Dioxazine compound, preparation method and application

Abstract

The invention relates to the technical field of organic synthesis, in particular to a dioxazine compound, a preparation method and application. The invention discloses a dioxazine compound which has a structure as shown in a formula 1: # imgabs0 #, in the formula 1, R1 and R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3 and CCH3CH3CH3; and X1, X2, X3, X4, X5, X6, X7 and X8 are independently selected from H, F, Cl, Br and I. The invention discloses a dioxazine compound, a preparation method and application, the dioxazine compound prepared by the method has good solubility, the dispersity of pigment is greatly improved, and the pigmentation process is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly to a dioxazine compound, a preparation method and an application thereof. Background Art

[0002] Compared with toxic heavy metal inorganic pigments, organic pigments are widely favored by the market due to their excellent properties such as bright colors, high chromaticity, and generally non-toxicity. The varieties of organic pigments currently produced include benzimidazolone, azo condensation, quinacridone, perylene series, pyrrolopyrrole dione, and quinophthalone pigments, etc. Copper phthalocyanine has unique optical and electrical properties and can be used as conductive rectifying materials, nonlinear optical materials, light storage materials, laser optical disc materials, and photochromic and photoinduced electron transfer materials, etc. In addition, phthalocyanine blue and its halogen derivatives prepared from copper phthalocyanine have bright colors, strong coloring power, and excellent weather resistance, and are widely used in fields such as plastics, inks, coatings, water-based inks, and fiber coloring, and occupy a very important position in organic pigments.

[0003] When the copper phthalocyanine produced in the prior art is used as an organic pigment, its antioxidant property is not good, and it contains metallic copper, resulting in easy degradation of high polymers.

[0004] Therefore, it is urgent to prepare an organic pigment with good antioxidant property and without metallic copper. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present application provides a dioxazine compound, a preparation method and an application thereof.

[0006] The target product of the present invention is a high-grade organic pigment with a widely used dioxazine chemical structure, mainly used in outdoor high-grade coatings such as vehicles, plastics, engineering plastics, rubbers, and artificial fibers, etc. Its characteristics are non-toxic, high temperature resistant (350 °C), light fastness (grade 8), migration resistance (grade 5), and resistance to various organic solvents (grade 5). Since it does not contain metals that are harmful to polymer materials and is safe and non-toxic, its application range is extremely wide.

[0007] In a first aspect, the present application provides a dioxazine compound, adopting the following technical solution:

[0008] A dioxazine compound has a structure shown in Formula 1:

[0009]

[0010] Wherein, R1 and R2 independently are selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0011] X1, X2, X3, X4, X5, X6, X7, X8 are independently selected from H, F, Cl, Br, and I.

[0012] In a second aspect, the present application provides a method for preparing a dioxazine compound, adopting the following technical solution:

[0013] A method for preparing a dioxazine compound, the synthetic process route of the preparation method is as follows:

[0014]

[0015]

[0016] Among them, R is independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0017] X is independently selected from H, F, Cl, Br, I;

[0018] R1, R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0019] X1, X2, X3, X4, X5, X6, X7, X8 are independently selected from H, F, Cl, Br, I.

[0020] Preferably, the specific steps of the preparation method are as follows:

[0021] (1) Dissolve carbazole in a solvent, add haloalkanes, and react under the action of a phase transfer catalyst to obtain N-alkylcarbazole;

[0022] (2) Dissolve N-alkylcarbazole in a solvent, add nitric acid and react to obtain 3-nitro-N-alkylcarbazole;

[0023] (3) Dissolve 3-nitro-N-alkylcarbazole in a solvent, and react with hydrogen under the action of a catalyst to obtain 3-amino-N-alkylcarbazole;

[0024] (4) Under alkaline conditions, react 3-amino-N-alkylcarbazole with tetrachlorobenzoquinone to form 2,5-dichloro-3,6-bis(9-alkyl-3-imino-carbazolyl)-1,4-benzoquinone, add a cyclizing agent and react to obtain a precipitate;

[0025] (5) Dissolve the precipitate in a solvent, react with a halogen under the action of a catalyst, and then separate to obtain the dioxazine compound shown in Formula 1.

[0026] Preferably, in the step (1), the haloalkane is chloroethane, bromoethane or iodoethane.

[0027] Preferably, in the step (1), the phase transfer catalyst is benzyl-N-triethylammonium chloride.

[0028] Preferably, in the step (1), the reaction temperature is 60°C - 150°C.

[0029] Preferably, in the step (1), the solvent used is a 40% by mass sodium hydroxide solution.

[0030] Preferably, in the step (1), the molar ratio of carbazole to haloalkane is 1:(1 - 2); the phase transfer catalyst is 1 - 2% of the total mass of carbazole and haloalkane.

[0031] Preferably, in the step (2), the reaction temperature is 25°C - 50°C.

[0032] Preferably, in the step (2), the solvent used is chlorobenzene.

[0033] Preferably, in the step (2), the molar ratio of N-alkylcarbazole to nitric acid is 1:(1 - 2).

[0034] Preferably, in the step (3), the reaction temperature is 100°C - 150°C and the reaction pressure is 0.1 MPa - 10 MPa.

[0035] Preferably, in the step (3), the solvent used is o-dichlorobenzene.

[0036] Preferably, in the step (3), the catalyst is an active nickel catalyst.

[0037] Preferably, in the step (3), the catalyst is 1 - 3% of the mass of 3-nitro-N-alkylcarbazole; the molar ratio of 3-nitro-N-alkylcarbazole to hydrogen is 1:(2 - 3).

[0038] Preferably, in the step (4), the cyclizing agent is benzenesulfonyl chloride; the base used in the step (4) is triethylamine.

[0039] Preferably, in the step (4), the temperature for the reaction with the cyclizing agent is 150°C - 180°C and the reaction time is 3 - 10 hours.

[0040] Preferably, in the step (4), the temperature for the reaction of 3-amino-N-alkylcarbazole with tetrachlorobenzoquinone is 30°C - 100°C.

[0041] Preferably, in the step (4), the molar ratio of 3-amino-N-alkylcarbazole, chloranil and base is (1.6 - 1.8):1:(2 - 2.1).

[0042] Preferably, in the step (4), the mass ratio of 2,5-dichloro-3,6-bis(9-alkyl-3-imino-carbazolyl)-1,4-benzoquinone to the ring-closing agent is 2:1.

[0043] Preferably, in the step (5), the solvent used is at least one of chlorosulfonic acid, aluminum trichloride or sodium chloride; the catalyst is anhydrous ferric trichloride or anhydrous aluminum trichloride; the halogen is chlorine, liquid bromine or iodine.

[0044] Preferably, in the step (5), the mass ratio of the precipitate, the catalyst and the halogen is (50 - 60):5:(7 - 95).

[0045] In a third aspect, the present application provides the use of a dioxazine compound in the preparation of a pigment, adopting the following technical solution:

[0046] The use of the above dioxazine compound or the dioxazine compound prepared by the above method in the process of preparing a pigment.

[0047] In a specific feasible embodiment, a preparation method of a dioxazine compound, the synthetic process route of the preparation method is as follows:

[0048] (1) Dissolve carbazole in a solvent (40% by mass sodium hydroxide solution), add haloalkanes (chloroethane, bromoethane or iodoethane), and under the action of a phase transfer catalyst (benzyl-N-triethylammonium chloride), generate the corresponding N-alkylcarbazole, and then obtain the pure product N-alkylcarbazole through separation;

[0049]

[0050] Wherein, R independently selects from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0051] X independently selects from H, F, Cl, Br, I.

[0052] (2) React N-alkylcarbazole with nitric acid in a solvent (chlorobenzene) to generate the corresponding 3-nitro-N-alkylcarbazole, and then obtain the pure product 3-nitro-N-alkylcarbazole through separation.

[0053]

[0054] Among them, R is independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0055] (3) 3-Nitro-N-alkylcarbazole reacts with hydrogen in a solvent (o-dichlorobenzene) under the action of a catalyst (active nickel catalyst) to form 3-amino-N-alkylcarbazole.

