Vietnamese blue azo derivative as well as preparation method and application thereof

Abstract

The invention discloses an ornamental blue azo derivative as well as a preparation method and application thereof, and relates to the technical field of dye compounds. According to the observation blue azo derivative provided by the invention, the observation blue mother nucleus is subjected to azo modification, and aryl phenol and / or arylamine are bridged with the observation blue mother nucleus by utilizing azo groups, so that the solubility of leuco acid formed by reduction of observation blue in dye liquor can be improved, the dyeing condition of the observation blue becomes milder, and the dyeing effect is better. The dyeing degree of 95% or above and the fixation rate of 92% or above can be obtained under the alkalescence condition of pH 7-8, the color depth is not lower than 9.2 K / S, and the color depth is remarkably superior to that of parent blue.

Description

Technical Field

[0001] This invention relates to the field of dye compound technology, specifically to a blue azo derivative, its preparation method, and its application. Background Technology

[0002] In recent years, with the increasing demand for natural pigments and the development of synthetic biology technology, indigoidine, as a sustainable natural blue pigment, has received widespread attention. However, as a typical vat dye, indigoidine usually needs to be reduced to its leuco form in an environment with pH ≥ 10 to achieve stability and good affinity for fabric fibers. Strongly alkaline environments can easily cause irreversible damage to fabric fibers. Improving the molecular structure can enhance the affinity of dye molecules for fibers. For example, existing technology CN109021614B discloses the introduction of conjugated azo groups into copper phthalocyanine molecules, which can significantly improve the affinity of copper phthalocyanine dyes for cellulose fibers, resulting in a class of reactive dyes with a fixation rate close to 100%. Therefore, it is urgent to improve the molecular structure of indigoidine and develop an indigoidine derivative with higher affinity for fabric fibers and the ability to achieve good dyeing under milder conditions. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a blue azo derivative, its preparation method, and its application.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: A blue azo derivative has the structure shown in formula (I): Formula (I); Furthermore, equation (I) can undergo the following tautomerism: R1 and R2 are each independently selected from either arylphenols or arylamines.

[0005] Indigo dye, a typical vat dye, typically requires reduction to its leuco form under pH ≥ 10 conditions before oxidation to achieve good dyeing results. The inventors of this application accidentally discovered in experiments that azotizing the indigo dye core, using azo groups to bridge arylphenols and / or arylamines to the core, can improve the solubility of the leuco acid formed during indigo reduction in the dye bath, making the dyeing conditions milder and improving the dye uptake and fixation rates of the fabric. Azo dyes in the art are usually disperse dyes, insoluble in water, and the azo groups easily decompose to form amino groups under the action of reducing agents, making conventional vat dyeing methods unsuitable. However, in this application, the azo structure can be stably linked to the indigo dye core and can synergistically maintain the stability of the leuco form under the alkaline conditions of vat dyeing. The presumed reason is that lanthanum has the structural characteristics of pyridinide, and during reduction, a base needs to be added to convert the keto structure into an enol structure in order to achieve good solubility. However, the intrinsic stability of the enol structure is not as good as that of the keto structure, which limits the transformation of the lanthanum core from the keto to the enol form. This results in the need to add a large amount of base to promote the improvement of the water solubility of lanthanum. In this application, the keto-enol tautomer of the lanthanum core and the azo-hydrazone tautomer of the azo structure can be coupled, which reduces the possibility of the azo structure breaking and decomposing into amino groups. At the same time, the leuco acid of lanthanum can also exist stably under weak alkaline conditions, which improves the water solubility of the dye and is conducive to improving the dyeing effect such as dyeing rate, fixation rate and color depth under milder conditions.

[0006] Preferably, R1 and R2 are each independently selected from any one of the following formulas: , , , , , .

[0007] More preferably, R1 and R2 are each independently selected from any one of the following formulas: , , , , , .

