5, 5 '-disubstituted hydroxy-3, 3'-dipyridyl derivative as well as preparation method and application thereof

Abstract

The invention relates to the technical field of chemical synthesis of dyes, and particularly discloses a 5, 5 '-disubstituted hydroxyl-3, 3'-dipyridyl derivative as well as a preparation method and application of the 5, 5 '-disubstituted hydroxyl-3, 3'-dipyridyl derivative. The structure of the 5, 5 '-disubstituted hydroxy-3, 3'-dipyridyl derivative is as shown in a formula (I) in the specification, the 5, 5 '-disubstituted hydroxy-3, 3'-dipyridyl derivative obtained by the preparation method has the advantages of high yield, stable structure, high temperature resistance and higher color development intensity, can be used as a dye to be applied to dyeing of fabrics made of different materials, and has the advantages of safe, simple and energy-saving preparation process, stable product quality and good reproducibility.

Description

Technical Field

[0001] The present application relates to the technical field of dye chemical synthesis, and in particular, to a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, a preparation method thereof, and an application thereof. Background Art

[0002] Indigoidine, also known as indigo blue, is a substance with a bicyclic structure formed by the condensation of two glutamine molecules under the action of indigoidine synthase. Indigoidine is a stable and brightly colored natural pigment with a variety of excellent properties and is widely used in fields such as cosmetics, textile printing and dyeing, and the medical industry.

[0003] However, indigoidine itself can only provide one color, which obviously cannot meet the market demand for natural pigments. At the same time, the amino group in the indigoidine structure is not conducive to the solubility of the dye. Therefore, a large amount of water or organic solvents are required during use, resulting in a large environmental pollution and being difficult to degrade, which is not sufficient to meet the requirements of green development. Therefore, appropriate modification of the indigoidine structure to synthesize new dyes can not only produce rich colors but also improve the use performance of the dyes. Summary of the Invention

[0004] The purpose of the present application is to overcome the deficiencies of the above-mentioned prior art and provide a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, a preparation method thereof, and an application thereof. The present application synthesizes a new dye, a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which has bright colors, deep dyeing, and good fastness after dyeing. In addition, the preparation method of the dye uses indigoidine as a raw material, is simple to prepare, convenient to purify, safe, simple, and energy-saving during the preparation process, and the product has stable quality, good reproducibility, and high yield, making it suitable for industrial production.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0006] The present application provides a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, and the structure of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative is shown in formula (I);

[0007]

[0008] Wherein,

[0009] A1 and A2 are independently selected from one of C, S, and P;

[0010] R1 and R2 are independently selected from C2-C20 alkyl, substituted C2-C20 alkyl, C2-C20 alkenyl, substituted C2-C20 alkenyl, C2-C20 alkynyl, substituted C2-C20 alkynyl, C3-C20 cycloalkyl, substituted C3-C20 cycloalkyl, C5-C20 aryl, substituted C5-C20 aryl, and heterocycles with or without substitution;

[0011] The heterocycles include one of furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthraquinone, anthraquinone;

[0012] n and m are independently selected from 0, 1 or 2;

[0013] w and q are independently selected from 0 or 1.

[0014] Guanlan is a natural blue pigment obtained by microbial fermentation and belongs to pyridine heterocyclic reduction dyes. Through a large number of studies and experiments, the inventors of this application modified guanlan as the parent body, introduced different derivative structures, and obtained the novel bipyridine dyes (5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives) of this application. The 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives have high chromogenic intensity. After dyeing, the color is bright, the dyeing is deep and the fastness is comprehensive, the solubility is good, and the performance is excellent.

[0015] As a preferred embodiment of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in this application, A1 and A2 are independently selected from C or S;

[0016] R1 and R2 are independently selected from C2-C18 alkyl, substituted C2-C18 alkyl, C2-C18 alkenyl, substituted C2-C18 alkenyl, C2-C18 alkynyl, substituted C2-C18 alkynyl, C3-C18 cycloalkyl, substituted C3-C18 cycloalkyl, C5-C18 aryl, substituted C5-C18 aryl, and heterocycles with or without substitution;

[0017] The heterocycles include one of furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthraquinone, anthraquinone.

[0018] In the technical solution of this application, by preferably selecting A1, A2, R1, and R2 of the above structural types, the obtained 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives have higher chromogenic intensity, the color after dyeing is more vivid, the dyeing is deep and the fastness is comprehensive, the solubility is better, and the performance is better.

