Preparation method of tert-amyl peroxide

Abstract

This invention belongs to the field of acyclic compound technology, specifically relating to a method for preparing tert-amyl peroxide. A tert-amyl hydrogen peroxide aqueous solution is added to a solvent and stirred to obtain a mixed solution. Under stirring conditions, p-toluenesulfonic acid and ferric phosphide are added sequentially to the mixed solution. After the addition is complete, stirring continues to produce reaction solution I. Under stirring conditions, acetic anhydride is added to reaction solution I. After the addition is complete, stirring continues to produce reaction solution II. A washing solution is added to reaction solution II, and the mixture is stirred and washed, then separated to obtain crude tert-amyl peroxide. The crude tert-amyl peroxide is washed, dried, and the solvent is removed to obtain tert-amyl peroxide. This invention avoids the problems of large amounts of hydrochloric acid produced by traditional acyl chloride methods and the corrosiveness caused by using sulfuric acid as a catalyst. Furthermore, ferric phosphide is magnetic, allowing for recycling through magnetic separation after the reaction. p-Toluenesulfonic acid can be regenerated through ion exchange resin, significantly reducing production costs.

Description

Technical Field

[0001] This invention belongs to the field of acyclic compound technology, specifically relating to a method for preparing tert-amyl peroxide acetate. Background Technology

[0002] tert-amyl peroxide, also known as tert-amyl peroxide, abbreviated as TAPA, has the molecular formula C7H. 14 O3, an organic peroxide, is characterized by good low-temperature activity and high oxygen content. It can be used as a polymerization initiator for styrene or styrene copolymers, as well as for the polymerization of methacrylates and vinyl acetate. It is an excellent low-temperature initiator for polyethylene. Tert-amyl peroxide has an accelerated decomposition temperature of 60℃ and relatively poor thermal stability. It should be handled with care to prevent damage to packaging and containers, and should be protected from impacts and vibrations. During storage, it should be kept away from fire and heat sources, and stored separately from acids, reducing agents, flammable materials, and combustibles. Currently, the commonly used industrial method for synthesizing tert-amyl peroxide involves using sulfuric acid as a catalyst and tert-amyl hydrogen peroxide and acetic anhydride as raw materials. This method has cumbersome post-processing steps and low yield.

[0003] Chinese patent CN119409610A discloses a method for preparing pentopenate peroxide and an initiator. Water is used as a solvent. While pentopenate hydrogen peroxide reacts with liquid alkali to generate pentopenate peroxide, the pentopenate peroxide undergoes a substitution reaction with pentopenoyl chloride to obtain pentopenate peroxide. However, the raw material pentopenoyl chloride used in this patent is extremely prone to hydrolysis under alkaline conditions, which can lead to hydrochloric acid corrosion of equipment. Furthermore, the drop rate of the reactants needs to be strictly controlled, which is not conducive to industrial production. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing tert-amyl peroxide, which is convenient to operate, has a high product yield, and is suitable for industrial applications.

[0005] The preparation method of tert-amyl peroxide acetate according to the present invention includes the following steps:

[0006] (1) Add tert-amyl hydrogen peroxide aqueous solution to the solvent and stir to obtain a mixed solution;

[0007] (2) Under stirring conditions, p-toluenesulfonic acid and iron phosphide (FeP) were added to the mixed solution in sequence. After the addition was completed, the reaction was stirred to obtain reaction solution I.

[0008] (3) Under stirring conditions, acetic anhydride was added to reaction solution I. After the addition was complete, the reaction was stirred to obtain reaction solution II.

[0009] (4) Add washing solution to reaction solution II, stir and wash, separate, and obtain crude tert-amyl peroxide;

[0010] (5) The crude tert-amyl peroxide product was washed, dried, and the solvent was removed to obtain tert-amyl peroxide.

[0011] In step (1), the solvent is one or more of dodecane, n-hexane or silicone oil, preferably dodecane, and the silicone oil includes methyl silicone oil; the concentration of the tert-amyl hydrogen peroxide aqueous solution is 80-95 wt.%, the stirring temperature is 0-45°C, and the stirring time is 5-30 min.

[0012] In step (1), the mass ratio of the tert-amyl hydrogen peroxide aqueous solution to the solvent is 0.276 to 14.02:1.

[0013] In step (2), the mass ratio of p-toluenesulfonic acid, ferric phosphide and the aqueous solution of tert-amyl hydrogen peroxide in step (1) is 0.023-0.131:0.075-0.12:1.

