Synthesis method of high-purity solvent green 3

Abstract

The invention discloses a synthesis method of high-purity solvent green 3. The synthesis method comprises the following steps: S1, replacing hydroxyl on hydroxyl-containing anthraquinone by using halide through nucleophilic substitution reaction to generate halogen atom substituted anthraquinone; and S2, replacing halogen atoms on the halogen atom substituted anthraquinone by using p-toluidine through nucleophilic substitution to generate solvent green 3. When the solvent green 3 is prepared by the method, the prepared solvent green 3 is high in yield and good in purity.

Description

Technical Field

[0001] The invention relates to the technical field of chemical dye synthesis, and in particular to a method for synthesizing high-purity Solvent Green 3. Background Art

[0002] Anthraquinone, chemical formula is C 14 H8O2 is an important natural quinone compound. Anthraquinone compounds are an indispensable raw material in chemical production and an important intermediate for dyes and pigments. Anthraquinone and its derivative dyes have a stable conjugated structure because they contain aromatic rings in the molecule. They are widely used in printing and dyeing industries because of their bright colors, good light fastness, good chemical stability, light resistance and oxidation resistance, excellent dyeing rate and color fastness. Some varieties have performance that cannot be achieved by any other type of dye or pigment. It is the second largest variety and output of dyes. According to its application performance, it is divided into acid dyes, vat dyes, disperse dyes, reactive dyes, solvent dyes, etc. Among solvent dyes, dyes with anthraquinone structure account for a large proportion. Not only that, but other dyes cannot surpass it in terms of application performance.

[0003] The chemical name of Solvent Green 3 is 1,4-di-p-toluaminoanthraquinone, also known as Transparent Green 5B. It is insoluble in water but soluble in organic solvents such as chloroform, benzene, chlorobenzene, xylene, DMF, etc. Solvent Green 3 is mainly used for the coloring of plastic resins and polyester fiber pulp, and can also be used for the coloring of daily plastics, organic glass, PVC packaging materials, industrial grease, ink, color masterbatch, petroleum products, coatings, etc.

[0004] At present, the industrial preparation of Solvent Green 3 uses high-boiling aromatic hydrocarbons such as nitrobenzene as solvents and undergoes a dehydration reaction at high temperature. The reaction temperature is high, resin byproducts are generated, the product has a certain solubility in the solvent, the yield is not high, and multi-component reagents such as catalysts and dispersants are required, and complex methods are required for separation, which undoubtedly increases impurities and reduces the purity of the reaction product. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method for synthesizing high-purity Solvent Green 3. The method of the present invention is used to prepare Solvent Green 3, and the prepared Solvent Green 3 has high yield and good purity.

[0006] The technical solution of the present invention is achieved in this way:

[0007] The present invention provides a method for synthesizing high-purity Solvent Green 3, comprising the following steps:

[0008] S1: 1,4-dihydroxyanthraquinone and dichlorothionyl are placed in a flask, benzene is added, stirred, and heated to reflux for 2-3 hours, and then barium chloride is added and filtered to obtain a 1,4-dichloroanthraquinone solution.

[0009] S2: Add p-toluidine benzene solution to the 1,4-dichloroanthraquinone solution, stir evenly and react at 70-75°C for 2-3h. After the reaction, heat to 80-85°C to evaporate benzene. Then, add sodium hydroxide solution to wash 3-5 times, then add deionized water to wash 3-5 times, filter, recrystallize with anhydrous ethanol and dry to obtain 1,4-di-p-toluidine anthraquinone.

[0010] Furthermore, in step S1, the molar ratio of 1,4-dihydroxyanthraquinone to thionyl chloride is 1:1-1:2.

[0011] The beneficial effect of adopting the above scheme is: the replacement of the hydroxyl group by the chlorine atom is completed by utilizing the nucleophilic substitution reaction of the halogen atom, and the reaction can be carried out without the need for a catalyst, which is simple and efficient.

[0012] Furthermore, the molar ratio of barium chloride to thionyl chloride added in step S1 is 1:1-2:1.

[0013] The beneficial effects of adopting the above scheme are: adding the barium ion solution to precipitate the sulfite ions to prevent them from oxidizing the amino groups in the subsequently added toluidine, and at the same time, the introduction of more chloride ions further promotes the substitution of the hydroxyl groups on 1,4-dihydroxyanthraquinone.

[0014] Furthermore, in step S2, the molar ratio of p-toluidine to 1,4-dihydroxyanthraquinone is 2:1-3:1.

[0015] The beneficial effect of adopting the above scheme is: the nucleophilic substitution reaction of the halogen atom is utilized again to complete the replacement of the chlorine atom by the amino group, and the reaction can also be carried out efficiently without the need for a catalyst.

[0016] Furthermore, the concentration of sodium hydroxide in step S2 is 5%-10%.

[0017] The beneficial effect of adopting the above scheme is that the hydroxide ions in the sodium hydroxide will undergo a nucleophilic substitution reaction with the chlorine atoms on the 1,4-dichloroanthraquinone that are not replaced by the amino group.

[0018] Anthraquinone containing two hydroxyl groups can be dissolved in 1% sodium hydroxide solution, while anthraquinone containing one hydroxyl group can only be dissolved in 5% sodium hydroxide solution. The introduction of hydroxide ions can remove the incompletely reacted 1,4-dichloroanthraquinone, which is converted into hydroxyl-containing anthraquinone and dissolved in sodium hydroxide.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Use multiple nucleophilic substitution reactions to complete group replacement, and use the characteristics of nucleophilic substitution that can be carried out efficiently without a catalyst to complete the reaction and purify, and the obtained product has high purity.