[0008] The azo derivatives containing the above-mentioned substituents exhibit higher selectivity during synthesis, which is beneficial for further industrial applications.

[0009] More preferably, the blue azo derivative has the structure shown in the following formula: , , , , , .

[0010] This invention also protects a method for preparing a blue azo derivative, comprising the following steps: S1. Under acidic solution conditions, cobalt blue and nitrite are mixed and reacted to obtain an intermediate; S2. Under alkaline solution conditions, the intermediate obtained in step S1 is mixed with the derivatizing reagent and reacted to obtain the blue azo derivative; the derivatizing reagent is arylphenol and / or arylamine.

[0011] Preferably, the nitrite in step S1 includes sodium nitrite.

[0012] Preferably, the temperature of the reaction in step S1 is 0-5°C.

[0013] In a specific embodiment of the present invention, the temperature of the reaction in step S1 is adjusted to 0-5°C by means of an ice-water bath.

[0014] Preferably, the pH of the acidic solution in step S1 is ≤3.

[0015] More preferably, the pH of the acidic solution in step S1 is 1-3.

[0016] More preferably, the acidic solution in step S1 comprises an aqueous solution of an inorganic acid with a concentration of 5-10 wt%, wherein the aqueous solution of the inorganic acid comprises at least one of an aqueous solution of hydrochloric acid and an aqueous solution of sulfuric acid.

[0017] In a specific embodiment of the present invention, the nitrite in step S1 is provided in the form of an aqueous nitrite solution. More specifically, step S1 involves: dispersing blue pigment in an acidic solution, adding the aqueous nitrite solution dropwise, and reacting. More specifically, the dropwise addition is slow. More specifically, the aqueous nitrite solution is prepared by dissolving nitrite in ice water. More specifically, the mass concentration of nitrite in the aqueous nitrite solution is 150-250 g / L.

[0018] Preferably, the molar ratio of coumarin to nitrite in step S1 is 1:(2-2.1). The molar ratio of coumarin to nitrite refers to the molar ratio of coumarin to nitrite in the aqueous solution of nitrite.

[0019] Preferably, the reaction time in step S1 is 10-30 min.

[0020] In a specific embodiment of the present invention, the intermediate obtained in step S1 exists in the form of an aqueous intermediate solution, and no post-processing is required, so step S2 can be performed directly.

[0021] Preferably, the temperature of the reaction in step S2 is 0-5°C.

[0022] In a specific embodiment of the present invention, step S2 adjusts the temperature of the reaction in step S1 to 0-5°C by means of an ice-water bath.

[0023] Preferably, the pH of the alkaline solution in step S2 is 8-10.

[0024] Preferably, the alkaline solution in step S2 comprises an aqueous sodium hydroxide solution. More preferably, the concentration of the aqueous sodium hydroxide solution is 2-10 wt%.

[0025] In a specific embodiment of the present invention, step S2 is as follows: dissolve the derivatizing reagent in an alkaline solution, add the intermediate solution obtained in step S1 dropwise, and react to obtain the blue azo derivative. More specifically, the pH of the reaction system is monitored in real time using a pH meter during the addition of the intermediate solution; if the pH is too low, sodium hydroxide solid is added to maintain the pH of the system at 8-10. More specifically, the addition is slow.

[0026] Preferably, the reaction time in step S2 is 30-60 min.

[0027] Preferably, the molar ratio of the intermediate to the derivatizing reagent in step S2 is 1:(2-2.1).

[0028] Preferably, the reaction in step S2 further includes adjusting the pH to <4 to precipitate the product. More preferably, the product precipitation is followed by solid-liquid separation, washing, and drying.

[0029] This invention also protects a reduction staining method for azo derivatives of sapphire blue, comprising the following steps: Under alkaline solution conditions, the blue azo derivative is mixed with a reducing agent and reacted to obtain a leuco acid solution of the blue azo derivative; the fabric is immersed in the leuco acid solution of the blue azo derivative, and then the fabric is taken out and oxidized to obtain the final product.

