A method for synthesizing disperse red 60 intermediate

Abstract

The invention discloses a method for synthesizing an intermediate for producing Disperse Red 60, comprising the following steps: using 1-aminoanthraquinone as a raw material, bromine as a brominating agent, and sulfuric acid as a reaction medium for bromination reaction, adding boric acid after the reaction reaches the end point, adding sulfur trioxide to adjust the acidity of the medium to 98% to 102%, heating to 80 to 110°C to react to the end point, and then adding water for separation, filtering, washing, and drying to obtain the Disperse Red 60 intermediate 1-amino-2-bromo-4-hydroxyanthraquinone. The invention has the advantages that after the bromination reaction of 1-aminoanthraquinone is completed, sulfur trioxide is used to replace oleum in the traditional process to increase the acidity required for the next hydrolysis reaction medium, reduce the overall reaction volume, and increase the solid-liquid ratio of the hydrolysis reaction, thereby reducing the amount of waste acid in the hydrolysis reaction and improving the reaction efficiency.

Description

Technical Field

[0001] The invention relates to the field of dye production, and in particular to a method for synthesizing a disperse red 60 intermediate. Background Art

[0002] Disperse Red 60, also known as Disperse Red FB and Disperse Red 3B, has the structural formula:

[0003]

[0004] Chemical name: 1-amino-2-phenoxy-4-hydroxyanthraquinone, an important anthraquinone disperse dye. It is mainly used for dyeing polyester and its blended fabrics. It can also be used as one of the three primary colors to prepare other color spectra such as disperse black and disperse gray. It can also be directly used in the ink industry. Due to its bright color and excellent color fastness, it is widely used in the printing and dyeing industry.

[0005] At present, the industry mostly adopts the condensation method of 1-amino-2-bromo-4-hydroxyanthraquinone and phenol to prepare it:

[0006]

[0007] As an intermediate of producing Disperse Red 60, 1-amino-2-bromo-4-hydroxyanthraquinone, the traditional synthesis method is to use 1-aminoanthraquinone as the main raw material, 95% concentrated sulfuric acid as the medium, bromine as the brominating agent to carry out bromination reaction to obtain 1-amino-2,4-dibromoanthraquinone, after the reaction is completed, 20% fuming sulfuric acid is added to the same reactor to adjust the acidity of the system to 100%, and then hydrolysis reaction is carried out to the end point, and then separation, filtration, water washing and drying are carried out to obtain the intermediate 1-amino-2-bromo-4-hydroxyanthraquinone.

[0008] Due to the characteristics of the bromination reaction, the maximum acidity of sulfuric acid used as the bromination medium should not exceed 95%, and an equivalent amount of water will be produced during the bromination process. Therefore, the maximum acidity of the system after the reaction is completed shall not exceed 92%. Under traditional hydrolysis conditions, that is, using 20% ​​oleum to adjust the acidity to 100%, the amount of oleum will be more than 1.8 times the amount of brominated sulfuric acid, making hydrolysis the link with the largest waste acid production in the entire Disperse Red 60 production process. In addition, this waste acid has high chromaticity, many impurities, and high concentration, making it difficult and costly to handle.

[0009] Therefore, it is a technical problem that those skilled in the art need to solve urgently to find a method for synthesizing a Disperse Red 60 intermediate that is advanced in process, reduces the amount of waste acid, and is environmentally friendly and efficient. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a method for synthesizing a disperse red 60 intermediate with low waste acid, which has the characteristics of simple operation and environmentally friendly process.

