,N-dimethylacetamide to a 25mL integrated electrolytic cell. Stir continuously with a magnetic bar at room temperature and air. Insert the tin sheet as anode and cathode into the electrolytic cell. React for 6h at a constant current of 12mA and monitor by TLC. After the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue is purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 15:1) to obtain the product 2t with a yield of 61%. The product is then qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra are tested by deuterated chloroform-d dissolution.

[0176] like Fig.39 As shown, 1 H NMR (400 MHz, CDCl3) δ 6.97 – 6.92 (m, 2H), 6.60 (t, J =7.6 Hz, 1H), 6.46 (d, J = 7.6 Hz, 1H), 3.58 (br, 1H), 3.29 (t, J = 5.6 Hz, 2H), 2.76 (t, J = 6.4 Hz, 2H), 1.96 – 1.90 (m, 2H).

[0177] like Fig.40 As shown, 13 C NMR (101 MHz, CDCl3) δ 144.8, 129.5, 126.7, 121.5, 117.0, 114.2, 42.0, 27.0, 22.2.

[0178] Embodiment 21

[0179] The N-phenylethanolamine Preparation:

[0180] 0.2 mmol of 2-(1-phenylhydrazine)ethanol, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the electrolytic cell was inserted with tin sheets as anode and cathode and stirred continuously with a magnetic bar. The reaction was carried out at a constant current of 12 mA for 6 h and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 5:1) to obtain the product 2u with a yield of 86%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0181] like Fig.41 As shown, 1 H NMR (400 MHz, CDCl3) δ 7.21 – 7.16 (m, 2H), 6.74 (t, J =7.6 Hz, 1H), 6.66 (d, J = 7.6 Hz, 2H), 3.82 (t, J = 5.2 Hz, 2H), 3.30 (t, J =5.2 Hz, 2H).

[0182] like Fig.42 As shown, 13 C NMR (101 MHz, CDCl3) δ 148.1, 129.3, 117.9, 113.2, 61.3, 46.1.

[0183] Embodiment 22

[0184] The OLED material intermediate 9,9-diphenyl-2-aminofluorene Preparation:

[0185] 0.2 mmol of 9,9-diphenyl-9H-fluorene-2-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added to a 25 mL integrated electrolytic cell. Under room temperature and air conditions, the mixture was continuously stirred with a magnetic bar, and a tin sheet was inserted into the electrolytic cell as the anode and cathode. The reaction was carried out at a constant current of 15 mA for 8 h and monitored by TLC. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45 °C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain the product 2v with a yield of 75%. The product was qualitatively analyzed by nuclear magnetic resonance, and the hydrogen and carbon spectra were tested by deuterated chloroform-d dissolution.

[0186] like Fig.43 As shown, 1 H NMR (400 MHz, DMSO-d6) δ 7.65 (d, J = 7.6 Hz, 1H), 7.57(d, J = 8.0 Hz, 1H), 7.32 – 7.21 (m, 8H), 7.14 – 7.10 (m, 5H), 6.64 – 6.60(m, 2H), 5.23 (br, 2H).

[0187] like Fig.44As shown, 13C NMR (101 MHz, DMSO-d6) δ 152.7, 150.0, 149.6, 146.7,141.3, 128.7, 128.3, 128.0, 127.9, 126.9, 126.1, 125.7, 121.6, 118.9, 114.0,111.5, 65.1.

[0188] The following Examples 23 to 58 have the same preparation process as Example 1, and are all used to prepare the 2a product of Example 1. The reaction conditions are shown in Table 1.

[0189]

[0190] According to the results in the above table, we can analyze:

[0191] (1) Screening of anode electrode materials for Examples 23-29

[0192] To a 25 mL integrated electrolytic cell, 0.2 mmol of biphenyl-4-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added. A tin electrode (Example 23), a zinc electrode (Example 24), an aluminum electrode (Example 25), a magnesium electrode (Example 26), an iron electrode (Example 27), a nickel electrode (Example 28), and a copper electrode (Example 29) were used as anodes, and a tin sheet electrode was used as a cathode. The reaction was carried out at room temperature and air conditions, and a magnetic stirrer was used continuously. The reaction was carried out at a constant current of 15 mA for 8 h, and TLC tracking and monitoring was performed. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a with corresponding yields of 87% (Example 23), 37% (Example 24), 14% (Example 25), 18% (Example 26), 19% (Example 27), 30% (Example 28), and 19% (Example 29). The above results show that the yield is optimal when the tin electrode is used as the anode.