[0014] In step (2), the total time for adding p-toluenesulfonic acid and ferric phosphide in sequence is 5 to 30 minutes, the addition temperature is 0 to 45°C, the stirring reaction time is 5 to 30 minutes, and the stirring reaction temperature is 0 to 45°C.

[0015] In step (3), the mass ratio of acetic anhydride to the aqueous solution of tert-amyl hydrogen peroxide in step (1) is 1:1.39 to 1.79, the addition time is 5 to 30 minutes, and the addition temperature is 0 to 30°C.

[0016] In step (3), the stirring reaction time is 30 to 300 minutes and the stirring reaction temperature is 0 to 45°C.

[0017] In step (4), the washing solution is an aqueous solution of sodium bicarbonate or an aqueous solution of sodium carbonate, preferably an aqueous solution of sodium carbonate; the concentration of the washing solution is 3 wt.% to saturation concentration, and the mass ratio of the washing solution to the aqueous solution of tert-amyl hydrogen peroxide in step (1) is 0.09-0.29:1.

[0018] The stirring and washing time in step (4) is 5 to 30 minutes, and the stirring and washing temperature is 0 to 45°C.

[0019] In step (5), the washing process involves washing with deionized water until the solution is neutral.

[0020] The reaction principle of this invention is as follows:

[0021] In a mixed solution of tert-amyl hydrogen peroxide (TAHP) and solvent, p-toluenesulfonic acid and iron phosphide are added sequentially. When p-toluenesulfonic acid comes into contact with tert-amyl hydrogen peroxide, the sulfonic acid group (-SO3H) protonates the peroxy bond of TAHP, lowering the dissociation barrier of the TAHP peroxy bond and placing the tert-amyl hydrogen peroxide in a highly active state. Subsequently, the Fe on the surface of iron phosphide (FeP)...3+ It undergoes a redox reaction with TAHP in a highly reactive state to generate highly reactive tert-amyl peroxide radicals (t-AmOO•) and H+. + and Fe 2+ The generated Fe 2+ It can also react with TAHP to regenerate Fe. 3+ tert-amyl oxygen radical (t-AmO•) and OH - Iron phosphide is reactivated, forming a sustainable catalytic cycle. Furthermore, the Fe on the surface of iron phosphide... 3+ As a Lewis acid site, it can form a coordinate bond with the carbonyl oxygen of acetic anhydride through electrostatic interaction, which increases the polarization of the C=O bond and significantly enhances the electrophilicity of the carbonyl carbon, putting acetic anhydride in a highly active state. The highly active tert-amyl peroxide radical (t-AmOO•) attacks the carbonyl carbon of acetic anhydride to generate a tetrahedral intermediate, which then undergoes heterolytic cleavage of the acyl oxygen bond (-OCOCH3) in the side chain of acetic anhydride to generate the product tert-amyl peroxide. After washing and drying, high-purity tert-amyl peroxide is obtained.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. The sulfonic acid matrix of p-toluenesulfonic acid protonates the peroxy bond of TAHP, placing the tert-amyl hydrogen peroxide in a highly active state. Subsequently, the Fe on the surface of iron phosphide... 3+ It undergoes a redox reaction with TAHP in a highly active state to generate tert-amyl peroxy radicals (t-AmOO•) and Fe. 2+ The generated Fe 2+ It can also react with TAHP to regenerate Fe. 3+ Iron phosphide is reactivated, forming a sustainable catalytic cycle, avoiding the decay of its catalytic activity, and significantly improving the activation conversion rate of raw materials and the overall reaction rate; in addition, the Fe on the surface of iron phosphide... 3+ It can form a coordinate bond with the carbonyl oxygen of acetic anhydride, increasing the polarization of the C=O bond and significantly enhancing the electrophilicity of the carbonyl carbon, thus placing acetic anhydride in a highly active state. The synergistic activation of the reaction substrate by p-toluenesulfonic acid and ferric phosphide allows both acetic anhydride and TAHP to be in a highly active state simultaneously, significantly lowering the reaction energy barrier and noticeably increasing the reaction rate. Simultaneously, the H+ provided by p-toluenesulfonic acid... + It can maintain an acidic environment and inhibit Fe 3+ Hydrolysis produces Fe(OH)3 precipitate, which lays the foundation for subsequent acetyl transfer and the generation of tert-amyl peroxy radical (t-AmOO•).