[0019] As a preferred embodiment of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, the halogenated C2-C20 alkyl group is a straight-chain or branched-chain alkyl group, and part or all of the hydrogen atoms on the alkyl group are substituted by halogen atoms;

[0020] The substituted or unsubstituted heterocyclic ring includes furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthraquinone, anthraquinone, and the substituent is one of halogen, C1-C3 alkyl, and halogenated C1-C3 alkyl on the aromatic ring or heterocyclic ring.

[0021] Preferably, the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives include the following structures:

[0022]

[0023] The present application also provides a preparation method of the above-mentioned 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, and the preparation method includes the following steps:

[0024] S1. Grind the indigo and disperse it in an acid solution for reaction to obtain an acidified product, filter and dry it, and then add it to an organic solvent to obtain a solution of the acidified product;

[0025] S2. Add a derivatizing reagent to the solution of the acidified product, then add an acid-binding agent and a catalyst, and react until there is no acidified product, which is determined as the end point of the reaction, to obtain a reaction solution;

[0026] S3. Add the reaction solution obtained in step S2 to deionized water, cool and stir to carry out purification treatment;

[0027] S4. Carry out solid-liquid separation on the reaction solution after purification treatment, and dry it to obtain 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives.

[0028] The reaction formula of the preparation method of the above-mentioned 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives is as follows:

[0029]

[0030] In the first step of the preparation method of the above-mentioned 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, the amino group in the raw material undergoes hydrolysis in an acid solution to generate a hydroxyl group, and then the hydroxyl group undergoes alkylation or acylation to obtain the target product.

[0031] In the technical solution of this application, the preparation method of the novel bipyridine dye (5,5'-disubstituted hydroxy-3,3'-bipyridine derivative) of this application uses indigo carmine as a raw material, which is simple to prepare, convenient to purify, safe, simple and energy-saving in the preparation process, with stable product quality, good reproducibility and high yield, and is suitable for industrial production.

[0032] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative described in this application, in the step S1, the acid solution is 30-80% sulfuric acid solution or 5-38% hydrochloric acid solution.

[0033] Preferably, in the step S1, the mass ratio of indigo carmine to the acid solution is (3-10):1.

[0034] This application adds an acid solution to convert the amino group into a hydroxyl group; this application uses the above-mentioned types of inorganic acids, which are cheap, safe, convenient to use, and can also be recycled.

[0035] Moreover, when indigo carmine and the acid solution adopt the above mass ratio, it has the advantages of fast reaction, sufficient stirring, high dispersibility, high yield, etc.

[0036] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative described in this application, the derivatizing reagent includes the following structures containing halogen or acyl halide groups: C2-C20 alkyl, substituted C2-C20 alkyl, C2-C20 alkenyl, substituted C2-C20 alkenyl, C2-C20 alkynyl, substituted C2-C20 alkynyl, C3-C20 cycloalkyl, substituted C3-C20 cycloalkyl, C5-C20 aryl, substituted C5-C20 aryl, and substituted or unsubstituted heterocycles containing halogen or acyl halide groups: furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthraquinone, anthraquinone; the substituents of the heterocycle are one of halogen, C1-C3 alkyl, and halogenated C1-C3 alkyl.

[0037] This application uses indigo carmine as a parent for modification, and by selecting the above types of derivatizing reagents, 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives with high chromogenic intensity, comprehensive dyeing fastness, good solubility and excellent performance can be obtained.

[0038] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative described in this application, the organic solvent includes one of dichloromethane, dichloroethane, chloroform, n-butane, n-hexane, n-pentane, tetrahydrofuran, carbon tetrachloride, dimethylformamide, and dimethylacetamide; preferably, the organic solvent includes one of tetrahydrofuran, carbon tetrachloride, dimethylformamide, and dimethylacetamide.

[0039] Using the above types of organic solvents is beneficial for the solid to fully combine with other reactants and accelerate the reaction rate.

[0040] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, the acid-binding agent includes at least one of triethylamine, triethylenediamine, dimethylamine, trimethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine, sodium tert-butoxide, potassium tert-butoxide, and n-butyllithium; preferably, the acid-binding agent includes at least one of triethylamine, trimethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine, sodium tert-butoxide, and potassium tert-butoxide.

[0041] Using the above types of acid-binding agents in the present application can more effectively promote the completion of the reaction, improve the efficiency, and also reduce the harm of by-products to the reaction equipment.