[0056]

[0057] Among them, R is independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0058] (4) Under alkaline conditions (triethylamine), 3-amino-N-alkylcarbazole reacts with tetrachlorobenzoquinone to form 2,5-dichloro-3,6-bis(9-alkyl-3-imino-carbazolyl)-1,4-benzoquinone. Adding a cyclizing agent (benzenesulfonyl chloride) and reacting at 150 - 180 °C for 3 - 10 hours to form a blue or purple precipitate (hereinafter referred to as the precipitate).

[0059]

[0060] Among them, R is independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0061] R1 and R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3.

[0062] (5) The precipitate is dissolved in a solvent (at least one of chlorosulfonic acid, aluminum trichloride or sodium chloride), and reacts with a halogen (chlorine gas, liquid bromine or iodine) under the action of a catalyst (anhydrous ferric trichloride or anhydrous aluminum trichloride), and after separation, the dioxazine compound shown in Formula 1 is obtained.

[0063]

[0064] Among them, R1 and R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3;

[0065] X1, X2, X3, X4, X5, X6, X7, X8 are independently selected from H, F, Cl, Br, I.

[0066] The crude pigment is subjected to a series of pigmentation processes (ball milling or kneading) to obtain an organic pigment with pigment function.

[0067] In summary, the present application includes at least one of the following beneficial technical effects:

[0068] The present application discloses a dioxazine compound, a preparation method and an application. The dioxazine compound prepared by the method of the present application has good solubility, greatly improves the dispersibility of the pigment, and simplifies the pigmentation process;

[0069] The dioxazine compound prepared by the method of the present application does not contain metals that are harmful to polymer materials, is safe and non-toxic, and has a wide range of applications;

[0070] The preparation method provided by the present application has a simple process, is easy to operate, and is easy to promote. Detailed Embodiments

[0071] The technical solutions of the present application are further described below through specific embodiments. The specific embodiments do not represent a limitation on the protection scope of the present application; some non-essential modifications and adjustments made by others based on the concept of the present application still fall within the protection scope of the present application.

[0072] All raw materials involved in the present application are commercially available products. The present application is further described in detail below in conjunction with examples and comparative examples.

[0073] Example 1:

[0074] 1. Preparation of N-ethylcarbazole:

[0075] In a 1000 ml three-necked flask equipped with a stirrer, a thermometer and a condenser, 300 g of a 40% sodium hydroxide aqueous solution by mass concentration, 100 g of carbazole with a calculated purity of 100%, 3 g of benzyl-N-triethylammonium chloride, and 140 g of chloroethane were added in sequence. The temperature was raised to 120 °C with stirring, and stirring was continued for 3 hours. The reaction was terminated by sampling and analyzing by liquid chromatography when the carbazole residue ≤ 1‰ (if > 1‰, continue the reaction). The unreacted chloroethane was distilled off, stirring was stopped, and the mixture was allowed to stand for 2 hours for stratification. The upper clear liquid (N-ethylcarbazole) was taken out to obtain about 110 g of the product.

[0076] 2. Preparation of 3-nitro-N-ethylcarbazole:

[0077] In a 1000-milliliter three-necked flask equipped with a thermometer and a stirrer, 100 grams of N-ethylcarbazole and 200 grams of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 grams of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt-ice bath, kept stirring at a low speed for 2 hours, filtered while maintaining the temperature, 50 milliliters of chlorobenzene at 0 °C was used to wash the material in the three-necked flask into the filter cake, the filter cake was washed with 500 milliliters of an aqueous solution at 30 °C containing 1% by mass of Nekal BX, and the filter cake was washed with pure water until pH ≥ 6. The filter cake was removed and dried at 70 °C to obtain 99.1 grams of the product (3-nitro-N-ethylcarbazole).

[0078] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0079] In a 1000-milliliter autoclave, 100 grams of 3-nitro-N-ethylcarbazole, 500 grams of o-dichlorobenzene, and 2 grams of Raney nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. It was heated to 150 °C, and hydrogen was introduced simultaneously. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen flow rate was controlled according to the reaction rate throughout the hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C), the pressure was released to atmospheric pressure, and the material was transferred to a 1000-milliliter beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 79.2 grams of 3-amino-N-ethylcarbazole.

[0080] 4. Pigment crude product precipitate:

[0081] In a 3000-milliliter three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 milliliters with o-dichlorobenzene, and the temperature was adjusted to 40 °C. 40 grams of triethylamine was added under stirring, the stirring was stopped, 47 grams of tetrachlorobenzoquinone was quickly added, and the stirring was started at a high speed for the condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach this temperature, it was heated to 70 °C, and the reaction was kept stirring for 120 minutes to obtain 105.1 grams of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0082] The temperature was further raised to 140 °C, 50 grams of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes. The reaction was kept stirring for 300 minutes, cooled to 130 °C, filtered with a Buchner funnel, the three-necked flask and the filter cake were washed with 1000 milliliters of o-dichlorobenzene at 130 °C, the filter cake was washed again with 200 milliliters of o-dichlorobenzene at room temperature, the filter cake was washed again with 200 milliliters of ethanol, and finally the filter cake was washed with 2000 milliliters of pure water, drained, and the filter cake was dried at 100 °C to obtain 100 grams of the pigment crude product precipitate.

[0083] 5. Crude Pigment (Dioxazine Compound):

[0084] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 50°C throughout the process. After that, add 22.3 grams of dry chlorine gas at a rate of 1 gram per hour. After completion, continue stirring for 2 hours. Then, evenly dilute it in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50°C during the whole process, and stir for 2 hours. Filter with a Buchner funnel and wash with water until the sulfate ion in the washing water meets the standard. Dry to obtain 70 grams of dry crude pigment blocks, and then pulverize to obtain the crude pigment.

[0085]

[0086] 6. Preparation of Finished Pigment:

[0087] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to stir and keep warm for 2 hours. Filter, wash with water until the chloride ions are qualified. Take out the filter cake, dry and pulverize to obtain 40 grams of the finished product.

[0088] Example 2:

[0089] 1. Preparation of N - ethylcarbazole:

[0090] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 150 grams of chloroethane. Stir and heat to 120°C, keep stirring and heating for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted chloroethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 111 grams of the product.

[0091] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0092] In a 1000 - milliliter three - necked flask equipped with a thermometer and a stirrer, add 100 grams of N - ethylcarbazole and 200 grams of chlorobenzene successively. Stir and heat up to 60°C. After the N - ethylcarbazole is completely dissolved, add 130 grams of 40% nitric acid by volume dropwise over 120 - 180 minutes. After addition, continue to stir at 30°C for 120 minutes. Cool down to 0 - 5°C with a salt - ice water bath, keep the temperature and stir at a low speed for 2 hours, filter while keeping the temperature, wash the materials in the three - necked flask with 50 milliliters of chlorobenzene at 0°C into the filter cake, wash the filter cake with 500 milliliters of 30°C aqueous solution containing 1% (by mass) Nekal BX, wash the filter cake with pure water until pH≥6, remove the filter cake, and dry it at 70°C to obtain 99.5 grams of the product (3 - nitro - N - ethylcarbazole).

[0093] 3. Preparation of 3 - amino - N - ethylcarbazole o - dichlorobenzene solution:

[0094] In a 1000 - milliliter autoclave, add 100 grams of 3 - nitro - N - ethylcarbazole, 500 grams of o - dichlorobenzene, and 2 grams of active nickel catalyst successively. Seal the autoclave and replace the air with vacuum nitrogen three times. Heat up to 150°C, and at the same time, introduce hydrogen. The maximum pressure in the autoclave is 1.5 MPa. Control the hydrogen flow rate according to the reaction rate during the whole hydrogenation process. After the reaction is completed, cool down to room temperature (25°C), release the pressure to atmospheric pressure, transfer the materials into a 1000 - milliliter beaker to separate the catalyst and water, and obtain a 3 - amino - N - ethylcarbazole o - dichlorobenzene solution containing 83.1 grams of 3 - amino - N - ethylcarbazole.