[0024] 2. When ferric phosphide comes into contact with p-toluenesulfonic acid, due to the electron delocalization effect of the Fe-P bond, Fe... 3+The reduced d-orbital electron cloud density enhances the Lewis acidity of iron phosphide. Simultaneously, the transfer of p-orbital electrons from P to Fe increases the nucleophilicity of the phosphorus sites. These highly nucleophilic phosphorus sites adsorb protons from p-toluenesulfonic acid via hydrogen bonding. A composite active center is formed between p-toluenesulfonic acid and FeP through hydrogen bonding, resulting in spatially close proximity of the active sites of the two catalysts. This provides the necessary steric conditions for the subsequent activation of the two substrates (acetic anhydride and tert-amyl peroxide), significantly reducing the steric hindrance of the tert-amyl peroxide radical attacking acetic anhydride and thus increasing the reaction rate. The highly reactive tert-amyl peroxide radical attacks the carbonyl carbon of acetic anhydride to generate a negatively charged tetrahedral intermediate, which then undergoes heterolytic cleavage of the acyloxy bond (-OCOCH3) in the acetic anhydride side chain, producing the target product, tert-amyl peroxide.

[0025] 3. In this invention, ferric phosphide and p-toluenesulfonic acid are used to synergistically catalyze the reaction of acetic anhydride with tert-amyl hydrogen peroxide to produce tert-amyl acetate peroxide, avoiding the large amount of hydrochloric acid produced by the traditional acyl chloride method and the corrosive problems caused by using sulfuric acid as a catalyst; at the same time, ferric phosphide is magnetic, and can be recycled through magnetic separation after the reaction, and p-toluenesulfonic acid can be regenerated through ion exchange resin, which greatly reduces the production cost. Attached Figure Description

[0026] Figure 1 The image shows the 1H NMR spectrum of the tert-amyl peroxide product from Example 1. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments.

[0028] Example 1

[0029] (1) Add 2.6g of dodecane to the reactor, then add 36.45g of 80wt.% tert-amyl hydrogen peroxide aqueous solution, stir at 0℃ for 5min to obtain a mixed solution;

[0030] (2) Under stirring conditions, 0.84 g of p-toluenesulfonic acid and 4.34 g of iron phosphide powder were added to the mixed solution obtained in step (1) in sequence. The addition temperature was controlled at 0-5℃. The total addition time of p-toluenesulfonic acid and iron phosphide powder was 30 min. After the addition was completed, the mixture was stirred at 0℃ for another 30 min to obtain reaction solution I.

[0031] (3) Under stirring conditions, add 20.62g of acetic anhydride with a purity of 99% to the reaction solution I obtained in step (2), control the addition temperature to 0-5℃, the addition time to 30min, and continue stirring the reaction at 0℃ for 300min to obtain reaction solution II;

[0032] (4) Add 400g of sodium carbonate aqueous solution with a concentration of 3wt.% to the reaction solution II obtained in step (3), and stir and wash for 30min at 0-5℃. After washing, stop stirring, separate, and obtain crude tert-amyl peroxide.

[0033] (5) The crude tert-amyl peroxide product was washed with deionized water until neutral, dried, and dodecane was removed to obtain 28.87 g of tert-amyl peroxide product. The content of tert-amyl peroxide was 95.7 wt.%, and the product yield was 94.49%. The 1H NMR spectrum of the tert-amyl peroxide product is shown below. Figure 1 , 1 H NMR (400 MHz, CDCl3, δ ppm): 2.17 (s, 3H), 1.66 (q, J=8 Hz, 2H), 1.33 (s, 6H), 0.88 (t, J=8 Hz, 3H).

[0034] Example 2

[0035] (1) Add 104.1g of n-hexane to the reactor, then add 28.78g of 95wt.% tert-amyl hydrogen peroxide aqueous solution, stir at 45℃ for 30min to obtain a mixed solution;

[0036] (2) Under stirring conditions, 3.75g of p-toluenesulfonic acid and 2.17g of iron phosphide powder were added to the mixed solution obtained in step (1) in sequence. The addition temperature was controlled at 40-45℃. The total addition time of p-toluenesulfonic acid and iron phosphide powder was 5min. After the addition was completed, the mixture was stirred at 45℃ for 5min to obtain reaction solution I.

[0037] (3) Under stirring conditions, add 20.62g of acetic anhydride with a purity of 99% to the reaction solution I obtained in step (2), control the addition temperature to 25-30℃, the addition time to 5min, and continue stirring the reaction at 45℃ for 30min to obtain reaction solution II;

[0038] (4) Add 100g of sodium bicarbonate aqueous solution with a saturated concentration to the reaction solution II obtained in step (3), stir and wash at 40-45℃ for 5min, stop stirring after washing, separate, and obtain crude tert-amyl peroxide.

