Preparation method of disperse black 9 compound

Abstract

The invention relates to the technical field of organic synthesis, in particular to a preparation method of a disperse black 9 compound, which comprises the following steps: S1, diazotization reaction: in an inert gas environment, performing diazotization reaction on p-phenylenediamine, nitrite and an inorganic acid aqueous solution to obtain a reaction solution; and S2, coupling reaction: adding N, N-bis (hydroxyethyl) aniline into the reaction liquid in the step S1 to perform coupling reaction, and after the reaction is finished, performing post-treatment to obtain the disperse black 9 compound. The nitrite is at least one of sodium nitrite and potassium nitrite. The inorganic acid aqueous solution is a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution and a nitric acid aqueous solution; the mass concentration of the inorganic acid aqueous solution is 30-80%. According to the preparation method, the target compound with high purity and high yield can be prepared by a one-pot method, and the preparation method is simple to operate, low in cost and environment-friendly.

Description

Technical Field

[0001] The present invention relates to a preparation method of Disperse Black 9 compound, belonging to the technical field of organic synthesis. Background Art

[0002] Disperse Black 9, also known as 2,2'-[4-(4-aminophenylazo)phenylimino]diethanol or 4-(4'-N,N-bis(2-hydroxyethyl)anilino)azobenzene, is a very important organic intermediate, which has wide applications in pharmaceuticals, pesticides, dyes, surfactants, etc. In the field of dyes, it is mainly used in personal care products such as cosmetics, and the purpose of using it in cosmetics is for hair dyes. In the chemical industry, this compound may also be used in other organic synthesis reactions or as a catalyst for certain specific chemical reactions. In the fields of pesticides and pharmaceuticals, due to the presence of active groups such as anilino and hydroxyethyl in its structure, it may have certain pharmacological activities or be used as a precursor for drug synthesis.

[0003] The patent with the publication number CN119570027B discloses a colored capped photosensitive polymer and its preparation method, uses, black photoresist, and black matrix. The raw materials for preparing the colored capped photosensitive polymer include a dianhydride monomer, an alcohol, a colored capped monomer, a first diamine monomer, and a second diamine monomer. The colored capped monomer includes Disperse Black 9. By using a colored group containing an azo structure to cap the molecular chain of the photosensitive polymer, not only can the OD value of the black photoresist be significantly improved, but also the black photoresist can have good mechanical properties and lithography properties. The patent with the publication number CN116590936B discloses an environmentally friendly liquid disperse dye microcapsule and its application in polyester fabric printing. Disperse Black 9 can be used as a disperse dye in the microcapsule. The patent with the publication number CN105925770B discloses a quenching oil that can make screws turn black spontaneously after quenching and a quenching method. Disperse Black 9 is used as a coloring agent in the quenching oil. The patent with the publication number JP2023542308A discloses a dyeing composition for keratin fibers and a dyeing method. Disperse Black 9 is used as a dye in the dyeing composition and can be used for hair dyeing.

[0004] In summary, Disperse Black 9 is an important organic synthesis intermediate with wide application value. However, so far, there is not much published information on the synthesis method of Disperse Black 9. Therefore, developing a scientific and green synthesis method and route is of great significance and value for the industry to prepare Disperse Black 9. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the present invention provides a preparation method of Disperse Black 9 compound. The preparation method can realize the one-pot preparation of the target compound with high purity and high yield, and has the advantages of simple operation, low cost, and environmental friendliness.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: A preparation method of Disperse Black 9 compound, and the preparation method is as follows: S1. Diazotization reaction: In an inert gas environment, p-phenylenediamine reacts with nitrite and aqueous inorganic acid solution to obtain a reaction solution through diazotization reaction; S2. Coupling reaction: Add N,N-bis(2-hydroxyethyl)aniline to the reaction solution in step S1 for coupling reaction, and after the reaction is completed, Disperse Black 9 compound is obtained through post-treatment.

[0007] Further, in step S1, the nitrite is at least one of sodium nitrite and potassium nitrite.

[0008] Further, in step S1, the aqueous inorganic acid solution is: aqueous hydrochloric acid solution, aqueous sulfuric acid solution or aqueous nitric acid solution; The mass concentration of the aqueous inorganic acid solution is 30% - 80%.