[0095] 4. Pigment crude precipitate:

[0096] In a 3000 - milliliter three - necked flask equipped with a condenser, a thermometer, and a stirrer, add the 3 - amino - N - ethylcarbazole o - dichlorobenzene solution, adjust the volume to 2000 milliliters with o - dichlorobenzene, adjust the temperature to 40°C, add 40 grams of triethylamine under stirring, stop stirring, quickly add 47 grams of tetrachlorobenzoquinone, start stirring at a high - speed position for condensation reaction. After 5 minutes, the temperature will automatically rise to 65 - 70°C. If it does not reach, heat up to 70°C and keep stirring and reacting for 120 minutes to obtain 106.3 grams of 2,5 - dichloro - 3,6 - bis(9 - ethyl - 3 - iminocarbazolyl) - 1,4 - benzoquinone.

[0097] Continue to heat up to 140°C, add 50 grams of benzenesulfonyl chloride, heat up to the reflux state (175 - 180°C) within 10 minutes, keep stirring and reacting for 300 minutes, cool down to 130°C, filter with a Buchner funnel, wash the three - necked flask and the filter cake with 1000 milliliters of o - dichlorobenzene at 130°C, then wash the filter cake with 200 milliliters of o - dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water, drain, dry the filter cake at 100°C to obtain 102.6 grams of pigment crude precipitate.

[0098] 5. Crude Pigment (Dioxazine Compound):

[0099] Into a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 60°C throughout the process. After that, add 44.6 grams of dry chlorine gas at a rate of 2 grams per hour. After completion, continue stirring for 2 hours. Then, evenly dilute it in 5000 milliliters of ice water within 30 minutes, with the temperature not exceeding 50°C during the whole process, and stir for 2 hours. Filter with a Buchner funnel and wash with water until the sulfate ions in the washing water meet the standard. Dry to obtain 81 grams of dry crude pigment blocks, and crush them to get the crude pigment.

[0100]

[0101] 6. Preparation of Finished Pigment:

[0102] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours in total. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to stir and keep warm for 2 hours. Filter, wash with water until the chloride ions are qualified. Take out the filter cake, dry and crush it to obtain 40 grams of the finished product.

[0103] Example 3:

[0104] 1. Preparation of N - ethylcarbazole:

[0105] Into a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, sequentially add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 150 grams of bromoethane. While stirring, heat up to 120°C and keep stirring for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 105.2 grams of the product.

[0106] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0107] In a 1000-milliliter three-necked flask equipped with a thermometer and a stirrer, add 100 grams of N-ethylcarbazole and 200 grams of chlorobenzene successively. Stir and heat up to 60 °C. After the N-ethylcarbazole is completely dissolved, add 130 grams of 40% nitric acid by volume dropwise over 120 - 180 minutes. After addition, continue to stir and keep warm at 30 °C for 120 minutes. Cool down to 0 - 5 °C with a salt-ice water bath, keep warm and stir at low speed for 2 hours, filter while keeping warm. Wash the materials in the three-necked flask with 50 milliliters of chlorobenzene at 0 °C into the filter cake. Wash the filter cake with 500 milliliters of an aqueous solution at 30 °C containing 1% by mass of Nekal BX. Wash the filter cake with pure water until pH ≥ 6. Remove the filter cake and dry it at 70 °C to obtain 99.3 grams of the product (3-nitro-N-ethylcarbazole).

[0108] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0109] In a 1000-milliliter autoclave, add 100 grams of 3-nitro-N-ethylcarbazole, 500 grams of o-dichlorobenzene, and 2 grams of active nickel catalyst successively. Seal the autoclave and replace the air with vacuum nitrogen three times. Heat up to 150 °C and simultaneously introduce hydrogen. The maximum pressure in the autoclave is 1.5 MPa. Control the hydrogen rate according to the reaction rate throughout the hydrogenation process. After the reaction is completed, cool down to room temperature (25 °C) and release the pressure to atmospheric pressure. Transfer the materials into a 1000-milliliter beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 82.1 grams of 3-amino-N-ethylcarbazole.

[0110] 4. Pigment crude precipitate:

[0111] In a 3000-milliliter three-necked flask equipped with a condenser, a thermometer, and a stirrer, add the 3-amino-N-ethylcarbazole o-dichlorobenzene solution. Adjust the volume to 2000 milliliters with o-dichlorobenzene and adjust the temperature to 40 °C. Add 40 grams of triethylamine under stirring, stop stirring, quickly add 47 grams of tetrachlorobenzoquinone, start stirring at a high speed position for condensation reaction. After 5 minutes, the temperature will automatically rise to 65 - 70 °C. If it does not reach, heat up to 70 °C and keep stirring and reacting for 120 minutes to obtain 107.3 grams of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0112] Continue to heat up to 140 °C, add 50 grams of benzenesulfonyl chloride, heat up to the reflux state (175 - 180 °C) within 10 minutes, keep stirring and reacting for 300 minutes, cool down to 130 °C, filter with a Buchner funnel, wash the three-necked flask and the filter cake with 1000 milliliters of o-dichlorobenzene at 130 °C, then wash the filter cake with 200 milliliters of o-dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water. Drain, dry the filter cake at 100 °C to obtain 108.6 grams of pigment crude precipitate.

[0113] 5. Crude Pigment (Dioxazine Compound):

[0114] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 45°C throughout the process. After that, add 47.4 grams of dry bromine dropwise at a rate of 3 grams per hour. After completion, continue stirring for 2 hours. Then, evenly dilute it in 5000 milliliters of ice water within 30 minutes, with the temperature not exceeding 50°C during the whole process. Stir for 2 hours, filter with a Buchner funnel, wash until the sulfate ion in the wash water meets the standard, and dry to obtain 82.6 grams of dry crude pigment cake. Crush it to get the crude pigment.

[0115]

[0116] 6. Preparation of Finished Pigment:

[0117] In a 2 - liter kneader, add 440 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue stirring and keeping warm for 2 hours. Filter, wash until the chloride ions are qualified. Take out the filter cake, dry and crush it to obtain 40 grams of the finished product.

[0118] Example 4:

[0119] 1. Preparation of N - ethylcarbazole:

[0120] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 135 grams of bromoethane. Stir and heat to 120°C, keep stirring and heating for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 105.3 grams of the product.

[0121] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0122] In a 1000 - milliliter three - necked flask equipped with a thermometer and a stirrer, 100 grams of N - ethylcarbazole and 200 grams of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N - ethylcarbazole was completely dissolved, 130 grams of 40% nitric acid by volume concentration was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt - ice water bath, kept stirring at a low speed for 2 hours, then filtered while keeping warm. The material in the three - necked flask was washed with 50 milliliters of chlorobenzene at 0 °C into the filter cake. The filter cake was washed with 500 milliliters of an aqueous solution at 30 °C containing 1% by mass of Nekal BX, and then washed with pure water until pH≥6. The filter cake was taken off and dried at 70 °C to obtain 99.2 grams of the product (3 - nitro - N - ethylcarbazole).

[0123] 3. Preparation of 3 - amino - N - ethylcarbazole o - dichlorobenzene solution:

[0124] In a 1000 - milliliter autoclave, 100 grams of 3 - nitro - N - ethylcarbazole, 500 grams of o - dichlorobenzene, and 2 grams of active nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. It was heated to 150 °C, and at the same time, hydrogen was introduced. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen flow rate was controlled according to the reaction rate during the whole hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C), and the pressure was released to atmospheric pressure. The material was transferred into a 1000 - milliliter beaker to separate the catalyst and water, obtaining a 3 - amino - N - ethylcarbazole o - dichlorobenzene solution containing 81.4 grams of 3 - amino - N - ethylcarbazole.

