Preparation method of anthraquinone derivative tetramine

Abstract

The invention discloses a preparation method of anthraquinone derivative tetramine, and belongs to the field of organic synthesis. According to the method, in a hydrogen atmosphere, a compound 1 is converted into a compound 2 in the presence of Pd / C, tetrahydrofuran and an additive, and the additive is any one of DMF, ammonia water, triethylamine or acetic acid. According to the method, the yield is improved, and a high-purity product can be obtained only through simple post-treatment. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the field of organic synthesis, and in particular to a method for preparing anthraquinone derivative tetraamine. Background Art

[0002] Chinese patent CN 113563212 A reports that 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, an anthraquinone derivative tetraamine, can be used to prepare black intrinsic polyimide. The black intrinsic polyimide has good mechanical properties, thermal stability and dielectric properties, and the optical transmittance of the entire band is less than 1%, which has good commercial application prospects.

[0003] Intrinsically Black Polyimide with Retained Insulation and Thermal Properties: A Black Anthraquinone Derivative Capable of Linear Copolymerization (Macromolecules. 2021, 54, 9307-9318), a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone is disclosed, which uses 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone as a starting material, N,N-dimethylformamide (DMF) as a reaction solvent, and Pd / C as a catalyst. The reaction is carried out under a hydrogen atmosphere, and finally 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone is obtained with a yield of 75%. Such a yield is still insufficient for industrial application. Summary of the invention

[0004] [Technical issues]

[0005] In order to solve the problem that the existing methods cannot achieve high yield and high purity, the present invention provides a preparation method for producing high-purity anthraquinone derivative tetraamine with higher yield and without complicated purification treatment.

[0006] [Technical solution]

[0007] A method for preparing anthraquinone derivative tetraamine, the reaction formula is as follows:

[0008]

[0009] The steps include:

[0010] Under a hydrogen atmosphere, compound 1 is converted into compound 2 in the presence of Pd / C, tetrahydrofuran (THF) and an additive, wherein the additive is selected from any one of DMF, ammonia water, triethylamine or acetic acid.

[0011] In one embodiment of the present invention, the partial pressure of hydrogen in the reaction system is 1.5-2.5 MPa.

[0012] In one embodiment of the present invention, the mass ratio of the Pd / C to the compound 1 is (0.05-0.1):1, and the Pd content in the Pd / C is 5%-10%.

[0013] In one embodiment of the present invention, the mass volume ratio of compound 1 to tetrahydrofuran is 1 g: (20-30) mL.

[0014] In one embodiment of the present invention, when the additive is aqueous ammonia, triethylamine or acetic acid, the mass ratio of the additive to compound 1 is (0.05-0.2):1.

[0015] In one embodiment of the present invention, the ammonia water is an aqueous solution of ammonia with an ammonia content of 10 wt% to 30 wt%.

[0016] In one embodiment of the present invention, when the additive is DMF, the mass ratio of the additive to compound 1 is (3-5):1.

[0017] In one embodiment of the present invention, the reaction temperature is 55-65°C, and can be 60°C.

[0018] In one embodiment of the present invention, the reaction time is 4-12 hours, and specifically 8 hours.

[0019] In one embodiment of the present invention, after the reaction is completed, the following post-treatment process is also included:

[0020] The reaction solution formed by the reaction is filtered, the filtrate is taken, the solvent is removed, and methanol is added for crystallization to obtain the target compound.

[0021] In one embodiment of the present invention, the temperature condition for methanol crystallization is 50-60°C.

[0022] In one embodiment of the present invention, the reaction mixture is stirred at 50-60° C. for 0.5 h-1.5 h, solid is precipitated, and the solid is filtered, rinsed and dried to obtain the target compound.

[0023] Functions and Effects of the Invention

[0024] According to the preparation method of the anthraquinone derivative tetraamine involved in the present invention, since tetrahydrofuran is used as the reaction solvent and one of triethylamine, ammonia water or DMF is additionally added as a reaction additive, the present invention not only improves the yield, but also only requires simple post-treatment to obtain a high-purity product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the hydrogen spectrum of compound 2 prepared in Example 1;

[0026] Figure 2 The HPLC spectrum of compound 2 prepared in Example 1. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail below in conjunction with embodiments.