[0030] Preferably, the pH of the alkaline solution is 7-8.

[0031] Preferably, the fabric includes at least one of cotton fabric and linen fabric.

[0032] Compared with the prior art, the present invention has the following beneficial effects: When cotton fabrics are dyed using the blue azo derivative provided in this application, a dyeing rate of over 95% and a fixation rate of over 92% can be obtained under weakly alkaline conditions of pH 7-8, with a color depth of not less than 9.2 K / S, which is significantly better than the parent blue. This indicates that the compound provided in this application has better water solubility under reduction dyeing conditions, and thus can achieve improved dyeing effect under milder conditions. Attached Figure Description

[0033] Figure 1 This is the liquid phase spectrum of the intermediate obtained in step S1 of Example 1 of the present invention.

[0034] Figure 2 This is the liquid phase spectrum of compound M1 obtained in Example 1 of the present invention.

[0035] Figure 3 This is a schematic diagram of the tautomerism of the blue azo derivative provided by the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents. The raw material information used in each embodiment and comparative example is as follows: Guanlan: Provided by Nanjing Hegu Life Biotechnology Co., Ltd.

[0037] Example 1 A blue azo derivative M1 has the structure shown in the following formula: ; M1.

[0038] The preparation method of the blue azo derivative M1 provided in this embodiment includes the following steps: S1. Weigh 0.001 mol of *Gynostemma pentaphyllum* into a beaker, and dissolve it in 10% hydrochloric acid at 0℃ (solution pH < 3) to obtain an acidic solution of *Gynostemma pentaphyllum*. Weigh 0.0021 mol of NaNO2 and dissolve it in five times its mass of ice water to obtain a NaNO2 solution. Add the prepared NaNO2 solution dropwise to the acidic solution of *Gynostemma pentaphyllum* at 0℃ to carry out a diazotization reaction for 20 min. After the reaction, an intermediate solution is obtained. Figure 1 The liquid phase spectrum of the obtained intermediate; S2. Weigh 0.002 mol of 2-naphthol into a beaker, dissolve it in 5% NaOH solution, slowly add the intermediate solution obtained in step S1 at 0℃, and carry out the coupling reaction under the condition of maintaining pH 9 (add an appropriate amount of sodium hydroxide solid when pH < 9 during the reaction) for 40 min; adjust the pH of the reaction solution to 3 after the reaction is completed to precipitate the product, filter, wash with pure water, and dry to obtain pure compound M1. Figure 2 The liquid phase spectrum of the obtained M1 compound is shown.

[0039] The intermediate obtained in step S1 of this embodiment was structurally characterized, and the data are as follows: 1H NMR (400 MHz, DMSO-d6) δ8.46 (s, 1H), 11.19 (s, 1H).

[0040] ; The structure of the intermediate blue diazonium salt.

[0041] The 1H NMR spectrum shows two sets of peaks, corresponding to two sets of hydrogen nuclei in the molecule. Considering their chemical environment, δ8.46 (s, 1H) is the proton peak of the alkene hydrogen in the molecule, while δ11.19 (s, 1H) corresponds to the imine peak on the ring. Compared with the structure of Guanlan, the amino group peak is missing, suggesting that the synthesized diazonium salt is the target product.

[0042] The structure of compound M1 obtained in this embodiment was characterized, and the data are as follows: 1H NMR (400 MHz, DMSO-d6)δ11.18 (s, 1H), 8.79 (brs, 1H), 8.08 (s,1H), 7.99 (d, 1H), 7.96 (d, 1H), 7.82 (s, 1H), 7.58 (s, 1H), 7.52 (s, 1H),6.97 (s, 1H).

[0043] ESI-MS m / z: 557.1 [MH] - .

[0044] ; The structure of compound M1.