[0125] 4. Crude pigment precipitate:

[0126] In a 3000 - milliliter three - necked flask equipped with a condenser, a thermometer, and a stirrer, the 3 - amino - N - ethylcarbazole o - dichlorobenzene solution was added. The volume was adjusted to 2000 milliliters with o - dichlorobenzene, and the temperature was adjusted to 40 °C. 40 grams of triethylamine was added under stirring, then the stirring was stopped, and 47 grams of tetrachlorobenzoquinone was quickly added. The stirring was started at a high - speed position for condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach, it was heated to 70 °C and kept stirring and reacting for 120 minutes to obtain 107.2 grams of 2,5 - dichloro - 3,6 - bis(9 - ethyl - 3 - iminocarbazolyl) - 1,4 - benzoquinone.

[0127] Continue to heat to 140 °C, add 50 grams of benzenesulfonyl chloride, heat to the reflux state (175 - 180 °C) within 10 minutes, keep stirring and reacting for 300 minutes, then cool to 130 °C. Filter with a Buchner funnel, wash the three - necked flask and the filter cake with 1000 milliliters of o - dichlorobenzene at 130 °C, then wash the filter cake with 200 milliliters of o - dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water. Filter it dry, and dry the filter cake at 100 °C to obtain 110.4 grams of the crude pigment precipitate.

[0128] 5. Crude Pigment (Dioxazine Compound):

[0129] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 60°C throughout the process. After that, add 94.8 grams of dry bromine dropwise at a rate of 3 grams per hour, and continue stirring for 2 hours after the addition. Dilute it evenly in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50°C throughout the process, and stir for 2 hours. Filter with a Buchner funnel and wash with water until the sulfate ion in the wash water meets the standard. Dry to obtain 106 grams of dry crude pigment cake, and then pulverize to obtain the crude pigment.

[0130]

[0131] 6. Preparation of the Finished Pigment:

[0132] In a 2 - liter kneader, add 40 grams of the crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and keep stirring for 2 hours. Filter, wash with water until the chloride ions are qualified. Take out the filter cake, dry and pulverize to obtain 40 grams of the finished product.

[0133] Example 5:

[0134] 1. Preparation of N - ethylcarbazole:

[0135] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a calculated purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 155 grams of chloroethane. Stir and heat to 120°C, keep stirring for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted chloroethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 106.8 grams of the product.

[0136] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0137] In a 1000 - milliliter three - necked flask equipped with a thermometer and a stirrer, add 100 grams of N - ethylcarbazole and 200 grams of chlorobenzene successively. Stir and heat up to 60 °C. After N - ethylcarbazole is completely dissolved, add 130 grams of 40% nitric acid by volume dropwise over 120 - 180 minutes. After addition, continue to stir at 30 °C for 120 minutes. Cool down to 0 - 5 °C with a salt - ice bath, keep warm and stir at low speed for 2 hours, then filter while keeping warm. Wash the materials in the three - necked flask with 50 milliliters of chlorobenzene at 0 °C into the filter cake. Wash the filter cake with 500 milliliters of 30 °C aqueous solution containing 1% (by mass) Nekal BX. Wash the filter cake with pure water until pH ≥ 6. Remove the filter cake and dry it at 70 °C to obtain 99 grams of the product (3 - nitro - N - ethylcarbazole).

[0138] 3. Preparation of 3 - amino - N - ethylcarbazole o - dichlorobenzene solution:

[0139] In a 1000 - milliliter autoclave, add 100 grams of 3 - nitro - N - ethylcarbazole, 500 grams of o - dichlorobenzene, and 2 grams of active nickel catalyst successively. Seal the autoclave and replace the air with vacuum nitrogen three times. Heat up to 150 °C and simultaneously introduce hydrogen. The maximum pressure in the autoclave is 1.5 MPa. Control the hydrogen flow rate according to the reaction rate during the whole hydrogenation process. After the reaction is completed, cool down to room temperature (25 °C) and release the pressure to atmospheric pressure. Transfer the materials into a 1000 - milliliter beaker to separate the catalyst and water, obtaining a 3 - amino - N - ethylcarbazole o - dichlorobenzene solution containing 80.1 grams of 3 - amino - N - ethylcarbazole.

[0140] 4. Pigment crude product precipitate:

[0141] In a 3000 - milliliter three - necked flask equipped with a condenser, a thermometer, and a stirrer, add the 3 - amino - N - ethylcarbazole o - dichlorobenzene solution. Adjust the volume to 2000 milliliters with o - dichlorobenzene and adjust the temperature to 40 °C. Add 40 grams of triethylamine under stirring, stop stirring, quickly add 47 grams of tetrachlorobenzoquinone, start stirring at a high - speed position for condensation reaction. After 5 minutes, the temperature will automatically rise to 65 - 70 °C. If it does not reach, heat up to 70 °C and keep warm and stir for 120 minutes to obtain 101.9 grams of 2,5 - dichloro - 3,6 - bis(9 - ethyl - 3 - iminocarbazolyl) - 1,4 - benzoquinone.

[0142] Continue to heat up to 140 °C, add 50 grams of benzenesulfonyl chloride, heat up to the reflux state (175 - 180 °C) within 10 minutes, keep warm and stir for 300 minutes, cool down to 130 °C, filter with a Buchner funnel, wash the three - necked flask and the filter cake with 1000 milliliters of o - dichlorobenzene at 130 °C, then wash the filter cake with 200 milliliters of o - dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water. Filter dry, and dry the filter cake at 100 °C to obtain 105.8 grams of the pigment crude product precipitate.

[0143] 5. Crude Pigment (Dioxazine Compound):

[0144] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours. The temperature throughout this process should not exceed 40°C. After that, add 14.9 grams of dry chlorine gas at a rate of 2 grams per hour. After completion, continue stirring for 2 hours and then evenly dilute it in 5000 milliliters of ice - water within 30 minutes. The temperature throughout this process should not exceed 50°C, and stir for 2 hours. Filter with a Buchner funnel and wash with water until the sulfate ion in the wash water meets the standard. Dry to obtain 66 grams of dry crude pigment cake, and crush it to get the crude pigment.

[0145]

[0146] 6. Preparation of Finished Pigment:

[0147] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue stirring and keeping warm for 2 hours. Filter, wash with water until the chloride ions are qualified. Take out the filter cake, dry and crush it to obtain 40 grams of finished product.

[0148] Example 6:

[0149] 1. Preparation of N - ethylcarbazole:

[0150] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, sequentially add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 160 grams of chloroethane. While stirring, heat up to 120°C and keep stirring for 3 hours. Take a sample for liquid chromatography analysis. When the carbazole residue ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted chloroethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 109.5 grams of product.

[0151] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0152] In a 1000-milliliter three-necked flask equipped with a thermometer and a stirrer, 100 grams of N-ethylcarbazole and 200 grams of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 grams of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt-ice bath, kept stirring at a low speed for 2 hours, filtered while maintaining the temperature, and the material in the three-necked flask was washed with 50 milliliters of chlorobenzene at 0 °C into the filter cake. The filter cake was washed with 500 milliliters of an aqueous solution at 30 °C containing 1% by mass of Nekal BX, and then washed with pure water until the pH ≥ 6. The filter cake was removed and dried at 70 °C to obtain 99.8 grams of the product (3-nitro-N-ethylcarbazole).

[0153] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0154] In a 1000-milliliter autoclave, 100 grams of 3-nitro-N-ethylcarbazole, 500 grams of o-dichlorobenzene, and 2 grams of Raney nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. It was heated to 150 °C, and hydrogen was introduced simultaneously. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen flow rate was controlled according to the reaction rate throughout the hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C), the pressure was released to atmospheric pressure, and the material was transferred to a 1000-milliliter beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 82.4 grams of 3-amino-N-ethylcarbazole.