[0193] (2) Screening of cathode electrode materials for Examples 23, 30-37

[0194] To a 25 mL integrated electrolytic cell, 0.2 mmol of biphenyl-4-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added, and the mixture was stirred continuously with a magnetic bar. A zinc electrode (Example 30), a stainless steel electrode (Example 31), a copper electrode (Example 32), a magnesium electrode (Example 33), an aluminum electrode (Example 34), a lead electrode (Example 35), a platinum electrode (Example 36), and a carbon electrode (Example 37) were used as cathodes, and a tin sheet electrode was used as an anode. The mixture was reacted at a constant current of 15 mA for 8 h under room temperature and air conditions, and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a with corresponding yields of 37% (Example 30), 33% (Example 31), 60% (Example 32), 61% (Example 33), 33% (Example 34), 80% (Example 35), 68% (Example 36), and 80% (Example 37). The above results show that the yield is optimal when the tin electrode is used as the anode.

[0195] (3) Screening of reaction solvents for Examples 23, 38-40

[0196] Add 0.2mmol of biphenyl-4-hydrazine, 0.2mmol of hydrochloric acid, and 0.4mmol of lithium acetate to a 25mL integrated electrolytic cell, respectively, with 6mL of N,N-dimethylacetamide (Example 23), 6mL of N,N-dimethylformamide (Example 38), 6mL of dimethyl sulfoxide (Example 39), and 6mL of acetonitrile (Example 40) as solvents, and stir continuously with a magnetic bar, respectively, with tin sheet electrodes as cathode and anode, react at a constant current of 15mA for 8h under room temperature and air conditions, and track and monitor by TLC; after the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue is purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a, with corresponding yields of 87% (Example 23), 75% (Example 38), 66% (Example 39), and 48% (Example 40). The above results show that the yield is optimal when N,N-dimethylacetamide is used as a solvent.

[0197] (4) Screening of reaction solvents for Examples 23, 41-44

[0198] To a 25 mL integrated electrolytic cell, 0.2 mmol of biphenyl-4-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate, and 6 mL of N,N-dimethylacetamide were added, and the mixture was stirred continuously with a magnetic bar. Tin sheet electrodes were used as cathode and anode, respectively. Under room temperature and air conditions, the reaction was carried out at a constant current of 15 mA for 8 h (Example 23), 5 mA for 20 h (Example 41), 7.5 mA for 16 h (Example 42), 10 mA for 12 h (Example 43), and 12.5 mA for 10 h (Example 44), and monitored by TLC tracking. After the reaction was completed, the reaction system was quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a with corresponding yields of 87% (Example 23), 35% (Example 41), 60% (Example 42), 71% (Example 43), and 82% (Example 44). The above results show that the yield is optimal when the reaction is carried out at a current of 15 mA for 8 hours.

[0199] (5) Screening of electrolyte dosage in Examples 23, 45-48

[0200] Add 0.2mmol of biphenyl-4-hydrazine, 0.2mmol of hydrochloric acid, 0.4mmol of lithium acetate (Example 23), 0.1mmol of lithium acetate (Example 45), 0.2mmol of lithium acetate (Example 46), 0.3mmol of lithium acetate (Example 47), 0.6mmol of lithium acetate (Example 48), and 6mL of N,N-dimethylacetamide to a 25mL integrated electrolytic cell, and stir continuously with a magnetic bar, use tin sheet electrodes as cathode and anode respectively, react at a constant current of 15mA for 8h under room temperature and air conditions, and monitor by TLC tracking; after the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue is purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a, with corresponding yields of 87% (Example 23), 77% (Example 45), 83% (Example 46), 85% (Example 47), and 73% (Example 48). The above results show that the yield is optimal when 0.4 mmol of lithium acetate is added.

[0201] (6) Screening of electrolytes in Examples 23, 49-58

[0202] To a 25 mL integrated electrolytic cell, 0.2 mmol of biphenyl-4-hydrazine, 0.2 mmol of hydrochloric acid, 0.4 mmol of lithium acetate (Example 23), 0.4 mmol of tetrabutylammonium hexafluorophosphate (Example 49), 0.4 mmol of tetrabutylammonium bromide (Example 50), 0.4 mmol of tetrabutylammonium iodide (Example 51), 0.4 mmol of tetrabutylammonium tetrafluoroborate (Example 52), 0.4 mmol of tetrabutylammonium p-toluenesulfonate (Example 53), 0.4 mmol of tetrabutylammonium acetate (Example 54), and 0.4 mmol of lithium perchlorate were added. 4mmol (Example 55), lithium tetrafluoroborate 0.4mmol (Example 56), magnesium perchlorate 0.4mmol (Example 57), sodium iodide 0.4mmol (Example 58), N,N-dimethylacetamide 6mL, and constantly stirred with a magnetic pole, with tin foil electrodes as cathode and anode, respectively, under room temperature and air conditions, at a constant current of 15mA for 8h, followed by TLC monitoring; after the reaction is completed, the reaction system is quenched with water, extracted with ethyl acetate, back-extracted with saturated brine, dried with anhydrous sodium sulfate, and distilled under reduced pressure at 45°C. The residue was purified by rapid silica gel column chromatography (ethyl acetate: petroleum ether = 4:1) to obtain product 2a with corresponding yields of 87% (Example 23), 37% (Example 49), 51% (Example 50), 70% (Example 51), 22% (Example 52), 35% (Example 53), 52% (Example 54), 73% (Example 55), 30% (Example 56), 73% (Example 57), and 46% (Example 58). The above results show that the yield is optimal when lithium acetate is used as the electrolyte.