[0045] Analysis of the 1H NMR spectroscopy data revealed a set of imine proton signals at δ 11.18 (s, 1H) in the low-field region. Seven proton signals were observed in the olefinic hydrogen and benzene ring elution regions from δ 8.08 (s, 1H) to 6.97 (s, 1H), corresponding to the benzene ring and double bond in the blue core and the 2-naphthol fragment in the structure. An isolated BRS peak at 8.79 (brs, 1H) was observed, presumably representing the proton elution of the hydroxyl group in 2-naphthol. Combined with ESI-MS calculations, the molecular weight was calculated to be 558, corresponding to compound M1, confirming the molecular structure as compound M1.

[0046] Example 2 A blue azo derivative M2 has the structure shown in the following formula: ; M2.

[0047] The preparation method of the blue azo derivative M2 provided in this embodiment differs from that in Example 1 only in that: The derivatizing reagent in step S2 is phenol.

[0048] The structure of compound M2 obtained in this embodiment was characterized, and the data are as follows: ESI-MS m / z: 457.1 [MH] - .

[0049] Example 3 A blue azo derivative M3 has the structure shown in the following formula: M3.

[0050] The preparation method of the blue azo derivative M3 provided in this embodiment differs from that in Example 1 only in that: The derivatizing reagent in step S2 is 1-naphthol.

[0051] The structure of compound M3 obtained in this embodiment was characterized, and the data are as follows: ESI-MS m / z: 557.1 [MH] - .

[0052] Example 4 A blue azo derivative M4 has the structure shown in the following formula: M4.

[0053] The preparation method of the blue azo derivative M4 provided in this embodiment differs from that in Example 1 only in that: The derivatizing reagent in step S2 is 2-naphthylamine.

[0054] The structure of compound M4 obtained in this embodiment was characterized, and the data are as follows: ESI-MS m / z: 555.1 [MH] - .

[0055] Example 5 A blue azo derivative M5 has the structure shown in the following formula: M5.

[0056] The preparation method of the blue azo derivative M5 provided in this embodiment differs from that in Example 1 only in that: The derivatizing reagent in step S2 is 1-naphthylamine.

[0057] The structure of compound M5 obtained in this embodiment was characterized, and the data are as follows: ESI-MS m / z: 555.2 [MH] - .

[0058] Example 6 A blue azo derivative M6 has the structure shown in the following formula: M6.

[0059] The preparation method of the blue azo derivative M4 provided in this embodiment differs from that in Example 1 only in that: The derivatizing reagent in step S2 is aniline.

[0060] The structure of the M6 ​​compound obtained in this embodiment was characterized, and the data are as follows: ESI-MS m / z: 455.2 [MH] - .

[0061] Example 7 A method for preparing a blue azo derivative M1 includes the following steps: S1. Weigh 0.001 mol of safflower blue into a beaker, add 10% hydrochloric acid at 25℃ to dissolve the safflower blue (solution pH < 3), and obtain an acidic solution of safflower blue; weigh 0.0021 mol of NaNO2, dissolve it in five times its mass of ice water to obtain a NaNO2 solution; add the prepared NaNO2 solution dropwise to the acidic solution of safflower blue at 5℃ to carry out a diazotization reaction, and the reaction time is 10 min; after the reaction, an intermediate solution is obtained. S2. Weigh 0.0021 mol of 2-naphthol into a beaker, dissolve it in 5% NaOH solution, slowly add the intermediate solution obtained in step S1 at 5℃, and carry out the coupling reaction under the condition of maintaining pH 8 (add an appropriate amount of sodium hydroxide solid when pH < 8 during the reaction) for 30 min; adjust the pH of the reaction solution to 2 after the reaction is completed to precipitate the product, filter, wash with pure water, and dry to obtain pure compound M1.

