Method for preparing parafuchsin

Abstract

The invention belongs to the technical field of dyes, and particularly relates to a method for preparing parafuchsin, which comprises the following steps: by taking 4, 4 ', 4'-triaminotriphenylmethane as a substrate and manganese dioxide as an oxidant, carrying out oxidation reaction under an acidic medium to obtain an intermediate product A, and carrying out alkalization treatment to obtain 4, 4 ', 4'-triaminotriphenylcarbinol. According to the method disclosed by the invention, the process difficulty of parafuchsin is solved, 4, 4 ', 4'-triaminotriphenylmethane is converted into 4, 4 ', 4'-triaminotriphenylcarbinol by utilizing a mode of combining an acidic medium with a mild and efficient oxidant, and the product is purified by utilizing solubility difference.

Description

Technical Field

[0001] The invention belongs to the technical field of dyes, and in particular relates to a method for preparing parafuchsia. Background Art

[0002] Paracarmine is a dye that was discovered and manufactured as early as the 19th century, and the manufacturing method has been used until now, but the yield is low, the materials are complex, and a large amount of three wastes are generated, which is difficult to meet the current environmental protection requirements. With the development of technology and the needs of the market environment, many manufacturers have invested a lot of manpower and material resources to study new processes to produce paracarmine dyes, but the new processes of the dyes are not mature, it is difficult to achieve the effect of replacing the old processes, and it is difficult to break through the industrial environmental protection requirements. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides a method for preparing parafuchsin, which solves the process difficulties of parafuchsin, converts 4,4',4"triaminotriphenylmethane into 4,4',4"triaminotrityl alcohol by combining an acidic medium with a mild and efficient oxidant, and purifies the product by utilizing the difference in solubility.

[0004] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0005] A method for preparing paracarmine comprises the following steps: using 4,4',4"triaminotriphenylmethane as a substrate and manganese dioxide as an oxidant, performing an oxidation reaction in an acidic medium to obtain an intermediate product A, and then performing an alkalization treatment to obtain 4,4',4"triaminotrityl alcohol.

[0006] The oxidant is porous manganese dioxide, and the amount of the porous manganese dioxide added is 50-65% of the mass of 4,4',4"triaminotriphenylmethane. In the present technical solution, manganese dioxide is a solid oxidant, and the oxidation system is a contact-type oxidation reaction. Therefore, when 4,4',4"triaminotriphenylmethane contacts manganese dioxide, the oxidation reaction can be realized. Porous manganese dioxide can greatly increase the specific surface area of ​​the oxidant and increase the contact area with the substrate, thereby improving the reaction efficiency and accelerating the reaction process.The preparation method of porous manganese dioxide comprises the following steps: a1, adding manganese sulfate to a sulfuric acid solution, and adding highly substituted hydroxypropyl cellulose, stirring evenly to obtain an acidic dispersion, wherein the concentration of the manganese sulfate is 200-500 g / L, the pH of the sulfuric acid solution is 5-6, the concentration of the highly substituted hydroxypropyl cellulose in the acidic dispersion is 10-40%, and the stirring speed for uniform stirring is 100-200 r / min; this step utilizes the solubility of manganese sulfate in the sulfuric acid solution to achieve a homogeneous dispersion effect, and the highly substituted hydroxypropyl cellulose has good water solubility and quickly dissolves in the acidic solution to obtain an acidic dispersion. dispersion; a2, adding potassium persulfate to the acidic dispersion, stirring evenly to obtain a clear solution, wherein the concentration of potassium persulfate in the acidic dispersion is 800-1000g / L, the stirring speed for uniform stirring is 100-200r / min, and the temperature is 5-10°C; this step utilizes low temperature conditions to ensure the relative stability of the peroxide to ensure that it forms a low-temperature homogeneous solution, a3, placing the clear solution in a reactor for constant temperature reaction for 8-10h, and obtaining a prefabricated block by secondary heating and pressing, wherein the temperature of the constant temperature reaction is 80-90°C; the temperature of the secondary heating and pressing is 110-120°C, and the pressing time is 2-4h , the pressure is 0.2-0.3MPa. This step uses temperature to gel the entire system and transform it into a stable gel. In this process, the gel property of the highly substituted hydroxypropyl cellulose itself homogenizes and disperses the entire solution, and at the same time, the reaction system is evenly distributed in the entire solution. Under this temperature condition, manganese sulfate is converted into manganese dioxide precipitation, and the manganese dioxide is evenly distributed in the entire system to form a high-quality porous structure. During the temperature pressing process, the entire system is pressed to improve the overall compactness, and the temperature pressing can ensure the gel stability of the highly substituted hydroxypropyl cellulose; a4, soak the prefabricated block in an ethanol aqueous solution for ultrasonic treatment 10-30min, after filtering, wash with ethanol aqueous solution 2-4 times, dry and crush to obtain porous manganese dioxide, the volume proportion of ethanol in the ethanol aqueous solution is 30-40%, the concentration of the prefabricated block in the ethanol aqueous solution is 100-200g / L, the ultrasonic frequency of the ultrasonic treatment is 50-80kHz, and the temperature is 5-10°C; the drying is under a nitrogen atmosphere, and the drying temperature is 100-120°C; this step uses ultrasonic treatment to form high-frequency vibration, and cooperates with the solubility of ethanol aqueous solution to highly substituted hydroxypropyl cellulose to achieve a dissolution effect, thereby forming a porous structure on the prefabricated block to obtain a porous manganese dioxide structure. The porous manganese dioxide has a uniform pore structure and good permeability, which greatly increases the specific surface area of ​​manganese dioxide, thereby achieving an improvement in the oxidation effect.