[0042] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, the molar ratio of the indigo, the derivative reagent, and the acid-binding agent is 1:(1.2 - 2.2):(1.2 - 2.2).

[0043] Using the above molar ratios of indigo, the derivative reagent, and the acid-binding agent in the present application can not only make the reaction proceed rapidly, stably, and with a high yield, but also avoid waste of materials caused by excess and the influence of by-products.

[0044] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, in step S2, the reaction temperature is 40 - 120 °C, and the reaction time is 1 - 24 h.

[0045] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, in step S3, the mass ratio of deionized water to the reaction solution is (3 - 5):1, and the temperature is controlled at 0 - 25 °C.

[0046] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, in step S4, the drying temperature is 50 - 80 °C.

[0047] In step S4, the solid-liquid separation includes using suction filtration or centrifugation methods.

[0048] As a preferred embodiment of the preparation method of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives described in the present application, the catalyst is a Lewis acid, preferably, the catalyst includes one of boron trifluoride, aluminum trichloride, iron trichloride, boron tribromide, aluminum tribromide, and iron tribromide;

[0049] The addition amount of the catalyst is 0.1% - 5% of the mass of indigo.

[0050] The present application also provides an application of the above 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives in fabric dyeing, and the fabric includes at least one of cotton, linen, wool, mulberry silk, regenerated fiber and chemical fiber.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] The present application provides a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, a preparation method and an application thereof. The present application uses indigo as a parent body for modification, introduces different derivative structures, and obtains a novel class of bipyridine dyes (5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives) shown in formula (I) of the present application. It has high color strength, good all-round dyeing fastness, good solubility and excellent performance. Moreover, the preparation method provided by the present application has continuous process steps, strong controllability, large throughput, and is suitable for large-scale industrial production. Description of the Drawings

[0053] Figure 1 It is the structural diagram of target product 1;

[0054] Figure 2 It is the structural diagram of target product 2;

[0055] Figure 3 It is the structural diagram of target product 3;

[0056] Figure 4 It is the structural diagram of target product 4;

[0057] Figure 5 It is the structural diagram of target product 5;

[0058] Figure 6 It is the structural diagram of target product 6;

[0059] Figure 7 It is the structural diagram of target product 7;

[0060] Figure 8 It is the structural diagram of target product 8;

[0061] Figure 9 It is the structural diagram of target product 9;

[0062] Figure 10 It is the structural diagram of target product 10;

[0063] Figure 11 It is the structural diagram of target product 11;

[0064] Figure 12 Structural diagram of target product 12;

[0065] Figure 13 Structural diagram of target product 13;

[0066] Figure 14 Structural diagram of target product 14;

[0067] Figure 15 Structural diagram of target product 15;

[0068] Figure 16 Structural diagram of target product 16;

[0069] Figure 17 Structural diagram of target product 17;

[0070] Figure 18 Structural diagram of target product 18;

[0071] Figure 19 Structural diagram of target product 19;

[0072] Figure 20 Structural diagram of target product 20.

[0073] Figure 21 Structural diagram of target product 21;

[0074] Figure 22 Structural diagram of target product 22;

[0075] Figure 23 Structural diagram of target product 23. Specific implementation manners

[0076] To better illustrate the purpose, technical solutions and advantages of the present application, the present application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0077] In the following embodiments, unless otherwise specified, the experimental methods used are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels, and the component raw materials used in each parallel experiment are all of the same kind.

[0078] The cyan blue used in the following embodiments is provided by Nanjing Hegu Life Biotechnology Co., Ltd. Structure identification of the target product: The synthesized product is sent to the Analysis and Testing Center of Nanjing Normal University for detection.

[0079] Example 1. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0080] This example provides a preparation method of a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, comprising the following steps:

[0081] 15 g of indigo was ground and dispersed in 80% sulfuric acid solution, and reacted at 100 °C for 7 h; after the reaction was completed, centrifugation was carried out, and the filter cake was dried in an oven at 60 °C. Then, diethyl sulfate and tetrahydrofuran were added to the suspension, and tetramethylethylenediamine was added (the molar ratio of indigo:diethyl sulfate:tetramethylethylenediamine was 1:2.2:2.2). Ferric chloride was added as a catalyst, and the addition amount was 0.8% of the mass of indigo. The reaction was carried out at 100 °C for 10 h; 5 times of deionized water was added to the obtained reaction solution to cool and stir, and purification treatment was carried out; centrifugation was carried out, and the filter cake was dried in an oven at 80 °C to obtain the target product 1.