[0011] In order to solve the above problems, the technical solution provided by the present invention is as follows:

[0012] A method for synthesizing a disperse red 60 intermediate comprises the following steps:

[0013] (1) Using 1-aminoanthraquinone as a raw material and bromine as a brominating agent, a bromination reaction is carried out in a sulfuric acid medium to an end point to obtain 1-amino-2,4-dibromoanthraquinone;

[0014]

[0015] (2) after the reaction in step (1) reaches the end point, the temperature is lowered, an amino protective agent and sulfur trioxide are added to increase the concentration of sulfuric acid in step (1), the temperature is continued to be raised to the end point, and then the temperature is lowered, water is added for separation, filtration, washing, and drying are performed to obtain the intermediate 1-amino-2-bromo-4-hydroxyanthraquinone of Disperse Red 60;

[0016]

[0017] Preferably, in step (1), the mass ratio of 1-aminoanthraquinone to sulfuric acid is 1:2.5 to 1:4.5, and the concentration of sulfuric acid is 85% to 95%. Further, the mass ratio of 1-aminoanthraquinone to bromine is 1:1.1 to 1:1.7,

[0018] Preferably, the bromine in step (1) is added dropwise for 5 to 8 hours. Further, the bromine in step (1) is added dropwise at a temperature of 70°C to 105°C for 3 to 5 hours.

[0019] Preferably, the acidity adjusted by adding sulfur trioxide in step (2) is 98% to 101%.

[0020] Preferably, the sulfur trioxide in step (2) is added dropwise, the insulation temperature of sulfur trioxide is 25°C to 40°C, the temperature of the reaction mass is 50°C to 70°C during the dropwise addition, the dropwise addition time is 1 to 2.5 hours, and after the dropwise addition is completed, the temperature is raised to 90 to 120°C, and the insulation time is greater than 3 hours.

[0021] Preferably, the amino protective agent in step (2) is one or more of boric acid, trioxymethylene, and urotropine, and the mass ratio of 1-aminoanthraquinone to the amino protective agent is 1:0.5 to 1:0.025.

[0022] Preferably, the product separation temperature in step (2) is 50° C. to 70° C., the separation acidity is 55% to 70%, and the separation time is greater than 3 hours.

[0023] The advantages of the present invention are: after the bromination reaction of 1-aminoanthraquinone is completed, sulfur trioxide is used to replace fuming sulfuric acid in the traditional process to increase the acidity required for the next hydrolysis reaction medium, reduce the overall reaction volume, and increase the solid-liquid ratio of the hydrolysis reaction, thereby reducing the amount of waste acid in the hydrolysis reaction, improving the reaction efficiency, and the obtained product has good purity and high yield. The method uses sulfur trioxide to adjust the acidity of the hydrolysis medium, and compared with the original process, the amount of waste acid is reduced by more than 50%, and the volume of the hydrolysis reaction material is reduced by more than 50%, which reduces the environmental pressure and improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The chromatogram and analysis results of Example 1 are shown below:

[0025] Figure 2 The chromatogram and analysis results of Example 2 are shown below:

[0026] Figure 3 The chromatogram and analysis results of Example 3 are shown in FIG. DETAILED DESCRIPTION

[0027] The present invention is described below with reference to examples, but the present invention is not limited thereto. In the art, simple replacement or improvement made by technicians in the field to the present invention belongs to the technical solution protected by the present invention.

[0028] Embodiment 1:

[0029] Put 150g of 95% sulfuric acid into a 500ml four-necked bottle, start stirring, add 50g of 1-aminoanthraquinone dry product while stirring, heat to 80℃ and start dripping 60g of bromine, drip it in 6 hours, keep warm for 3 hours until the end point, cool to 50℃, add 12g of boric acid, drip 52g of liquid sulfur trioxide with a temperature of 25℃ at this temperature, drip it in 1.5 hours, then heat to 90℃ and keep warm for 4 hours until the end point. Cool to 50℃, drip 138g of soft water at this temperature, drip it for 3.5 hours, keep warm for 1 hour after the dripping is completed, filter, wash the filter cake with 75℃ hot water until it is neutral, and obtain 68.4g of intermediate dry product after drying, with a content of 98.73%.

