A method for preparing nitrile compounds

Abstract

This invention discloses a method for preparing nitrile compounds, comprising using aldehydes and trimethylsilyl azide as reaction raw materials. N Using bromosuccinimide as a photocatalyst and a 28W 395nm LED lamp as the light source, nitriles are synthesized at room temperature. This invention's synthesis method eliminates the need for Lewis acids, protic acid catalysts, and strong oxidants. Furthermore, the reaction conditions are mild, the operation is simple, and the yield is high, demonstrating significant economic and practical value. It also holds broad application prospects in the field of pharmaceutical synthesis.

Description

Technical Field

[0001] This invention belongs to the fields of pharmaceutical intermediate synthesis and organic chemical technology, and specifically relates to a method for preparing nitrile compounds. Technical Background Nitriles, as important organic chemical intermediates, are widely used in the synthesis of fibers, resins, rubber, pharmaceuticals, pesticides, and dyes, and are also applied in industries such as electroplating, steel quenching, and mineral processing. Therefore, developing synthetic methods for nitrile compounds and expanding the diversity of nitrile compounds has always been a research hotspot in the field of fine organic synthesis. Currently, nitrile compounds can be prepared via cyanidation of haloalkanes, dehydration of aldoloximes, dehydration of amides, acetonitrile radical addition, propylene cyanidation, Sandmeyer reaction, Rosenmond-von Braun reaction, and transition metal-catalyzed coupling reactions. Most of these methods utilize highly toxic cyaniding reagents (such as sodium cyanide and potassium cyanide), high temperature and high pressure conditions, toxic reagents, strong oxidants, or metal catalysts. Under the severe global situation of low-carbon emission reduction, there is an urgent need to develop a mild and simple preparation method.

[0002] Aldehydes have been reported as commercial starting materials for the synthesis of nitriles. For example, in 2012, Stephan Enthaler's group successfully synthesized 100 aldehydes. oUnder C conditions, a one-step condensation dehydration synthesis of nitrile from aldehydes and hydroxylamine hydrochloride was successfully achieved using Lewis acid Zn salts (Tetrahedron Letters, 2012, 53, 882-885). Simultaneously, some supported metal catalysts can also achieve the condensation dehydration of aldehydes and hydroxylamine to prepare nitrile (Chinese Journal of Catalysis, 2013, 34, 704-710). In 2016, N. Karak's group successfully achieved the reaction of aldehydes with potassium ferricyanide to prepare nitrile using a nano-silver catalyst (Tetrahedron Letters, 2016, 57, 549-553). In 2023, Wu's group successfully achieved the condensation dehydration / oxidation synthesis of nitrile from aldehydes and ammonium acetate using the organic photocatalyst 4-CzIPN under co-oxidation with TEMPO and air (Science China Chemistry, 2023, 66, 2852-2857). In 2024, Mohammad Mehdi Khodaei's group successfully achieved the reaction of aldehydes and azides to prepare nitriles at room temperature using trifluoromethanesulfonic acid catalysis (International Journal of Biological Macromolecules, 2024, 256, 128445). However, the above methods all have some drawbacks, such as the need for metal catalysts or protic acid catalysts, high or high reaction temperatures and long reaction times, and the need to add additional stoichiometric amounts of oxidants.

[0003] Therefore, it is particularly important to find a green, efficient, environmentally friendly, and mild synthetic route for the preparation of nitrile compounds. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing nitrile compounds.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: using aldehyde as a raw material and trimethylsilyl azide as a nitrogen source. NUsing bromosuccinimide as a catalyst, a nitrile compound is prepared in one step by reacting in an organic solvent under light irradiation and room temperature conditions. The synthetic route is as follows: Equation (1); Among them, R 1 It is selected from any one of C1-8 alkyl, phenyl, benzyl, styryl, indole, benzofuran, thiophene, and pyridine.

[0008] In a preferred embodiment of the preparation method described in this invention, the molar ratio of Formula I to Formula II is 1:1 to 3.

[0009] As a preferred embodiment of the preparation method described in this invention, wherein: N The molar ratio of bromosuccinimide to the aldehyde shown in Formula I is 0.1 to 0.3:1.

