阅读说明：本技术 一种对苯二甲酸的合成方法 (A kind of synthetic method of terephthalic acid (TPA) ) 是由 吴水保 于 2018-05-25 设计创作，主要内容包括：一种对苯二甲酸的合成方法,包括以下步骤：(1)取20mL对二甲基苯置于反应釜中,加入溶剂,控制反应釜的温度为160-170℃,反应压力为0.85-0.9MPa,控制反应釜中氧气的体积分数为30-35%,再加入1,4-二氯-2,3-二氯蒽醌与N-羧基邻苯二甲酰亚胺金属催化剂,反应6-8h后停止；(2)将上述反应液降温至室温,再加入N,N-二甲基甲酰胺稀释溶解,所述N,N-二甲基甲酰胺的加入量为对二甲苯体积的8-10倍,得到的白色结晶或粉末即为目标产物；本发明通过金属催化剂将对二甲苯在高温低压下氧化合成对苯二甲酸,反应路线简单、综合原料成本低、收率高。(A kind of synthetic method of terephthalic acid (TPA), the following steps are included: (1) takes 20mL to be placed in reaction kettle dimethyl benzene, solvent is added, the temperature for controlling reaction kettle is 160-170 DEG C, reaction pressure 0.85-0.9MPa, and the volume fraction for controlling oxygen in reaction kettle is 30-35%, add 1, chloro- 2, the 3- dichloroanthraquinone of 4- bis- and N- carboxyl phthalimide metallic catalyst stop after reacting 6-8h；(2) above-mentioned reaction solution is cooled to room temperature, adds n,N-Dimethylformamide dilution dissolution, the additional amount of the n,N-Dimethylformamide is 8-10 times of paraxylene volume, and obtained white crystals or powder are target product；The present invention by metallic catalyst by paraxylene the oxidative synthesis terephthalic acid (TPA) under high-temperature low-pressure, simple, the comprehensive cost of material of reaction route is low, high income.)

1. a kind of synthetic method of terephthalic acid (TPA), it is characterised in that the following steps are included:

(1) it takes 20mL to be placed in reaction kettle dimethyl benzene, solvent is added, the temperature for controlling reaction kettle is 160-170 DEG C, reaction Pressure is 0.85-0.9MPa, and the volume fraction for controlling oxygen in reaction kettle is 30-35%, adds chloro- 2, the 3- dichloro of Isosorbide-5-Nitrae-two Anthraquinone and N- carboxyl phthalimide metallic catalyst stop, chloro- 2, the 3- dichloroanthraquinone of the Isosorbide-5-Nitrae-two after reacting 6-8h Additional amount with N- carboxyl phthalimide is respectively the 6-6.5% and 4-4.5% of paraxylene volume；

(2) above-mentioned reaction solution is cooled to room temperature, adds n,N-Dimethylformamide dilution dissolution, the N, N- dimethyl methyl The additional amount of amide is 8-10 times of paraxylene volume, and obtained white crystals or powder are target product.

2. a kind of synthetic method of terephthalic acid (TPA) according to claim 1, it is characterised in that: in the step (1) Solvent is acetonitrile.

Technical field

The present invention relates to technical field of organic synthesis, the synthetic method of specifically a kind of terephthalic acid (TPA).

Background technique

Terephthalic acid (TPA), also known as p- phthalic acid are the maximum dicarboxylic acids of yield, are mainly made by paraxylene, are Produce the primary raw material of polyester.It is solid under room temperature.Heat non-fusible, 300 DEG C or more distil.If being heated in closed container, It can be melted in 425 DEG C.Water is insoluble under room temperature.Mainly for the manufacture of synthesis polyester resin, synthetic fibers and plasticizer etc..

Terephthalic acid (TPA) is just had found in 19th century, until ICI Ltd., Britain in 1949 finds PTA After (or derivatives thereof dimethyl terephthalate (DMT)) is manufacture polyester primary raw material, just start to produce extensively.The world pair in 1981 Phthalic acid yield has reached 3.485Mt.First industrialized production method is nitric acid oxidation method.With the hair of polyester industrial The method for producing terephthalic acid (TPA) from plurality of raw materials, through a variety of ways has been developed in exhibition.It is most economical, using most wide It is the high-temperature liquid-phase oxidizing process using paraxylene as raw material, this method high income, process is short.Paraxylene low-temperature oxidation method reacts item Part is milder, and corrosivity is small, but process is longer, only uses in a small number of factories.Also it has been proposed that first making paraxylene through ammonification oxygen Change reaction and generate terephthalonitrile, then hydrolysis generates PTA, but this method is not mass produced also.

Therefore, for problems existing for above-mentioned synthetic method, the synthetic method for researching and developing a kind of terephthalic acid (TPA) is this The very urgent requirement of industry.

Summary of the invention

The purpose of the present invention is to many deficiencies existing for the synthetic method of above-mentioned terephthalic acid (TPA), provide a kind of anti- Answer the synthetic method of low, high income the terephthalic acid (TPA) of simple, the comprehensive cost of material of route.

The present invention provides a kind of synthetic methods of terephthalic acid (TPA), comprising the following steps:

(1) it takes 20mL to be placed in reaction kettle dimethyl benzene, solvent is added, the temperature for controlling reaction kettle is 160-170 DEG C, reaction Pressure is 0.85-0.9MPa, and the volume fraction for controlling oxygen in reaction kettle is 30-35%, adds chloro- 2, the 3- dichloro of Isosorbide-5-Nitrae-two Anthraquinone and N- carboxyl phthalimide metallic catalyst stop, chloro- 2, the 3- dichloroanthraquinone of the Isosorbide-5-Nitrae-two after reacting 6-8h Additional amount with N- carboxyl phthalimide is respectively the 6-6.5% and 4-4.5% of paraxylene volume；

(2) above-mentioned reaction solution is cooled to room temperature, adds n,N-Dimethylformamide dilution dissolution, the N, N- dimethyl methyl The additional amount of amide is 8-10 times of paraxylene volume, and obtained white crystals or powder are target product.

Preferably, the solvent in heretofore described step (1) is acetonitrile.

The present invention by metallic catalyst by paraxylene oxidative synthesis terephthalic acid (TPA), reaction route under high-temperature low-pressure Simply, comprehensive cost of material is low, high income, and chloro- 2, the 3- dichloroanthraquinone of Isosorbide-5-Nitrae-two is urged with N- carboxyl phthalimide metal The catalytic effect of agent is substantially better than industrial gold metal catalyst, is Selectivity for paraxylene oxidative synthesis p-methylbenzoic acid Industrialized production provides a new way more economical and environmentally friendly.

Specific embodiment