A method for preparing an n-cyano compound
By carrying out an addition condensation reaction between phthalic anhydride or succinic anhydride and cyanamide or calcium cyanamide under alkaline conditions, the problems of high toxicity and high cost in the synthesis of existing cyano compounds have been solved, and safe, low-cost and efficient preparation of N-cyano compounds has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NINGXIA UNIVERSITY
- Filing Date
- 2026-03-24
- Publication Date
- 2026-06-16
Smart Images
Figure CN122212995A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for preparing N-cyano compounds. Background Technology
[0002] Cyano compounds play a vital role due to their unique biological activity. Traditionally, cyano compounds are obtained by nucleophilic addition of cyanide salts or metal-bound cyanide sources with aryl diazonium salts or aryl / alkyl halides. They play a role in the treatment of a variety of diseases, such as rilpivirine for the treatment of human immunodeficiency virus infection (1a), tofacitinib for the treatment of moderate to severe rheumatoid arthritis (1b), and escitalopram for the treatment of depression (1c).
[0003]
[0004] In 1991, Domeier's group first reported a method for synthesizing N-cyanophthalimide and N-cyanosuccinimide. This method uses bromoformonitrile and succinic anhydride or phthalimide or acetone solvent at 0°C, with triethylamine as the catalyst. The yield is 59-77%. The reaction uses the highly toxic bromoformonitrile and is a hazardous chemical process.
[0005]
[0006] In 2024, Lim's group reported a method for synthesizing N-cyanophthalimide. This method uses (Z)-2-(1-(hydroxyimino)-2-oxopropyl)isoindene-1,3-dione in dichloromethane solvent and diethylaminotrifluoride as catalyst. The reaction raw materials are not easy to obtain, the preparation is complicated and the cost is high.
[0007]
[0008] Although scientists are increasingly studying cyanidation reactions, the choice of cyanide reagent remains a major obstacle to green development. Calcium cyanamide and monocyanamide are readily available and inexpensive chemical products with low toxicity. Their reaction processes are simple and easy to operate, environmentally friendly, and produce low-cost products. Monocyanamide is an important compound with both amino and cyano functional groups. Many compounds with amino or cyano functional groups are widely used in pharmaceuticals, pesticides, dyes, and new materials. Calcium cyanamide can provide CN... - Ions, also known as "N≡C–N" 2- "Fragments involved in heterocyclic synthesis are inexpensive, and the main byproducts are inorganic calcium salts, which are easy to separate and environmentally friendly. Therefore, the development of cyanidation reagents constructed using cyanamide or calcium cyanide as substrates is of great significance." Summary of the Invention
[0009] The purpose of this invention is to provide a method for preparing N-cyano compounds, thereby solving the problems raised in existing cyanidation reactions.
[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing N-cyano compounds, comprising the following steps: Organic acid anhydrides, cyaniding reagents, catalysts, and solvents are mixed and subjected to an addition condensation reaction to obtain N-cyano compounds; The cyaniding agent is cyanamide or calcium cyanamide.
[0011] Furthermore, in the preparation method, the organic acid anhydride is phthalic anhydride or succinic anhydride.
[0012] Furthermore, in the preparation method, the molar ratio of the organic acid anhydride to the cyaniding reagent is 1:0.1~3.
[0013] Furthermore, in the preparation method, the catalyst includes one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium acetate, potassium phosphate, potassium carbonate, potassium bicarbonate, ammonium bicarbonate, and sodium bicarbonate.
[0014] Furthermore, in the preparation method, the molar ratio of the organic acid anhydride to the catalyst is 1:0.01~0.3.
[0015] Furthermore, in the preparation method, the solvent includes one or more of the following: water, methanol, ethanol, dichloromethane, 1,2-dichloroethane, acetonitrile, benzene, toluene, acetone, tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, ethylene glycol, and polyethylene glycol.
[0016] Furthermore, in the preparation method, the volume ratio of the solvent to the molar amount of the organic acid anhydride is 1 mL: 0.001~1 mmol.