[0021] 2. The preparation process uses less reaction aids, saving costs and avoiding pollution. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Reagent Description:

[0024] Thionyl chloride, 1,4-dihydroxyanthraquinone, benzene, p-toluidine, barium chloride, sodium hydroxide, analytical grade, Sinopharm Chemical Reagent Co., Ltd.

[0025] Example 1

[0026] This embodiment provides a low-pollution solvent green 3, which specifically includes the following steps:

[0027] S1: Place 15 mol of 1,4-dihydroxyanthraquinone and 15 mol of thionyl chloride in a 500 mL flask, add 10 mL of benzene, stir, heat to reflux and react for 2.5 h, then add 15 mL of 1 mol mL -1 The barium chloride was filtered to obtain a 1,4-dichloroanthraquinone solution.

[0028] S2: Add 10 mL of 3 mol·mL 1,4-dichloroanthraquinone solution -1 The benzene solution of p-toluidine was stirred evenly and then heated to 70°C for 2.5 hours. Precipitation was observed during the reaction. After the reaction was completed, the temperature was raised to 80°C to evaporate the benzene, and then 5% sodium hydroxide solution was added and stirred for washing. This was repeated 3 times and then deionized water was added for washing 3 times. After filtration, it was dissolved in 100 mL of anhydrous ethanol, first heated to 75°C and then cooled to 0°C for recrystallization. The obtained crystals were placed in an oven and dried at 80°C for 10 hours to obtain 1,4-di-p-toluidine anthraquinone.

[0029] Example 2

[0030] The difference between this embodiment and embodiment 1 is that:

[0031] The amount of thionyl chloride added in step S1 is 20 mol.

[0032] The other parts are exactly the same as those in Example 1.

[0033] Example 3

[0034] The difference between this embodiment and embodiment 1 is that:

[0035] The amount of thionyl chloride added in step S1 is 25 mol. The other parts are exactly the same as those in Example 1.

[0036] Example 4

[0037] The difference between this embodiment and embodiment 1 is that:

[0038] The amount of thionyl chloride added in step S1 is 30 mol. The other parts are exactly the same as those in Example 1.

[0039] Example 5

[0040] The difference between this embodiment and embodiment 1 is that:

[0041] The amount of barium chloride solution added in step S1 is 30 mL. The other parts are exactly the same as those in Example 1.

[0042] Example 6

[0043] The difference between this embodiment and embodiment 1 is that:

[0044] The amount of p-toluidine solution added in step S2 is 13 mL. The other parts are exactly the same as those in Example 1.

[0045] Example 7

[0046] The difference between this embodiment and embodiment 1 is that:

[0047] The amount of p-toluidine solution added in step S2 is 15 mL. The other parts are exactly the same as those in Example 1.

[0048] Comparative Example 1

[0049] The difference between this embodiment and embodiment 1 is that:

[0050] The halide in step S1 is trimethyl sulfoxide bromide. The other parts are exactly the same as those in Example 1.

[0051] Comparative Example 2

[0052] The difference between this embodiment and embodiment 1 is that:

[0053] The halide in step S1 is trimethyl sulfoxide iodide. The other parts are exactly the same as those in Example 1.

[0054] Comparative Example 3

[0055] The difference between this embodiment and embodiment 1 is that:

[0056] In step S2, 5 mol of concentrated sulfuric acid is added as a catalyst. The other parts are exactly the same as those in Example 1.

[0057] Tests and Results

[0058] The results are shown in Table 1.

[0059] Table 1

[0060] project Yield (%) purity(%) Example 1 80 98 Example 2 82 98 Example 3 85 98 Example 4 88 97 Example 5 87 99 Example 6 86 98 Example 7 88 97 Comparative Example 1 75 98 Comparative Example 2 70 97 Comparative Example 3 75 88

[0061] As can be seen from Table 1, the Solvent Green 3 prepared in this embodiment has good purity, the highest being 99%, the lowest purity being not less than 97%, and the lowest yield being not less than 80%.

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for synthesizing high-purity Solvent Green 3, characterized in that: The following steps are involved: S1: using a halide to replace the hydroxyl group on the hydroxyl-containing anthraquinone by a nucleophilic substitution reaction to generate a halogen atom to replace the anthraquinone; S2: using p-toluidine to replace the halogen atom on the anthraquinone by nucleophilic substitution to generate solvent green 3.

2. A method for synthesizing high-purity Solvent Green 3 according to claim 1, characterized in that: The halide in step S1 is thionyl chloride.

3. A method for synthesizing high-purity Solvent Green 3 according to claim 1, characterized in that: The hydroxyl-containing anthraquinone in step S1 is 1,4-dihydroxyanthraquinone.

4. A method for synthesizing high-purity Solvent Green 3 according to claim 1, characterized in that: The reaction process in step S1 requires the addition of a precipitant.

5. A method for synthesizing high-purity Solvent Green 3 according to claim 4, characterized in that: The precipitant is barium chloride.

6. A method for synthesizing high-purity Solvent Green 3 according to claim 2 or 3, characterized in that: The molar ratio of 1,4-dihydroxyanthraquinone to thionyl chloride in step S1 is 1:1-1:

2.

7. A method for synthesizing high-purity Solvent Green 3 according to claim 2 or 5, characterized in that: The molar ratio of barium chloride to thionyl chloride in step S1 is 1:1-2:

1.

8. A method for synthesizing high-purity Solvent Green 3 according to claim 3, characterized in that: The molar ratio of p-toluidine to 1,4-dihydroxyanthraquinone in step S2 is 2:1-3:

1.

9. A method for synthesizing high-purity Solvent Green 3 according to claim 1, characterized in that: The product solvent green 3 in step S2 is purified by a cleaning solution.

10. A method for synthesizing high-purity Solvent Green 3 according to claim 9, characterized in that: The cleaning solution includes 5% sodium hydroxide solution.