A method for synthesizing 2-bromophenanthrene

Abstract

This invention relates to the field of compound synthesis technology, specifically disclosing a method for synthesizing 2-bromophenanthrene. The method includes the following steps: adding phenanthrene to a solvent, then adding sodium hydroxide and sodium bromide to the solvent, followed by dropwise addition of an aqueous solution of sodium hypobromite, stirring the reaction mixture to obtain the product 2-bromophenanthrene. The synthesis method provided by this invention is low-cost and has a high yield.

Description

Technical Field

[0001] This invention relates to the field of compound synthesis technology, and in particular to a method for synthesizing 2-bromophenanthroline. Background Technology

[0002] 2-Bromophenanthrene compounds and their derivatives are very important pharmaceutical and optoelectronic material intermediates, and are key core structures that are frequently used in drug and optoelectronic material research and development.

[0003] The synthesis of 2-bromophenanthrene has been reported, but the current synthetic methods are limited, and the reaction steps are long or the raw materials are expensive. There is an urgent need to develop better synthetic routes.

[0004] Therefore, it is of great significance to develop new methods for the synthesis of 2-bromophenanthrene and to realize a simpler method that is more conducive to industrial production of 2-bromophenanthrene. Summary of the Invention

[0005] The main technical problem solved by this invention is to provide a method for synthesizing 2-bromophenanthrene.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for synthesizing 2-bromophenanthrene, involving the following reaction formula: The synthesis method includes the following steps: adding the compound phenanthrene to a solvent, then adding sodium hydroxide and sodium bromide to the solvent, followed by adding an aqueous solution of sodium hypobromite dropwise, stirring the reaction to obtain the product 2-bromophenanthrene.

[0007] In one embodiment of the present invention, the solvent is acetic acid and ethanol.

[0008] In one embodiment of the present invention, the volume ratio of acetic acid to ethanol is acetic acid:ethanol = 1:(1-4). For example, acetic acid and ethanol can be mixed in volume ratios of 1:1, 1:2, 1:3, 1:4 or any other ratio within the range of 1:(1-4).

[0009] In a preferred embodiment of the present invention, the volume ratio of acetic acid to ethanol is acetic acid:ethanol = 1:3.

[0010] In one embodiment of the present invention, the amounts of phenanthrene and acetic acid are: 5-30 mL of acetic acid for every 0.01 mol of phenanthrene. Preferably, 5-20 mL of acetic acid for every 0.01 mol of phenanthrene. More preferably, 5-10 mL of acetic acid for every 0.01 mol of phenanthrene.

[0011] In one embodiment of the present invention, the molar ratio of phenanthrene to sodium hydroxide is 1:(1-3). For example, the molar ratio of phenanthrene to sodium hydroxide can be 1:1, 1:2, 1:3, or any other ratio within the range of 1:(1-3).

[0012] In a preferred embodiment of the present invention, the molar ratio of phenanthrene to sodium hydroxide is 1:2.

[0013] As one embodiment of the present invention, the molar ratio of phenanthrene to sodium bromide is 1:(0.8-1.2). For example, the molar ratio of phenanthrene to sodium bromide can be 1:0.8, 1:0.9, 1:1.0, 1:1.05, 1:1.1, 1:1.2, or any other ratio within the range of 1:(0.8-1.2).

[0014] In a preferred embodiment of the present invention, the molar ratio of phenanthrene to sodium bromide is 1:1.05.

[0015] In one embodiment of the present invention, the molar ratio of phenanthrene to sodium hypobromite is 1:(2-3). For example, the molar ratio of phenanthrene to sodium hypobromite can be 1:2, 1:2.5, 1:3, or any other ratio within the range of 1:(2-3).

[0016] In a preferred embodiment of the present invention, the molar ratio of phenanthrene to sodium hypobromite is 1:2.

[0017] In one embodiment of the present invention, the volume ratio of water to acetic acid in the sodium hypobromite aqueous solution is (2-4):1.

[0018] Preferably, the volume ratio of water to acetic acid in the sodium hypobromite aqueous solution is 3:1.

[0019] In one embodiment of the present invention, the reaction is carried out at 0-10°C.

[0020] As one embodiment of the present invention, the synthesis method includes the following steps: S1: Mix the compound phenanthrene with acetic acid and ethanol, then add sodium bromide, stir and cool down to 0-10℃, add sodium hydroxide, maintain the reaction system temperature at 0-10℃, add sodium hypobromide aqueous solution dropwise, and then stir the reaction at 0-10℃. S2: After the reaction is complete, water is added to the reaction system, then the mixture is filtered, the resulting filter cake is washed with water, and then recrystallized and purified to obtain 2-bromophenanthrene.