Claims

1. A method for electrochemically synthesizing amine compounds, characterized in that: A hydrazine compound, hydrochloric acid and an electrolyte are added to a solvent to form a reaction system, and a metal is used as an anode and a cathode to perform constant current preparation. The current used is 8-15 mA. After the reaction is completed, the reactant is post-treated to obtain an amine compound; The molar ratio of the hydrazine compound, hydrochloric acid and electrolyte is 1:0.5-2:0.5-4; The concentration of the hydrazine compound is 0.033 mmol / mL, the concentration of hydrochloric acid is 0.017-0.067 mmol / mL in terms of HCl, and the concentration of the electrolyte is 0.017-0.133 mmol / mL; The structural formula of the hydrazine compound is Formula 1, Formula 2, Formula 3, Formula 4 or Formula 5: ； Wherein, in Formula 1, the R 1 is 4-phenyl, 4-benzyl, hydrogen, 2-phenyl, 2-benzyl, 3-methoxy-4-phenyl; in Formula 2, R 2 is phenyl, R 1 is hydrogen, 4-methoxy, 4-ethyl acetate, 3-methoxy, 3,4-dimethyl, aryl, 1-naphthyl, or R 2 is methyl, R 1 is hydrogen, 4-methoxy, 4-methyl, 4-cyano, 2-phenyl, or R 1 is hydrogen, R 2 is 2-hydroxyethyl; in Formula 3, R 1 Methyl, phenyl; The metal of the anode is one of tin sheet, zinc sheet, aluminum sheet, magnesium sheet, iron sheet, nickel sheet and copper sheet, and the metal of the cathode is one of tin sheet, zinc sheet, aluminum sheet, magnesium sheet, stainless steel sheet, carbon sheet, copper sheet, platinum sheet and lead sheet; The solvent is one of N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide and acetonitrile; The electrolyte is one of lithium acetate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutyltetrafluoroboric acid, tetrabutylammonium p-toluenesulfonate, tetrabutylammonium acetate, lithium perchlorate, lithium tetrafluoroborate, magnesium perchlorate and sodium iodide.

2. The method for electrochemically synthesizing amine compounds according to claim 1, characterized in that: The prepared amine compound is 4-aminobiphenyl, 4-aminodiphenylmethane, aniline, o-aminobiphenyl, o-benzylaniline, 3-methoxy-4-phenylaniline, 2-amino-9,9-dimethylfluorene, diphenylamine, 4-methoxydiphenylamine, 4-(phenylamino)ethyl benzoate, 3-methoxydiphenylamine, 3,4-dimethyldiphenylamine, iminodibenzyl, 1-naphthylaminobenzene, N-methylaniline, N-methyl-p-aminoanisole, N-methyl-p-methylaniline, N-methyl-4-cyanoaniline, N-methylbiphenyl-2-amine, 1,2,3,4-tetrahydroquinoline, N-phenylethanolamine or 9,9-diphenyl-2-aminofluorene.

3. The method for electrochemically synthesizing amine compounds according to claim 1, characterized in that: The constant current reaction time is 6-8h, and the reaction temperature is 20-30°C; when the constant current preparation is performed, a diaphragm-free single-chamber electrolytic cell is used.

4. The method for electrochemically synthesizing amine compounds according to claim 1, characterized in that: The post-treatment is to first quench with water, then extract with an organic reagent, then back-extract with saturated brine, dry with anhydrous sodium sulfate, then distill under reduced pressure, and purify with silica gel column chromatography.

5. The method for electrochemically synthesizing amine compounds according to claim 4, characterized in that: The organic reagent is ethyl acetate, dichloromethane or petroleum ether.

6. The method for electrochemically synthesizing amine compounds according to claim 5, characterized in that: During the silica gel column chromatography purification, the eluent used is a mixture of ethyl acetate and petroleum ether in a volume ratio of 4:1-15:1.

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