[0082] The structural diagram of the target product 1 is as Figure 1 shown.

[0083] Characterization of the target product 1: HRMS (m / z, %): 307.09 ([M+H] + , 100).

[0084] Example 2. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0085] This example provides a preparation method of a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, including the following steps:

[0086] 20 g of indigo was ground and dispersed in 70% sulfuric acid solution, and reacted at 90 °C for 10 h; after the reaction was completed, centrifugation was carried out, and the filter cake was dried in an oven at 60 °C. Then, 4-chloro-1-butene and dimethylformamide were added to the suspension, and tetramethylethylenediamine was added (the molar ratio of indigo:4-chloro-1-butene:tetramethylethylenediamine was 1:2.2:2.2). Boron trifluoride was added as a catalyst, and the addition amount was 4% of the mass of indigo. The reaction was carried out at 100 °C for 10 h; 5 times of deionized water was added to the obtained reaction solution to cool and stir, and purification treatment was carried out; centrifugation was carried out, and the filter cake was dried in an oven at 80 °C to obtain the target product 2.

[0087] The structural diagram of the target product 2 is as Figure 2 shown.

[0088] Characterization of the target product 2: HRMS (m / z, %): 359.12 ([M+H] + , 100).

[0089] Example 3. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0090] This embodiment provides a preparation method of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0091] Grind 20 g of indigo and disperse it in 60% sulfuric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add 2-bromoheptane and dimethylformamide to the suspension, add tetramethylethylenediamine (the molar ratio of indigo: 2-bromoheptane: tetramethylethylenediamine is 1: 2.2: 2.2), add aluminum trichloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 90 °C for 12 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 3.

[0092] The structural diagram of the target product 3 is as Figure 3 shown.

[0093] Characterization of the target product: 3HRMS (m / z, %): 463.29 ([M+H] + , 100).

[0094] Example 4. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0095] This embodiment provides a preparation method of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0096] Grind 10 g of indigo and disperse it in 80% sulfuric acid solution, and react at 90 °C for 6 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 70 °C, then add 100 g of dimethylformamide to a 500 mL three-necked round-bottom flask for full dispersion, dropwise add bromobenzene and triethylamine (the molar ratio of indigo: bromobenzene: triethylamine is 1: 2.2: 2.2), add aluminum trichloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 100 °C for 10 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 4.

[0097] The structural diagram of the target product 4 is as Figure 4 shown.

[0098] Characterization of the target product: HRMS (m / z, %): 401.12 ([M+H] + , 100).

[0099] Example 5. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0100] This embodiment provides a preparation method of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0101] Grind 25 g of indigo and disperse it in 30% hydrochloric acid solution, and react at 100 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 2-bromopyridine and tetrahydrofuran to the suspension, add triethylamine (the molar ratio of indigo:2-bromopyridine:triethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 1% of the mass of indigo, and react at 100 °C for 18 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 5.

[0102] The structural diagram of the target product 5 is as Figure 5 shown.

[0103] Characterization of the target product 5: HRMS (m / z, %): 405.08 ([M+H] + , 100).

[0104] Example 6. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0105] This embodiment provides a preparation method of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0106] Grind 25 g of indigo and disperse it in 80% sulfuric acid solution, and react at 100 °C for 8 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 4-bromoindole and carbon tetrachloride to the suspension, add triethylamine (the molar ratio of indigo:4-bromoindole:triethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 2% of the mass of indigo, and react at 100 °C for 18 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 6.

[0107] The structural diagram of the target product 6 is as Figure 6 shown.

[0108] Characterization of the target product 6: HRMS (m / z, %): 556.22 ([M+H] + , 100).

[0109] Example 7. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0110] This embodiment provides a method for preparing 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0111] Grind 25 g of indigo and disperse it in 70% sulfuric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 4-chloropiperidine and tetrahydrofuran to the suspension, add triethylamine (the molar ratio of indigo:4-chloropiperidine:triethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, react at 120 °C for 24 h; add 5 times deionized water to the above obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 7 is obtained.

[0112] The structural diagram of the target product 7 is as Figure 7 shown.

[0113] Characterization of the target product 7: HRMS (m / z, %): 417.17 ([M+H] + , 100).

