A method for synthesizing high-yield 4,4'-diaminobenzene sulfonanilide

Abstract

The present application relates to the technical field of synthesis of 4,4'-diaminobenzene sulfonanilide, and provides a synthesis method of 4,4'-diaminobenzene sulfonanilide with high yield, S1, p-acetylamino benzene sulfonyl chloride and p-phenylenediamine are mixed, the pH is adjusted to 7.5-8.0, under the action of a catalyst, an amide reaction is performed to obtain a mixture; S2, the mixture is added to an alkaline solution, after hydrolysis, decolorization, filtration, the pH is adjusted to 7.5-8.0, and filtration is performed to obtain 4,4'-diaminobenzene sulfonanilide; in step S2, the catalyst comprises tetrabutylammonium bromide and a catalytic aid in a mass ratio of 4:1-1.5, and the catalytic aid comprises tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.5-1. Through the technical scheme, the problem of low yield of 4,4'-diaminobenzene sulfonanilide in the related art is solved.

Description

Technical Field

[0001] This invention relates to the field of synthetic technology of 4,4'-diaminobenzenesulfonyl aniline, and more specifically, to a method for synthesizing 4,4'-diaminobenzenesulfonyl aniline in high yield. Background Technology

[0002] 4,4'-Diaminobenzenesulfonyl aniline is an important intermediate in the synthesis of sulfonamides. Its molecular structure consists of two benzene rings linked by sulfonylamino groups, with amino groups attached to the para positions of the two benzene rings. This unique structure endows it with good chemical activity and application value, and it is widely used in many fields such as pharmaceuticals, dyes, and polymer materials.

[0003] With the rapid development of the pharmaceutical, dye and polymer materials industries, the market demand for 4,4'-diaminobenzenesulfonyl aniline continues to grow, while higher requirements are being placed on the production efficiency of its products. The synthesis yield is a core factor affecting the production cost and market competitiveness of the products.

[0004] Therefore, a method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield is needed. Summary of the Invention

[0005] This invention proposes a high-yield synthesis method for 4,4'-diaminobenzenesulfonyl aniline, which solves the problem of low yield of 4,4'-diaminobenzenesulfonyl aniline in related technologies.

[0006] The technical solution of the present invention is as follows: This invention provides a method for synthesizing 4,4'-diaminobenzenesulfonyl aniline in high yield, comprising the following steps: S1. After mixing p-acetaminobenzenesulfonyl chloride and p-phenylenediamine, the pH is adjusted to 7.5~8.0, and the mixture is obtained by amidation reaction under the action of a catalyst; S2. The mixture is added to an alkaline solution, hydrolyzed, decolorized, filtered, and the pH is adjusted to 7.5-8.0. After filtration, 4,4'-diaminobenzenesulfonyl aniline is obtained. In step S2, the catalyst comprises tetrabutylammonium bromide and a catalyst promoter in a mass ratio of 4:1 to 1.5, wherein the catalyst promoter comprises tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.5 to 1.

[0007] As a further technical solution, the amount of catalyst added is 6% of the mass of p-phenylenediamine.

[0008] As a further technical solution, in step S2, the filtered material is further subjected to recrystallization, drying, and pulverization; the recrystallization solvent used in the recrystallization process includes anhydrous ethanol and water in a volume ratio of 4~5:1.

[0009] In this invention, the crude 4,4'-diaminobenzenesulfonyl aniline obtained after hydrolysis is further subjected to a recrystallization process. After recrystallization, the purity of 4,4'-diaminobenzenesulfonyl aniline is further improved. The preferred recrystallization solvent includes anhydrous ethanol and water in a volume ratio of 4 to 5:1, which can further improve the purity of 4,4'-diaminobenzenesulfonyl aniline.

[0010] As a further technical solution, the recrystallization process is as follows: after adding the material to the recrystallization solvent and mixing it at 60~65℃, the mixture is cooled to room temperature at a rate of 0.5~1.5℃ / min.

[0011] In the preferred recrystallization solvent of this invention, the cooling rate is limited to 0.5~1.5℃ / min, which allows the target product to precipitate slowly without encapsulating impurities or causing local oversaturation, thereby further improving the purity of 4,4'-diaminobenzenesulfonyl aniline.

