A preparation method of disperse black 9 compound

Abstract

The present invention relates to the technical field of organic synthesis, and more particularly to a method for preparing a Disperse Black 9 compound. The method comprises the following steps: S1, diazotization reaction: under an inert gas environment, diazotization reaction of p-phenylenediamine, nitrite, and an inorganic acid aqueous solution to obtain a reaction solution; S2, coupling reaction: adding N,N-bishydroxyethylaniline to the reaction solution of step S1 for a coupling reaction, and after completion of the reaction, post-processing 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 selected from the group consisting of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, and nitric acid aqueous solution; the mass concentration of the inorganic acid aqueous solution is 30% to 80%. The method can achieve a one-pot preparation of a target compound with high purity and high yield, and is simple to operate, low-cost, and environmentally friendly.

Description

Technical Field

[0001] The invention relates to a preparation method of a disperse black 9 compound, and belongs 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(hydroxyethylanilino)aminoazobenzene), is a very important organic intermediate with a wide range of applications in pharmaceuticals, pesticides, dyes, and surfactants. Dyes are primarily used in cosmetics and other personal care products, and in 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 pesticides and pharmaceuticals, due to the presence of active groups such as aniline and hydroxyethyl groups in its structure, it may possess certain pharmacological activities or serve as a precursor for drug synthesis.

[0003] Patent publication number CN119570027B discloses a colored end-capped photosensitive polymer and its preparation method, application, black photoresist, and black matrix. The raw materials for the preparation of the colored end-capped photosensitive polymer include a dianhydride monomer, an alcohol, a colored end-capping monomer, a first diamine monomer, and a second diamine monomer. The colored end-capping monomer includes Disperse Black 9. By capping the photosensitive polymer molecular chain with a colored group containing an azo structure, not only can the OD value of the black photoresist be significantly improved, but also the black photoresist has better mechanical properties and photolithographic performance. Patent 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. Patent publication number CN105925770B discloses a quenching oil and quenching method that can cause screws to spontaneously turn black after quenching. Disperse Black 9 is used as a colorant in the quenching oil. Patent publication number JP2023542308A discloses a dyeing composition and a dyeing method for keratin fibers. Disperse Black 9 is used as a dye in the dyeing composition and can be used for dyeing hair.

[0004] In summary, Disperse Black 9 is an important organic synthesis intermediate with broad application value. However, to date, there is not much public information on its synthesis method. Therefore, developing a scientific and green synthesis method and route is of great significance and value for the preparation of Disperse Black 9 within the industry. Summary of the Invention

[0005] The present invention aims to address the deficiencies in the prior art and provides a method for preparing a disperse black 9 compound. The method can achieve a one-pot preparation of a 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, the preparation method is:

[0007] S1. Diazotization reaction:

[0008] Under an inert gas environment, p-phenylenediamine, nitrite and an inorganic acid aqueous solution are subjected to a diazotization reaction to obtain a reaction liquid;

[0009] S2, coupling reaction:

[0010] N,N-bis(hydroxyethyl)aniline was added to the reaction solution of step S1 to carry out coupling reaction. After the reaction was completed, the disperse black 9 compound was obtained through post-treatment.

[0011] Furthermore, in step S1, the nitrite is at least one of sodium nitrite and potassium nitrite.

[0012] Furthermore, in step S1, the inorganic acid aqueous solution is: hydrochloric acid aqueous solution, sulfuric acid aqueous solution or nitric acid aqueous solution;

[0013] The mass concentration of the inorganic acid aqueous solution is 30%-80%.

[0014] Furthermore, the molar ratio of the nitrite to p-phenylenediamine is (1.0-1.5):1.

[0015] Furthermore, the molar ratio of the inorganic acid to p-phenylenediamine in the inorganic acid aqueous solution is (2.0-4.0):1.

[0016] Furthermore, 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.

[0017] Furthermore, the molar ratio of p-phenylenediamine to N,N-bis(hydroxyethyl)aniline is 1:(0.8-1.2).

[0018] Furthermore, in step S2, the coupling reaction temperature is -10~5°C, and the coupling reaction time is 10~20h.

[0019] Furthermore, in step S2, the post-treatment process is: after the reaction is completed, solid-liquid separation is performed to obtain a crude product of Disperse Black 9 compound, and then recrystallization is performed to obtain Disperse Black 9 compound.

[0020] Furthermore, 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, 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.