[0009] Further, the molar ratio of the nitrite to p-phenylenediamine is (1.0 - 1.5):1.

[0010] Further, the molar ratio of the inorganic acid to p-phenylenediamine in the aqueous inorganic acid solution is (2.0 - 4.0):1.

[0011] Further, in step S1, the temperature of the diazotization reaction is -20~10°C, and the time of the diazotization reaction is 10~60 min.

[0012] Further, the molar ratio of p-phenylenediamine to N,N-bis(2-hydroxyethyl)aniline is 1:(0.8 - 1.2).

[0013] Further, in step S2, the temperature of the coupling reaction is -10~5°C, and the time of the coupling reaction is 10~20 h.

[0014] Further, in step S2, the post-treatment process is: after the reaction is completed, the crude Disperse Black 9 compound is obtained through solid-liquid separation, and then the Disperse Black 9 compound is obtained through recrystallization.

[0015] Further, the recrystallization process is: under heating conditions, the crude Disperse Black 9 compound is dissolved in chloroform, the insoluble impurities are filtered out while it is hot, after the filtrate is cooled to room temperature, ethanol is added to the filtrate for crystallization, and finally the Disperse Black 9 compound product is obtained through solid-liquid separation and drying.

[0016] The beneficial effects of the present invention are: The preparation method of the disperse black 9 compound described in the present invention is prepared by a one-pot method, which avoids the cumbersome intermediate separation process, is easy to operate, has less three-waste emissions, reduces the labor intensity in the production process, and thus has the advantages of low cost and environmental friendliness. In addition, the preparation method described in the present invention is prepared by a one-pot method, with a high product yield, the product yield is not less than 90%, and the product purity is not less than 94%. Moreover, the preparation method described in the present invention uses p-phenylenediamine as the starting material, the pigment source is wide and easily available, and the raw material cost is low.

[0017] In the preparation method described in the present invention, the active site of the self-coupling of aniline is mainly the para-position, while the para-position of p-phenylenediamine is occupied, so the self-coupling activity after diazotization at one end is significantly reduced. In addition, because the diazo group after diazotization at one end is a strong electron-withdrawing group, it can weaken the basicity of the amino group that is not diazotized and is in the conjugated system with it, thereby inhibiting the progress of its double diazotization reaction. By controlling reasonable process conditions, the target product with high yield and high purity is finally obtained. Description of the Drawings

[0018] Figure 1 It is the liquid chromatogram of the disperse black 9 prepared in Example 1; Figure 2 It is the liquid chromatogram of the disperse black 9 prepared in Comparative Example 1. Detailed Description of the Invention

[0019] The following is a detailed description of the specific embodiments of the present invention. The present invention can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0021] A preparation method of a disperse black 9 compound, the preparation method is as follows: S1. Diazotization reaction: In an inert gas environment, p-phenylenediamine reacts with nitrite and an inorganic acid aqueous solution to carry out a diazotization reaction to obtain a reaction solution; S2. Coupling reaction: Add N,N-bis(2-hydroxyethyl)aniline to the reaction solution in step S1 to carry out a coupling reaction, and after the reaction is completed, the disperse black 9 compound is obtained through post-treatment.

[0022] The process route of the disperse black 9 compound is as follows: .

[0023] Among them, the synthesis process diagram of Disperse Black 9 compound is as follows: .

[0024] The resonance formula of p-aminodiazobenzene is as follows: .

[0025] Specifically, in step S1, the nitrite is at least one of sodium nitrite and potassium nitrite.

[0026] Specifically, in step S1, the inorganic acid aqueous solution is: hydrochloric acid aqueous solution, sulfuric acid aqueous solution or nitric acid aqueous solution; The mass concentration of the inorganic acid aqueous solution is 30% - 80%.

[0027] Specifically, the molar ratio of the nitrite to p-phenylenediamine is (1.0 - 1.5):1.

[0028] Specifically, the molar ratio of the inorganic acid to p-phenylenediamine in the inorganic acid aqueous solution is (2.0 - 4.0):1.