[0007] The acidic medium is an acetic acid-hydrogen chloride mixture, and the molar ratio of acetic acid to hydrogen chloride is 1:1.

[0008] The concentration of the 4,4',4" triaminotriphenylmethane in the acidic medium is 100-250 g / L.

[0009] The alkalization treatment uses a sodium hydroxide solution with a mass fraction of 10%.

[0010] The specific steps of the method include:

[0011] Step 1, adding 4,4',4" triaminotriphenylmethane to an acidic medium and stirring evenly to form an acidic liquid; the stirring speed is 200-400r / min; in this step, 4,4',4" triaminotriphenylmethane is added to an acidic medium to form a stable stirring, and the acidic medium is an HCl-acetic acid solution,

[0012] Step 2, adding manganese dioxide and stirring evenly to obtain a reaction solution, and reacting at a constant temperature for 2-20 hours, and obtaining a crude liquid after the reaction is completed, wherein the stirring speed for the uniform stirring is 300-500r / min, and the temperature for the constant temperature reaction is 80-100°C; in this step, an oxidant is added to the entire acidic medium to form stirring, and manganese dioxide is used as an oxidant to form a reaction to obtain a crude liquid containing a product;

[0013] Step 3, the crude product solution is filtered while hot at 80°C, the filtrate is adjusted to pH 4-5 with 30% HCl, cooled and crystallized, and then filtered to obtain a crystal;

[0014] Step 4, after dissolving the above crystals in hot water, add 10% sodium hydroxide solution dropwise to neutralize to pH=8, cool to room temperature and filter and dry to obtain para-fuchsin, wherein the temperature of the hot water is 80°C.

[0015] The reaction mechanism of this process is as follows:

[0016]

[0017] It can be seen from the above description that the present invention has the following advantages:

[0018] 1. The present invention solves the process difficulties of para-carmine, converts 4,4',4"triaminotriphenylmethane into 4,4',4"triaminotrityl alcohol by combining an acidic medium with a mild and efficient oxidant, and purifies the product by utilizing the difference in solubility.

[0019] 2. The present invention uses porous manganese dioxide as an oxidant, which avoids deep oxidation and damage to the amino group, and improves the reaction efficiency and reaction yield. DETAILED DESCRIPTION

[0020] The present invention is described in detail with reference to the embodiments, but no limitation is imposed on the claims of the present invention.

[0021] Example 1

[0022] A method for preparing paracarmine comprises the following steps: using 4,4',4"triaminotriphenylmethane as a substrate and manganese dioxide as an oxidant, performing an oxidation reaction in an acidic medium to obtain an intermediate product A, and then performing an alkalization treatment to obtain 4,4',4"triaminotrityl alcohol.