[0155] 4. Pigment crude product precipitate:

[0156] In a 3000-milliliter three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 milliliters with o-dichlorobenzene, and the temperature was adjusted to 40 °C. 40 grams of triethylamine was added with stirring, and then the stirring was stopped. 47 grams of tetrachlorobenzoquinone was quickly added, and the stirring was started at a high speed for the condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach this temperature, it was heated to 70 °C and kept stirring for 120 minutes to obtain 104.3 grams of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0157] The temperature was further raised to 140 °C, 50 grams of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes and kept stirring for 300 minutes. Then it was cooled to 130 °C and filtered with a Buchner funnel. The three-necked flask and the filter cake were washed with 1000 milliliters of o-dichlorobenzene at 130 °C, then the filter cake was washed with 200 milliliters of o-dichlorobenzene at room temperature, washed again with 200 milliliters of ethanol, and finally washed with 2000 milliliters of pure water. After suction drying, the filter cake was dried at 100 °C to obtain 108.9 grams of the pigment crude product precipitate.

[0158] 5. Crude Pigment (Dioxazine Compound):

[0159] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours. The temperature throughout this process should not exceed 30°C. After that, add 7.5 grams of dry chlorine gas at a rate of 1 gram per hour. After completion, continue stirring for 2 hours and then evenly dilute it in 5000 milliliters of ice - water within 30 minutes. The temperature throughout this process should not exceed 50°C. Stir for 2 hours, filter with a Buchner funnel, wash with water until the sulfate ion in the wash water meets the standard, and then dry to obtain 62 grams of dry crude pigment blocks. Crush them to get the crude pigment.

[0160]

[0161] 6. Preparation of the Finished Pigment:

[0162] In a 2 - liter kneader, add 40 grams of the crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for a total of 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to stir while maintaining the temperature for 2 hours. Filter, wash with water until the chloride ions are qualified, take out the filter cake, dry, and crush to obtain 40 grams of the finished product.

[0163] Example 7:

[0164] 1. Preparation of N - ethylcarbazole:

[0165] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of a 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 140 grams of bromoethane. While stirring, heat up to 120°C and keep stirring for 3 hours. Take a sample for liquid chromatography analysis. When the carbazole residue ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 108.1 grams of the product.

[0166] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0167] In a 1000-milliliter three-necked flask equipped with a thermometer and a stirrer, 100 grams of N-ethylcarbazole and 200 grams of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 grams of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt-ice bath, kept stirring at a low speed for 2 hours, filtered while maintaining the temperature, and the material in the three-necked flask was washed with 50 milliliters of chlorobenzene at 0 °C into the filter cake. The filter cake was washed with 500 milliliters of an aqueous solution at 30 °C containing 1% by mass of Nekal BX, and then washed with pure water until the pH ≥ 6. The filter cake was removed and dried at 70 °C to obtain 99.7 grams of the product (3-nitro-N-ethylcarbazole).

[0168] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0169] In a 1000-milliliter autoclave, 100 grams of 3-nitro-N-ethylcarbazole, 500 grams of o-dichlorobenzene, and 2 grams of active nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. It was heated to 150 °C, and hydrogen was introduced simultaneously. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen rate was controlled according to the reaction rate throughout the hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C), and the pressure was released to atmospheric pressure. The material was transferred to a 1000-milliliter beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 80.6 grams of 3-amino-N-ethylcarbazole.

[0170] 4. Pigment crude product precipitate:

[0171] In a 3000-milliliter three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 milliliters with o-dichlorobenzene, and the temperature was adjusted to 40 °C. 40 grams of triethylamine was added under stirring, and then the stirring was stopped. 47 grams of tetrachlorobenzoquinone was quickly added, and the stirring was started at a high speed for the condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach this temperature, it was heated to 70 °C, and the reaction was kept stirring for 120 minutes to obtain 103.9 grams of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0172] The temperature was further raised to 140 °C, 50 grams of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes. The reaction was kept stirring for 300 minutes, then cooled to 130 °C, filtered with a Buchner funnel, and the three-necked flask and the filter cake were washed with 1000 milliliters of o-dichlorobenzene at 130 °C, then the filter cake was washed with 200 milliliters of o-dichlorobenzene at room temperature, washed again with 200 milliliters of ethanol, and finally washed with 2000 milliliters of pure water. After suction drying, the filter cake was dried at 100 °C to obtain 108.6 grams of the pigment crude product precipitate.

[0173] 5. Crude Pigment (Dioxazine Compound):

[0174] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 30°C throughout the process. After that, add 15.8 grams of dry bromine dropwise at a rate of 3 grams per hour. After completion, continue stirring for 2 hours, and then evenly dilute it in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50°C during the whole process. Stir for 2 hours, filter with a Buchner funnel, wash until the sulfate ion in the washing water meets the standard, and dry to obtain 66 grams of crude pigment dry cake. Crush it to get the crude pigment.

[0175]

[0176] 6. Preparation of Finished Pigment:

[0177] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue stirring for 2 hours while keeping warm. Filter, wash until the chloride ions are qualified. Take out the filter cake, dry, and crush to obtain 40 grams of the finished product.

[0178] Example 8:

[0179] 1. Preparation of N - ethylcarbazole:

[0180] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a calculated purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 155 grams of bromoethane. Stir and heat to 120°C, keep stirring for 3 hours, and take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 107.6 grams of the product.

[0181] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0182] In a 1000 mL three-necked flask equipped with a thermometer and a stirrer, 100 g of N-ethylcarbazole and 200 g of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 g of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, stirring was continued at 30 °C for 120 minutes. The temperature was lowered to 0 - 5 °C using a salt-ice bath, and low-speed stirring was maintained for 2 hours. Filtration was carried out while maintaining the temperature, and the material in the three-necked flask was washed with 50 mL of chlorobenzene at 0 °C into the filter cake. The filter cake was washed with 500 mL of an aqueous solution at 30 °C containing 1% by mass of Nekal BX. The filter cake was washed with pure water until pH ≥ 6. The filter cake was removed and dried at 70 °C to obtain 100.1 g of the product (3-nitro-N-ethylcarbazole).

[0183] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0184] In a 1000 mL autoclave, 100 g of 3-nitro-N-ethylcarbazole, 500 g of o-dichlorobenzene, and 2 g of active nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. The temperature was raised to 150 °C, and hydrogen was simultaneously introduced. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen rate was controlled according to the reaction rate throughout the hydrogenation. After the reaction ended, the temperature was lowered to room temperature (25 °C), and the pressure was released to atmospheric pressure. The material was transferred to a 1000 mL beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 80.8 g of 3-amino-N-ethylcarbazole.

[0185] 4. Pigment crude product precipitate:

[0186] In a 3000 mL three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 mL with o-dichlorobenzene, and the temperature was adjusted to 40 °C. 40 g of triethylamine was added under stirring, and then the stirring was stopped. 47 g of tetrachlorobenzoquinone was quickly added, and the stirring was started at a high speed for condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach, it was heated to 70 °C, and stirring was maintained for 120 minutes to obtain 105.5 g of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0187] The temperature was further raised to 140 °C, 50 g of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes. Stirring was maintained for 300 minutes, and then the temperature was lowered to 130 °C. Filtration was carried out using a Buchner funnel. The three-necked flask and the filter cake were washed with 1000 mL of o-dichlorobenzene at 130 °C, then the filter cake was washed with 200 mL of o-dichlorobenzene at room temperature, and the filter cake was washed again with 200 mL of ethanol, and finally the filter cake was washed with 2000 mL of pure water. After suction drying, the filter cake was dried at 100 °C to obtain 110.8 g of the pigment crude product precipitate.

[0188] 5. Crude Pigment (Dioxazine Compound):

[0189] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 40°C throughout the process. After that, add 31.6 grams of dry bromine dropwise at a rate of 3 grams per hour. After completion, continue stirring for 2 hours. Then, evenly dilute it in 5000 milliliters of ice water within 30 minutes, with the temperature not exceeding 50°C during the whole process, and stir for 2 hours. Filter with a Buchner funnel, wash with water until the sulfate ion in the wash water meets the standard, dry to obtain 74 grams of dry crude pigment blocks, and crush them to get the crude pigment.

[0190]

[0191] 6. Preparation of Finished Pigment:

[0192] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to stir and keep warm for 2 hours. Filter, wash with water until the chloride ions are qualified; take out the filter cake, dry and crush it to obtain 40 grams of the finished product.