[0021] The beneficial effects of the present invention are:

[0022] The preparation method of the dispersed black 9 compound of the present invention adopts a one-pot process to prepare, avoiding the tedious intermediate separation process, being easy to operate, having low three-waste discharge, reducing the labor intensity in the production process, and thus the preparation method has the advantages of low cost and environmental friendliness. In addition, the preparation method of the present invention adopts a one-pot process to prepare, with a high product yield of not less than 90% and a product purity of not less than 94%. Moreover, the preparation method of the present invention uses p-phenylenediamine as a starting raw material, and pigment sources are widely available, with low raw material cost.

[0023] In the preparation method described herein, the active site for aniline self-coupling is primarily at the para position, while the para position of p-phenylenediamine is occupied. Consequently, the self-coupling activity of p-phenylenediamine is significantly reduced after diazotization of one end. Furthermore, because the diazo group after diazotization of one end is a strong electron-withdrawing group, it can weaken the basicity of the undiazotized amino group in the conjugated system, thereby inhibiting the dizotization reaction. By controlling reasonable process conditions, the target product is ultimately obtained in high yield and high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a liquid chromatogram of Disperse Black 9 prepared in Example 1;

[0025] Figure 2 This is the liquid chromatogram of Disperse Black 9 prepared in Comparative Example 1. DETAILED DESCRIPTION

[0026] The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0028] A preparation method of Disperse Black 9 compound, the preparation method comprising:

[0029] S1. Diazotization reaction:

[0030] Under an inert gas environment, p-phenylenediamine, nitrite and an inorganic acid aqueous solution are subjected to a diazotization reaction to obtain a reaction liquid;

[0031] S2, coupling reaction:

[0032] N,N-bis(hydroxyethyl)aniline was added to the reaction solution of step S1 to carry out coupling reaction. After the reaction was completed, the disperse black 9 compound was obtained through post-treatment.

[0033] The process route of the disperse black 9 compound is as follows:

[0034] .

[0035] Among them, the synthesis process diagram of Disperse Black 9 compound is as follows:

[0036] .

[0037] The resonance formula of p-aminobenzenediazonium is as follows:

[0038] .

[0039] Specifically, in step S1, the nitrite is at least one of sodium nitrite and potassium nitrite.

[0040] Specifically, in step S1, the inorganic acid aqueous solution is: hydrochloric acid aqueous solution, sulfuric acid aqueous solution or nitric acid aqueous solution;

[0041] The mass concentration of the inorganic acid aqueous solution is 30%-80%.

[0042] Specifically, the molar ratio of the nitrite to p-phenylenediamine is (1.0-1.5):1.

[0043] Specifically, the molar ratio of the inorganic acid to p-phenylenediamine in the inorganic acid aqueous solution is (2.0-4.0):1.

[0044] Specifically, 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.

[0045] Specifically, the molar ratio of p-phenylenediamine to N,N-bis(hydroxyethyl)aniline is 1:(0.8-1.2).

[0046] Specifically, in step S2, the coupling reaction temperature is -10~5°C, and the coupling reaction time is 10~20h.

[0047] Specifically, in step S2, the post-treatment process is: after the reaction is completed, solid-liquid separation is performed to obtain a crude product of Disperse Black 9 compound, and then recrystallization is performed to obtain Disperse Black 9 compound.

[0048] Specifically, 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, 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.

[0049] Example 1

[0050] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0051] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered out while hot. After the filtrate was cooled to room temperature, an equal volume of ethanol was added thereto under stirring, and the mixture was stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9 fine product with a yield of 90.5%. The purity of the product by liquid chromatography was above 94.76%. The liquid chromatography results showed that the product was Figure 1 The liquid chromatography data are shown in Table 1 below.

[0052] Table 1 Figure 1 Liquid chromatography data

[0053]

[0054] Example 2

[0055] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -10 ° C. The diazotization reaction was carried out at -10 ° C for 30 min. After the reaction was completed, 11.7 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C and the coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0056] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered out while hot. After the filtrate was cooled to room temperature, an equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly and allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9 fine product with a yield of 90.6% and a purity of 94.1% as determined by liquid chromatography.

[0057] Example 3

[0058] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to 0°C. The diazotization reaction was carried out at 0°C for 30 min. After the reaction was completed, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0°C for the coupling reaction for 10 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0059] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 90.5%, and the purity by liquid chromatography was 94.2%.

[0060] Example 4

[0061] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to 0°C. The diazotization reaction was carried out at 0°C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to -5°C for the coupling reaction for 20 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0062] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol and chloroform were added to the filtrate under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.7%, and the purity of the liquid chromatography test was 94.1%.

[0063] Example 5

[0064] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to 0°C. The diazotization reaction was carried out at 0°C for 30 min. After the reaction was completed, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 3°C for the coupling reaction for 12 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0065] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol and chloroform were added to the filtrate under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 90.5%, and the purity by liquid chromatography was 94.0%.