[0029] Specifically, in step S1, the temperature of the diazotization reaction is -20~10°C, and the time of the diazotization reaction is 10~60 min.

[0030] Specifically, the molar ratio of p-phenylenediamine to N,N-bis(2-hydroxyethyl)aniline is 1:(0.8 - 1.2).

[0031] Specifically, in step S2, the temperature of the coupling reaction is -10~5°C, and the time of the coupling reaction is 10~20 h.

[0032] Specifically, in step S2, the post-treatment process is: after the reaction is completed, the crude product of Disperse Black 9 compound is obtained by solid-liquid separation, and then the Disperse Black 9 compound is obtained by recrystallization.

[0033] Specifically, the recrystallization process is: under heating conditions, the crude product of Disperse Black 9 compound is dissolved in chloroform, the insoluble impurities are filtered out while it is hot, after the filtrate is cooled to room temperature, ethanol is added to the filtrate for crystallization, and finally the Disperse Black 9 compound product is obtained by solid-liquid separation and drying.

[0034] Example 1 Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C, and a diazotization reaction was carried out at -5 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the target product Disperse Black 9 crude product was obtained by filtration.

[0035] The Disperse Black 9 crude product obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol having the same volume as chloroform was added thereto with stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.5%, and the purity detected by liquid phase was above 94.76%. The liquid chromatography was as Figure 1 shown, and the data of the liquid chromatography are shown in Table 1 below.

[0036] Table 1 Figure 1 The data of the liquid chromatography in

[0037] Example 2 Under a nitrogen atmosphere, 11.1 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 7.0 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -10 °C, and a diazotization reaction was carried out at -10 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the target product Disperse Black 9 crude product was obtained by filtration.

[0038] The Disperse Black 9 crude product obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol having the same volume as chloroform was added thereto with stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.6%, and the purity detected by liquid phase was 94.1% Example 3 Under a nitrogen atmosphere, 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled at 0 °C, and diazotization reaction was carried out at 0 °C for 30 min. After the reaction ended, the obtained reaction solution was not separated and treated, and 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was directly added thereto. The coupling reaction was carried out at 0 °C for 10 h. After the reaction ended, the target product Disperse Black 9 crude product was obtained by filtration.

[0039] The Disperse Black 9 crude product obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then left to crystallize, and then filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.5%, and the purity detected by liquid phase was 94.2%.

[0040] Example 4 Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and a mixed solution of 7.0 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled at 0 °C, and diazotization reaction was carried out at 0 °C for 30 min. After the reaction ended, the obtained reaction solution was not separated and treated, and 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was directly added thereto. The coupling reaction was carried out at -5 °C for 20 h. After the reaction ended, the target product Disperse Black 9 crude product was obtained by filtration.

[0041] The Disperse Black 9 crude product obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then left to crystallize, and then filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.7%, and the purity detected by liquid phase was 94.1%.

[0042] Example 5 Under a nitrogen atmosphere, 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at 0 °C, and a diazotization reaction was carried out at 0 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto, and a coupling reaction was carried out at a controlled temperature of 3 °C for 12 h. After the reaction was completed, the reaction mixture was filtered to obtain the crude product of Disperse Black 9.

[0043] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 90.5%, and the purity detected by liquid phase was 94.0%.

[0044] Example 6 Under a nitrogen atmosphere, 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -8 °C, and a diazotization reaction was carried out at -8 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto, and a coupling reaction was carried out at a controlled temperature of -3 °C for 15 h. After the reaction was completed, the reaction mixture was filtered to obtain the crude product of Disperse Black 9.

[0045] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 91.3%, and the purity detected by liquid phase was 94.2%.

[0046] Example 7 Under a nitrogen atmosphere, 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 12.75 g (0.15 mol) of potassium nitrite and hydrochloric acid aqueous solution (0.4 mol, mass concentration 30%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -10 °C, and a diazotization reaction was carried out at -10 °C for 10 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 21.7 g (0.12 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at a controlled temperature of 5 °C for 10 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0047] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 91.4%, and the purity detected by liquid phase was 94.1%.