[0023] The oxidant is porous manganese dioxide, and the amount of the porous manganese dioxide added is 50% of the mass of 4,4',4" triaminotriphenylmethane. The preparation method of the porous manganese dioxide comprises the following steps: a1, adding manganese sulfate to a sulfuric acid solution, and adding high-substituted hydroxypropyl cellulose, stirring evenly to obtain an acidic dispersion, wherein the concentration of the manganese sulfate is 200 g / L, the pH of the sulfuric acid solution is 5, the concentration of the high-substituted hydroxypropyl cellulose in the acidic dispersion is 10%, and the stirring speed for stirring evenly is 100 r / min; a2, adding potassium persulfate to the acidic dispersion, stirring evenly to obtain a clear solution, wherein the concentration of the potassium persulfate in the acidic dispersion is 800 g / L, and the stirring speed for stirring evenly is 100 r / min. The stirring speed is 100r / min and the temperature is 5°C. a3. The clarified solution is placed in a reactor for constant temperature reaction for 8h, and a prefabricated block is obtained by secondary temperature pressing. The temperature of the constant temperature reaction is 80°C; the temperature of the secondary temperature pressing is 110°C, the pressing time is 2h, and the pressure is 0.2MPa. a4. The prefabricated block is immersed in an ethanol aqueous solution and ultrasonically treated for 10min. After filtering, it is washed twice with an ethanol aqueous solution, dried and crushed to obtain porous manganese dioxide. The volume proportion of ethanol in the ethanol aqueous solution is 30%, the concentration of the prefabricated block in the ethanol aqueous solution is 100g / L, the ultrasonic frequency of the ultrasonic treatment is 50kHz, and the temperature is 5°C; the drying is carried out under a nitrogen atmosphere, and the drying temperature is 100°C.

[0024] The acidic medium is an acetic acid-hydrogen chloride mixture, and the molar ratio of acetic acid to hydrogen chloride is 1:1.

[0025] The concentration of the 4,4',4" triaminotriphenylmethane in the acidic medium is 100 g / L.

[0026] The alkalization treatment uses a sodium hydroxide solution with a mass fraction of 10%.

[0027] The specific steps of the method include:

[0028] Step 1, add 4,4',4" triaminotriphenylmethane to an acidic medium and stir evenly to form an acidic liquid; the stirring speed is 200r / min; the acidic medium is a hydrochloric acid acetic acid solution,

[0029] Step 2, adding manganese dioxide and stirring evenly to obtain a reaction solution, and reacting at a constant temperature for 2-20 hours, and obtaining a crude product solution after the reaction is completed, wherein the stirring speed for the uniform stirring is 300 r / min, and the temperature for the constant temperature reaction is 80° C.;

[0030] Step 3, the crude product solution is filtered while hot at 80°C, the filtrate is adjusted to pH 4-5 with 30% HCl, cooled and crystallized, and then filtered to obtain a crystal;

[0031] Step 4, after dissolving the above crystals in hot water, add 10% sodium hydroxide solution dropwise to neutralize to pH=8, cool to room temperature and filter and dry to obtain para-fuchsin, wherein the temperature of the hot water is 80°C.

[0032] The product of this example is basic para-purple, with a yield of 69.2%, a purity of 89.3%, and a recovery rate of the oxidant of 99.4%.

[0033] Example 2

[0034] A method for preparing paracarmine comprises the following steps: using 4,4',4"triaminotriphenylmethane as a substrate and manganese dioxide as an oxidant, performing an oxidation reaction in an acidic medium to obtain an intermediate product A, and then performing an alkalization treatment to obtain 4,4',4"triaminotrityl alcohol.