[0193] Example 9:

[0194] 1. Preparation of N - ethylcarbazole:

[0195] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 160 grams of bromoethane. Stir and heat to 120°C, keep warm and stir for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 110.5 grams of the product.

[0196] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0197] In a 1000 - milliliter three - necked flask equipped with a thermometer and a stirrer, add 100 grams of N - ethylcarbazole and 200 grams of chlorobenzene successively. Stir and heat up to 60 °C. After the N - ethylcarbazole is completely dissolved, add 130 grams of 40% nitric acid by volume dropwise over 120 - 180 minutes. After addition, continue to stir and keep warm at 30 °C for 120 minutes. Cool down to 0 - 5 °C with a salt - ice water bath, keep warm and stir at low speed for 2 hours, then filter while keeping warm. Wash the materials in the three - necked flask with 50 milliliters of chlorobenzene at 0 °C into the filter cake. Wash the filter cake with 500 milliliters of 30 °C aqueous solution containing 1% (by mass) Nekal BX. Wash the filter cake with pure water until pH ≥ 6. Remove the filter cake and dry it at 70 °C to obtain 99.1 grams of the product (3 - nitro - N - ethylcarbazole).

[0198] 3. Preparation of 3 - amino - N - ethylcarbazole o - dichlorobenzene solution:

[0199] In a 1000 - milliliter autoclave, add 100 grams of 3 - nitro - N - ethylcarbazole, 500 grams of o - dichlorobenzene, and 2 grams of active nickel catalyst successively. Seal the autoclave and replace the air with vacuum nitrogen three times. Heat up to 150 °C and simultaneously introduce hydrogen. The maximum pressure in the autoclave is 1.5 MPa. Control the hydrogen flow rate according to the reaction rate during the whole hydrogenation process. After the reaction is completed, cool down to room temperature (25 °C) and release the pressure to atmospheric pressure. Transfer the materials into a 1000 - milliliter beaker to separate the catalyst and water, obtaining a 3 - amino - N - ethylcarbazole o - dichlorobenzene solution containing 78.6 grams of 3 - amino - N - ethylcarbazole.

[0200] 4. Crude pigment precipitate:

[0201] In a 3000 - milliliter three - necked flask equipped with a condenser, a thermometer, and a stirrer, add the 3 - amino - N - ethylcarbazole o - dichlorobenzene solution. Adjust the volume to 2000 milliliters with o - dichlorobenzene and adjust the temperature to 40 °C. Add 40 grams of triethylamine under stirring, stop stirring, quickly add 47 grams of tetrachlorobenzoquinone, start stirring at a high - speed position for condensation reaction. After 5 minutes, the temperature will automatically rise to 65 - 70 °C. If it does not reach, heat up to 70 °C and keep stirring and reacting for 120 minutes to obtain 102.5 grams of 2,5 - dichloro - 3,6 - bis(9 - ethyl - 3 - iminocarbazolyl) - 1,4 - benzoquinone.

[0202] Continue to heat up to 140 °C, add 50 grams of benzenesulfonyl chloride, heat up to the reflux state (175 - 180 °C) within 10 minutes, keep stirring and reacting for 300 minutes, cool down to 130 °C, filter with a Buchner funnel, wash the three - necked flask and the filter cake with 1000 milliliters of o - dichlorobenzene at 130 °C, then wash the filter cake with 200 milliliters of o - dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water. Drain, dry the filter cake at 100 °C to obtain 105.1 grams of the crude pigment precipitate.

[0203] 5. Crude Pigment (Dioxazine Compound):

[0204] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 40°C throughout the process. After that, add 15.8 grams of dry bromine at a rate of 3 grams per hour, and then pass in 7.1 grams of dry chlorine at a rate of 1 gram per hour. After completion, continue stirring for 2 hours, and then evenly dilute it in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50°C throughout the process. Stir for 2 hours, filter with a Buchner funnel, and wash with water until the sulfate ion in the washing water meets the standard. Dry to obtain 70 grams of crude pigment dry cake; pulverize to obtain the crude pigment.

[0205]

[0206] 6. Preparation of Finished Pigment:

[0207] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours in total; take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to stir and keep warm for 2 hours. Filter, wash with water until the chloride ions are qualified; take out the filter cake, dry and pulverize to obtain 40 grams of the finished product.

[0208] Example 10:

[0209] 1. Preparation of N - ethylcarbazole:

[0210] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 165 grams of bromoethane. Stir and heat to 120°C, keep warm and stir for 3 hours. Take a sample for liquid chromatography analysis. When the residual carbazole ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for layer separation for 2 hours. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 110.1 grams of the product.

[0211] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0212] In a 1000 mL three-necked flask equipped with a thermometer and a stirrer, 100 g of N-ethylcarbazole and 200 g of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 g of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt-ice bath and kept stirring at low speed for 2 hours, then filtered while maintaining the temperature. The material in the three-necked flask was washed with 50 mL of chlorobenzene at 0 °C into the filter cake, and the filter cake was washed with 500 mL of an aqueous solution at 30 °C containing 1% by mass of Nekal BX. The filter cake was washed with pure water until pH ≥ 6. The filter cake was removed and dried at 70 °C to obtain 99.4 g of the product (3-nitro-N-ethylcarbazole).

[0213] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0214] In a 1000 mL autoclave, 100 g of 3-nitro-N-ethylcarbazole, 500 g of o-dichlorobenzene, and 2 g of Raney nickel catalyst were successively added. The autoclave was closed and purged with vacuum nitrogen three times. It was heated to 150 °C while hydrogen was introduced. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen flow rate was controlled according to the reaction rate throughout the hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C) and the pressure was released to atmospheric pressure. The material was transferred to a 1000 mL beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 80.5 g of 3-amino-N-ethylcarbazole.

[0215] 4. Crude pigment precipitate:

[0216] In a 3000 mL three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 mL with o-dichlorobenzene and the temperature was adjusted to 40 °C. 40 g of triethylamine was added under stirring, then the stirring was stopped, and 47 g of tetrachlorobenzoquinone was quickly added. The stirring was started at a high speed for the condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach this temperature, it was heated to 70 °C and kept stirring and reacting for 120 minutes to obtain 104.8 g of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0217] The temperature was further raised to 140 °C, 50 g of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes. It was kept stirring and reacting for 300 minutes, then cooled to 130 °C and filtered with a Buchner funnel. The three-necked flask and the filter cake were washed with 1000 mL of o-dichlorobenzene at 130 °C, then the filter cake was washed with 200 mL of o-dichlorobenzene at room temperature, washed again with 200 mL of ethanol, and finally washed with 2000 mL of pure water. After suction drying, the filter cake was dried at 100 °C to obtain 109.3 g of the crude pigment precipitate.

[0218] 5. Crude Pigment (Dioxazine Compound):

[0219] In a 500 - milliliter three - necked flask, add 500 grams of chlorosulfonic acid with a purity of 99%. While stirring, evenly add 58.9 grams of the crude pigment precipitate within 30 minutes. Then add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 40°C throughout the process. After that, add 15.8 grams of dry bromine dropwise at a rate of 3 grams per hour, adjust the temperature to 50°C, and pass in 14.2 grams of dry chlorine at a rate of 2 grams per hour. After completion, continue stirring for 2 hours. Then, evenly dilute it in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50°C throughout the process, and stir for 2 hours. Filter with a Buchner funnel, wash with water until the sulfate ion in the wash water meets the standard, dry, to obtain 73 grams of dry crude pigment cake, and crush it to get the crude pigment.

[0220]

[0221] 6. Preparation of Finished Pigment:

[0222] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and keep stirring for 2 hours. Filter, wash with water until the chloride ions are qualified. Take out the filter cake, dry, and crush to obtain 40 grams of the finished product.