[0048] Example 8 Under a nitrogen atmosphere, 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.2 mol, mass concentration 80%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -20 °C, and a diazotization reaction was carried out at -20 °C for 60 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 14.5 g (0.08 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at a controlled temperature of -10 °C for 20 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0049] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 91.1%, and the purity detected by liquid phase was 94.0%.

[0050] Example 9 Under a nitrogen atmosphere, 11.1 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 7.0 g (0.1 mol) of sodium nitrite and nitric acid aqueous solution (0.3 mol, mass concentration 40%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -10 °C, and diazotization reaction was carried out at -10 °C for 30 min. Without separation treatment of the obtained reaction solution after the reaction, 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was directly added thereto, and coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0051] The crude Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then left to crystallize. Then it was filtered and dried to obtain the fine product of Disperse Black 9. The yield was 90.7%, and the purity detected by liquid phase was 94.1%.

[0052] It can be seen from the experimental results of Examples 1-9 above that: by using the preparation method described in the present invention to prepare Disperse Black 9, a high-yield and high-purity Disperse Black 9 product can be obtained by a one-pot method, and the operation is simple without complicated post-treatment operations.

[0053] Comparative Example 1 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a measured mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C for diazotization reaction for 30 min, and then 35 mL (0.2 mol) of 40% fluoboric acid was added. After reacting for a period of time, the generated precipitate was filtered by suction while it was cold, and washed successively with absolute ethanol and ether, and then dried in a dryer to obtain phenyl diazonium fluoborate, and the yield was 90.3%.

[0054] 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water and 5 mL of 20% hydrochloric acid aqueous solution were successively added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. After cooling to 0 °C, 20.7 g (0.1 mol) of phenyl diazonium fluoborate obtained in the above step was added thereto, and coupling reaction was carried out for 12 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0055] The crude Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and the insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain the refined Disperse Black 9. The yield was 90.2%, and the purity detected by liquid phase was 85.05%. The liquid chromatography was as Figure 2 shown, and the data of the liquid chromatography are shown in Table 2 below. However, the total two-step yield based on p-phenylenediamine was 81.0%.

[0056] Table 2 Figure 2 The data of the liquid chromatography in

[0057] Comparative Example 2 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and a measured mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.3 mol, mass concentration of 50%) which had been pre-cooled was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled at -10 °C for a diazotization reaction for 30 min. Then, 36 mL (0.2 mol) of 40% fluoboric acid was added, and after reacting for a period of time, the formed precipitate was filtered by suction while it was cold, and washed successively with absolute ethanol and ether, and then dried in a dryer to obtain benzene diazonium fluoborate of p-aminofluoboric acid, and the yield was 90.1%.

[0058] 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water and 5 mL of sulfuric acid aqueous solution with a mass concentration of 10% were successively added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. After cooling to 0 °C, 20.7 g (0.1 mol) of the benzene diazonium fluoborate of p-aminofluoboric acid obtained in the above step was added thereto, and a coupling reaction was carried out for 12 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0059] The crude Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and the insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain the refined Disperse Black 9. The yield was 90.2%, and the purity detected by liquid phase was 84.7%. However, the total two-step yield based on p-phenylenediamine was 81.0%.

[0060] Comparative Example 3 Add 10.9 g (0.1 mol) of p-phenylenediamine to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Start stirring, and while stirring, slowly add a measured mixed solution of pre-cooled sodium nitrite 6.9 g (0.1 mol) and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) to it. Control the temperature of the system and the mixed solution at 0 °C for the diazotization reaction for 30 min. Then add 35 mL (0.2 mol) of 40% fluoboric acid. After reacting for a period of time, filter the formed precipitate while it is cold, and wash it successively with absolute ethanol and ether. Place it in a desiccator to dry to obtain p-aminobenzenediazonium fluoborate, with a yield of 89.1%.

[0061] Add 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water and 5 mL of 20% hydrochloric acid aqueous solution to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. After cooling to 0 °C, add 20.7 g (0.1 mol) of p-aminobenzenediazonium fluoborate obtained in the above step to it, and carry out the coupling reaction for 10 h. After the reaction is completed, filter to obtain the crude product of Disperse Black 9.

