Preparation method of di-(2-hydroxy isopropyl) benzene

Abstract

The invention provides the preparation method of the di-(2-hydroxy isopropyl) benzene, and the method has the advantages of high reaction rate, high selectivity, high product purity, safety, high efficiency and higher practical value.

Description

Technical Field

[0001] The invention belongs to the field of fine organic synthesis, and specifically relates to a method for preparing di-(2-hydroxyisopropyl)benzene. Background Art

[0002] Di-(2-hydroxyisopropyl)benzene (BIPB) is the main raw material of diisopropylbenzene. BIPB is a widely used crosslinking agent. As an upgraded and environmentally friendly product of DCP, it has the characteristics of low dosage, low odor and good compression deformation resistance. Therefore, the demand for BIPB will become better and better.

[0003] At present, the invention patent CN102911015B discloses a method for producing di-(2-hydroxyisopropyl)benzene. After diisopropylbenzene is oxidized, the reaction solution is reduced, and the dihydroperoxide isopropylbenzene and the corresponding benzyl alcohol byproduct in the reaction solution are reduced to obtain di-(2-hydroxyisopropyl)benzene and then centrifuged. In the reduction stage, the reduction is carried out in the oil-water two-phase, and the reaction temperature needs to be controlled at 120-180°C. The reaction rate is low, the selectivity is low, and the reaction temperature is high. Therefore, the risk of the reaction is high and it is easy to get out of control, and the crystallization separation efficiency is low, and the operation is complicated.

[0004] At present, the invention patent CN117800810A discloses a method for preparing α,α'-dihydroxy-1,3-diisopropylbenzene. After diisopropylbenzene is oxidized, it is reduced using hydrogen sulfide reaction gas, and the dihydroperoxide isopropylbenzene and the corresponding benzyl alcohol byproduct in the reaction solution are reduced to obtain di-(2-hydroxyisopropyl)benzene, which is then cooled, crystallized and filtered for separation. This method uses acidic gas to reduce peroxides, which will cause peroxide decomposition, reduce reaction selectivity, and have a high reaction safety risk. Therefore, a safe and efficient method for preparing di-(2-hydroxyisopropyl)benzene is urgently needed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for preparing di-(2-hydroxyisopropyl)benzene. The method utilizes an alkaline solution to extract the peroxide in the oxidation reaction liquid to an alkaline phase and then performs a reduction reaction. The method has a fast reaction rate, a high reduction reaction selectivity, a more stable reaction, a high safety factor, and good industrial value.

[0006] A method for preparing di-(2-hydroxyisopropyl)benzene comprises the following steps:

[0007] S1: continuously introducing diisopropylbenzene, air and dilute alkali solution into a reactor for continuous reaction to obtain an oxidation reaction solution;

[0008] S2: extracting the oxidation reaction liquid with an alkaline solution to obtain a raffinate phase and an alkaline phase, and recycling the raffinate phase to the reactor;

[0009] S3: adding the alkaline phase obtained in step S2 to an aqueous solution of a reducing substance to reduce the crude product of di-(2-hydroxyisopropyl)benzene;

[0010] S4: The crude di-(2-hydroxyisopropyl)benzene product is dissolved using MIBK and / or MC to obtain a first mixed solution;

[0011] S5: countercurrently washing the first mixed solution with water;

[0012] S6: The first mixed solution after washing is cooled and crystallized to obtain di-(2-hydroxyisopropyl)benzene.

[0013] Preferably, in S1 of the present invention, the diisopropylbenzene includes one or more of m-diisopropylbenzene, p-diisopropylbenzene, m-diisopropylbenzene monohydroperoxide, and p-diisopropylbenzene monohydroperoxide; the dilute alkali solution may be one or more of sodium hydroxide and sodium carbonate solution, and the concentration of the dilute alkali solution is preferably 0.1wt%-10wt%, such as 0.5, 1, 2, 3, 5, 8wt% or a range consisting of any two thereof;

[0014] Preferably, in S1 of the present invention, the mass ratio of diisopropylbenzene to dilute alkali solution is 1:1-20:1; the mass ratio of diisopropylbenzene to oxygen in the air is (2-3):1; the reaction temperature is 60-120°C; and the reaction pressure is 0.1-0.6MPa(G).