[0017] Furthermore, in the preparation method, the conditions for the addition condensation reaction include: a reaction temperature of 40~90℃ and a reaction time of 4~6h.
[0018] Furthermore, in the preparation method, the addition condensation reaction is carried out in air or under a protective atmosphere, wherein the protective atmosphere is nitrogen or argon.
[0019] Furthermore, in the preparation method, after the addition condensation reaction is completed, saturated sodium bicarbonate is added to quench the reaction, the reaction solution is added to the extraction solvent, and the mixture is separated and extracted three times with water. The organic phase is dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue is dissolved in methanol and filtered. The resulting solution is concentrated under reduced pressure and then recrystallized with methanol or purified by column chromatography to obtain N-cyano compounds.
[0020] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing N-cyano compounds (specifically N-cyanophthalimide or N-cyanosuccinimide). Under alkaline conditions, phthalic anhydride / succinic anhydride reacts with cyanamide / calcium cyanamide. The alkaline conditions are created using alkaline salt compounds, resulting in a simple catalytic system and a green solvent. Compared to traditional cyaniding reagents, the cyaniding reagent synthesized using cyanamide or calcium cyanamide as the cyano source exhibits advantages such as high safety, low cost, and ease of operation. Therefore, this invention eliminates the need for toxic cyaniding reagents, has a wide range of applications, effectively reduces production costs, improves yield and chemoselectivity, and has a short reaction time, enabling the efficient, rapid, and convenient synthesis of N-cyano compounds. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.
[0022] Figure 1 N-cyanophthalimide of Example 1 1 H NMR (500MHz); Figure 2 N-cyanophthalimide of Example 1 13 C NMR (126MHz); Figure 3 This is the high-resolution mass spectrum of N-cyanophthalimide from Example 1; Figure 4 N-cyanosuccinimide of Example 2 1 H NMR (500MHz); Figure 5 N-cyanosuccinimide of Example 2 13 C NMR (126MHz); Figure 6 This is a high-resolution mass spectrum of N-cyanosuccinimide from Example 2. Detailed Implementation
[0023] This invention provides a method for preparing N-cyano compounds, comprising the following steps: Organic acid anhydrides, cyaniding reagents, catalysts, and solvents are mixed and subjected to an addition condensation reaction to obtain N-cyano compounds; The cyaniding agent is cyanamide or calcium cyanamide.
[0024] In this invention, the following reaction occurs during the preparation of the N-cyano compounds: .
[0025] In this invention, the organic acid anhydride is preferably phthalic anhydride or succinic anhydride. When the organic acid anhydride is phthalic anhydride, the N-cyano compound is N-cyanophthalimide; when the organic acid anhydride is succinic anhydride, the N-cyano compound is N-cyanosuccinimide.
[0026] In this invention, the cyaniding reagent is preferably cyanamide.
[0027] In this invention, the molar ratio of the organic acid anhydride to the cyaniding reagent is preferably 1:0.1~3, more preferably 1:2~3, and even more preferably 1:2.5.
[0028] In this invention, the catalyst preferably comprises one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium acetate, potassium phosphate, potassium carbonate, potassium bicarbonate, ammonium bicarbonate, and sodium bicarbonate, more preferably sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium bicarbonate, ammonium bicarbonate, or sodium bicarbonate, and even more preferably sodium bicarbonate. The common characteristic of the above catalysts is that they are basic compounds; therefore, catalysts conforming to the above types can all achieve the reactions described in this application.
[0029] In this invention, the molar ratio of the organic acid anhydride to the catalyst is preferably 1:0.01~0.3, more preferably 1:0.05~0.15, and even more preferably 1:0.1.