[0010] In a preferred embodiment of the preparation method described in this invention, the organic solvent is one of chloroform, dichloromethane, 1,2-dichloroethane, and ethyl acetate.

[0011] In a preferred embodiment of the preparation method described in this invention, the reaction temperature is 20-25°C, the reaction time is 2-3 hours, and the reaction is carried out under a nitrogen atmosphere.

[0012] In a preferred embodiment of the preparation method described in this invention, the light source used for the photoreaction is a 28-40W 395nm LED lamp.

[0013] As a preferred embodiment of the preparation method described in this invention, after the reaction is completed, dichloromethane and water are added for extraction and washing. The organic phase is washed with saturated brine, dried with anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The product nitrile is then obtained by vacuum distillation or recrystallization.

[0014] Beneficial effects of this invention: This invention uses aldehyde I, as shown in formula (1), as the reaction raw material. N Using bromosuccinimide (NBS, 20 mol%) as a catalyst, trimethylsilyl azide (TMSN3, 2 equivalents) as a nitrogen source, and chloroform as the reaction solvent, the reaction was carried out at room temperature under a nitrogen atmosphere for 2-3 hours under 28 W 395 nm LED irradiation. After the reaction, water was added to quench the reaction, and the aqueous phase was extracted three times with dichloromethane. The combined organic phases were washed once with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. The product nitrile was obtained by vacuum distillation or recrystallization, with a yield of up to 93%. The synthesis method of this invention does not use corrosive Lewis acids and protic acids, and it does not require heating or an autoclave, which has important value in industrial production. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The 1H NMR spectrum of 4-phenylbenzonitrile 3a obtained in Example 1 of this invention; Figure 2 This is the carbon NMR spectrum of 4-phenylbenzonitrile 3a obtained in Example 1 of the present invention. Detailed Implementation

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0017] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0018] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0019] Unless otherwise specified, all raw materials used in this invention are commercially available in the field.

[0020] The synthetic route described in this invention is shown in formula (1): Equation (1); Among them, R 1 Selected from C1-8 alkyl, phenyl, benzyl, styryl, indole, benzofuran, thiophene, and pyridine.

[0021] Example 1 This embodiment provides a method for preparing 4-phenylbenzonitrile 3a, the specific steps of which are as follows: (1) The reaction raw material 4-phenylbenzaldehyde (1.82 g, 10 mmol), N1-Bromosuccinimide (0.356 g, 2 mmol, 20 mol%) was added to a 50 mL round-bottom flask, and a magnetic stir bar was added. Nitrogen source TMSN3 (2.63 mL, 20 mmol) was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 3 h under irradiation with a 28 W 395 nm LED lamp.

[0022] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain product 3a (white solid, yield 93%, 1.66 g).

[0023] Figure 1 The 1H NMR spectrum of 4-phenylbenzonitrile 3a obtained in Example 1 of this invention; Figure 2 This is the carbon NMR spectrum of 4-phenylbenzonitrile 3a obtained in Example 1 of the present invention.

[0024] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.71 (q, J = 8.7 Hz, 4H), 7.63-7.56(m, 2H), 7.52-7.39 (m, 3H). 13 IR (cm -1 ): 3060, 3031, 2226,1929, 1682, 1605, 1580, 1556, 1509, 1484, 1447, 1396, 1311, 1284, 1265, 1178,1007, 847, 836, 818, 770, 738, 723, 697. Example 2 This embodiment provides a method for preparing cinnamonitrile 3b, the specific steps of which are as follows: (1) The reaction raw material cinnamaldehyde (1.32 g, 10 mmol), N0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 3 h under irradiation with a 28 W 395 nm LED lamp.

[0025] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, and the product 3b (pale yellow liquid, yield 90%, 1.16 g) was obtained by vacuum distillation.

[0026] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.49-7.38 (m, 6H), 5.89 (dd, J =16.7, 0.9 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 150.63, 133.54, 131.25, 129.15,127.38, 118.18, 96.37. IR (cm -1 ): 3059, 3028, 2216, 1617, 1511, 1493, 1448,1207, 966, 748, 688. Example 3 This embodiment provides N The preparation method of 3-methylindole-3-carboxynitrile 3c includes the following specific steps: (1) Prepare the reaction raw materials N 1-Methyl-3-formylindole (1.59 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 3 h under 28 W 395 nm LED light irradiation.