[0223] Example 11:

[0224] 1. Preparation of N - ethylcarbazole:

[0225] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a calculated purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 155 grams of chloroethane. Stir and heat to 120°C, keep stirring for 3 hours. Take a sample for liquid chromatography analysis. When the carbazole residue ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted chloroethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 107.8 grams of the product.

[0226] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0227] In a 1000 mL three-necked flask equipped with a thermometer and a stirrer, 100 g of N-ethylcarbazole and 200 g of chlorobenzene were successively added. The mixture was stirred and heated to 60 °C. After the N-ethylcarbazole was completely dissolved, 130 g of 40% nitric acid by volume was added dropwise over 120 - 180 minutes. After addition, the mixture was kept stirring at 30 °C for 120 minutes. It was cooled to 0 - 5 °C in a salt-ice bath, kept stirring at a low speed for 2 hours, filtered while keeping warm, and the material in the three-necked flask was washed with 50 mL of chlorobenzene at 0 °C into the filter cake. The filter cake was washed with 500 mL of an aqueous solution at 30 °C containing 1% by mass of Nekal BX, and then washed with pure water until pH≥6. The filter cake was removed and dried at 70 °C to obtain 99.2 g of the product (3-nitro-N-ethylcarbazole).

[0228] 3. Preparation of 3-amino-N-ethylcarbazole o-dichlorobenzene solution:

[0229] In a 1000 mL autoclave, 100 g of 3-nitro-N-ethylcarbazole, 500 g of o-dichlorobenzene, and 2 g of Raney nickel catalyst were successively added. The autoclave was sealed and purged with vacuum nitrogen three times. It was heated to 150 °C while hydrogen was introduced simultaneously. The maximum pressure in the autoclave was 1.5 MPa, and the hydrogen flow rate was controlled according to the reaction rate throughout the hydrogenation process. After the reaction ended, it was cooled to room temperature (25 °C), and the pressure was released to atmospheric pressure. The material was transferred to a 1000 mL beaker to separate the catalyst and water, obtaining a 3-amino-N-ethylcarbazole o-dichlorobenzene solution containing 81.7 g of 3-amino-N-ethylcarbazole.

[0230] 4. Pigment crude precipitate:

[0231] In a 3000 mL three-necked flask equipped with a condenser, a thermometer, and a stirrer, the 3-amino-N-ethylcarbazole o-dichlorobenzene solution was added, and the volume was adjusted to 2000 mL with o-dichlorobenzene, and the temperature was adjusted to 40 °C. 40 g of triethylamine was added under stirring, and then the stirring was stopped. 47 g of tetrachlorobenzoquinone was quickly added, and the stirring was started at a high speed for the condensation reaction. After 5 minutes, the temperature would automatically rise to 65 - 70 °C. If it did not reach this temperature, it was heated to 70 °C, and the reaction was kept stirring for 120 minutes to obtain 105.6 g of 2,5-dichloro-3,6-bis(9-ethyl-3-imino-carbazolyl)-1,4-benzoquinone.

[0232] The temperature was further raised to 140 °C, 50 g of benzenesulfonyl chloride was added, and the temperature was raised to the reflux state (175 - 180 °C) within 10 minutes. The reaction was kept stirring for 300 minutes, then cooled to 130 °C, filtered with a Buchner funnel, and the three-necked flask and the filter cake were washed with 1000 mL of o-dichlorobenzene at 130 °C, then the filter cake was washed with 200 mL of o-dichlorobenzene at room temperature, washed again with 200 mL of ethanol, and finally washed with 2000 mL of pure water. After suction drying, the filter cake was dried at 100 °C to obtain 108.4 g of the pigment crude precipitate.

[0233] 5. Crude Pigment (Dioxazine Compound):

[0234] In a 500 - milliliter three - necked flask, add 462 grams of anhydrous aluminum trichloride with a purity of 99% and 100 grams of sodium chloride. Stir and heat to 180 °C to form a molten salt. Uniformly add 58.9 grams of the crude pigment precipitate within 30 minutes, add 5 grams of anhydrous ferric chloride, and continue stirring for 2 hours, with the temperature not exceeding 180 °C throughout the process. Then add 22.3 grams of dry chlorine gas at a rate of 1 gram per hour. After completion, continue stirring for 2 hours, and uniformly dilute it in 5000 milliliters of ice - water within 30 minutes, with the temperature not exceeding 50 °C throughout the process. Stir for 2 hours, filter with a Buchner funnel, wash with water until the chloride ions in the washing water meet the standard, dry, and obtain 70 grams of crude pigment dry cake. Crush it to obtain the crude pigment.

[0235]

[0236] 6. Preparation of Finished Pigment:

[0237] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. At a temperature of 100 °C, knead for a total of 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90 °C and continue to stir and keep warm for 2 hours. Filter, wash with water until the chloride ions are qualified, take out the filter cake, dry, and crush to obtain 40 grams of the finished product.

[0238] Example 12:

[0239] 1. Preparation of N - ethylcarbazole:

[0240] In a 1000 - milliliter three - necked flask equipped with a stirrer, thermometer, and condenser, successively add 300 grams of 40% sodium hydroxide aqueous solution by mass concentration, 100 grams of carbazole with a converted purity of 100%, 3 grams of benzyl - N - triethylammonium chloride, and 170 grams of bromoethane. Stir and heat to 120 °C, keep warm and stir for 3 hours. Take a sample for liquid chromatography analysis. When the carbazole residue ≤ 1‰, end the reaction (if > 1‰, continue the reaction). Distill out the unreacted bromoethane, stop stirring, keep warm, and let it stand for 2 hours to separate layers. Take out the upper clear liquid (N - ethylcarbazole) to obtain about 108.7 grams of the product.

[0241] 2. Preparation of 3 - nitro - N - ethylcarbazole:

[0242] In a 1000 - milliliter three - necked flask equipped with a thermometer and a stirrer, add 100 grams of N - ethylcarbazole and 200 grams of chlorobenzene successively. Stir and heat up to 60 °C. After the N - ethylcarbazole is completely dissolved, add 130 grams of 40% nitric acid by volume dropwise over 120 - 180 minutes. After adding, continue to stir and keep warm at 30 °C for 120 minutes. Cool down to 0 - 5 °C with a salt - ice water bath, keep warm and stir at low speed for 2 hours, then filter while keeping warm. Wash the materials in the three - necked flask with 50 milliliters of chlorobenzene at 0 °C into the filter cake. Wash the filter cake with 500 milliliters of an aqueous solution at 30 °C containing 1% (by mass) of Nekal BX. Wash the filter cake with pure water until pH ≥ 6. Remove the filter cake and dry it at 70 °C to obtain 101.4 grams of the product (3 - nitro - N - ethylcarbazole).

[0243] 3. Preparation of 3 - amino - N - ethylcarbazole o - dichlorobenzene solution:

[0244] In a 1000 - milliliter autoclave, add 100 grams of 3 - nitro - N - ethylcarbazole, 500 grams of o - dichlorobenzene, and 2 grams of active nickel catalyst successively. Seal the autoclave and replace the air with vacuum nitrogen three times. Heat up to 150 °C, and at the same time, introduce hydrogen. The maximum pressure in the autoclave is 1.5 MPa. Control the hydrogen flow rate according to the reaction rate during the whole hydrogenation process. After the reaction is completed, cool down to room temperature (25 °C), release the pressure to atmospheric pressure, transfer the materials into a 1000 - milliliter beaker to separate the catalyst and water, and obtain a 3 - amino - N - ethylcarbazole o - dichlorobenzene solution containing 80.8 grams of 3 - amino - N - ethylcarbazole.

[0245] 4. Crude pigment precipitate:

[0246] In a 3000 - milliliter three - necked flask equipped with a condenser, a thermometer, and a stirrer, add the 3 - amino - N - ethylcarbazole o - dichlorobenzene solution, adjust the volume to 2000 milliliters with o - dichlorobenzene, and adjust the temperature to 40 °C. Add 40 grams of triethylamine under stirring, stop stirring, quickly add 47 grams of tetrachlorobenzoquinone, start stirring at a high - speed position for condensation reaction. After 5 minutes, the temperature will automatically rise to 65 - 70 °C. If it does not reach, heat up to 70 °C and keep stirring and reacting for 120 minutes to obtain 106.3 grams of 2,5 - dichloro - 3,6 - bis(9 - ethyl - 3 - iminocarbazolyl) - 1,4 - benzoquinone.