[0012] As a further technical solution, in step S1, the p-acetaminobenzenesulfonyl chloride is wet p-acetaminobenzenesulfonyl chloride with a water content of 30%~35%.

[0013] As a further technical solution, in step S1, the amount of p-phenylenediamine added is 30% to 35% of the mass of wet p-acetaminobenzenesulfonyl chloride.

[0014] As a further technical solution, in step S1, the solvent used to adjust the pH is an 8wt% sodium carbonate aqueous solution.

[0015] As a further technical solution, in step S1, the temperature of the amidation reaction is 30~35℃, and the reaction time is 5~6h.

[0016] As a further technical solution, in step S2, the reagent used to adjust the pH is a 0.6~0.7 mol / L hydrochloric acid aqueous solution.

[0017] As a further technical solution, in step S2, the alkaline solution is an aqueous solution of sodium hydroxide with a concentration of 3~4 mol / L.

[0018] As a further technical solution, in step S2, the hydrolysis temperature is 94~96℃ and the hydrolysis time is 3~3.5h.

[0019] The working principle and beneficial effects of this invention are as follows: The use of tetrabutylammonium bromide, tetraethylammonium bromide, and phenyltrimethylammonium bromide as catalysts in the amidation process in this invention improves the reaction efficiency and increases the yield of 4,4'-diaminobenzenesulfonylaniline. In existing technologies, tetrabutylammonium bromide is often used alone as a catalyst, resulting in limited phase transfer compatibility and poor simultaneous solubility in both the aqueous and oil phases of the reaction system. The ternary mixed catalyst system used in this invention utilizes tetrabutylammonium bromide, which has good oil solubility but weak water solubility, while tetraethylammonium bromide exhibits better water solubility. This solves the problem of weak interactions between tetrabutylammonium bromide, tetrabutylammonium bromide, and phenyltrimethylammonium bromide with the reactants, further improving the catalytic effect, reducing side reactions, and increasing the yield and purity of 4,4'-diaminobenzenesulfonylaniline. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] In the following embodiments and comparative examples: The preparation method of p-acetaminobenzenesulfonyl chloride is as follows: 2 kg of water and 750 g of p-aminobenzenesulfonic acid are mixed, heated to 80 °C and reacted for 2 h, then cooled to room temperature, filtered by pressure, washed until neutral, and dried in a vacuum dryer at 60 °C for 4 h to obtain p-acetaminobenzenesulfonic acid; 755 g of chlorosulfonic acid is heated to 30 °C and p-acetaminobenzenesulfonic acid is added, reacted at 60 °C for 2 h, the product is added to 1.7 kg of ice water, heated to 60 °C for hydrolysis, cooled to room temperature, filtered by a filter press, and washed with 520 g of circulating water until neutral to obtain p-acetaminobenzenesulfonyl chloride (wet p-acetaminobenzenesulfonyl chloride, with a water content of 30%).

[0022] Example 1 A method for synthesizing 4,4'-diaminobenzenesulfonyl aniline in high yield includes the following steps: S1. After mixing p-acetaminobenzenesulfonyl chloride (1 kg), p-phenylenediamine (327 g) and catalyst (0.2 g), the pH was adjusted to 7.5 with 8 wt% sodium carbonate aqueous solution, and the mixture was kept at 30 °C for 6 h. After filtration and washing with water, the mixture was obtained. The catalyst consists of tetrabutylammonium bromide and a catalyst promoter in a mass ratio of 4:1, and the catalyst promoter consists of tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.5. S2. Add the mixture to a sodium hydroxide aqueous solution (200 mL, 3 mol / L), control the temperature at 95℃, hydrolyze for 3 h, add 15 g of activated carbon for decolorization for 30 min, cool to room temperature, filter, adjust the pH to 7.5 with a 0.6 mol / L hydrochloric acid aqueous solution, filter, wash with water, dry and pulverize to obtain 4,4'-diaminobenzenesulfonyl aniline.

[0023] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.5%, and the purity was 98.36%.