[0030] In this invention, the solvent preferably includes one or more of the following: water, methanol, ethanol, dichloromethane, 1,2-dichloroethane, acetonitrile, benzene, toluene, acetone, tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, ethylene glycol, and polyethylene glycol. More preferably, it includes dichloromethane, 1,2-dichloroethane, acetone, tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, or N,N-dimethylacetamide, and even more preferably, 1,4-dioxane. The solvent is only used to dissolve the organic acid anhydride; the solvent itself does not participate in the reaction. Therefore, any solvent capable of dissolving organic acid anhydrides can achieve the reaction described in this application.
[0031] In this invention, the volume ratio of the solvent to the molar amount of the organic acid anhydride is preferably 1 mL: 0.001~1 mmol, more preferably 1 mL: 0.01~1 mmol, and even more preferably 1 mL: 0.1 mmol. The amount of solvent used is sufficient as long as the organic acid anhydride is dissolved in the solvent.
[0032] In this invention, the conditions for the addition condensation reaction include: the reaction temperature is preferably 40~90℃, more preferably 50~70℃, and even more preferably 60℃; the reaction time is preferably 4~6h, more preferably 4~5h, and even more preferably 4h.
[0033] In this invention, the addition condensation reaction is preferably carried out in air or a protective atmosphere, and more preferably in a protective atmosphere.
[0034] In this invention, the protective atmosphere is preferably nitrogen or argon, and more preferably argon.
[0035] In this invention, after the addition condensation reaction is completed, saturated sodium bicarbonate is added to quench the reaction. The reaction solution is then added to the extraction solvent and separated from water three times. The organic phase is dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue is dissolved in methanol and filtered. The resulting solution is concentrated under reduced pressure and then separated and purified by recrystallization with methanol or column chromatography to obtain N-cyano compounds.
[0036] In this invention, the extraction solvent is preferably ethyl acetate or dichloromethane, and more preferably dichloromethane.
[0037] In this invention, the purification method is preferably methanol recrystallization or column chromatography, and more preferably methanol recrystallization.
[0038] No restrictions are placed on the parameters and conditions for the post-processing described above; any solution well-known to those skilled in the art can be used.
[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0040] Example 1
[0041] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0042] Phthalic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium bicarbonate (0.02 mmol, 0.1 equiv), and 1,2-dichloroethane (DCE) (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid with a separation yield of 85%.
[0043] Structural identification of N-cyanophthalimide: Nuclear magnetic resonance data: 1 H NMR (500 MHz, CDCl3) δ8.10-8.09 (m, 2H), 8.03-8.01 (m,2H); 13 C NMR (126 MHz, CDCl3) δ163.1, 136.8, 131.3, 125.5, 103.4.
[0044] Figure 1 , Figure 2 The analysis results show that the target product obtained is correct.
[0045] Example 2
[0046] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0047] Succinic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium bicarbonate (0.02 mmol, 0.1 equiv), and acetone (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a yield of 44%.
[0048] Structural identification of N-cyanosuccinimide: Nuclear magnetic resonance data: 1H NMR (500 MHz, CDCl3) δ2.70-2.89 (m, 2H); 13 C NMR (126 MHz, DMSO-d6) δ172.54, 103.74, 29.22.
[0049] Figure 4 , Figure 5 The analysis results show that the target product obtained is correct.
[0050] Example 3
[0051] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0052] Phthalic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.02 mmol, 0.1 equiv), and DCE (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and separated and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid product with a separation yield of 59%.
[0053] Example 4
[0054] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0055] Succinic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.02 mmol, 0.1 equiv), and acetone (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a separation yield of 74%.
[0056] Example 5
[0057] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0058] Phthalic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), potassium carbonate (0.02 mmol, 0.1 equiv), and DCE (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid with a separation yield of 53%.
[0059] Example 6
[0060] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0061] Succinic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), potassium carbonate (0.02 mmol, 0.1 equiv), and acetone (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a yield of 53%.
[0062] Example 7
[0063] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0064] Phthalic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), sodium bicarbonate (0.01 mmol, 0.05 equiv), and DCE (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid product with a separation yield of 74%.
[0065] Example 8
[0066] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0067] Succinic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.01 mmol, 0.05 equiv), and acetone (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a yield of 60%.