[0062] The crude product of Disperse Black 9 obtained in the above step is dissolved in hot chloroform (30 mL), and insoluble impurities are filtered off while it is hot. After the filtrate is cooled to room temperature, add ethanol with the same volume as chloroform to it under stirring and stir evenly, then let it stand for crystallization. Then filter and dry to obtain the fine product of Disperse Black 9, with a yield of 90.2% and a purity of 84.9% detected by liquid phase. However, the total two-step yield based on p-phenylenediamine is 80.4%.

[0063] Comparative Example 4 Add 10.9 g (0.1 mol) of p-phenylenediamine to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Start stirring, and while stirring, slowly add a measured mixed solution of pre-cooled sodium nitrite 6.9 g (0.1 mol) and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) to it. Control the temperature of the system and the mixed solution at 0 °C for the diazotization reaction for 30 min. Then add 35 mL (0.2 mol) of 40% fluoboric acid. After reacting for a period of time, filter the formed precipitate while it is cold, and wash it successively with absolute ethanol and ether. Place it in a desiccator to dry to obtain p-aminobenzenediazonium fluoborate, with a yield of 90.1%.

[0064] Into a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% hydrochloric acid aqueous solution were successively added. After cooling to -5 °C, 20.7 g (0.1 mol) of the phenyl diazonium fluoroborate obtained in the above step was added thereto, and a coupling reaction was carried out for 20 h. After the reaction was completed, the crude product of Disperse Black 9 was obtained by filtration.

[0065] The crude product of Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL), and the insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 90.2%, and the purity detected by liquid phase was 85.1%. However, the total two-step yield based on p-phenylenediamine was 81.0%.

[0066] Comparative Example 5 10.9 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and a mixed solution of a measured amount of pre-cooled sodium nitrite 6.9 g (0.1 mol) and sulfuric acid aqueous solution (0.3 mol, mass concentration of 50%) was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled at 0 °C for a diazotization reaction for 30 min, and then 35 mL (0.2 mol) of 40% fluoboric acid was added. After reacting for a period of time, the generated precipitate was filtered by suction while cold, and washed successively with absolute ethanol and ether, and then dried in a dryer to obtain phenyl diazonium fluoroborate, and the yield was 90.1%.

[0067] Into a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% hydrochloric acid aqueous solution were successively added. After cooling to 3 °C, 20.7 g (0.1 mol) of the phenyl diazonium fluoroborate obtained in the above step was added thereto, and a coupling reaction was carried out for 12 h. After the reaction was completed, the crude product of Disperse Black 9 was obtained by filtration.

[0068] The crude product of Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL), and the insoluble impurities were filtered off while hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 90.2%, and the purity detected by liquid phase was 84.8%. However, the total two-step yield based on p-phenylenediamine was 81.0%.

[0069] Comparative Example 6 Add 10.9 g (0.1 mol) of p-phenylenediamine to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Start stirring, and while stirring, slowly add a measured mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.3 mol, mass concentration 50%) that has been pre-cooled. Control the temperature of the system and the mixed solution at -8 °C for the diazotization reaction for 30 min. Then add 35 mL (0.2 mol) of 40% fluoboric acid. After reacting for a period of time, filter the formed precipitate while it is still cold, and wash it successively with absolute ethanol and ether. Place it in a desiccator to dry to obtain p-aminobenzenediazonium fluoborate, with a yield of 90.1%.

[0070] Add 11.7 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline, 30 mL of water, and 5 mL of 20% hydrochloric acid aqueous solution to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. After cooling to -3 °C, add 20.7 g (0.1 mol) of p-aminobenzenediazonium fluoborate obtained in the above step, and carry out the coupling reaction for 15 h. After the reaction is completed, filter to obtain the crude product of Disperse Black 9.

[0071] The crude product of Disperse Black 9 obtained in the above step is dissolved in hot chloroform (30 mL), and insoluble impurities are filtered off while it is hot. After the filtrate is cooled to room temperature, add ethanol with the same volume as chloroform to it under stirring and stir evenly, then let it stand for crystallization. Then filter and dry to obtain the fine product of Disperse Black 9, with a yield of 90.2% and a purity of 84.9% detected by liquid phase. However, the total two-step yield based on p-phenylenediamine is 81.0%.