[0247] Continue to heat up to 140 °C, add 50 grams of benzenesulfonyl chloride, heat up to the reflux state (175 - 180 °C) within 10 minutes, keep stirring and reacting for 300 minutes, cool down to 130 °C, filter with a Buchner funnel, wash the three - necked flask and the filter cake with 1000 milliliters of o - dichlorobenzene at 130 °C, then wash the filter cake with 200 milliliters of o - dichlorobenzene at room temperature, wash the filter cake with 200 milliliters of ethanol again, and finally wash the filter cake with 2000 milliliters of pure water. Drain, dry the filter cake at 100 °C to obtain 109.7 grams of the crude pigment precipitate.

[0248] 5. Crude Pigment (Dioxazine Compound):

[0249] Implement in a 500 - milliliter three - necked flask. Add 462 grams of anhydrous aluminum trichloride with a purity of 99% and 100 grams of sodium chloride. Stir and heat up to 180°C to form a molten salt. Uniformly add 58.9 grams of the crude pigment precipitate within 30 minutes. Add 5 grams of anhydrous ferric chloride and continue stirring for 2 hours, with the temperature not exceeding 180°C throughout the process. Then add 15.8 grams of dry bromine at a rate of 3 grams per hour, and then pass in 14.2 grams of dry chlorine at a rate of 2 grams per hour. After completion, continue stirring for 2 hours. Dilute it uniformly in 5000 milliliters of ice water within 30 minutes, with the temperature not exceeding 50°C throughout the process, and stir for 2 hours. Filter with a Buchner funnel and wash with water until the chloride ions in the wash water meet the standard; dry to obtain 73 grams of crude pigment dry cake; pulverize to obtain the crude pigment.

[0250]

[0251] 6. Preparation of Finished Pigment:

[0252] In a 2 - liter kneader, add 40 grams of crude pigment, 400 grams of 325 - mesh fine salt, and 80 grams of diethylene glycol. Keep the temperature at 100°C and knead for a total of 10 hours. Take out the kneaded paste and add it to 4000 milliliters of water. Stir until there are no lumps, then heat to 80 - 90°C and continue to keep warm and stir for 2 hours. Filter and wash with water until the chloride ions are qualified. Take out the filter cake, dry and pulverize to obtain 40 grams of the finished product.

[0253] Application Example:

[0254] Polycarbonate plastic itself has oxidizing properties, and the phthalocyanine pigment used as a colorant fades during the processing of polycarbonate plastic.

[0255] When the phthalocyanine pigment is used as a colorant for polyethylene plastic, the polyethylene plastic products show powdering after being placed for half a year.

[0256] When the products prepared in Examples 1 - 12 are used as colorants during the processing of polycarbonate plastic, no fading phenomenon will occur.

[0257] When the products prepared in Examples 1 - 12 are used as colorants for polyethylene plastic, the polyethylene plastic products will not show powdering after being placed for half a year.

[0258] The high - grade organic pigment with a dioxazine chemical structure prepared in this application is mainly used in outdoor high - grade coatings such as for vehicles, plastics, engineering plastics, rubber, and artificial fibers, etc. Its characteristics are non - toxic, high - temperature resistant (300°C), light fastness (grade 8), migration resistance (grade 5), and solvent resistance (grade 5). Since it does not contain metals that are destructive to polymer materials and is safe and non - toxic, its application range is extremely wide.

Claims

1. A dioxazine compound, characterized in that, It has the structure shown in Formula 1: Among them, R1 and R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3; X1, X2, X3, X4, X5, X6, X7, X8 are independently selected from H, F, Cl, Br, I.

2. A method for preparing the dioxazine compound according to claim 1, characterized in that, The synthetic process route of the preparation method is as follows: Among them, R is independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3; X is independently selected from H, F, Cl, Br, I; R1 and R2 are independently selected from H, CH3, C2H5, CH2CH2CH3, CH3CHCH3, CH2CH2CH2CH3, CH3CH2CHCH3, CCH3CH3CH3; X1, X2, X3, X4, X5, X6, X7, X8 are independently selected from H, F, Cl, Br, I.

3. The preparation method according to claim 2, characterized in that, The specific steps of the preparation method are as follows: (1) Dissolve carbazole in a solvent, add haloalkanes, and react under the action of a phase transfer catalyst to obtain N-alkylcarbazole; (2) Dissolve N-alkylcarbazole in a solvent, add nitric acid and react to obtain 3-nitro-N-alkylcarbazole; (3) Dissolve 3-nitro-N-alkylcarbazole in a solvent and react with hydrogen under the action of a catalyst to obtain 3-amino-N-alkylcarbazole; (4) Under alkaline conditions, react 3-amino-N-alkylcarbazole with tetrachlorobenzoquinone to form 2,5-dichloro-3,6-bis(9-alkyl-3-imino-carbazolyl)-1,4-benzoquinone, add a ring-closing agent and react to obtain a precipitate; (5) Dissolve the precipitate in a solvent, react with a halogen under the action of a catalyst, and then separate to obtain the dioxazine compound shown in Formula 1.

4. The preparation method according to claim 3, wherein: The haloalkanes in step (1) are chloroethane, bromoethane or iodoethane; The phase transfer catalyst in step (1) is benzyl-N-triethylammonium chloride; The solvent used in step (1) is a 40% sodium hydroxide solution by mass concentration.

5. The preparation method according to claim 3, wherein: The solvent used in step (2) is chlorobenzene; The solvent used in step (3) is o-dichlorobenzene; The catalyst in step (3) is an active nickel catalyst.

6. The preparation method according to claim 3, wherein: The ring-closing agent in step (4) is benzenesulfonyl chloride; The base used in step (4) is triethylamine.

7. The preparation method according to claim 3, characterized in that: The solvent used in step (5) is at least one of chlorosulfonic acid, aluminum trichloride or sodium chloride; the catalyst is anhydrous ferric trichloride or anhydrous aluminum trichloride; the halogen is chlorine, liquid bromine or iodine.

8. The preparation method according to claim 3, wherein: The reaction temperature in step (1) is 60°C - 150°C; The reaction temperature in step (2) is 25°C - 50°C In step (3), the reaction temperature is 100°C - 150°C, and the reaction pressure is 0.1 MPa - 10 MPa. In step (4), the temperature for the reaction with the ring-closing agent is 150°C - 180°C, and the reaction time is 3 - 10 hours. In step (4), the temperature for the reaction of 3-amino-N-alkylcarbazole with tetrachlorobenzoquinone is 30°C - 100°C.

9. The preparation method according to claim 3, characterized in that: In step (1), the molar ratio of carbazole to haloalkanes is 1∶(1 - 2); the phase transfer catalyst is 1 - 2% of the total mass of carbazole and haloalkanes. In step (2), the molar ratio of N-alkylcarbazole to nitric acid is 1∶(1 - 2). In step (3), the catalyst is 1 - 3% of the mass of 3-nitro-N-alkylcarbazole; the molar ratio of 3-nitro-N-alkylcarbazole to hydrogen is 1∶(2 - 3). In step (4), the molar ratio of 3-amino-N-alkylcarbazole to tetrachlorobenzoquinone and base is (1.6 - 1.8)∶1∶(2 - 2.1). In step (4), the mass ratio of 2,5-dichloro-3,6-bis(9-alkyl-3-imino-carbazolyl)-1,4-benzoquinone to the ring-closing agent is 2∶∶. In step (5), the mass ratio of the precipitate, catalyst, and halogen is (50 - 60)∶5∶(7 - 95).

10. Use of the dioxazine compound according to claim 1 or the dioxazine compound prepared by the method according to any one of claims 2 - 9 in the preparation of pigments.

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