Preparation method of 2,5-diamino terephthalic acid

A technology of diaminoterephthalic acid and nitroterephthalic acid, which is applied in the preparation of 2,5-diaminoterephthalic acid and the field of 2,5-diaminoterephthalic acid, can solve complex processes, Problems such as low yield and complicated processing can achieve the effects of high purity, high yield and easy availability of raw materials

Inactive Publication Date: 2015-06-10
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above-mentioned technical problems in the prior art, the present invention provides a kind of preparation method of 2,5-diaminoterephthalic acid, and the preparation method of described this 2,5-diaminoterephthalic acid solves the problem of The method for preparing 2,5-diaminoterephthalic acid in the prior art is complex in process, low in yield, and complicated technical problems in follow-up processing

Method used

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  • Preparation method of 2,5-diamino terephthalic acid
  • Preparation method of 2,5-diamino terephthalic acid

Examples

Experimental program
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Effect test

Embodiment 1

[0020] (1) Preparation of 2,5-dinitroterephthalic acid

[0021] Add 20.5g of terephthalic acid into a 500mL three-necked flask equipped with a stirrer, condenser and thermometer, add dropwise 55.2g of 98% sulfuric acid, and 121.8g of 68% nitric acid. After the dropwise addition, control the temperature at 100°C and react for 4 hours. Subsequently, 55.2 g of 98% sulfuric acid and 156.4 g of 68% nitric acid were added dropwise. After the dropwise addition, the temperature was controlled at 80° C., and the reaction was carried out for 12 hours. After the reaction, cool down, put the reaction mixture into ice water, filter the precipitate, recrystallize the filtrate in hot water, filter, and dry to obtain 26.9 g of white solid 2,5-dinitroterephthalic acid, yield 85.1% .

[0022] (2) Preparation of 2,5-diaminoterephthalic acid

[0023] Add 350mL of concentrated hydrochloric acid into a 500mL three-neck flask equipped with a stirrer, condenser and thermometer, start stirring and s...

Embodiment 2

[0025] (1) Preparation of 2,5-dinitroterephthalic acid

[0026] Add 20.5g of terephthalic acid into a 500mL three-necked flask equipped with a stirrer, condenser and thermometer, add dropwise 46.1g of 98% sulfuric acid, and 105.7g of 68% nitric acid. After the dropwise addition, control the temperature at 100°C and react for 3h. Then, 46.1 g of 98% sulfuric acid and 141.0 g of 68% nitric acid were added dropwise. After the dropwise addition, the temperature was controlled at 80° C., and the reaction was carried out for 12 hours. After the reaction, cool down, put the reaction mixture into ice water, filter the precipitate, recrystallize the filtrate in hot water, filter, and dry to obtain 27.6 g of white solid 2,5-dinitroterephthalic acid with a yield of 87.3% .

[0027] (2) Preparation of 2,5-diaminoterephthalic acid

[0028] Add 250mL of concentrated hydrochloric acid into a 500mL three-neck flask equipped with a stirrer, condenser and thermometer, start stirring and slowl...

Embodiment 3

[0030] (1) Preparation of 2,5-dinitroterephthalic acid

[0031] Add 20.5g of terephthalic acid into a 500mL three-necked flask equipped with a stirrer, condenser and thermometer, add dropwise 46.1g of 98% sulfuric acid, and 105.7g of 68% nitric acid. After the dropwise addition, control the temperature at 90°C and react for 3h. Subsequently, 46.1 g of 98% sulfuric acid and 141.0 g of 68% nitric acid were added dropwise. After the dropwise addition, the temperature was controlled at 70° C., and the reaction was carried out for 12 hours. After the reaction, cool down, put the reaction mixture into ice water, filter the precipitate, recrystallize the filtrate in hot water, filter, and dry to obtain 25.4 g of white 2,5-dinitroterephthalic acid with a yield of 80.4%.

[0032] (2) Preparation of 2,5-diaminoterephthalic acid

[0033] Add 250mL of concentrated hydrochloric acid into a 500mL three-neck flask equipped with a stirrer, condenser and thermometer, start stirring and slowly...

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Abstract

The invention discloses a preparation method of 2,5-diamino terephthalic acid. The preparation method of 2,5-diamino terephthalic acid comprises a nitratlon reaction step of nitrifying terephthalic acid by using concentrated nitric acid in concentrated sulfuric acid to prepare 2,5-binitro terephthalic acid; and a reduction reaction step of reducing 2,5-binitro terephthalic acid in the presence of a reducing agent to prepare 2,5-diamino terephthalic acid. The preparation method of 2,5-diamino terephthalic acid is low-cost and easily available in raw material, easily controllable in reaction process parameters, simple to operate, high in yield, high in purity and high in industrial practicality.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to a kind of 2,5-diaminoterephthalic acid, specifically a preparation method of 2,5-diaminoterephthalic acid. Background technique [0002] 2,5-diaminoterephthalic acid is an important organic intermediate for the synthesis of resins and polyester fibers, especially one of the key monomers for the synthesis of polyamides and polyesters. [0003] 2,5-diaminoterephthalic acid, molecular formula: C 8 h 8 N 2 o 4 , molecular weight: 196.16, its structure is as follows: [0004] [0005] At present, relevant information shows that there are two main methods for the synthesis of 2,5-diaminoterephthalic acid: 1) Ghaemy et al. use terephthalic acid as raw material in Chinese Chemical Letters (2009,20(7):800-804) , obtain 2,5-diaminoterephthalic acid through nitration and iron powder reduction, but the total yield of this method is low, and the aftertreatment is annoying, the iron sludg...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/62C07C227/04
Inventor 余焓于娜冯颖高静韩生
Owner SHANGHAI INST OF TECH
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