Synthesis method of dimethyl 2,6-naphthalenedicarboxylate

A technology of dimethyl naphthalate and a synthetic method, which is applied in the preparation of carboxylic acid esters, chemical instruments and methods, and the preparation of organic compounds, can solve the problems of severe equipment corrosion, long reaction time, and high alkyd ratio, and achieve Reduced reaction time, good selectivity, and the effect of inhibiting etherification

Active Publication Date: 2021-01-19
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is a fatal defect in this synthesis method, that is, the alkyd-acid ratio is too high, and the high purity of the esterification product is obtained on the basis of consuming raw materials.
[0007] As can be seen from the above analysis, the known 2,6-NDC synthesis method has the following defects: (1) the synthesis method is severely corrosive to equipment and produces a large amount of waste water; (3) The catalyst added in the synthesis process makes the later purification process difficult, and the catalyst is difficult to recycle

Method used

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  • Synthesis method of dimethyl 2,6-naphthalenedicarboxylate
  • Synthesis method of dimethyl 2,6-naphthalenedicarboxylate
  • Synthesis method of dimethyl 2,6-naphthalenedicarboxylate

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Embodiment 1

[0024] The ionic liquid synthesis of the present invention can be carried out as follows. The first step is to synthesize the ylide. First, melt 1,3-propane sultone into a liquid state in a water bath at 40°C, then weigh 0.1mol of 1,3-propane sultone into a 250ml three-necked flask, and add about 150ml of ethyl acetate to make it It dissolves. Place the three-necked flask in an ice-water bath. The three-necked flask is equipped with agitator. Turn on the agitator, and then add 0.1 mol of alkyl substituent imidazole dropwise. After the dropwise addition, move the three-necked flask into a water bath and heat to 70°C. The reaction was stirred for 6h. After the reaction was complete, it was filtered with suction, and the obtained solid was washed three times with ethyl acetate, and finally vacuum-dried or rotary evaporated to remove residual ethyl acetate. During the first step of the reaction, the main reactions are as follows:

[0025]

[0026] The second reaction is the...

Embodiment 2

[0034] Adopt embodiment 1 synthetic route to synthesize 120 g of methanol, 12 g of 2,6-NDA, 3.4 g of 2,6-NDC and 1.2 g of the above-mentioned ionic liquid catalyst were added into a 500 ml stainless steel reactor. A packing tower is installed on the top of the stainless steel reaction kettle, and the packing tower is filled with molecular sieves to remove the water generated in the reaction system and make the reaction move in the positive direction. At the beginning of the reaction, the whole system was replaced with nitrogen three times to remove the air in the system, and then pressurized to 1Mpa. Turn on the heating so that the temperature in the kettle rises to 130° C., and at the same time turn on the stirring. When the temperature in the kettle rose to 130°C, the timing was started, and experiments with reaction times of 2h, 3h, and 4h were carried out respectively. The reaction product is pressed into the collection tank, and after the temperature is cooled to 40°C,...

Embodiment 3

[0039] Adopt embodiment 1 synthetic route to synthesize 120 g of methanol, 12 g of 2,6-NDA and 1.2 g of the above-mentioned ionic liquid catalyst were added into a 500 ml stainless steel reactor. The system was replaced with nitrogen three times to remove the air in the system, and then pressurized to 1Mpa. Turn on the heating so that the temperature in the kettle rises to 120° C., and at the same time turn on the stirring. When the temperature in the kettle rose to 120°C, the timer was started, and the reaction was terminated after 5 hours of reaction. The reaction product is pressed into the collection tank, and after the temperature is cooled to 40°C, the pressure is released. The resulting product was filtered and then dried in a vacuum oven.

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Abstract

The invention relates to a synthesis method of dimethyl 2,6-naphthalenedicarboxylate (2,6-NDC), and mainly solves the technical problems of long reaction time, low conversion rate, poor selectivity, poor catalyst recyclability and the like in an existing synthesis method. The synthesis method provided by the invention comprises the following step: reacting 2,6-naphthalenedicarboxylic acid with methanol by taking an imidazole sulfonic acid functionalized ionic liquid as a catalyst. The catalyst methanol solution is recycled at the temperature of 50-100 DEG C, so that the re-reaction solution contains 1-10 wt% of 2,6-NDC, the reaction time in the recycling process is greatly shortened, and the efficiency of the whole process is improved. The synthesis method can be used for efficient synthesis of 2,6-NDC.

Description

technical field [0001] The invention relates to a method for synthesizing dimethyl 2,6-naphthalene dicarboxylate (2,6-NDC), which can effectively improve reaction conversion rate, selectivity and catalyst cycle efficiency, and shorten reaction time. Background technique [0002] Compared with traditional polyethylene terephthalate (PET), polyethylene naphthalate (PEN) has benzene rings in the system replaced by naphthalene rings with better rigidity, thus endowing PEN with PET has more excellent performance, its potential use covers all the fields where PET can be applied, and it can provide better performance. First PEN for CO 2 and O 2 The transmittance of PEN is only about 30% of that of traditional PET, and PEN has better air tightness, so PEN film can better store food. At the same time, PEN has high modulus, high strength, tensile resistance and creep resistance, so that PEN can be used in the manufacture of tires, conveyor belts and high-pressure conveying pipes, e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/08C07C69/76B01J31/02
CPCC07C67/08B01J31/0284B01J2231/49C07C69/76Y02P20/584
Inventor 秦春曦陈亮曹禄赵文彬
Owner CHINA PETROLEUM & CHEM CORP
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