[0072] Comparative Example 1 - Comparative Example 6 are non-one-pot methods for preparing Disperse Black 9 under different conditions. These preparation methods require additional purification operations for intermediates, and the yields of Disperse Black 9 obtained under each condition are lower than those in Examples 1 - 9 of the present invention. It can be seen that the present invention synthesizes an important compound Disperse Black 9 with wide application value by a one-pot method, and this method has significant advantages such as simple operation, low cost, low price and easy availability of raw materials.

[0073] Comparative Example 7 Prepare Disperse Black 9 by the same method as in Example 1, except that: in this Comparative Example 7, the concentration of the inorganic acid aqueous solution is reduced, and the mass concentration of the sulfuric acid aqueous solution in this Comparative Example 7 is 10%. The specific preparation process is as follows: Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 10%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C, and a diazotization reaction was carried out at -5 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto, and a coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the reaction mixture was filtered to obtain a crude product of Disperse Black 9.

[0074] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol having the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain a fine product of Disperse Black 9. The yield was 80%, and the purity detected by liquid phase was 95.3%.

[0075] Comparative Example 8 Disperse Black 9 was prepared by the same method as in Example 1, except that: in this Comparative Example 8, the concentration of the inorganic acid aqueous solution was increased, and the mass concentration of the aqueous sulfuric acid solution in this Comparative Example 8 was 95%. The specific preparation process was as follows: Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 95%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C, and a diazotization reaction was carried out at -5 °C for 30 min. After the reaction was completed, the resulting reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto, and a coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the reaction mixture was filtered to obtain a crude product of Disperse Black 9.

[0076] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol having the same volume as chloroform was added thereto under stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain a fine product of Disperse Black 9. The yield was 82%, and the purity detected by liquid phase was 94.0%.

[0077] From the data comparison of Comparative Example 7, Comparative Example 8 and Example 1, it can be seen that: if the concentration of the inorganic acid aqueous solution is too low or too high, it will lead to a decrease in the yield of Disperse Black 9. Because when the concentration of the inorganic acid aqueous solution is too low, the conversion rate of nitrous acid will be relatively low, which will affect the conversion rate of the diazotization reaction, and then lead to a decrease in the target product; when the concentration of the inorganic acid aqueous solution is too high, the conversion of nitrous acid will be too fast and nitrous acid is likely to escape, thus affecting the diazotization reaction, and then leading to a decrease in the target product. Therefore, using the concentration of the inorganic acid aqueous solution defined in the present invention is more conducive to obtaining Disperse Black 9 compounds with high yield and high purity.

[0078] Comparative Example 9 Disperse Black 9 was prepared by the same method as in Example 1, except that: in this Comparative Example 9, the amount of inorganic acid used was reduced, and the amount of sulfuric acid used in this Comparative Example 9 was 0.1 mol. The specific process is as follows: Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and sulfuric acid aqueous solution (0.1 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled at -5 °C, and diazotization reaction was carried out at -5 °C for 30 min. After the reaction was completed, the obtained reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto, and the coupling reaction was carried out at 0 °C for 12 h. After the reaction was completed, the target product, crude Disperse Black 9, was obtained by filtration.

[0079] The crude Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto while stirring and stirred evenly, then allowed to stand for crystallization, and then filtered and dried to obtain the fine product of Disperse Black 9. The yield was 83%, and the purity detected by liquid phase was 95.1%.

[0080] Comparative Example 10 Disperse Black 9 was prepared by the same method as in Example 1, except that: in this Comparative Example 10, the amount of inorganic acid used was increased, and the amount of sulfuric acid used in this Comparative Example 10 was 0.5 mol. The specific process is as follows: Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.5 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C, and a diazotization reaction was carried out at -5 °C for 30 min. After the reaction ended, the resulting reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at 0 °C for 12 h. After the reaction ended, the target product, crude disperse black 9, was obtained by filtration.

[0081] The crude disperse black 9 obtained in the above step was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol having the same volume as the chloroform was added thereto under stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain the fine product of disperse black 9. The yield was 89%, and the purity detected by liquid phase was 88.3%.