[0066] Example 6

[0067] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -8 ° C. The diazotization reaction was carried out at -8 ° C for 30 min. After the reaction was completed, the reaction solution was directly added with 11.7 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline without separation treatment. The temperature was controlled at -3 ° C for coupling reaction for 15 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0068] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol and chloroform were added to the filtrate under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 91.3%, and the purity by liquid chromatography was 94.2%.

[0069] Example 7

[0070] 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. The stirring was started and a mixed solution of 12.75 g (0.15 mol) of potassium nitrite and an aqueous hydrochloric acid solution (0.4 mol, mass concentration 30%) that had been cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -10°C. The diazotization reaction was carried out at -10°C for 10 min. After the reaction was completed, 21.7 g (0.12 mol) of N,N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled at 5°C for the coupling reaction for 10 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0071] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol and chloroform were added to the filtrate under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 91.4%, and the purity by liquid chromatography was 94.1%.

[0072] Example 8

[0073] 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. The stirring was started and a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.2 mol, mass concentration 80%) that had been cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to be -20 ° C. The diazotization reaction was carried out at -20 ° C for 60 min. After the reaction was completed, the reaction solution obtained was directly added with 14.5 g (0.08 mol) of N, N-bis(hydroxyethyl)aniline without separation treatment. The temperature was controlled at -10 ° C for coupling reaction for 20 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0074] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol and chloroform were added to the filtrate under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 91.1%, and the purity by liquid chromatography was 94.0%.

[0075] Example 9

[0076] 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. The stirring was started and a mixed solution of 7.0 g (0.1 mol) of sodium nitrite and an aqueous nitric acid solution (0.3 mol, mass concentration 40%) that had been cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -10 ° C. The diazotization reaction was carried out at -10 ° C for 30 min. After the reaction was completed, 11.7 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C and the coupling reaction was carried out for 12 h. After the reaction was completed, the crude product of the target product, Disperse Black 9, was obtained by filtration.

[0077] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 90.7%, and the purity by liquid chromatography was 94.1%.

[0078] From the experimental results of Examples 1 to 9 above, it can be seen that the preparation method of the present invention can be used to prepare Disperse Black 9 with high yield and high purity in one pot, and the operation is simple without complicated post-processing operations.

[0079] Comparative Example 1

[0080] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9 g (0.1 mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9 g (0.1 mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, 50% mass concentration) was slowly added while stirring. The temperature of the system and the mixed solution was controlled at -5°C for diazotization reaction for 30 min. Then, 35 mL (0.2 mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 90.3%.

[0081] To a 100mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7g (0.098mol) of N,N-bis(hydroxyethyl)aniline, 30mL of water and 5mL of a 20% aqueous hydrochloric acid solution were added in sequence. After cooling to 0°C, 20.7g (0.1mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 12h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0082] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), and insoluble impurities were filtered out while hot. After the filtrate was cooled to room temperature, an equal volume of ethanol was added thereto under stirring, and the mixture was stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9 fine product. The yield was 90.2%, and the purity of the product by liquid chromatography was 85.05%. The liquid chromatography results showed that the product had a purity of 85.05%. Figure 2 The liquid chromatography data are shown in Table 2. The total yield of the two steps based on p-phenylenediamine was 81.0%.

[0083] Table 2 Figure 2 Liquid chromatography data

[0084]

[0085] Comparative Example 2

[0086] To a 100mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9g (0.1mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9g (0.1mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3mol, 50% mass concentration) was slowly added while stirring. The temperature of the system and the mixed solution was controlled at -10°C for diazotization reaction for 30min. Then, 36mL (0.2mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 90.1%.

[0087] To a 100mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7g (0.098mol) of N,N-bis(hydroxyethyl)aniline, 30mL of water and 5mL of a 10% aqueous sulfuric acid solution were added in sequence. After cooling to 0°C, 20.7g (0.1mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 12h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0088] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. Under stirring, an equal volume of ethanol was added to the chloroform, stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9. The yield was 90.2%, and the purity of the liquid phase test was 84.7%. However, the total yield of the two steps was 81.0% based on p-phenylenediamine.

[0089] Comparative Example 3

[0090] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9 g (0.1 mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9 g (0.1 mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration of 50%) was slowly added while stirring. The temperature of the system and the mixed solution was controlled to 0°C for diazotization reaction for 30 min, and then 35 mL (0.2 mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 89.1%.