[0068] Example 9
[0069] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0070] Phthalic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.01 mmol, 0.05 equiv), and DCE (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid product with a yield of 51%.
[0071] Example 10
[0072] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0073] Succinic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), potassium carbonate (0.01 mmol, 0.05 equiv), and acetone (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a separation yield of 59%.
[0074] Example 11
[0075] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0076] Phthalic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium bicarbonate (0.02 mmol, 0.1 equiv), and 1,4-dioxane (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid product with a yield of 71%.
[0077] Example 12
[0078] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0079] Succinic anhydride (0.2 mmol, 1.0 equiv), cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.02 mmol, 0.1 equiv), and 1,4-dioxane (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the mixture was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a yield of 41%.
[0080] Example 13
[0081] This embodiment provides a method for preparing N-cyanophthalimide, the reaction formula of which is as follows, including the following steps:
[0082] Phthalic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), sodium bicarbonate (0.01 mmol, 0.05 equiv), and 1,4-dioxane (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to dichloromethane and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a white solid product with a yield of 69%.
[0083] Example 14
[0084] This embodiment provides a method for preparing N-cyanosuccinimide, the reaction formula of which is as follows, including the following steps:
[0085] Succinic anhydride (0.2 mmol, 1.0 equiv), calcium cyanamide (0.5 mmol, 2.5 equiv), sodium carbonate (0.01 mmol, 0.05 equiv), and 1,4-dioxane (2 mL) were added to a 25 mL Shrek tube. After thorough mixing, the mixture was stirred at 60 °C for 4 h under argon protection. After the reaction was completed, 2 mL of saturated sodium bicarbonate solution was added to quench the reaction. The reaction solution was then added to ethyl acetate and extracted three times with water. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol and filtered. The resulting solution was concentrated under reduced pressure and then recrystallized from methanol to obtain a cinnamon-colored solid with a yield of 49%.
[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing an N-cyano compound, characterized in that, Includes the following steps: Organic acid anhydrides, cyaniding reagents, catalysts, and solvents are mixed and subjected to an addition condensation reaction to obtain N-cyano compounds; The cyaniding agent is cyanamide or calcium cyanamide.
2. The preparation method according to claim 1, characterized in that, The organic acid anhydride is phthalic anhydride or succinic anhydride.
3. The preparation method according to claim 1 or 2, characterized in that, The molar ratio of the organic acid anhydride to the cyaniding reagent is 1:0.1~3.
4. The preparation method according to claim 1, characterized in that, The catalyst includes one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium acetate, potassium phosphate, potassium carbonate, potassium bicarbonate, ammonium bicarbonate, and sodium bicarbonate.
5. The preparation method according to claim 1 or 4, characterized in that, The molar ratio of the organic acid anhydride to the catalyst is 1:0.01~0.
3.
6. The preparation method according to claim 1, characterized in that, The solvent includes one or more of the following: water, methanol, ethanol, dichloromethane, 1,2-dichloroethane, acetonitrile, benzene, toluene, acetone, tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, ethylene glycol, and polyethylene glycol.
7. The preparation method according to claim 1 or 6, characterized in that, The volume ratio of the solvent to the molar amount of the organic acid anhydride is 1 mL: 0.001~1 mmol.
8. The preparation method according to claim 1, characterized in that, The conditions for the addition condensation reaction include: a reaction temperature of 40~90℃ and a reaction time of 4~6h.
9. The preparation method according to claim 1 or 8, characterized in that, The addition condensation reaction is carried out in air or under a protective atmosphere, wherein the protective atmosphere is nitrogen or argon.
10. The preparation method according to claim 1, characterized in that, After the addition condensation reaction is completed, saturated sodium bicarbonate is added to quench the reaction. The reaction solution is then added to the extraction solvent and separated from water three times. The organic phase is dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue is dissolved in methanol and filtered. The resulting solution is concentrated under reduced pressure and then separated and purified by recrystallization with methanol or by column chromatography to obtain N-cyano compounds.