[0015] Preferably, in S1 of the present invention, the residence time of the raw materials is controlled to control the content of cumene dihydroperoxide in the oxidation reaction liquid to 8-15 wt %, and the alkaline solution extraction step S2 is performed.

[0016] Preferably, in S2 of the present invention, the alkaline solution is selected from one or both of sodium hydroxide and potassium hydroxide solutions, the concentration of the alkaline solution is preferably 2-10wt%, more preferably 3-5wt%, and the extraction temperature is controlled at 10-50°C, preferably 15-25°C.

[0017] Preferably, in S2 of the present invention, the mass ratio of the alkaline solution to the oxidation reaction liquid is 0.3-3:1, such as 0.3:1, 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1 or a range consisting of any two thereof, more preferably 0.3-1.5:1;

[0018] Preferably, in S2 of the present invention, an extraction tower is used for extraction, such as a pulse extraction tower or a rotary disk extraction tower, and multiple countercurrent extractions are preferably performed, such as 3-7 stages, more preferably 5-7 stages;

[0019] In S2 of the present invention, the oxidation reaction liquid (excluding the solvent) mainly contains unreacted raw material diisopropylbenzene, oxidation intermediate diisopropylbenzene hydroperoxide, and substances such as diisopropylbenzene hydroperoxide and diisopropylbenzene hydroperoxide. After the alkaline solution extraction in step S2, the alkaline phase mainly contains diisopropylbenzene hydroperoxide and diisopropylbenzene hydroperoxide, while other substances will remain in the raffinate phase and can be returned to the S1 reactor for reuse.

[0020] Preferably, in S3 of the present invention, the reducing substance is selected from one or more of sodium sulfide, sodium sulfite, and sodium thiosulfate, and the concentration of the solution is preferably 5-25wt%.

[0021] Preferably, in S3 of the present invention, the mass ratio of the alkaline phase to the aqueous solution of the reducing substance is (1-3): (1-3).

[0022] In a specific embodiment, in S3, the time for adding the alkali phase is controlled to be 1-10 hours.

[0023] Preferably, the mixture is aged for 0.5-4 h after the addition of the alkali phase is completed, so that the reduction reaction is more complete. After the reduction reaction is completed, the crude di-(2-hydroxyisopropyl)benzene product is filtered and separated.

[0024] Preferably, the reaction temperature of the entire reduction process including addition of the alkali phase and aging is controlled at 10-40°C.

[0025] Preferably, in S4 of the present invention, the dissolution temperature is controlled to be 80-100° C., and the mass ratio of MIBK and / or MC to the crude di-(2-hydroxyisopropyl)benzene product is 1.5-3:1;

[0026] Preferably, in S5 of the present invention, the water washing temperature is 80-100°C, the mass ratio of water to the first mixed liquid is 1:(5-10), and the number of countercurrent water washing stages is preferably multiple, more preferably 3-5 stages.

[0027] Preferably, in S6 of the present invention, the cooling rate is 1-5K / min, and the temperature is cooled to 40-50°C to obtain di-(2-hydroxyisopropyl)benzene.

[0028] In the method for preparing di-(2-hydroxyisopropyl)benzene of the present invention, although the various steps are displayed in numerical order, these steps are not necessarily performed in the order indicated by the numbers, unless otherwise specified herein, and the execution of these steps is not strictly limited in order, and they can be performed in other orders, and at least part of the steps can include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of other sub-steps or stages.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The method provided by this patent provides a method for safely and efficiently preparing a crude product of di-(2-hydroxyisopropyl)benzene, with a reduction reaction yield of ≥96%. A separation process for removing inorganic salts and organic heavy component impurities in the crude product is proposed, and the obtained di-(2-hydroxyisopropyl)benzene product has a purity of ≥98.5wt%, preferably ≥99wt%, which ensures the purity of the product and minimizes the generation of three wastes. DETAILED DESCRIPTION

[0031] The following embodiments further illustrate the technical solutions provided by the present invention, but the present invention is not limited to the listed embodiments, and also includes any other known changes within the scope of the present invention.

[0032] Raw material information:

[0033] Diisopropyl aladin;

[0034] Anhydrous sodium sulfite Aladdin;

[0035] Sodium sulfide Aladdin;

[0036] Sodium Thiosulfate Aladdin;

[0037] Sodium hydroxide Aladdin;

[0038] Analytical instruments:

[0039] Shimadzu LC-20A liquid chromatograph, chromatographic column: Shimadzu phenyl column, mobile phase: water: acetonitrile ratio 1:1, analysis temperature: 30 °C, analysis time: 2 h.