[0027] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, and the product 3c (pale yellow liquid, yield 85%, 1.326 g) was obtained by vacuum distillation.

[0028] Data representation:1 H NMR (400 MHz, CDCl3) δ 7.75 (d, J = 7.8 Hz, 1H), 7.55 (s,1H), 7.42-7.28 (m, 3H), 3.85 (s, 3H). 13 IR (cm -1 ): 3117, 2218, 1531, 1472, 1381, 1358, 1132, 742. Example 4 This embodiment provides a method for preparing phenylacetonitrile 3d, the specific steps of which are as follows: (1) The reaction raw material phenylacetaldehyde (1.20 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under 28 W 395 nm LED light irradiation.

[0029] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, and impurities were removed by vacuum distillation to obtain the product 3d (colorless liquid, yield 80%, 0.936 g).

[0030] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.42-7.31 (m, 5H), 3.75 (s, 2H). 13 CNMR (101 MHz, CDCl3) δ 130.01, 129.16, 128.06, 127.96, 117.98, 53.57, 23.61.IR (cm -1 ): 3064, 3032, 2921, 2250, 1602, 1496, 1454, 1415, 1076, 1029, 940,734, 695, 614. Example 5 This embodiment provides a method for preparing 4-hydroxy-3,5-dimethoxybenzonitrile 3e, the specific steps of which are as follows: (1) The reaction raw material 4-hydroxy-3,5-dimethoxybenzaldehyde (1.82 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask, and a magnetic stir bar was added. TMSN3 (2.63 mL, 20 mmol) of nitrogen source was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 3 h under irradiation with a 28 W 395 nm LED lamp.

[0031] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain the product 3e (yellow solid, yield 90%, 1.61 g).

[0032] Data representation: 1 H NMR (400 MHz, CDCl3) δ 6.87 (s, 2H), 6.00 (s, 1H), 3.91 (s, 6H). 13 C NMR (101 MHz, CDCl3) δ 147.19, 139.31, 119.37, 109.18, 102.29,56.60. IR (cm -1 ): 3372, 3016, 2941, 2842, 2222, 1606, 1513, 1488, 1455, 1423,1336, 1253, 1219, 1145, 1116, 792, 621. Example 6 This embodiment provides a method for preparing benzofuran-2-carboxynitrile 3f, the specific steps of which are as follows: (1) The reaction raw material benzofuran-2-carboxaldehyde (1.46 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 3 h under irradiation with a 28 W 395 nm LED lamp.

[0033] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, and the product 3f (yellow liquid, yield 82%, 1.173 g) was obtained by vacuum distillation.

[0034] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.68 (d, J = 7.9 Hz, 1H), 7.59-7.48(m, 2H), 7.46 (s, 1H), 7.40-7.33 (m, 1H). 13 IR (cm -1 ): 2232,1613, 1556, 1446, 1383, 1343, 1195, 1181, 953, 868, 828, 750, 631, 608. Example 7 This embodiment provides a method for preparing 3g of benzo[1,4]dioxane-6-carboxynitrile, the specific steps of which are as follows: (1) The reaction raw material benzo[1,4]dioxane-6-carboxaldehyde (1.64 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under 28 W 395 nm LED light irradiation.

[0035] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain 3g of the product (white solid, yield 92%, 1.48 g).

[0036] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.13-7.04 (m, 2H), 6.89-6.84 (m,1H), 4.31-4.26 (m, 2H), 4.26-4.22 (m, 2H). 13IR (cm -1 ):3072, 2954, 2224, 1607, 1579, 1507, 1317, 1292, 1243, 1122, 1061, 1041, 908,880, 811, 712, 613. Example 8 This embodiment provides a method for preparing 4-iodobenzonitrile 3h, the specific steps of which are as follows: (1) The reaction raw material 4-iodobenzaldehyde (2.32 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask, and a magnetic stir bar was added. TMSN3 (2.63 mL, 20 mmol) of nitrogen source was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere, and the reaction was carried out at room temperature (25 °C) for 2 h under irradiation with a 28 W 395 nm LED lamp.