[0114] Example 8. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and a preparation method thereof

[0115] This embodiment provides a method for preparing 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0116] Grind 20 g of indigo and disperse it in 70% sulfuric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 10-undecenoyl chloride and dimethylformamide to the suspension, add triethylamine (the molar ratio of indigo:10-undecenoyl chloride:triethylamine is 1:2.2:2.2), add boron trifluoride as a catalyst, and the addition amount is 3% of the mass of indigo, react at 120 °C for 15 h; add 5 times deionized water to the above obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 8 is obtained.

[0117] The structural diagram of the target product 8 is as Figure 8 shown.

[0118] Characterization of the target product 8: HRMS (m / z, %): 305 ([M+H] + , 100).

[0119] Example 9. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and a preparation method thereof

[0120] This embodiment provides a method for preparing 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0121] Grind 25 g of indigo and disperse it in 70% sulfuric acid solution, and react at 80 °C for 15 h; after the reaction is completed, centrifuge, and dry the filter cake in an oven at 50 °C. Then, add furan carbonyl chloride and carbon tetrachloride to the suspension, add tetramethylethylenediamine (the molar ratio of indigo: furan carbonyl chloride: tetramethylethylenediamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 120 °C for 18 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 9.

[0122] The structural diagram of the target product 9 is as Figure 9 shown.

[0123] Characterization of the target product 9: HRMS (m / z, %): 439.3 ([M+H] + , 100).

[0124] Example 10. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0125] This embodiment provides a method for preparing 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0126] Grind 20 g of indigo and disperse it in 80% sulfuric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, and dry the filter cake in an oven at 50 °C. Then, add cyclopentyl carbonyl chloride and carbon tetrachloride to the suspension, add triethylamine (the molar ratio of indigo: cyclopentyl carbonyl chloride: triethylamine is 1:2.2:2.2), add boron trifluoride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 100 °C for 10 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, and dry the filter cake in an oven at 80 °C to obtain the target product 10.

[0127] The structural diagram of the target product 10 is as Figure 10 shown.

[0128] Characterization of the target product 10: HRMS (m / z, %): 443.14 ([M+H] + , 100).

[0129] Example 11. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0130] This example provides a preparation method for 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0131] Grind 20 g of cyanine blue and disperse it in a 30% hydrochloric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 4-pyrimidinecarbonyl chloride and dimethylacetamide to the suspension, add triethylamine (the molar ratio of cyanine blue: 4-pyrimidinecarbonyl chloride: triethylamine is 1:2.2:2.2), add boron trifluoride as a catalyst, and the addition amount is 0.5% of the mass of cyanine blue, and react at 105 °C for 13 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and perform purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 11 is obtained.

[0132] The structural diagram of the target product 11 is as Figure 11 shown.

[0133] Characterization of the target product 11: HRMS (m / z, %): 463.06 ([M+H] + , 100).

[0134] Example 12. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0135] This example provides a preparation method for 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, comprising the following steps:

[0136] Grind 20 g of cyanine blue and disperse it in an 80% sulfuric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 50 °C, then add 2-naphthoyl chloride and carbon tetrachloride to the suspension, add triethylamine (the molar ratio of cyanine blue: 2-naphthoyl chloride: triethylamine is 1:2.2:2.2), add boron trifluoride as a catalyst, and the addition amount is 2.5% of the mass of cyanine blue, and react at 115 °C for 9 h; add 5 times deionized water to the obtained reaction solution to cool and stir, and perform purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 12 is obtained.

[0137] The structural diagram of the target product 12 is as Figure 12 shown.

[0138] Characterization of the target product 12: HRMS (m / z, %): 559.11 ([M+H] + , 100).

[0139] Example 13. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0140] This example provides a preparation method for 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, including the following steps:

[0141] Grind 20 g of indigo and disperse it in 30% hydrochloric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add 1-butylsulfonyl chloride and DMF to the suspension, add dimethylamine (the molar ratio of indigo: 1-butylsulfonyl chloride: dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 5% of the mass of indigo, react at 130 °C for 10 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and perform purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 13.

[0142] The structural diagram of the target product 13 is as Figure 13 shown.

[0143] Characterization of the target product 13: HRMS (m / z, %): 491.5 ([M+H] + , 100).