[0035] The oxidant is porous manganese dioxide, and the amount of the porous manganese dioxide added is 65% of the mass of 4,4',4" triaminotriphenylmethane. The preparation method of the porous manganese dioxide comprises the following steps: a1, adding manganese sulfate to a sulfuric acid solution, and adding high-substituted hydroxypropyl cellulose, stirring evenly to obtain an acidic dispersion, wherein the concentration of the manganese sulfate is 500 g / L, the pH of the sulfuric acid solution is 6, the concentration of the high-substituted hydroxypropyl cellulose in the acidic dispersion is 40%, and the stirring speed for stirring evenly is 200 r / min; a2, adding potassium persulfate to the acidic dispersion, stirring evenly to obtain a clear solution, wherein the concentration of the potassium persulfate in the acidic dispersion is 1000 g / L, and the stirring speed for stirring evenly is 200 r / min. The speed is 200r / min, the temperature is 10°C, a3, the clarified solution is placed in a reactor for constant temperature reaction for 10h, and a prefabricated block is obtained by secondary heating and pressing, the temperature of the constant temperature reaction is 90°C; the temperature of the secondary heating and pressing is 120°C, the pressing time is 4h, and the pressure is 0.3MPa; a4, the prefabricated block is immersed in an ethanol aqueous solution and ultrasonically treated for 30min, after filtering, it is washed with an ethanol aqueous solution for 4 times, and dried and crushed to obtain porous manganese dioxide, the volume proportion of ethanol in the ethanol aqueous solution is 40%, the concentration of the prefabricated block in the ethanol aqueous solution is 200g / L, the ultrasonic frequency of the ultrasonic treatment is 80kHz, and the temperature is 10°C; the drying is carried out under a nitrogen atmosphere, and the drying temperature is 120°C.

[0036] The acidic medium is an acetic acid-hydrogen chloride mixture, and the molar ratio of acetic acid to hydrogen chloride is 1:1.

[0037] The concentration of the 4,4',4" triaminotriphenylmethane in the acidic medium is 250 g / L.

[0038] The alkalization treatment uses a sodium hydroxide solution with a mass fraction of 10%.

[0039] The specific steps of the method include:

[0040] Step 1, adding 4,4',4" triaminotriphenylmethane to an acidic medium and stirring evenly to form an acidic liquid; the stirring speed is 400r / min; the acidic medium is HCl-acetic acid solution,

[0041] Step 2, adding manganese dioxide and stirring evenly to obtain a reaction solution, and reacting at a constant temperature for 20 hours, and obtaining a crude product solution after the reaction is completed, wherein the stirring speed for the uniform stirring is 500 r / min, and the temperature for the constant temperature reaction is 100° C.;

[0042] Step 3, the crude product solution is filtered while hot at 80°C, the filtrate is adjusted to pH 4-5 with 30% HCl, cooled and crystallized, and then filtered to obtain a crystal;

[0043] Step 4, after dissolving the above crystals in hot water, add 10% sodium hydroxide solution dropwise to neutralize to pH=8, cool to room temperature and filter and dry to obtain para-fuchsin, wherein the temperature of the hot water is 80°C.

[0044] The product of this example is basic para-purple, with a yield of 71.6%, a purity of 90.1%, and a recovery rate of the oxidant of 99.5%.

[0045] Example 3

[0046] A method for preparing paracarmine comprises the following steps: using 4,4',4"triaminotriphenylmethane as a substrate and manganese dioxide as an oxidant, performing an oxidation reaction in an acidic medium to obtain an intermediate product A, and then performing an alkalization treatment to obtain 4,4',4"triaminotrityl alcohol.

[0047] The oxidant is porous manganese dioxide, and the amount of the porous manganese dioxide added is 60% of the mass of 4,4',4" triaminotriphenylmethane. The preparation method of the porous manganese dioxide comprises the following steps: a1, adding manganese sulfate to a sulfuric acid solution, and adding high-substituted hydroxypropyl cellulose, stirring evenly to obtain an acidic dispersion, wherein the concentration of the manganese sulfate is 400 g / L, the pH of the sulfuric acid solution is 6, the concentration of the high-substituted hydroxypropyl cellulose in the acidic dispersion is 20%, and the stirring speed for stirring evenly is 150 r / min; a2, adding potassium persulfate to the acidic dispersion, stirring evenly to obtain a clear solution, wherein the concentration of the potassium persulfate in the acidic dispersion is 900 g / L, and the stirring speed for stirring evenly is 150 r / min. The stirring speed is 150r / min and the temperature is 9°C. a3. The clarified solution is placed in a reactor for constant temperature reaction for 9h, and a prefabricated block is obtained by secondary temperature pressing. The temperature of the constant temperature reaction is 85°C; the temperature of the secondary temperature pressing is 115°C, the pressing time is 3h, and the pressure is 0.2MPa. a4. The prefabricated block is immersed in an ethanol aqueous solution and ultrasonically treated for 20min. After filtering, it is washed with an ethanol aqueous solution for 3 times, dried and crushed to obtain porous manganese dioxide. The volume proportion of ethanol in the ethanol aqueous solution is 35%, the concentration of the prefabricated block in the ethanol aqueous solution is 150g / L, the ultrasonic frequency of the ultrasonic treatment is 70kHz, and the temperature is 8°C; the drying is carried out under a nitrogen atmosphere, and the drying temperature is 110°C.