[0040] Example 1

[0041] In the reactor, diisopropylbenzene and 0.1wt% sodium hydroxide solution are controlled to be fed in a mass ratio of 1:1, and the mass ratio of diisopropylbenzene to oxygen in the air is 3:1. The reaction temperature is controlled to be 90°C, the reaction pressure is 0.3MPa(G), and the content of dihydroperoxide isopropylbenzene in the obtained reaction solution is controlled to be 10wt% by controlling the residence time of the raw materials. The oxidation reaction solution is extracted with 3wt% sodium hydroxide solution, and five-stage countercurrent extraction is performed according to the mass ratio of sodium hydroxide solution to the oxidation reaction solution of 1:1. The extraction temperature is 25°C, and the oil phase is recycled to the reactor after extraction. The alkaline phase is added dropwise to a 5wt% sodium sulfite solution, and the mass ratio of the alkaline phase to the sodium sulfite solution is 1:3. The initial dropping temperature is controlled to be 10°C, the dropping time is 4h, and the aging time is 1h. After aging, the reaction solution is filtered at 10°C to obtain a crude di-(2-hydroxyisopropyl)benzene product, and the reduction reaction yield is 98%.

[0042] The crude product was dissolved in MIBK solution to obtain the first mixed solution, the dissolution temperature was controlled at 80°C, and the mass ratio of MIBK to the crude product was 3:1. The mass ratio of water for washing to the first mixed solution was 1:5, and three-stage countercurrent washing was performed at a water washing temperature of 80°C to obtain an oil phase. The oil phase was cooled and crystallized at a cooling rate of 1K / min to 40°C. Finally, the sodium ion content of the refined di-(2-hydroxyisopropyl)benzene was 40ppm, and the product purity was 99.5wt%.

[0043] Example 2

[0044] In the reactor, diisopropylbenzene and 5wt% sodium hydroxide solution are controlled to be fed in a mass ratio of 18:1, and the mass ratio of diisopropylbenzene to oxygen in the air is 3:1. The reaction temperature is controlled to be 90°C, the reaction pressure is 0.3MPa(G), and the residence time is controlled to obtain a dihydroperoxide isopropylbenzene content of 10wt% in the reaction solution. The oxidation reaction solution is extracted with 5wt% sodium hydroxide solution, the mass ratio of sodium hydroxide solution to the oxidation reaction solution is 0.6:1, and 7-stage countercurrent extraction is performed. The extraction temperature is 20°C, and the oil phase is recycled to the reactor after extraction. The alkaline phase is added dropwise to a 25wt% sodium sulfide solution, and the mass ratio of the alkaline phase to the sodium sulfide solution is 5:3. The initial dropping temperature is controlled to be 40°C, the dropping time is 1h, and the aging time is 4h. After aging, the reaction solution is filtered at 40°C to obtain a crude di-(2-hydroxyisopropyl)benzene product, and the reduction reaction yield is 96%.

[0045] The crude product was dissolved in MIBK solution to obtain a first mixed solution, the dissolution temperature was controlled at 100°C, and the mass ratio of MIBK to the crude product was 1.5:1. The mass ratio of water for washing to the first mixed solution was 1:10, and 5-stage countercurrent washing was performed at a water washing temperature of 90°C to obtain an oil phase. The oil phase was cooled and crystallized at a cooling rate of 3K / min to 40°C. Finally, the sodium ion content of the refined di-(2-hydroxyisopropyl)benzene was 90ppm, and the product purity was 98.5wt%.

[0046] Example 3

[0047] In the reactor, diisopropylbenzene and 2wt% sodium hydroxide solution are controlled to be fed in a mass ratio of 4:1, and the mass ratio of diisopropylbenzene to oxygen in the air is 3:1. The reaction temperature is 100°C, the reaction pressure is 0.5MPa(G), and the residence time is controlled to obtain a dihydroperoxide isopropylbenzene content of 10wt% in the reaction solution. The oxidation reaction solution is extracted with a 4wt% sodium hydroxide solution, the mass ratio of the sodium hydroxide solution to the oxidation reaction solution is 0.9:1, and a 6-stage countercurrent extraction is performed. The extraction temperature is 25°C, and the oil phase is recycled to the reactor after extraction. The alkaline phase is added dropwise to a 15wt% sodium sulfite solution, and the mass ratio of the alkaline phase to the sodium sulfite solution is 1:1. The initial dropping temperature is controlled to be 30°C, the dropping time is 3h, and the aging time is 2h. After aging, the reaction solution is filtered at 40°C to obtain a crude di-(2-hydroxyisopropyl)benzene product, and the reduction reaction yield is 97%.