[0062] Example 8 A method for preparing a blue azo derivative M1 includes the following steps: S1. Weigh 0.001 mol of safflower into a beaker, add 10% hydrochloric acid at 0℃ to dissolve the safflower (solution pH < 3), and obtain an acidic solution of safflower; weigh 0.002 mol of NaNO2, dissolve it with 5 times its mass of ice water to obtain a NaNO2 solution; add the prepared NaNO2 solution dropwise to the acidic solution of safflower at 0℃ to carry out a diazotization reaction for 20 min; after the reaction, an intermediate solution is obtained.

[0063] S2. Weigh 0.002 mol of 2-naphthol into a beaker, dissolve it in 5% NaOH solution, slowly add the intermediate solution obtained in step S1 at 0℃, and carry out the coupling reaction at pH=7 (add an appropriate amount of sodium hydroxide solid when pH<7 during the reaction) for 40 min; adjust the pH of the reaction solution to 2 after the reaction to precipitate the product, filter, wash with pure water, and dry to obtain pure compound M1.

[0064] Example 9 A method for preparing a blue azo derivative M1 includes the following steps: S1. Weigh 0.001 mol of safflower blue into a beaker, add 10% hydrochloric acid at 0℃ to dissolve the safflower blue (solution pH < 3), and obtain an acidic solution of safflower blue; weigh 0.0021 mol of NaNO2, dissolve it in five times its mass of ice water to obtain a NaNO2 solution; add the prepared NaNO2 solution dropwise to the acidic solution of safflower blue at 2℃ to carry out a diazotization reaction, and the reaction time is 30 min; after the reaction, an intermediate solution is obtained. S2. Weigh 0.002 mol of 2-naphthol into a beaker, dissolve it in 5% NaOH solution, slowly add the intermediate solution obtained in step S1 at 2℃, and carry out the coupling reaction under the condition of maintaining pH 10 (add an appropriate amount of sodium hydroxide solid when pH < 10 during the reaction). The reaction lasts for 60 minutes. Then adjust the pH of the reaction solution to 3 to precipitate the product. After filtration, washing with pure water, and drying, obtain the pure product of compound M1.

[0065] Performance testing Yield testing: Detecting the actual yield of the dried product and calculating its theoretical yield. The actual yield / theoretical yield is the yield.

[0066] Purity testing: HPLC was used for detection. Chromatographic conditions: mobile phase: gradient elution of methanol and pure water, as shown in the gradient table below: The wavelength was 600 nm, the flow rate was 1.0 mL / min, the sample solution was DMSO, the injection volume was 10 μL, the column temperature was 35℃, and the run time was 20 min. The chromatographic column was Galasil EF-C18M 4.6 mmid × 250 mm L (SN B06211801). Under these conditions, the purity of the Guanlan standard was calculated by liquid chromatography.

[0067] Dyeing effect test: The reducing agent sodium hydrosulfite was added to the dye bath containing the compounds obtained in the examples of indigo dyeing and stirred for reduction. Sodium hydroxide solution was added to adjust the pH of the dyeing solution to 7.0-8.0. The solution was then placed at 50-60℃ for reduction to obtain the reduced leuco dyeing solutions of each group of compounds. Cotton textiles were immersed in the dyeing solution at a liquor ratio of 1:15 and dyed at a constant temperature of 60℃. Eight cycles of immersion were performed during the dyeing process. After each immersion, the textiles were removed and air-dried for oxidation. This process was repeated until the desired color depth was achieved. After dyeing, the fabric samples were thoroughly washed with water, dried, and soaped (95℃, 10 minutes). Finally, they were dried again to obtain the dyed textiles. The dyed fabric samples were taken, cut into pieces, and extracted with solvents such as DMF at 95℃ to desorb the fixed dye. The extract was combined with the dyeing residue and all washing water, and after adjusting the volume, the absorbance at the maximum absorption wavelength was measured. Using the Lambert-Beer law, the dye uptake rate (the ratio of the amount of dye on the fiber to the initial amount of dye) and fixation rate (the ratio of the amount of dye fixed on the fiber to the initial amount of dye) are calculated by measuring the change in dye concentration in the dye bath before and after dyeing.