[0091] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% aqueous hydrochloric acid solution were added in sequence. After cooling to 0°C, 20.7 g (0.1 mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 10 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0092] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. Under stirring, an equal volume of ethanol and chloroform was added thereto, stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9 fine product with a yield of 90.2% and a liquid phase purity of 84.9%. However, the total yield of the two steps was 80.4% based on p-phenylenediamine.

[0093] Comparative Example 4

[0094] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9 g (0.1 mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9 g (0.1 mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration of 50%) was slowly added while stirring. The temperature of the system and the mixed solution was controlled to 0°C for diazotization reaction for 30 min, and then 35 mL (0.2 mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 90.1%.

[0095] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% aqueous hydrochloric acid solution were added in sequence. After cooling to -5 °C, 20.7 g (0.1 mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 20 h. After the reaction was completed, the crude target product, Disperse Black 9, was obtained by filtration.

[0096] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. Under stirring, an equal volume of ethanol and chloroform was added thereto, stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9 fine product with a yield of 90.2% and a purity of 85.1% as determined by liquid chromatography. However, the total yield of the two steps was 81.0% based on p-phenylenediamine.

[0097] Comparative Example 5

[0098] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9 g (0.1 mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9 g (0.1 mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, mass concentration of 50%) was slowly added while stirring. The temperature of the system and the mixed solution was controlled to 0°C for diazotization reaction for 30 min, and then 35 mL (0.2 mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 90.1%.

[0099] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% aqueous hydrochloric acid solution were added in sequence. After cooling to 3 ° C, 20.7 g (0.1 mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0100] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. Under stirring, an equal volume of ethanol was added to the chloroform, stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9. The yield was 90.2%, and the purity of the liquid phase test was 84.8%. However, the total yield of the two steps was 81.0% based on p-phenylenediamine.

[0101] Comparative Example 6

[0102] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 10.9 g (0.1 mol) of p-phenylenediamine was added, and stirring was started. A mixed solution of 6.9 g (0.1 mol) of pre-cooled sodium nitrite and an aqueous sulfuric acid solution (0.3 mol, 50% mass concentration) was slowly added while stirring. The temperature of the system and the mixed solution was controlled at -8°C for 30 min of diazotization reaction. Then, 35 mL (0.2 mol) of 40% fluoroboric acid was added. After a period of reaction, the generated precipitate was filtered while cold, washed with anhydrous ethanol and ether in sequence, and dried in a desiccator to obtain p-aminofluoroboric acid benzene diazonium salt with a yield of 90.1%.

[0103] To a 100 mL four-necked reaction flask equipped with a stirrer and a thermometer, 11.7 g (0.098 mol) of N,N-bis(hydroxyethyl)aniline, 30 mL of water, and 5 mL of a 20% aqueous hydrochloric acid solution were added in sequence. After cooling to -3 ° C, 20.7 g (0.1 mol) of p-aminofluoroboric acid benzene diazonium salt obtained in the above step was added thereto. The coupling reaction was carried out for 15 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0104] The crude product of Disperse Black 9 obtained in the above steps was dissolved in hot chloroform (30 mL), insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. Under stirring, an equal volume of ethanol was added to the chloroform, stirred evenly, and then allowed to stand for crystallization. The product was then filtered and dried to obtain Disperse Black 9. The yield was 90.2%, and the purity of the liquid phase test was 84.9%. However, the total yield of the two steps was 81.0% based on p-phenylenediamine.

[0105] Comparative Examples 1-6 are non-one-pot methods for preparing Disperse Black 9 under different conditions. These preparation methods require additional purification of the intermediate, and the yields of Disperse Black 9 obtained using various conditions are all lower than those of Examples 1-9 of the present invention. This demonstrates that the one-pot method of the present invention synthesizes Disperse Black 9, an important compound with broad application value, and offers significant advantages such as simple operation, low cost, and readily available and inexpensive raw materials.

[0106] Comparative Example 7

[0107] Disperse Black 9 was prepared by the same method as in Example 1, except that the concentration of the inorganic acid aqueous solution was reduced in Comparative Example 7. The mass concentration of the sulfuric acid aqueous solution in Comparative Example 7 was 10%. The specific preparation process was as follows:

[0108] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0109] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 80%, and the purity of the liquid chromatography test was 95.3%.

[0110] Comparative Example 8

[0111] Disperse Black 9 was prepared by the same method as in Example 1, except that the concentration of the inorganic acid aqueous solution was increased in Comparative Example 8. The mass concentration of the sulfuric acid aqueous solution in Comparative Example 8 was 95%. The specific preparation process was as follows:

[0112] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0113] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 82%, and the purity of the liquid chromatography test was 94.0%.

