Preparation method of 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane

Abstract

This invention belongs to the field of organic compound preparation technology, specifically relating to a method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane. Using 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and m-nitrobenzoyl chloride as raw materials, the raw materials are mixed and reacted separately in the presence of a strongly polar organic base solvent. After the reaction, a polar precipitate is added, and the mixture is filtered to obtain high-purity 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane. The obtained product achieves a purity of over 99.9% without further purification, meeting the purity requirements for electronic products. Furthermore, the single reaction solvent can be repeatedly recycled, eliminating the need for secondary purification to achieve the required purity. The operation is simple and suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of organic compound preparation technology, specifically relating to a method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane. Background Technology

[0002] 2,2-Bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane is one of the important raw materials for the preparation of polyimide resins and polyesterimide resins. At the same time, it is also a good heat-resistant modifier or curing agent for epoxy resins.

[0003] However, a search revealed few reports on 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane, especially regarding its preparation methods. The mainstream synthesis methods in patents all use acetone as a solvent. For example, Japanese patents such as JP2010026359 and JP2010008851 use propylene oxide as an acid-binding agent and carry out an amidation reaction at an ultra-low temperature of -15°C. The solid product precipitated after the reaction is directly used in the next reaction without purification. Experiments revealed that, firstly, the purity of the obtained product was insufficient, generally only around 98% purity by HPLC, with numerous impurities. Secondly, the use of explosive, low-boiling-point propylene oxide resulted in low safety and difficult recovery. Furthermore, the ring-opening product of propylene oxide reacted with the product, generating impurities that were difficult to remove, and the yield was low, around 90%. Japanese patent 2016117688 uses a mixed solution of toluene, tetrahydrofuran, and N-methylpyrrolidone for acylation to prepare the product. Using a mixed solvent avoids the use of the low-boiling-point solvent propylene oxide, thus preventing the generation of related impurities. However, the use of a mixed solvent results in a large number of residual solvent types in the product, posing a risk to subsequent reactions. Moreover, the recovery of the mixed solvent is difficult, making it unsuitable for large-scale industrial production. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing 2,2-bis[3-(3-nitrobenzoyl)-4-hydroxyphenyl]hexafluoropropane.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane,

[0007] The reaction equation is:

[0008]

[0009] Using 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and m-nitrobenzoyl chloride as raw materials, the raw materials were mixed and reacted separately in the presence of a strongly polar organic base solvent. After the reaction, a polar precipitate was added, and the mixture was filtered to obtain high-purity 2,2-bis[3-(3-nitrobenzoamide)-4-hydroxyphenyl]hexafluoropropane.

[0010] Furthermore, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane is mixed with a strongly polar organic base solvent to form a homogeneous solution. Then, m-nitrobenzoyl chloride dissolved in the strongly polar organic base is added dropwise at 0-25℃. After the addition, the mixture is kept at 15-30℃ for 1-2 hours. After post-treatment, a polar precipitant is added, and a large amount of solid is precipitated. The solid is filtered to obtain the product 2,2-bis[3-(3-nitrobenzoamide)-4-hydroxyphenyl]hexafluoropropane.

[0011] The post-treatment involves adding the precipitate to the reaction solution within 0.5-1 hour after the reaction. After addition, the reaction solution is heated to 30-70℃ (preferably 50-55℃) and stirred for 1-5 hours. After the precipitate precipitates, the solution is cooled to 0-10℃ and stirred for another 0.5-1 hour. The solution is then filtered, washed with the precipitate, and dried under vacuum at 60-100℃ (preferably 80-90℃) to obtain pure 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl].

[0012] The resulting product can achieve a purity of over 99.9% without purification, meeting the purity requirements for electronic products. Furthermore, the single reaction solvent can be repeatedly recycled and reused, and the product does not require secondary purification to meet the purity requirements. The operation is simple and suitable for industrial production.

[0013] The precipitate is one of methanol, ethanol, 1,4-dioxane, and acetone.

[0014] The mass ratio of the precipitate to the total amount of the strongly polar organic base solvent used (i.e., the sum of the strongly polar organic base solvents used for 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and m-nitrobenzoyl chloride) is 2:1 to 10:1. Preferably, it is 4:1 to 5:1. This allows for easy separation of the precipitate from the strongly polar organic base solvent during solvent recovery, and also helps improve product purity, reduce product loss, and increase yield.

[0015] The molar ratio of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane to m-nitrobenzoyl chloride is 1:2.0-2.5, preferably 1:2.1-2.2.

[0016] The strongly polar organic base solvent used in the reaction of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and m-nitrobenzoyl chloride is one of pyridine, 2-methylpyridine, or triethylamine. The main purpose of using a strongly polar organic base solvent is to provide a homogeneous medium for the reaction, dissolve the raw materials, absorb the acidic hydrogen chloride gas generated during the reaction, reduce the generation of impurities, and promote the reaction equilibrium to the right.

[0017] The mass ratio of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane to a strongly polar organic base solvent is 1:2.0-5.0.

[0018] The mass ratio of m-nitrobenzoyl chloride to a strongly polar organic base is 1:0.2-1:2.0.