[0048] The crude product was dissolved in MIBK solution to obtain a first mixed solution, the dissolution temperature was controlled at 90°C, and the mass ratio of MIBK to the crude product was 2:1. The mass ratio of water for washing to the first mixed solution was 1:7, and 4-stage countercurrent washing was performed at a washing temperature of 100°C to obtain an oil phase. The oil phase was cooled and crystallized at a cooling rate of 3K / min to 40°C. Finally, the sodium ion content of the refined di-(2-hydroxyisopropyl)benzene was 80ppm, and the product purity was 99wt%.

[0049] Comparative Example 1

[0050] Compared with Example 1, the difference is that the oxidation reaction liquid is not extracted with alkaline solution and then reduced, specifically:

[0051] In the reactor, diisopropylbenzene and 0.1wt% sodium hydroxide solution are fed in a mass ratio of 1:1, and the mass ratio of diisopropylbenzene to oxygen in the air is 3:1. The reaction temperature is controlled to be 90°C, the reaction pressure is 0.3MPa(G), and the content of dihydroperoxide isopropylbenzene in the reaction solution is controlled to be 10wt% by the residence time of the raw materials. The obtained oxidation reaction solution is directly reduced with 15wt% sodium sulfite solution, the mass ratio of the oxidation reaction solution to 15wt% sodium sulfite is 3:1, the dropping temperature is controlled at 80°C, the dropping time is 20h, the aging time is 20h, and after obtaining the reduction reaction solution, the reaction solution is filtered at 10°C to obtain a crude di-(2-hydroxyisopropyl)benzene product, and the reduction reaction yield is only 85%.

[0052] The crude product was dissolved in MIBK solution to obtain a first mixed solution, the dissolution temperature was controlled at 80°C, and the mass ratio of MIBK to the crude product was 3:1. The mass ratio of water for washing to the first mixed solution was 1:5, and three-stage countercurrent extraction and washing were performed at a water washing temperature of 80°C to obtain an oil phase. The oil phase was cooled and crystallized at a cooling rate of 1K / min to 40°C. The purity of the final product was 95wt%.

[0053] Comparative Example 2

[0054] Compared with Example 1, the difference is that after obtaining the crude reaction product, the MIBK dissolution and water washing countercurrent extraction steps are not performed (i.e., S4 and S5 are omitted), and the crude di-(2-hydroxyisopropyl)benzene product obtained by the reduction reaction is directly subjected to cooling crystallization, and the cooling rate is controlled to be 1K / min and cooled to 40° C. The final di-(2-hydroxyisopropyl)benzene product has a Na ion content of 1wt% and a product purity of 93wt%.

[0055] The results of the above examples and comparative examples are as follows:

[0056] The invention provides a preparation method of di-(2-hydroxyisopropyl)benzene. The method comprises the following steps: using diisopropylbenzene as a raw material to continuously react to obtain an oxidation reaction liquid, extracting peroxides in the oxidation reaction liquid by using a high-concentration alkali solution to achieve water-oil separation, and performing a reduction reaction on the peroxides in the alkali phase, wherein the reduction reaction yield is ≥96%; dissolving a crude di-(2-hydroxyisopropyl)benzene product by using MIBK and / or MC, and performing a water countercurrent extraction operation, thereby better removing impurities such as inorganic salts in the crude product; and finally performing cooling crystallization to obtain a di-(2-hydroxyisopropyl)benzene product with a purity of ≥98.5wt%, preferably ≥99wt%.