[0021] In one embodiment of the present invention, the recrystallization purifying agent is ethanol.

[0022] The method for synthesizing 2-bromophenanthrene provided by this invention uses sodium bromide and sodium hypobromite as the bromine source and sodium hydroxide as the base. Sodium acetate is generated within the acetic acid system and participates in the reaction. By adjusting the amount of solvent and aqueous solution added during the reaction, the quantitative production of the bromine source is controlled. Furthermore, by utilizing the characteristic that the product precipitates immediately upon formation in the system, the generation of polybrominated products is greatly reduced, thus significantly ensuring the purity and quality of the product. This method significantly reduces reaction costs, uses inexpensive raw materials, has a short reaction step, generates 2-bromophenanthrene in one step, operates under mild conditions, is simple to operate, and has a high yield, making it suitable for large-scale production. Attached Figure Description

[0023] Figure 1 It is the 2-bromophenanthrene prepared in Example 1 of this invention. 1 H-NMR spectrum. Detailed Implementation

[0024] The technical solution of the present invention will be described in detail below through specific embodiments. These embodiments are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention.

[0025] Unless otherwise specified, the pharmaceutical agents used in the following embodiments are all commercially available products.

[0026] The technical solution of the present invention will be described below with reference to specific embodiments.

[0027] Example 1 This embodiment provides a method for synthesizing 2-bromophenanthrene, the reaction formula of which is: The synthesis process is as follows: Add 1.78 g (0.01 mol) of phenanthrene to 10 mL of acetic acid, then stir and add 30 mL of ethanol, followed by 1.08 g (0.0105 mol) of sodium bromide. While stirring, slowly cool to approximately 5°C. Add sodium hydroxide (0.8 g, 0.02 mol) in portions, maintaining the temperature below 10°C. After the addition is complete, cool the system to approximately 5°C and slowly add an aqueous solution of sodium hypobromite (2.38 g, 0.02 mol) (using 30 mL of water). During the addition, maintain the reaction temperature at 5-6°C. During the addition, products will precipitate and the system will become viscous; control the stirring speed to ensure uniform mixing. After adding the sodium hypobromite aqueous solution, maintain the temperature at 5-6°C and continue the reaction until the phenanthrene reacts completely.

[0028] To end the reaction, 30 mL of water was added to the reaction system, and then the mixture was filtered. The filter cake was washed with water and recrystallized from the filter cake with ethanol to give 2.41 g of the product 2-bromophenanthrene, with a yield of 94%.

[0029] Example 2 This embodiment provides a method for synthesizing 2-bromophenanthrene. The reaction formula is the same as in Example 1, and the synthesis process is as follows: Add 1.78 g (0.01 mol) of phenanthrene to 20 mL of acetic acid, then stir and add 20 mL of ethanol, followed by 1.03 g (0.01 mol) of sodium bromide. While stirring, slowly cool to approximately 5°C. Add sodium hydroxide (0.4 g, 0.01 mol) in portions, maintaining the temperature below 10°C. After the addition is complete, cool the system to approximately 5°C and slowly add an aqueous solution of sodium hypobromite (2.38 g, 0.02 mol) (using 40 mL of water). During the addition, maintain the reaction temperature at 5-6°C. During the addition, products will precipitate and the system will become viscous; control the stirring speed to ensure uniform mixing. After adding the sodium hypobromite aqueous solution, maintain the temperature at 5-6°C and continue the reaction until the phenanthrene reacts completely.

[0030] To end the reaction, 30 mL of water was added to the reaction system, and then the mixture was filtered. The filter cake was washed with water and recrystallized from the filter cake with ethanol to give 2.27 g of the product 2-bromophenanthrene, with a yield of 88%.

[0031] Example 3 This embodiment provides a method for synthesizing 2-bromophenanthrene. The reaction formula is the same as in Example 1, and the synthesis process is as follows: Add 1.78 g (0.01 mol) of phenanthrene to 10 mL of acetic acid, then stir and add 40 mL of ethanol, followed by 1.24 g (0.012 mol) of sodium bromide. While stirring, slowly cool to approximately 5°C. Add sodium hydroxide (1.2 g, 0.03 mol) in portions, maintaining the temperature below 10°C. After the addition is complete, cool the system to approximately 5°C and slowly add an aqueous solution of sodium hypobromite (3.57 g, 0.03 mol) (using 40 mL of water). During the addition, maintain the reaction temperature at 5-6°C. During the addition, products will precipitate and the system will become viscous; control the stirring speed to ensure uniform mixing. After adding the sodium hypobromite aqueous solution, maintain the temperature at 5-6°C and continue the reaction until the phenanthrene reacts completely.