[0019] The beneficial effects of this invention are as follows:

[0020] Using a single, strongly polar organic base as a solvent, which has not been reported in the literature, can be used both as a reaction solvent to dissolve materials and as an acid-binding agent. This significantly improves reaction selectivity, reduces side reactions, and allows for the high-yield and high-purity acquisition of the target product by adding the precipitate after the reaction. This reduces the number of reaction purification steps, and the product purity can reach over 99.9%, meeting the purity requirements for electronic products. Furthermore, the single reaction solvent can be repeatedly recycled and reused, making the operation simple. The product does not require secondary purification to meet the purity requirements, making it suitable for industrial production. Detailed Implementation

[0021] The technical solution of the present invention will be described in detail below through specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various modifications or alterations to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0022] The method of this invention is simple and uses a single solvent. This solvent provides a homogeneous medium for the reaction, dissolves the raw materials, absorbs the acidic hydrogen chloride gas generated during the reaction, reduces impurities, promotes the reaction equilibrium to the right, and facilitates solvent recovery and reuse. The reaction conditions are mild, the cost is low, the product has high purity, and the product is environmentally friendly. Through optimization of the process steps and conditions, the yield and purity are improved, making it more suitable for industrial production and meeting the purity requirements of intermediates for the preparation of high-purity electronic chemicals.

[0023] All raw materials used in the following examples are commercially available products.

[0024] Example 1

[0025] Add 250 ml of pyridine to a reaction flask, then add 100 g of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. After stirring and dissolving until clear, lower the temperature to 20°C. Add a mixture of 103 g of m-nitrobenzoyl chloride and 30 ml of pyridine dropwise to the reaction flask over 0.5 h, maintaining the reaction temperature no higher than 30°C. After the addition is complete, continue the reaction at 25°C for 2 h. After the reaction is complete, add 1200 ml of methanol, then raise the temperature to 60°C and stir for 2 h. Lower the temperature to 10°C and continue stirring for 0.5 h. Filter, wash with 100 ml of methanol, and dry under vacuum at 85-90°C and -0.095 MPa to obtain pure HFN with a mass of 174.2 g. The purity of 2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane is 96.2%, and the product purity (HPLC) is 99.92%.

[0026] Example 2

[0027] Measure 300 ml of 2-methylpyridine and add it to a reaction flask. Add 100 g of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and stir until dissolved and clear. After clearing, lower the temperature to 20°C. Add a mixture of 105 g of m-nitrobenzoyl chloride and 35 ml of 2-methylpyridine dropwise to the reaction flask over 1 hour. Maintain the reaction temperature at no higher than 30°C. After the addition is complete, continue the reaction at 20°C for 2 hours. After the reaction is complete, add 1500 ml of ethanol. After the addition is complete, raise the temperature to 80°C and stir for 2 hours. Cool to 0°C and continue stirring for 0.5 hours. Filter and wash with 100 ml of ethanol to obtain pure HFN. The mass is 175.3 g, the yield based on 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane is 96.6%, and the product purity (HPLC) is 99.96%.

[0028] Example 3

[0029] Measure 300 ml of triethylamine and add it to a reaction flask. Add 100 g of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and stir until dissolved and clear. After clearing, lower the temperature to 20°C. Add a mixture of 106 g of m-nitrobenzoyl chloride and 50 ml of triethylamine dropwise to the reaction flask over 1 hour, maintaining the reaction temperature no higher than 30°C. After the addition is complete, continue the reaction at 25°C for 2 hours. After the reaction is complete, add 1500 ml of methanol. After the addition is complete, raise the temperature to 60°C and stir for 2 hours. Cool to 10°C and continue stirring for 0.5 hours. Filter and wash with 100 ml of methanol to obtain pure HFN. The mass is 176.2 g, the yield (based on 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane) is 97.1%, and the product purity (HPLC) is 99.93%.

Claims

1. A method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane, characterized in that: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane was mixed with a strongly polar organic base solvent to form a homogeneous solution. Then, m-nitrobenzoyl chloride dissolved in the strongly polar organic base was added dropwise at 0-25℃. After the addition, the mixture was kept at 15-30℃ for 1-2 hours. After the reaction, a polar precipitant was added, and a large amount of solid was precipitated. The solid was filtered to obtain the product 2,2-bis[3-(3-nitrobenzoamide)-4-hydroxyphenyl]hexafluoropropane. The strongly polar organic base solvent is one of pyridine, 2-methylpyridine, and triethylamine.

2. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The post-treatment involves adding the precipitate to the reaction solution within 0.5-1 hour after the reaction. After addition, the reaction solution is heated to 30-70°C and stirred for 1-5 hours. After the precipitate precipitates, the temperature is lowered to 0-10°C and stirred for another 0.5-1 hour. The solution is then filtered, washed with the precipitate, and dried under vacuum at 60-100°C and -0.090-0.095 MPa to obtain pure 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl].

3. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The precipitate is one of methanol, ethanol, 1,4-dioxane, and acetone.

4. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The mass ratio of the precipitate to the total mass of the strongly polar organic base solvent used is 2:1-10:

1.

5. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The molar ratio of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane to m-nitrobenzoyl chloride is 1:2.0-2.

5.

6. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The mass ratio of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane to a strongly polar organic base solvent is 1:2.0-5.

0.

7. The method for preparing 2,2-bis[3-(3-nitrobenzamido)-4-hydroxyphenyl]hexafluoropropane according to claim 1, characterized in that: The mass ratio of m-nitrobenzoyl chloride to a strongly polar organic base is 1:0.2-1:2.0.

Images