[0028] In the following examples, unless otherwise specified, all chemical reagents are commercially available products.

[0029] In the following examples, 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone was prepared according to the method described in Chinese patent CN113563212 A, and the purity was ≥98.0%.

[0030] In the following examples, 10 wt % ammonia water was obtained by diluting commercially available ammonia water with water and was titrated before use.

[0031] In the following examples, 10% Pd / C refers to a Pd / C catalyst having a Pd content of 10 wt%, which is a commercially available product.

[0032] <Example 1>

[0033] Preparation method of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone

[0034] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, and the reaction formula is as follows:

[0035]

[0036] The steps include:

[0037] Add 10g of compound 1 to the autoclave, add 1g of 10% Pd / C, 300mL of THF, and 38.0g of DMF in sequence, replace hydrogen in the autoclave, fill with hydrogen until the pressure in the autoclave is 2.0MPa, heat to 60°C, and keep warm for 8h. Sampling and testing, the reaction is complete. Open the autoclave, filter the reaction liquid, take the filtrate, evaporate tetrahydrofuran under reduced pressure, add 80g of methanol, heat to 55°C, stir for 1h, solid precipitates, filter the solid, rinse with methanol, and dry to obtain 6.1g of compound 2, with a yield of 85.3% and a purity of 99.0%.

[0038] <Example 2>

[0039] Preparation method of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone

[0040] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, and the reaction formula is as follows:

[0041]

[0042] The steps include:

[0043] Add 10g of compound 1 to the autoclave, add 1g of 10% Pd / C, 300mL of THF, and 38g of triethylamine in sequence, replace hydrogen in the autoclave, fill with hydrogen until the pressure in the autoclave is 2.0MPa, heat to 60°C, and keep warm for 8h. Take samples for testing, the reaction is complete. Open the autoclave, filter the reaction liquid, take the filtrate, evaporate tetrahydrofuran under reduced pressure, add 80g of methanol, heat to 55°C, stir for 1h, solid precipitates, filter the solid, rinse with methanol, and dry to obtain 5.6g of compound 2 product with a purity of 89.8%.

[0044] <Example 3>

[0045] Preparation method of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone

[0046] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, and the reaction formula is as follows:

[0047]

[0048] The steps include:

[0049] Add 10g of compound 1 to the autoclave, add 1g of 10% Pd / C, 300mL of THF, and 1g of additives in sequence, replace hydrogen in the autoclave, fill with hydrogen until the pressure in the autoclave is 2.0MPa, heat to 60°C, and keep warm for 8h. Sampling and testing, the reaction is complete. Open the autoclave, filter the reaction liquid, take the filtrate, evaporate tetrahydrofuran under reduced pressure, add 80g of methanol, heat to 55°C, stir for 1h, solid precipitates, filter the solid, rinse with methanol, and dry to obtain compound 2 product.

[0050] The yield and purity of different additives are shown in Table 2.

[0051] Table 2 Effects of different additives in catalytic reactions

[0052] Serial number additive Product Quality Product Purity 1 Acetic acid 5.6g 65.0％ 2 Triethylamine 5.4g 85.2％ 3 10wt% ammonia water 6.1g 89.7％ 4 DMF 5.2g 77.3％ 5 none 5.0g 77.5％

[0053] Combined with Table 1-2, it can be seen that under certain dosage conditions, the use of alkaline reagents such as triethylamine, ammonia water, etc. as additives can obtain more ideal yields and purities compared to acetic acid as an additive; however, compared with the use of an appropriate amount of DMF, the use of alkaline reagents as additives still has insufficient purity of the product, and the product needs to be further recrystallized using water to obtain compound 2 with a purity of more than 95%.

[0054] <Comparative Example 1>

[0055] Preparation method of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone

[0056] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, comprising the following steps:

[0057] Add 10g of compound 1 to the autoclave, add 1g of 10% Pd / C and 300mL of DMF in sequence, replace hydrogen in the autoclave, fill with hydrogen until the pressure in the autoclave is 2.0MPa, heat to 60°C, and keep warm for reaction. Take a sample when the reaction reaches 8h, and the raw material conversion rate is 79.8% by HPLC detection. Take a sample when the reaction reaches 24h, and the raw material conversion rate is 87.0% by HPLC detection. Open the autoclave when the reaction reaches 26h, filter the reaction liquid, take the filtrate, add 200mL of water, stir at room temperature for 1h, solid precipitates, filter the solid, wash with water, and dry to obtain 5.5g of compound 2 with a purity of 92.2%.