[0144] Example 14. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0145] This example provides a preparation method for 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, including the following steps:

[0146] Grind 20 g of indigo and disperse it in 80% sulfuric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add isopropylsulfonyl chloride and dimethylacetamide to the suspension, add dimethylamine (the molar ratio of indigo: isopropylsulfonyl chloride: dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, react at 100 °C for 20 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and perform purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 14.

[0147] The structural diagram of the target product 14 is as Figure 14 shown.

[0148] Characterization of the target product 14: HRMS (m / z, %): 463.04 ([M+H] + , 100).

[0149] Example 15, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0150] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, including the following steps:

[0151] Grind 20 g of indigo and disperse it in 30% hydrochloric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add benzenesulfonyl chloride and DMF to the suspension, add dimethylamine (the molar ratio of indigo:benzenesulfonyl chloride:dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, with an addition amount of 3.5% of the mass of indigo, react at 110 °C for 10 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 15.

[0152] The structural diagram of the target product 15 is as Figure 15 shown.

[0153] Characterization of the target product 15: HRMS (m / z, %): 531.01 ([M + H] + , 100).

[0154] Example 16, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0155] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, including the following steps:

[0156] Grind 20 g of indigo and disperse it in 30% hydrochloric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add 1-naphthalenesulfonyl chloride and DMF to the suspension, add dimethylamine (the molar ratio of indigo:1-naphthalenesulfonyl chloride:dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, with an addition amount of 4.5% of the mass of indigo, react at 100 °C for 10 h; add 5 times deionized water to the above-obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 16.

[0157] The structural diagram of the target product 16 is as Figure 16 shown.

[0158] Characterization of the target product 16: HRMS (m / z, %): 631.04 ([M + H] + , 100).

[0159] Example 17, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0160] This example provides a preparation method of a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, including the following steps:

[0161] Grind 20 g of indigo and disperse it in 80% sulfuric acid solution, react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add 8-quinolinesulfonyl chloride and DMF to the suspension, add dimethylamine (the molar ratio of indigo: 8-quinolinesulfonyl chloride: dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, react at 130 °C for 10 h; add 5 times deionized water to the above obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 17 is obtained.

[0162] The structural diagram of the target product 17 is as Figure 17 shown.

[0163] Characterization of the target product 17: HRMS (m / z, %): 633.03 ([M+H] + , 100).

[0164] Example 18, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0165] This example provides a preparation method of a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, including the following steps:

[0166] Grind 20 g of indigo and disperse it in 80% sulfuric acid solution, react at 100 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add piperidine-1-sulfonyl chloride and DMF to the suspension, add dimethylamine (the molar ratio of indigo: piperidine-1-sulfonyl chloride: dimethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, react at 140 °C for 15 h; add 5 times deionized water to the above obtained reaction solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C, and the target product 18 is obtained.

[0167] The structural diagram of the target product 18 is as Figure 18 shown.

[0168] Characterization of the target product 18: HRMS (m / z, %): 545.09 ([M+H] + , 100).

[0169] Example 19, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0170] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which includes the following steps:

[0171] Grind 20 g of indigo and disperse it in 30% hydrochloric acid solution, and react at 110 °C for 9 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add dicyclohexylphosphoryl chloride and DMF to the suspension, add triethylamine (the molar ratio of indigo: dicyclohexylphosphoryl chloride: triethylamine is 1:2.2:2.2), add ferric chloride as a catalyst, and the addition amount is 1% of the mass of indigo, and react at 100 °C for 8 h; add 5 times deionized water to the obtained reaction product solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 19.

[0172] The structural diagram of the target product 19 is as Figure 19 shown.

[0173] Characterization of the target product 19: HRMS (m / z, %): 675.28 ([M + H] + , 100).

[0174] Example 20, A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0175] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which includes the following steps:

[0176] Grind 20 g of indigo and disperse it in 30% hydrochloric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add dicyclohexylphosphoryl chloride and DMF to the suspension, add triethylamine (the molar ratio of indigo: dicyclohexylphosphoryl chloride: triethylamine is 1:2.2:2.2), add aluminum chloride as a catalyst, and the addition amount is 1% of the mass of indigo, and react at 100 °C for 8 h; add 5 times deionized water to the obtained reaction product solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 20.

[0177] The structural diagram of the target product 20 is as Figure 20 shown.

[0178] Characterization of the target product 20: HRMS (m / z, %): 675.28 ([M + H] + , 100).