[0024] Example 2 A method for synthesizing 4,4'-diaminobenzenesulfonyl aniline in high yield includes the following steps: S1. After mixing p-acetaminobenzenesulfonyl chloride (1 kg), p-phenylenediamine (327 g) and catalyst (0.2 g), the pH was adjusted to 8.0 with 8 wt% sodium carbonate aqueous solution, and the mixture was kept at 35℃ for 5 h. After filtration and washing with water, the mixture was obtained. The catalyst consists of tetrabutylammonium bromide and a catalyst promoter in a mass ratio of 4:1, and the catalyst promoter consists of tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.5. S2. Add the mixture to a sodium hydroxide aqueous solution (200 mL, 3 mol / L), control the temperature at 95℃, hydrolyze for 3 h, add 30 g of activated carbon for decolorization for 30 min, cool to room temperature, filter, adjust the pH to 8.0 with a 0.7 mol / L hydrochloric acid aqueous solution, filter, wash with water, dry and pulverize to obtain 4,4'-diaminobenzenesulfonyl aniline.

[0025] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.4%, and the purity was 98.38%.

[0026] Example 3 Compared with Example 1, the catalyst in this example is composed of tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:1.

[0027] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 87.2%, and the purity was 98.41%.

[0028] Example 4 Compared to Example 1, the catalyst in this example consists of tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.3.

[0029] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 85.4%, and the purity was 98.31%.

[0030] Example 5 Compared with Example 1, the catalyst in this example is composed of tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:1.2.

[0031] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 84.5%, and the purity was 98.27%.

[0032] Example 6 Compared with Example 1, step S2 in this example is as follows: S2, the mixture is added to a sodium hydroxide solution (200 mL, 3 mol / L), the temperature is controlled at 95°C, and after hydrolysis for 3 h, 15 g of activated carbon is added for decolorization for 30 min, then cooled to room temperature, filtered, and the pH is adjusted to 7.5 using a 0.6 mol / L hydrochloric acid aqueous solution. After filtration, it is added to the recrystallization solvent, mixed at 60°C, and cooled to room temperature at a cooling rate of 1°C / min. After filtration, it is washed with water, dried, and pulverized to obtain 4,4'-diaminobenzenesulfonylaniline; wherein the recrystallization solvent is composed of anhydrous ethanol and water in a volume ratio of 4:1.

[0033] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 85.9%, and the purity was 99.11%.

[0034] Example 7 Compared to Example 6, the recrystallization solvent in this example consists of anhydrous ethanol and water in a volume ratio of 4.5:1.

[0035] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.2%, and the purity was 99.36%.

[0036] Example 8 Compared to Example 6, the recrystallization solvent in this example consists of anhydrous ethanol and water in a volume ratio of 5:1.

[0037] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.1%, and the purity was 99.21%.

[0038] Example 9 Compared with Example 1, step S2 in this example is as follows: S2, the mixture is added to a sodium hydroxide solution (200 mL, 3 mol / L), the temperature is controlled at 95°C, and after hydrolysis for 3 h, 15 g of activated carbon is added for decolorization for 30 min, then cooled to room temperature, filtered, and the pH is adjusted to 7.5 using a 0.6 mol / L hydrochloric acid aqueous solution. After filtration, it is added to the recrystallization solvent, mixed at 60°C, and cooled to room temperature at a cooling rate of 1°C / min. After filtration, it is washed with water, dried, and pulverized to obtain 4,4'-diaminobenzenesulfonylaniline; wherein the recrystallization solvent is composed of anhydrous ethanol and water in a volume ratio of 4:1.

[0039] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.2%, and the purity was 99.22%.

[0040] Example 10 Compared with Example 1, step S2 in this example is as follows: S2, the mixture is added to a sodium hydroxide solution (200 mL, 3 mol / L), the temperature is controlled at 95°C, and after hydrolysis for 3 h, 15 g of activated carbon is added for decolorization for 30 min, then cooled to room temperature, filtered, and the pH is adjusted to 7.5 using a 0.6 mol / L hydrochloric acid aqueous solution. After filtration, it is added to the recrystallization solvent, mixed at 60°C, and cooled to room temperature at a cooling rate of 1°C / min. After filtration, it is washed with water, dried, and pulverized to obtain 4,4'-diaminobenzenesulfonylaniline; wherein the recrystallization solvent is composed of anhydrous ethanol and water in a volume ratio of 4:1.

[0041] The yield of 4,4'-diaminobenzenesulfonyl aniline in this example was determined to be 86.0%, and the purity was 99.24%.