[0039] (5) The crude tert-amyl peroxide product was washed with deionized water until neutral, dried, and n-hexane was removed to obtain 29.05g of tert-amyl peroxide product; the content of tert-amyl peroxide was 94.8wt.% and the product yield was 94.18%.

[0040] Example 3

[0041] (1) Add 29.24g of methyl silicone oil to the reactor, then add 36.76g of 85wt.% tert-amyl hydrogen peroxide aqueous solution, stir at 10℃ for 15min to obtain a mixed solution;

[0042] (2) Under stirring conditions, 2.56g of p-toluenesulfonic acid and 3.74g of iron phosphide powder were added to the mixed solution obtained in step (1) in sequence. The addition temperature was controlled at 10-15℃. The total addition time of p-toluenesulfonic acid and iron phosphide powder was 15min. After the addition was completed, the mixture was stirred at 15℃ for 10min to obtain reaction solution I.

[0043] (3) Under stirring conditions, add 20.62g of acetic anhydride with a purity of 99% to the reaction solution I obtained in step (2), control the addition temperature to 10-15℃, the addition time to 20min, and continue stirring the reaction at 15℃ for 120min to obtain reaction solution II;

[0044] (4) Add 150g of 10wt.% sodium carbonate aqueous solution to the reaction solution II obtained in step (3), stir and wash at 10-15℃ for 15min. After washing, stop stirring and separate to obtain crude tert-amyl peroxide.

[0045] (5) The crude tert-amyl peroxide product was washed with deionized water until neutral, dried, and methyl silicone oil was removed to obtain 29.21g of tert-amyl peroxide product; the content of tert-amyl peroxide was 95.1wt. and the product yield was 95%.

[0046] Comparative Example 1

[0047] Without adding iron phosphide powder, the other operations were the same as in Example 1, yielding 24.15g of tert-amyl peroxide product. The content of tert-amyl peroxide was found to be 82.14 wt.%, and the product yield was 67.84%.

[0048] Comparative Example 2

[0049] Without adding p-toluenesulfonic acid, the other operations were the same as in Example 1, yielding 22.54g of tert-amyl peroxide product. The content of tert-amyl peroxide was 78.71 wt.%, and the product yield was 60.67%.

Claims

1. A method for preparing tert-amyl peroxide, characterized in that... Includes the following steps: (1) Add tert-amyl hydrogen peroxide aqueous solution to the solvent and stir to obtain a mixed solution; (2) Under stirring conditions, p-toluenesulfonic acid and ferric phosphide were added to the mixed solution in sequence. After the addition was completed, the reaction was stirred to obtain reaction solution I. (3) Under stirring conditions, acetic anhydride was added to reaction solution I. After the addition was complete, the reaction was stirred to obtain reaction solution II. (4) Add washing solution to reaction solution II, stir and wash, separate, and obtain crude tert-amyl peroxide; (5) The crude tert-amyl peroxide product was washed, dried, and the solvent was removed to obtain tert-amyl peroxide; In step (2), the mass ratio of p-toluenesulfonic acid, ferric phosphide and the aqueous solution of tert-amyl hydrogen peroxide in step (1) is 0.023-0.131:0.075-0.12:

1.

2. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (1), the solvent is one or more of dodecane, n-hexane or silicone oil, the concentration of the tert-amyl hydrogen peroxide aqueous solution is 80-95 wt.%, the stirring temperature is 0-45℃, and the stirring time is 5-30 min.

3. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (1), the mass ratio of the tert-amyl hydrogen peroxide aqueous solution to the solvent is 0.276 to 14.02:

1.

4. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (2), the total time for adding p-toluenesulfonic acid and ferric phosphide in sequence is 5 to 30 minutes, the addition temperature is 0 to 45°C, the stirring reaction time is 5 to 30 minutes, and the stirring reaction temperature is 0 to 45°C.

5. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (3), the mass ratio of acetic anhydride to the aqueous solution of tert-amyl hydrogen peroxide in step (1) is 1:1.39 to 1.79, the addition time is 5 to 30 minutes, and the addition temperature is 0 to 30°C.

6. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (3), the stirring reaction time is 30 to 300 minutes and the stirring reaction temperature is 0 to 45°C.

7. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (4), the washing solution is an aqueous solution of sodium bicarbonate or an aqueous solution of sodium carbonate, and the concentration of the washing solution is 3 wt.% to saturation concentration.

8. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... The stirring and washing time in step (4) is 5 to 30 minutes, and the stirring and washing temperature is 0 to 45°C.

9. The method for preparing tert-amyl peroxide according to claim 1, characterized in that... In step (5), the washing process involves washing with deionized water until the solution is neutral.

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