[0037] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain the product 3h (yellowish-gray solid, yield 88%, 2.02 g).

[0038] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.87-7.81 (m, 2H), 7.40-7.33 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 138.53, 133.20, 118.26, 111.75, 100.37. IR (cm -1 ): 2224, 1909, 1578, 1475, 1391, 1011, 817, 540. Example 9 This embodiment provides a method for preparing 4-methoxybenzonitrile 3i, the specific steps of which are as follows: (1) The reaction raw material 4-methoxybenzaldehyde (1.36 g, 10 mmol), N0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under irradiation with a 28 W 395 nm LED lamp.

[0039] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain product 3i (white solid, yield 84%, 1.12 g).

[0040] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.31-7.23 (m, 2H), 6.69-6.61 (m,2H), 3.56 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 162.87, 133.96, 119.27, 114.78,103.84, 55.57. IR (cm -1 ): 2972, 2938, 2841, 2562, 2252, 2222, 1606, 1509,1260, 1172, 1024, 835, 734, 548. Example 10 This embodiment provides a method for preparing 4-benzyloxybenzonitrile 3j, the specific steps of which are as follows: (1) The reaction raw material 4-benzyloxybenzaldehyde (2.12 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under irradiation with a 28 W 395 nm LED lamp.

[0041] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain product 3j (white solid, yield 93%, 1.94 g).

[0042] Data representation: 1H NMR (400 MHz, CDCl3) δ 7.57-7.51 (m, 2H), 7.48-7.32 (m,5H), 7.06-6.97 (m, 2H), 5.10 (s, 2H). 13 C NMR (101 MHz, CDCl3) δ 162.02,135.85, 134.06, 128.84, 128.48, 127.61, 119.31, 115.68, 104.15, 70.30. IR(cm -1 ): 2221, 1606, 1509, 1262, 1026, 835, 731, 549. Example 11 This embodiment provides a method for preparing 3,4-dimethoxybenzonitrile 3k, the specific steps of which are as follows: (1) The reaction raw material 3,4-dimethoxybenzaldehyde (1.66 g, 10 mmol), N 0.356 g of bromosuccinimide (2 mmol, 20 mol%) was added to a 50 mL round-bottom flask, and a magnetic stir bar was added. TMSN3 (2.63 mL, 20 mmol) of nitrogen source was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere, and the reaction was carried out at room temperature (25 °C) for 2 h under irradiation with a 28 W 395 nm LED lamp.

[0043] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain the product 3k (white solid, yield 90%, 1.47 g).

[0044] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.04-6.96 (m, 1H), 6.82 (d, J = 2.0Hz, 1H), 6.65 (d, J = 8.4 Hz, 1H), 3.66 (s, 3H), 3.62 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 152.65, 148.95, 126.19, 119.06, 113.69, 111.15, 103.45, 55.83. IR(cm -1): 3000, 2971, 2836, 2223, 1597, 1515, 1270, 1243, 1157, 1138, 1029,1018, 810. Example 12 This embodiment provides a method for preparing 2-naphthonitrile 3l, the specific steps of which are as follows: (1) The reaction raw material 2-naphthaldehyde (1.56 g, 10 mmol), N 0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under 28 W 395 nm LED light irradiation.

[0045] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was recrystallized to obtain product 3l (white solid, yield 93%, 1.43 g).

[0046] Data representation: 1 H NMR (400 MHz, CDCl3) δ 8.13 (s, 1H), 7.83 (t, J = 9.3 Hz, 3H), 7.65-7.50 (m, 3H). 13 IR (cm -1 ): 2226, 1593, 1380,1272, 904, 870, 825, 755. Example 13 This embodiment provides a method for preparing 2-methoxybenzonitrile 3m, the specific steps of which are as follows: (1) The reaction raw material 2-methoxybenzaldehyde (1.36 g, 10 mmol), N0.356 g, 2 mmol, 20 mol% of bromosuccinimide was added to a 50 mL round-bottom flask. A magnetic stir bar was added, and 2.63 mL, 20 mmol of nitrogen source TMSN3 was dissolved in 10 mL of dry chloroform. The above solution was slowly added dropwise to the reaction flask under a nitrogen atmosphere. The reaction was carried out at room temperature (25 °C) for 2 h under irradiation with a 28 W 395 nm LED lamp.