[0030] Embodiment 2:

[0031] Put 180g of 92% sulfuric acid into a 500ml four-necked bottle, start stirring, add 50g of 1-aminoanthraquinone dry product while stirring, heat to 90℃ and start dripping 62g of bromine, drip it in 6.5 hours, keep warm for 3 hours after the dripping is completed to the end point, cool to 55℃, add 15g of boric acid, drip 81.8g of liquid sulfur trioxide with a temperature of 25℃ at this temperature, drip it in 1.5 hours, then heat to 90℃ and keep warm for 3.5 hours to reach the end point. Cool to 60℃, drip 143g of soft water at this temperature, drip it for 3.5 hours, keep warm for 1 hour after the dripping is completed, filter, wash the filter cake with 75℃ hot water until it is neutral, and dry it to obtain 69.1g of intermediate dry product with a content of 98.81%.

[0032] Embodiment 3:

[0033] Put 172g of 94% sulfuric acid into a 500ml four-necked bottle, start stirring, add 50g of 1-aminoanthraquinone dry product while stirring, heat to 85℃ and start dripping 65g of bromine, drip it in 5 hours, keep warm for 3.5 hours until the end point, cool to 50℃, add 3g of urotropine, drip 65.1g of liquid sulfur trioxide with a temperature of 35℃ at this temperature, drip it in 1.5 hours, then heat to 90℃ and keep warm for 4 hours until the end point. Cool to 50℃, drip 130g of soft water at this temperature, drip it for 3.5 hours, keep warm for 1 hour after dripping, filter, wash the filter cake with 75℃ hot water until neutral, and dry to obtain 67.7g of intermediate dry product with a content of 98.81%.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all fall within the protection scope of the present invention.

Claims

1. A method for synthesizing a disperse red 60 intermediate, characterized in that: The following steps are involved: (1) using 1-aminoanthraquinone as a raw material and bromine as a brominating agent, carrying out a bromination reaction in a sulfuric acid medium to an end point to obtain 1-amino-2,4-dibromoanthraquinone; the mass ratio of 1-aminoanthraquinone to sulfuric acid in step (1) is 1:2.5 to 1:4.5, and the concentration of sulfuric acid is 85% to 95%; (2) after the reaction in step (1) reaches an end point, the temperature is lowered, an amino protective agent and sulfur trioxide are added to increase the concentration of sulfuric acid in step (1), the temperature is continued to be raised to react to an end point, and then the intermediate 1-amino-2-bromo-4-hydroxyanthraquinone of Disperse Red 60 is obtained by cooling, adding water for separation, filtering, washing and drying; the acidity adjusted by adding sulfur trioxide in step (2) is 98% to 101%; in step (2), the amino protective agent is one or more of boric acid, trioxymethylene and urotropine, and the mass ratio of 1-aminoanthraquinone to the amino protective agent is 1:0.5 to 1:0.025; 2. The method for synthesizing the disperse red 60 intermediate according to claim 1, wherein: The mass ratio of 1-aminoanthraquinone to bromine in step (1) is 1:1.1 to 1:1.

7.

3. The method for synthesizing the disperse red 60 intermediate according to claim 1, characterized in that: The bromine in step (1) is added dropwise over a period of 5 to 8 hours.

4. The method for synthesizing the disperse red 60 intermediate according to claim 1, wherein: The temperature for adding bromine in step (1) is 70°C to 105°C, and the insulation time after the addition is 3 to 5 hours.

5. The method for synthesizing the disperse red 60 intermediate according to any one of claims 1 to 4, characterized in that: In the step (2), sulfur trioxide is added dropwise, the insulation temperature of sulfur trioxide is 25°C to 40°C, the temperature of the reaction material is 50°C to 70°C during the dropwise addition, the dropwise addition time is 1 to 2.5 hours, and the temperature is raised to 90 to 120°C after the dropwise addition is completed, and the insulation time is greater than 3 hours.

6. The method for synthesizing the disperse red 60 intermediate according to any one of claims 1 to 4, characterized in that: In the step (2), the product separation temperature is 50° C. to 70° C., the separation acidity is 55% to 70%, and the separation time is greater than 3 hours.

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