[0114] Comparison of the data in Comparative Examples 7 and 8 with Example 1 shows that if the concentration of the aqueous inorganic acid solution is too low or too high, the yield of Disperse Black 9 will decrease. This is because when the concentration of the aqueous inorganic acid solution is too low, the conversion rate of nitrous acid is low, thereby affecting the conversion rate of the diazotization reaction and causing a decrease in the target product. When the concentration of the aqueous inorganic acid solution is too high, the conversion of nitrous acid is too fast, and nitrous acid easily escapes, thereby causing the diazotization reaction and causing a decrease in the target product. Therefore, the aqueous inorganic acid solution concentration defined by the present invention is more conducive to obtaining a high-yield, high-purity Disperse Black 9 compound.

[0115] Comparative Example 9

[0116] Disperse Black 9 was prepared by the same method as in Example 1, except that the amount of inorganic acid used in this Comparative Example 9 was reduced, and the amount of sulfuric acid used in this Comparative Example 9 was 0.1 mol. The specific process was as follows:

[0117] 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. The stirring was started and a mixed solution of 6.9 g (0.1 mol) of sodium nitrite and an aqueous sulfuric acid solution (0.1 mol, mass concentration 50%) that had been cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0118] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 83%, and the purity of the liquid chromatography test was 95.1%.

[0119] Comparative Example 10

[0120] Disperse Black 9 was prepared by the same method as in Example 1, except that the amount of inorganic acid was increased in Comparative Example 10, and the amount of sulfuric acid in Comparative Example 10 was 0.5 mol. The specific process was as follows:

[0121] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0122] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 89%, and the purity of the liquid chromatography test was 88.3%.

[0123] From the comparison of the data of Comparative Example 9, Comparative Example 10 and Example 1, it can be seen that if the amount of inorganic acid 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 is increased, it will lead to waste of raw materials and increase the impurity content in the system. Under the same post-treatment conditions, the purity of the product is significantly reduced.

[0124] Comparative Example 11

[0125] Disperse Black 9 was prepared by the same method as in Example 1, except that the amount of nitrite was increased in Comparative Example 11, and the amount of nitrous acid in Comparative Example 11 was 0.25 mol. The specific process was as follows:

[0126] 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. The stirring was started and 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 cooled in advance was slowly added thereto while stirring. The temperature of the system and the mixed solution was controlled to -5 ° C. The diazotization reaction was carried out at -5 ° C for 30 min. After the reaction was completed, 11.6 g (0.098 mol) of N, N-bis(hydroxyethyl)aniline was directly added thereto without separation treatment. The temperature was controlled to 0 ° C. The coupling reaction was carried out for 12 h. After the reaction was completed, the target product, Disperse Black 9 crude product, was obtained by filtration.

[0127] The crude Disperse Black 9 obtained in the above step was dissolved in hot chloroform (30 mL). Insoluble impurities were filtered out while hot, and the filtrate was cooled to room temperature. An equal volume of ethanol was added to the chloroform under stirring, and the mixture was stirred evenly. The mixture was allowed to stand for crystallization, and then filtered and dried to obtain the refined Disperse Black 9. The yield was 89.2%, and the purity by liquid chromatography was 87.2%.

[0128] From the comparison of the data of Comparative Example 11 and Example 1, it can be seen that if the amount of nitrite is increased, the impurity content in the system will increase, and under the same post-treatment conditions, the purity of the product will be significantly reduced.

[0129] The technical features of the above-described embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] For those skilled in the art, several variations and improvements may be made without departing from the scope of the present invention, which all fall within the scope of protection of the present invention. The scope of protection of the present invention shall be based on 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, p-phenylenediamine is subjected to a diazotization reaction with a nitrite and an inorganic acid aqueous solution to obtain a reaction solution; the mass concentration of the inorganic acid aqueous solution is 30%-80%; the molar ratio of the nitrite to p-phenylenediamine is (1.0-1.5):1; the molar ratio of the inorganic acid to p-phenylenediamine in the inorganic acid aqueous solution is (2.0-4.0):1; S2, coupling reaction: N,N-bis(hydroxyethyl)aniline was added to the reaction solution of step S1 to carry out coupling reaction. After the reaction was completed, the disperse black 9 compound was obtained through post-treatment.

2. The method for preparing a disperse black 9 compound according to claim 1, wherein: 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, wherein: In step S1, the inorganic acid aqueous solution is: hydrochloric acid aqueous solution, sulfuric acid aqueous solution or nitric acid aqueous solution.

4. The method for preparing a disperse black 9 compound according to claim 1, wherein: 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.

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

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

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

8. The method for preparing a disperse black 9 compound according to claim 7, 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, 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.

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