[0068] The results of the above performance tests are shown in Table 1-2 below: Table 1. Yields and purity of compounds obtained in each example Table 2. Staining effects of the compounds obtained in each example As shown in Table 2 above, the dyeing of cotton fabrics using the blue azo derivative provided in this application can achieve a dyeing rate of over 95% and a fixation rate of over 92% under weakly alkaline conditions of pH 7-8, with a color depth of not less than 9.2 K / S, which is significantly better than the parent blue. This indicates that the compound provided in this application has superior water solubility under reduction dyeing conditions, and thus can achieve improved dyeing results under milder conditions.

[0069] As can be seen from the data in Tables 1-2 above, when the yield and purity of the compounds in each embodiment are similar (or even lower), the compounds obtained in the preferred embodiments 1 and 6 of this invention have a higher coloring rate, while the compound in the preferred embodiment 4 of this invention has a higher fixation rate and color depth K / S when the coloring rates are not significantly different.

[0070] As can be seen from the data in Examples 7-9 of Table 1 above, the compounds prepared using the preferred conditions of this invention can achieve higher yields and purity. This is because the diazotization reaction has high requirements for reaction time, the molar ratio of intermediates to derivatizing reagents, and pH. If the reaction parameters are not well controlled, the resulting product may not only have a low yield and be difficult to process, but the target product may also not be obtained.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A blue azo derivative, characterized in that, It has the structure shown in equation (I): Formula (I); Furthermore, equation (I) can undergo the following tautomerism: R1 and R2 are each independently selected from either arylphenols or arylamines.

2. The blue azo derivative as described in claim 1, characterized in that, The arylphenol is selected from any one of phenol, naphthol, phenanthrene, and anthraquinone; The arylamine is selected from any one of aniline, naphthylamine, phenanthreneamine, and anthraceneamine.

3. The blue azo derivative as described in claim 1 or 2, characterized in that, R1 and R2 are each independently selected from any of the following formulas: 、 、 、 、 、 。 4. The blue azo derivative as described in claim 3, characterized in that, R1 and R2 are each independently selected from any of the following formulas: 、 、 、 、 、 。 5. The blue azo derivative as described in claim 4, characterized in that, The blue azo derivative has the structure shown in the following formula: 、 、 、 、 、 。 6. The method for preparing the blue azo derivative according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Under acidic solution conditions, cobalt blue and nitrite are mixed and reacted to obtain cobalt blue diazo intermediate; S2. Under alkaline solution conditions, the intermediate obtained in step S1 is mixed with the derivatizing reagent and reacted to obtain the blue azo derivative; the derivatizing reagent is arylphenol and / or arylamine.

7. The method for preparing the blue azo derivative as described in claim 6, characterized in that, The reaction temperature in step S1 is 0-5℃; The pH of the acidic solution described in step S1 is ≤3; The molar ratio of blue to nitrite in step S1 is 1:(2-2.1).

8. The method for preparing the blue azo derivative as described in claim 6, characterized in that, The reaction temperature in step S2 is 0-5℃; The pH of the alkaline solution described in step S2 is 8-10; The molar ratio of the intermediate to the derivatizing reagent in step S2 is 1:(2-2.1).

9. The reduction staining method for the blue azo derivative according to any one of claims 1 to 5, characterized in that, Includes the following steps: Under alkaline solution conditions, the blue azo derivative is mixed with a reducing agent and reacted to obtain a leuco acid solution of the blue azo derivative; the fabric is then immersed in the leuco acid solution of the blue azo derivative, and then the fabric is removed and oxidized in the air to obtain the final product.

10. The reduction staining method for the blue azo derivative as described in claim 9, characterized in that, The pH of the alkaline solution is 7-8.

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