[0179] Example 21. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0180] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which includes the following steps:

[0181] Grind 20 g of indigo and disperse it in a 30% hydrochloric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add butyryl chloride and dimethylacetamide to the suspension, add triethylamine (the molar ratio of indigo: butyryl chloride: triethylamine is 1:1.2:2.2), add aluminum trichloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 100 °C for 2 h; then add n-butyl bromide (the molar ratio of indigo: n-butyl bromide is 1:1.2), and react at 100 °C for another 3 h; add 5 times deionized water to the obtained reaction product solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 21.

[0182] The structural diagram of the target product 21 is as Figure 21 shown.

[0183] Characterization of the target product 21: HRMS (m / z, %): 377.13 ([M+H] + , 100).

[0184] Example 22. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0185] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which includes the following steps:

[0186] Grind 20 g of indigo and disperse it in a 30% hydrochloric acid solution, and react at 90 °C for 10 h; after the reaction is completed, centrifuge, dry the filter cake in an oven at 60 °C, then add butylsulfonyl chloride and DMF to the suspension, add triethylamine (the molar ratio of indigo: butylsulfonyl chloride: triethylamine is 1:1.2:2), add boron trifluoride as a catalyst, and the addition amount is 1% of the mass of indigo, and react at 100 °C for 1 h; then add butyryl chloride (the molar ratio of indigo: butyryl chloride is 1:1.2), and react at 100 °C for another 2 h; add 5 times deionized water to the obtained reaction product solution to cool and stir, and carry out purification treatment; centrifuge, dry the filter cake in an oven at 80 °C to obtain the target product 22.

[0187] The structural diagram of the target product 22 is as Figure 22 shown.

[0188] Characterization of the target product 22: HRMS (m / z, %): 427.07 ([M+H] + , 100).

[0189] Example 23. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative and its preparation method

[0190] This example provides a preparation method for a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, which includes the following steps:

[0191] Grind 20 g of indigo and disperse it in a 30% hydrochloric acid solution, and react at 90 °C for 10 h; after the reaction is completed, perform centrifugation, dry the filter cake in an oven at 60 °C, then add butylsulfonyl chloride and DMF to the suspension, add triethylamine (the molar ratio of indigo:butylsulfonyl chloride:triethylamine is 1:1.2:2.2), add aluminum trichloride as a catalyst, and the addition amount is 0.5% of the mass of indigo, and react at 90 °C for 1 h; then add bromobutene (the molar ratio of indigo:bromobutene is 1:1.2), and react at 100 °C for another 4 h; add 5 times deionized water to the above-obtained reaction product solution to cool and stir, and perform purification treatment; perform centrifugation, and dry the filter cake in an oven at 80 °C to obtain the target product 23.

[0192] The structural diagram of the target product 23 is as Figure 23 shown.

[0193] Characterization of the target product 23: HRMS (m / z, %): 411.08 ([M+H] + , 100).

[0194] Using reaction conditions similar to those in the above example, only changing the reagents, the prepared derivatives are shown in Table 1.

[0195] Table 1

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254]

[0255]

[0256]

[0257]

[0258]

[0259]

[0260]

[0261] Test Example: Application of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives in dyeing

[0262] Dye the cotton fabric with the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives obtained in the above examples according to the following process:

[0263] 2% (o.w.f) of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives, reduce with 2 times of sodium hydrosulfite, adjust to pH 5 with 0.5 mL / L of citric acid, dye at 25 °C for 10 min, and the bath ratio is 1:30.

[0264] After the dyeing is completed, take out the dyed fabric sample, wash it, dry it, and solve the K / S value of the dye by using the Lambert-Beer law.

[0265] Test the various properties of the dye according to the standards and record the test results in Table 2 below.

[0266]

[0267]

[0268]

[0269] The 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives of Examples 1 to 20 and the above-mentioned 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives with different numbers can dye fabrics of various materials, with their K / S values reaching above 10, the dyeing rate reaching above 80%, and the color fastness to washing, sublimation, acid spot, sunlight, and wet rubbing all reaching Grade 4. Since it is impossible to list all, the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives with the remaining unmentioned numbers also have the above similar dyeing effects and are all within the protection scope of this application.

[0270] Based on the existing cyan, a class of 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives is obtained through chemical synthesis methods in this application. They have stable color, are resistant to temperature under acidic conditions, high temperature and low temperature, and have a very broad application scope and application prospects for industrial production.

[0271] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application rather than to limit the protection scope of this application. Although this application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of this application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of this application.

