阅读说明：本技术 一种间苯二甲酸的合成方法 (A kind of synthetic method of M-phthalic acid ) 是由 吴水保 于 2018-05-25 设计创作，主要内容包括：一种间苯二甲酸的合成方法,包括以下步骤：(1)取20mL间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间二甲苯体积的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间二甲苯在高温低压下氧化合成间苯二甲酸,反应路线简单、综合原料成本低、收率高。(A kind of synthetic method of M-phthalic acid, the following steps are included: (1) takes dimethyl benzene between 20mL to be placed in reaction kettle, 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 meta-xylene volume, and obtained white crystals or powder are target product；The present invention by metallic catalyst by meta-xylene the oxidative synthesis M-phthalic acid 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 M-phthalic acid, it is characterised in that the following steps are included:

(1) it takes dimethyl benzene between 20mL to be placed in reaction kettle, 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 meta-xylene 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 meta-xylene volume, and obtained white crystals or powder are target product.

2. a kind of synthetic method of M-phthalic acid 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 M-phthalic acid.

Background technique

M-phthalic acid, also known as p- phthalic acid are the maximum dicarboxylic acids of yield, are mainly made by meta-xylene, 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..

M-phthalic acid is just had found in 19th century, until ICI Ltd., Britain in 1949 finds PTA After (or derivatives thereof dimethyl isophthalate) is manufacture polyester primary raw material, just start to produce extensively.Between the worlds 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 M-phthalic acid 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 meta-xylene as raw material, this method high income, process is short.Meta-xylene 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 meta-xylene through ammonification oxygen Change reaction and generate m-dicyanobenzene, 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 M-phthalic acid 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 M-phthalic acid, provide a kind of anti- Answer the synthetic method of low, high income the M-phthalic acid of simple, the comprehensive cost of material of route.

The present invention provides a kind of synthetic methods of M-phthalic acid, comprising the following steps:

(1) it takes dimethyl benzene between 20mL to be placed in reaction kettle, 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 meta-xylene 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 meta-xylene 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 meta-xylene oxidative synthesis M-phthalic acid, 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, synthesizes m-methyl benzoic acid for meta-xylene selective oxidation Industrialized production provides a new way more economical and environmentally friendly.

Specific embodiment