[0047] (2) After the reaction was completed, water was added to quench the reaction, the aqueous phase was extracted three times with dichloromethane, the combined organic phases were washed once with saturated brine, dried with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the crude product was distilled under reduced pressure to obtain the product 3m (colorless liquid, yield 75%, 0.98 g).

[0048] Data representation: 1 H NMR (400 MHz, CDCl3) δ 7.53-7.39 (m, 2H), 7.01-6.86 (m,2H), 3.84 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 161.1, 134.6, 133.6, 120.8,116.6, 111.4, 101.4, 56.0. IR (cm -1 ): 2973, 2948, 2841, 2228, 1599, 1494,1288, 1260, 1020, 756. Comparative Example 1 The difference from Example 1 is that step (1) is changed N The amount of 1-bromosuccinimide (NBS) catalyst is shown in Table 1. Other reaction parameters remain unchanged, and the effect on the yield is shown in Table 1.

[0049] Table 1. Effect of catalyst dosage on the reaction process

[0050] Comparative Example 2 The difference from Example 1 is that the amount of nitrogen source TMSN3 is changed in step (1), while other reaction parameters remain unchanged. The effect on the yield is shown in Table 2.

[0051] Table 2 Effect of nitrogen source dosage on the reaction process

[0052] Comparative Example 3 The difference from Example 1 is that in step (1), TMSN3 is replaced with other nitrogen sources, while other reaction parameters remain unchanged. The effect on yield is shown in Table 3.

[0053] Table 3. Effects of other nitrogen sources during the reaction process

[0054] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a nitrile compound, characterized in that: include, Using the aldehyde shown in Formula I as the raw material and the trimethylsilane azide shown in Formula II as the nitrogen source, N Using bromosuccinimide as a catalyst, the reaction is carried out in an organic solvent under light and room temperature conditions to prepare the nitrile compound shown in Formula III in one step. The synthetic route is shown in Formula (1): Equation (1); Among them, R 1 It is selected from any one of C1-8 alkyl, phenyl, benzyl, styryl, indole, benzofuran, thiophene, and pyridine.

2. The preparation method according to claim 1, characterized in that: The molar ratio of aldehyde to trimethylsilyl azide is 1:1 to 3.

3. The preparation method according to claim 2, characterized in that: The molar ratio of aldehyde to trimethylsilyl azide is 1:2~3.

4. The preparation method according to claim 1, characterized in that: N The molar ratio of bromosuccinimide to aldehyde is 0.1~0.3:

1.

5. The preparation method according to claim 4, characterized in that: N The molar ratio of bromosuccinimide to aldehyde is 0.2~0.3:

1.

6. The preparation method according to claim 1, characterized in that: Organic solvents include one of chloroform, dichloromethane, 1,2-dichloroethane, and ethyl acetate.

7. The preparation method according to claim 1, characterized in that: The reaction temperature is 20-25℃; the reaction time is 2-3 hours; and the reaction is carried out under a nitrogen atmosphere.

8. The preparation method according to claim 1, characterized in that: The light source used for the photoreaction is a 28-40W 395nm LED.

9. The preparation method according to claim 1, characterized in that: The method for preparing the nitrile compound shown in formula (III) includes, at room temperature, mixing an aldehyde, trimethylsilyl azide, and... N - Bromosuccinimide reacts with an organic solvent under nitrogen atmosphere.

10. The preparation method according to claim 9, characterized in that: The process also includes adding dichloromethane and water for extraction and washing after the reaction is complete, washing the organic phase with saturated brine, drying with anhydrous sodium sulfate, removing the solvent under reduced pressure, and then distilling or recrystallizing under reduced pressure to obtain the product nitrile.

Images