[0032] To end the reaction, 30 mL of water was added to the reaction system, and then the mixture was filtered. The filter cake was washed with water and recrystallized from the filter cake with ethanol to give 2.30 g of the product 2-bromophenanthrene, with a yield of 89%.

[0033] Example 4 This embodiment provides a method for synthesizing 2-bromophenanthrene. The reaction formula is the same as in Example 1, and the synthesis process is as follows: Add 178g (1mol) of phenanthrene to 800mL of acetic acid, then stir and add 2400mL of ethanol. Next, add 108g (1.05mol) of sodium bromide. While stirring, slowly cool to approximately 5°C. Add sodium hydroxide (80g, 2mol) in portions, maintaining the temperature below 10°C. After the addition is complete, cool the system to approximately 5°C and slowly add an aqueous solution of sodium hypobromite (238g, 2mol) (using 2400mL of water). During the addition, maintain the reaction temperature at 5-6°C. During the addition, products will precipitate and the system will become viscous; control the stirring speed to ensure uniform mixing. After adding the sodium hypobromite aqueous solution, maintain the temperature at 5-6°C and continue the reaction until the phenanthrene reacts completely.

[0034] To end the reaction, 1000 mL of water was added to the reaction system, and then the mixture was filtered. The filter cake was washed with water and recrystallized from the filter cake with ethanol to give 239 g of the product 2-bromophenanthrene, with a yield of 93%.

[0035] Referring to Example 4, two more batches of experiments were conducted, with yields of 95% and 94%, respectively.

[0036] The 2-bromophenanthroline obtained in Example 1 was analyzed by nuclear magnetic resonance. 1 H-NMR spectrum as follows Figure 1 As shown, LCMS analysis indicates the product purity is greater than 95%.

[0037] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for synthesizing 2-bromophenanthroline, characterized in that, The reaction formulas involved are: ； The synthesis method includes the following steps: adding the compound phenanthrene to a solvent, then adding sodium hydroxide and sodium bromide to the solvent, followed by adding an aqueous solution of sodium hypobromite dropwise, stirring the reaction, and obtaining the product 2-bromophenanthrene.

2. The synthesis method according to claim 1, characterized in that, The solvents are acetic acid and ethanol.

3. The synthesis method according to claim 2, characterized in that, The volume ratio of acetic acid to ethanol is: acetic acid: ethanol = 1: (1-4); preferably, acetic acid: ethanol = 1:

3.

4. The synthesis method according to claim 1, characterized in that, The molar ratio of phenanthrene to sodium hydroxide is 1:(1-3); preferably, the molar ratio of phenanthrene to sodium hydroxide is 1:

2.

5. The synthesis method according to claim 1, characterized in that, The molar ratio of phenanthrene to sodium bromide is 1:(0.8-1.2); preferably, the molar ratio of phenanthrene to sodium bromide is 1:1.

05.

6. The synthesis method according to claim 1, characterized in that, The molar ratio of phenanthrene to sodium hypobromite is 1:(2-3); preferably, the molar ratio of phenanthrene to sodium hypobromite is 1:

2.

7. The synthesis method according to claim 1, characterized in that, The volume ratio of water to acetic acid in the sodium hypobromide aqueous solution is (2-4):

1.

8. The synthesis method according to claim 1, characterized in that, The reaction is carried out at 0-10°C.

9. The synthesis method according to any one of claims 1-8, characterized in that, The method steps include: S1: Mix phenanthrene with acetic acid and ethanol, then add sodium bromide, stir and cool to 0-10℃, add sodium hydroxide, maintain the reaction system temperature at 0-10℃, add sodium hypobromide aqueous solution dropwise, and then stir the reaction at 0-10℃. S2: After the reaction is complete, water is added to the reaction system, then the mixture is filtered, the resulting filter cake is washed with water, and then recrystallized and purified to obtain 2-bromophenanthrene.

10. The synthesis method according to claim 9, characterized in that, The recrystallization purifying agent is ethanol.

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