[0042] Comparative Example 1 Compared to Example 1, the catalyst in this comparative example is only tetrabutylammonium bromide.

[0043] The yield of 4,4'-diaminobenzenesulfonyl aniline in this comparative example was determined to be 82.0%, and the purity was 98.22%.

[0044] Comparative Example 2 Compared to Example 1, the catalyst in this comparative example consists of tetrabutylammonium bromide and tetraethylammonium bromide in a mass ratio of 4:1.

[0045] The yield of 4,4'-diaminobenzenesulfonyl aniline in this comparative example was determined to be 82.3%, and the purity was 98.21%.

[0046] Comparative Example 3 Compared to Example 1, the catalyst in this comparative example consists of tetrabutylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 4:1.

[0047] The yield of 4,4'-diaminobenzenesulfonyl aniline in this comparative example was determined to be 82.5%, and the purity was 98.17%.

[0048] Comparative Example 4 Compared to Example 1, the catalyst in this comparative example is only tetraethylammonium bromide.

[0049] The yield of 4,4'-diaminobenzenesulfonyl aniline in this comparative example was determined to be 81.4%, and the purity was 98.01%.

[0050] Comparative Example 5 Compared to Example 1, the catalyst in this comparative example is only phenyltrimethylammonium bromide.

[0051] The yield of 4,4'-diaminobenzenesulfonyl aniline in this comparative example was determined to be 81.2%, and the purity was 97.72%.

[0052] Comparing the yields and purities of the above examples and comparative examples, it can be seen that, compared with Example 1, Comparative Examples 1-5 changed the type of catalyst, and the yields and purities of 4,4'-diaminobenzenesulfonyl aniline in Comparative Examples 1-5 were all lower than those in Example 1, indicating that the catalyst specified in this invention can improve the yield and purity of 4,4'-diaminobenzenesulfonyl aniline; compared with Example 1, Examples 6-10 added a recrystallization process, and the purities of 4,4'-diaminobenzenesulfonyl aniline in Examples 6-10 were all higher than those in Example 1.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing 4,4'-diaminobenzenesulfonyl aniline in high yield, characterized in that, Includes the following steps: S1. After mixing p-acetaminobenzenesulfonyl chloride and p-phenylenediamine, the pH is adjusted to 7.5~8.0, and the mixture is obtained by amidation reaction under the action of a catalyst; S2. The mixture is added to an alkaline solution, hydrolyzed, decolorized, filtered, and the pH is adjusted to 7.5-8.

0. After filtration, 4,4'-diaminobenzenesulfonyl aniline is obtained. In step S2, the catalyst comprises tetrabutylammonium bromide and a catalyst promoter in a mass ratio of 4:1 to 1.5, wherein the catalyst promoter comprises tetraethylammonium bromide and phenyltrimethylammonium bromide in a mass ratio of 5:0.5 to 1.

2. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S2, the filtered material is further subjected to recrystallization, drying, and pulverization; the recrystallization solvent used in the recrystallization process includes anhydrous ethanol and water in a volume ratio of 4~5:

1.

3. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 2, characterized in that, The recrystallization process is as follows: after adding the product to the recrystallization solvent and mixing it at 60~65℃, the mixture is cooled to room temperature at a rate of 0.5~1.5℃ / min.

4. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S1, the p-acetaminobenzenesulfonyl chloride is wet p-acetaminobenzenesulfonyl chloride with a water content of 30%~35%.

5. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 4, characterized in that, In step S1, the amount of p-phenylenediamine added is 30% to 35% of the mass of wet p-acetaminobenzenesulfonyl chloride.

6. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S1, the solvent used to adjust the pH is an 8wt% sodium carbonate aqueous solution.

7. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S1, the amidation reaction is carried out at a temperature of 30-35°C for 5-6 hours.

8. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S4, the reagent used to adjust the pH is a 0.6~0.7 mol / L hydrochloric acid aqueous solution.

9. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S2, the alkaline solution is an aqueous solution of sodium hydroxide with a concentration of 3-4 mol / L.

10. The method for synthesizing 4,4'-diaminobenzenesulfonyl aniline with high yield according to claim 1, characterized in that, In step S2, the hydrolysis temperature is 94~96℃ and the hydrolysis time is 3~3.5h.