Claims

1. A 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative, characterized in that: The structure of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative is shown in formula (I); in, A1 and A2 are independently selected from one of C, S and P; R1 and R2 are independently selected from C2-C20 alkyl, substituted C2-C20 alkyl, C2-C20 alkenyl, substituted C2-C20 alkenyl, C2-C20 alkynyl, substituted C2-C20 alkynyl, C3-C20 cycloalkyl, substituted C3-C20 cycloalkyl, C5-C20 aryl, substituted C5-C20 aryl, and substituted or unsubstituted heterocyclic ring; The heterocyclic ring includes one of furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthrenequinone and anthraquinone; n, m are independently selected from 0, 1 or 2; w and q are independently selected from 0 or 1.

2. The 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative according to claim 1, characterized in that: Said A1 and A2 are independently selected from C or S; R1 and R2 are independently selected from C2-C18 alkyl, substituted C2-C18 alkyl, C2-C18 alkenyl, substituted C2-C18 alkenyl, C2-C18 alkynyl, substituted C2-C18 alkynyl, C3-C18 cycloalkyl, substituted C3-C18 cycloalkyl, C5-C18 aryl, substituted C5-C18 aryl, and substituted or unsubstituted heterocyclic ring; The heterocyclic ring includes one of furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthrenequinone and anthraquinone; The substituent is one of halogen, C1-C3 alkyl, and halogenated C1-C3 alkyl on the aromatic ring or heterocyclic ring.

3. The 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative according to claim 1, characterized in that: The 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives include any of the following structures:

4. The method for preparing a 5,5'-disubstituted hydroxy-3,3'-bipyridine derivative according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: S1, grinding the indigo plant and dispersing it in an acid solution to react, obtaining an acidified product, filtering and drying it, and adding it to an organic solvent to obtain a solution of the acidified product; S2, adding a derivatizing agent to the solution of the acidified product, and then adding an acid-binding agent and a catalyst to react until no acidified product is present, which is determined as the reaction endpoint, to obtain a reaction solution; S3, adding deionized water to the reaction solution obtained in step S2, cooling and stirring, and performing purification treatment; S4. The purified reaction solution is subjected to solid-liquid separation and dried to obtain 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives.

5. The preparation method according to claim 4, characterized in that: The derivatizing agent is a halogen or haloformyl-containing structure: C2-C20 alkyl, substituted C2-C20 alkyl, C2-C20 alkenyl, substituted C2-C20 alkenyl, C2-C20 alkynyl, substituted C2-C20 alkynyl, C3-C20 cycloalkyl, substituted C3-C20 cycloalkyl, C5-C20 aryl, substituted C5-C20 aryl, and substituted or unsubstituted heterocyclic ring; The heterocyclic ring includes one of furan, thiophene, pyrrole, thiazole, imidazole, pyridine, piperidine, pyrazine, pyridazine, indole, quinoline, pteridine, acridine, naphthalene, phenanthrene, anthracene, pyrene, naphthoquinone, phenanthrenequinone and anthraquinone; The substituent is one of halogen, C1-C3 alkyl, and halogenated C1-C3 alkyl on the aromatic ring or heterocyclic ring.

6. The preparation method according to claim 4, characterized in that: The organic solvent includes one of dichloromethane, dichloroethane, chloroform, n-butane, n-hexane, n-pentane, tetrahydrofuran, carbon tetrachloride, dimethylformamide and dimethylacetamide.

7. The preparation method according to claim 4, characterized in that: The acid binding agent includes at least one of triethylamine, triethylenediamine, dimethylamine, trimethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine, sodium tert-butoxide, potassium tert-butoxide and n-butyllithium.

8. The preparation method according to claim 4, characterized in that: The molar ratio of the indigo plant color, the derivatization reagent and the acid-binding agent is 1:(1.2-2.2):(1.2-2.2).

9. The preparation method according to claim 4, characterized in that: The catalyst is a Lewis acid, preferably, the catalyst includes one of boron trifluoride, aluminum trichloride, ferric trichloride, boron tribromide, aluminum tribromide, and ferric tribromide; The added amount of the catalyst is 0.1% to 5% of the blue mass.

10. Use of the 5,5'-disubstituted hydroxy-3,3'-bipyridine derivatives according to any one of claims 1 to 3 in fabric dyeing, characterized in that: The fabric comprises at least one of cotton, linen, wool, mulberry silk, regenerated fiber and chemical fiber.

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