[0057] By analyzing Comparative Example 1 and Example 1, it is generally found in the prior art that the oxidation reaction liquid is directly subjected to reduction reaction, and the required reduction reaction temperature is relatively high. It can be found that if the alkali solution extraction step is not used, and the oxidation reaction liquid is directly reduced, even if the reduction process temperature is increased to 80°C relative to 10-40°C of the present application (if the reduction reaction is almost impossible at 40°C), the reduction reaction time is prolonged, and the final product yield can only reach 85%, and the purity of the product obtained by crystallization is 95wt%. Therefore, in the reduction stage, the reduction is carried out in water and oil phases, the reaction temperature is high, the risk is high and it is easy to lose control, and the reaction rate and selectivity of the reduction reaction are low.

[0058] Comparing Example 1 with Comparative Example 2, the MIBK and / or MC dissolving crude product and the water washing countercurrent extraction step provided by the present invention can achieve the removal of impurities such as inorganic salts remaining in the product, improve the crystallization separation efficiency, and improve the purity of the di-(2-hydroxyisopropyl)benzene product.

Claims

1. A method for preparing di-(2-hydroxyisopropyl)benzene, characterized in that: The following steps are involved: S1: continuously introducing diisopropylbenzene, air and dilute alkali solution into a reactor for continuous reaction to obtain an oxidation reaction solution; S2: extracting the oxidation reaction liquid with an alkaline solution to obtain a raffinate phase and an alkaline phase, and recycling the raffinate phase to the reactor; S3: adding the alkaline phase obtained in step S2 to an aqueous solution of a reducing substance to reduce the crude product of di-(2-hydroxyisopropyl)benzene; S4: the crude di-(2-hydroxyisopropyl)benzene product obtained in S3 is dissolved using MIBK and / or MC to obtain a first mixed solution; S5: countercurrently washing the first mixed solution with water; S6: The first mixed solution after washing is cooled and crystallized to obtain di-(2-hydroxyisopropyl)benzene.

2. The preparation method according to claim 1, characterized in that: The diisopropylbenzene described in S1 includes one or more of m-diisopropylbenzene, p-diisopropylbenzene, m-diisopropylbenzene monohydroperoxide, and p-diisopropylbenzene monohydroperoxide; And / or: the dilute alkali solution includes one or more of sodium hydroxide and sodium carbonate solution, preferably the concentration of the dilute alkali solution is 0.1-10wt%; Preferably, the mass ratio of diisopropylbenzene to dilute alkali solution is (1-20):1; Preferably, the mass ratio of diisopropylbenzene to oxygen in air is (2-3):

1.

3. The preparation method according to claim 1 or 2, characterized in that: The reaction temperature of the oxidation reaction in S1 is 60-120°C, and the reaction pressure is 0.1-0.6MPaG.

4. The preparation method according to claim 1, characterized in that: The alkaline solution in S2 includes one or both of sodium hydroxide and potassium hydroxide solutions, and the concentration of the alkaline solution is preferably 2-10wt%, more preferably 3-5wt%; Preferably, the mass ratio of the alkaline solution to the oxidation reaction liquid in S2 is 0.3-3:

1.

5. The preparation method according to claim 1 or 4, characterized in that: The extraction temperature in S2 is 10-50°C, preferably 15-25°C; Preferably, the extraction is performed using an extraction tower for multi-stage countercurrent extraction, and the number of stages is preferably 3-7.

6. The preparation method according to claim 1, characterized in that: S3: the reducing substance includes one or more of sodium sulfide, sodium sulfite and sodium thiosulfate; Preferably, the concentration of the reducing substance aqueous solution is 5-25 wt %.

7. The preparation method according to claim 1 or 6, characterized in that: The addition time of the alkali phase in S3 is controlled within 1-10 hours, and the addition temperature is controlled within 10-40°C; Preferably, the base phase is added and aged for 0.5-4 h to obtain a crude product of di-(2-hydroxyisopropyl)benzene.

8. The preparation method according to claim 1, characterized in that: S4 controls the dissolution temperature to be 80-100°C, and the mass ratio of MIBK and / or MC to the crude product to be 1.5-3:

1.

9. The preparation method according to claim 1, characterized in that: The water washing temperature of S5 is 80-100°C, and the mass ratio of water to the first mixed liquid is 1.5-3:1; Preferably, the water washing adopts multi-stage countercurrent water washing, and the number of stages is preferably 3-5 stages.

10. The preparation method according to claim 1, characterized in that: In S6, the cooling rate is 1-5K / min, and the temperature is reduced to 40-50℃.