[0048] The acidic medium is an acetic acid-hydrogen chloride mixture, and the molar ratio of acetic acid to hydrogen chloride is 1:1.

[0049] The concentration of the 4,4',4" triaminotriphenylmethane in the acidic medium is 150 g / L.

[0050] The alkalization treatment uses a sodium hydroxide solution with a mass fraction of 10%.

[0051] The specific steps of the method include:

[0052] Step 1, add 4,4',4" triaminotriphenylmethane to an acidic medium and stir evenly to form an acidic liquid; the stirring speed is 300r / min; the acidic medium is a hydrochloric acid acetic acid solution,

[0053] Step 2, adding manganese dioxide and stirring evenly to obtain a reaction solution, and reacting at a constant temperature for 8 hours, and obtaining a crude product solution after the reaction is completed, wherein the stirring speed of the stirring evenly is 400 r / min, and the temperature of the constant temperature reaction is 90° C.;

[0054] Step 3, the crude product solution is filtered while hot at 80°C, the filtrate is adjusted to pH 4-5 with 30% HCl, cooled and crystallized, and then filtered to obtain a crystal;

[0055] Step 4, after dissolving the above crystals in hot water, add 10% sodium hydroxide solution dropwise to neutralize to pH=8, cool to room temperature and filter and dry to obtain para-fuchsin, wherein the temperature of the hot water is 80°C.

[0056] The product of this example is basic para-purple, with a yield of 70.5%, a purity of 89.7%, and a recovery rate of the oxidant of 99.4%.

[0057] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for preparing parachrome, characterized in that: With 4,4',4"triaminotriphenylmethane as substrate and manganese dioxide as oxidant, an oxidation reaction is carried out in an acidic medium to obtain an intermediate product, which is then subjected to alkalization treatment to obtain 4,4',4"triaminotrityl alcohol.

2. The method for preparing parafuchsin according to claim 1, wherein: The oxidant is porous manganese dioxide, and the amount of the porous manganese dioxide added is 50-65% of the mass of 4,4',4"triaminotriphenylmethane.

3. The method for preparing parafuchsin according to claim 1, characterized in that: The acidic medium is an acetic acid-hydrogen chloride mixture.

4. The method for preparing parafuchsin according to claim 3, characterized in that: The molar ratio of the acetic acid to the hydrogen chloride is 1:

1.

5. The method for preparing parafuchsin according to claim 1, characterized in that: The concentration of the 4,4',4" triaminotriphenylmethane in the acidic medium is 100-250 g / L.

6. The method for preparing parafuchsin according to claim 1, characterized in that: The alkalization treatment uses a sodium hydroxide solution with a mass fraction of 10%.

7. The method for preparing parafuchsin according to claim 1, characterized in that: The specific steps of the method include: Step 1, adding 4,4',4" triaminotriphenylmethane to an acidic medium and stirring evenly to form an acidic liquid; the stirring speed is 200-400r / min; the acidic medium is HCl-acetic acid solution, Step 2, adding manganese dioxide and stirring evenly to obtain a reaction solution, and reacting at a constant temperature for 2-20 hours, and obtaining a crude product solution after the reaction is completed, wherein the stirring speed for the uniform stirring is 300-500 r / min, and the temperature for the constant temperature reaction is 80-100° C.; Step 3, the crude product solution is filtered while hot at 80°C, the filtrate is adjusted to pH 4-5 with 30% HCl, cooled and crystallized, and then filtered to obtain a crystal; Step 4, after dissolving the above crystals in hot water, add 10% sodium hydroxide solution dropwise to neutralize to pH=8, cool to room temperature and filter and dry to obtain para-fuchsin, wherein the temperature of the hot water is 80°C.

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