[0058] <Comparative Example 2>

[0059] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, comprising the following steps:

[0060] 10 g of compound 1 was added to the autoclave, followed by 1 g of 10% Pd / C, 300 mL of ethanol, and 38.0 g of DMF. The autoclave was replaced with hydrogen until the pressure inside reached 2.0 MPa, and the temperature was raised to 60°C for 26 h. After the reaction, only trace amounts of product were found by HPLC.

[0061] <Comparative Example 3>

[0062] This embodiment provides a method for preparing 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, comprising the following steps:

[0063] Add 10g of compound 1 to the autoclave, add 1g of 10% Pd / C, 300mL of 10wt% dilute hydrochloric acid, and 38.0g of DMF in sequence, replace the hydrogen in the autoclave, fill with hydrogen until the pressure in the autoclave is 2.0MPa, raise the temperature to 60°C, and keep the temperature for 26h. After the reaction is completed, HPLC detection shows that there is basically no reaction and no target product is produced.

[0064] Functions and Effects of the Embodiments

[0065] According to the preparation method of the anthraquinone derivative tetraamine involved in the above embodiment, since tetrahydrofuran is used as the reaction solvent and a specific appropriate amount of DMF, ammonia water, triethylamine or acetic acid is additionally added as a reaction additive, the present application can effectively improve the reaction yield and product purity.

[0066] Furthermore, if the solvent is selected from the common solvents for palladium carbon reduction of existing aromatic nitro substrates to amino groups, such as DMF, ethanol, dilute hydrochloric acid, etc., it is found that none of them are suitable for the substrate of the present invention, and the target product of the present invention cannot be obtained efficiently and with high purity. However, using tetrahydrofuran as a solvent in combination with the reaction system of the present invention can obtain the target product efficiently and with high purity.

[0067] Furthermore, there are also great differences in the reactivity of several additives. A better reaction effect can be obtained by selecting a specific appropriate amount of DMF to be combined with the above tetrahydrofuran reaction system.

[0068] Furthermore, by adding methanol during the post-treatment process of the reaction, compound 2 with a purity of more than 98% can be directly precipitated, which greatly saves the post-treatment steps and effectively improves the production efficiency.

[0069] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A method for preparing anthraquinone derivative tetraamine, characterized in that: The reaction formula is as follows: The steps include: Under a hydrogen atmosphere, compound 1 reacts in the presence of Pd / C, tetrahydrofuran and an additive to obtain compound 2. Wherein, the additive is selected from any one of DMF, ammonia water, triethylamine or acetic acid.

2. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, The partial pressure of hydrogen in the reaction system is 1.5-2.5 MPa.

3. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, The mass ratio of Pd / C to compound 1 is (0.05-0.1): 1, The Pd content in the Pd / C is 5%-10%.

4. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, The mass volume ratio of compound 1 to tetrahydrofuran is 1 g: (20-30) mL.

5. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, When the additive is ammonia water, triethylamine or acetic acid, the mass ratio of the additive to compound 1 is (0.05-0.2):

1.

6. The method for preparing anthraquinone derivative tetraamine according to claim 5, characterized in that: in, The ammonia water is an aqueous solution of ammonia with an ammonia content of 10wt%-30wt%.

7. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, When the additive is DMF, the mass ratio of the additive to compound 1 is (3-5):

1.

8. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, The reaction temperature is 55-65°C.

9. The method for preparing anthraquinone derivative tetraamine according to claim 1, characterized in that: in, The reaction time is 4-12h.

10. The method for preparing anthraquinone derivative tetraamine according to any one of claims 1 to 9, characterized in that: After the reaction is completed, the following post-processing process is also included: The reaction solution formed by the reaction is filtered, the filtrate is taken, the solvent is removed, and methanol is added for crystallization to obtain the target compound.

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