[0082] From the data comparison of Comparative Example 9, Comparative Example 10 and Example 1, it can be seen that if the amount of inorganic acid used is reduced, the conversion rate of the diazotization reaction is low, which ultimately affects the yield of the target product; if the amount of inorganic acid used is increased, it will lead to waste of raw materials and also increase the impurity content in the system. Under the same post-treatment conditions, the product purity decreases significantly.

[0083] Comparative Example 11 Disperse black 9 was prepared by the same method as in Example 1, except that: in this Comparative Example 11, the amount of nitrite used was increased. The amount of nitrous acid used in this Comparative Example 11 was 0.25 mol. The specific process was as follows: Under a nitrogen atmosphere, 10.8 g (0.1 mol) of p-phenylenediamine was added to a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer. Stirring was started, and while stirring, a mixed solution of 17.25 g (0.25 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration 50%) that had been pre-cooled was slowly added thereto. The temperature of the system and the mixed solution was controlled at -5 °C, and a diazotization reaction was carried out at -5 °C for 30 min. After the reaction ended, the resulting reaction solution was not separated and treated, and directly 11.6 g (0.098 mol) of N,N-bis(2-hydroxyethyl)aniline was added thereto. The coupling reaction was carried out at 0 °C for 12 h. After the reaction ended, the target product, crude disperse black 9, was obtained by filtration.

[0084] The crude Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and the insoluble impurities were filtered off while it was hot. After the filtrate was cooled to room temperature, ethanol with the same volume as chloroform was added thereto under stirring, and the mixture was stirred evenly and then allowed to stand for crystallization. Then, it was filtered and dried to obtain the refined Disperse Black 9 with a yield of 89.2% and a purity of 87.2% detected by liquid phase.

[0085] It can be seen from the data comparison between Comparative Example 11 and Example 1 that if the dosage of nitrite increases, the impurity content in the system will increase, and under the same post-treatment conditions, the product purity will decrease significantly.

[0086] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0087] For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. The protection scope of the present invention shall be subject to the appended claims.

Claims

1. A method for preparing a disperse black 9 compound, characterized in that: The preparation method is: S1. Diazotization reaction: Under an inert gas environment, diazotization reaction is performed on p-phenylenediamine, nitrite and an inorganic acid aqueous solution to obtain a reaction solution; S2, coupling reaction: N,N-bis(hydroxyethyl)aniline is added to the reaction solution of step S1 to carry out coupling reaction, and after the reaction is completed, disperse black 9 compound is obtained through post-treatment.

2. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: In step S1, the nitrite is at least one of sodium nitrite and potassium nitrite.

3. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: In step S1, the inorganic acid aqueous solution is: hydrochloric acid aqueous solution, sulfuric acid aqueous solution or nitric acid aqueous solution; The mass concentration of the inorganic acid aqueous solution is 30%-80%.

4. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: The molar ratio of the nitrite to p-phenylenediamine is (1.0-1.5):

1.

5. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: The molar ratio of the inorganic acid to p-phenylenediamine in the inorganic acid aqueous solution is (2.0-4.0):

1.

6. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: In step S1, the temperature of the diazotization reaction is -20 to 10°C, and the time of the diazotization reaction is 10 to 60 minutes.

7. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: The molar ratio of p-phenylenediamine to N,N-bis(hydroxyethyl)aniline is 1:(0.8-1.2).

8. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: In step S2, the coupling reaction temperature is -10~5°C, and the coupling reaction time is 10~20h.

9. The method for preparing a disperse black 9 compound according to claim 1, characterized in that: In step S2, the post-treatment process is: after the reaction is completed, a crude product of Disperse Black 9 compound is obtained by solid-liquid separation, and then a Disperse Black 9 compound is obtained by recrystallization.

10. The method for preparing a disperse black 9 compound according to claim 9, characterized in that: The recrystallization process is as follows: under heating conditions, the crude product of Disperse Black 9 compound is dissolved in chloroform, insoluble impurities are filtered out while hot, and after the filtrate cools to room temperature, ethanol is added to the filtrate for crystallization, and finally the Disperse Black 9 compound product is obtained by solid-liquid separation and drying.

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