- Preparation process for terephthaloyl chloride
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The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation process for terephthaloyl chloride. Under the irradiation of a LED light source, an excesschlorine gas is introduced into a p-xylene to obtain crude product of 1.4-2 (trichloromethyl) benzene, excess chlorine gas is absorbed by alkali liquor; the obtained crude product of 1,4-2 (trichloromethyl) benzene and a terephthalic acid react under the action of a catalyst, adopt nitrogen to drive out the hydrogen chloride gas produced by the reaction until no hydrogen chloride gas is released,and a crude product of the terephthaloyl chloride is obtained; decolorizing agent is added to the crude product of terephthaloyl chloride, and the terephthaloyl chloride is obtained by rectification under vacuum. The preparation process has the advantages of simple process, easy-to-get raw materials, low cost, convenient operation, high product quality, stable quality and the like.
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Paragraph 0023; 0024; 0027; 0028; 0031; 0032
(2019/01/23)
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- A second (trichloromethyl) benzene and two (chloroformyl) benzenetrisamide preparation method
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The present invention relates to a method for preparing bis(trichloromethyl)benzene through a photochemical reaction and preparing bis(chloroformyl)benzene through the further reaction of the bis(trichloromethyl)benzene. According to the present invention, di(methyl)benzene is added to a reactor, chlorine gas is introduced under the control of the illuminance of an incident light source and the reaction temperature, the obtained reaction mixture is subjected to a simple treatment so as to obtain the high purity bis(trichloromethyl)benzene; with the bis(trichloromethyl)benzene of the present invention, the high purity bis(chloroformyl)benzene, one of the aramid fiber production raw materials, can be conveniently obtained; and the preparation method of the present invention has the following advantages that the solvent, the free radical initiator, the photosensitizer and other third components can not be inproduced, and only the stage-control of the reaction condition and the wavelength and the intensity of the light source are required so as to improve the product purity.
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Paragraph 0102; 0103
(2017/02/24)
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- B (trichloromethyl) benzene molecular distillation purification method
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The invention discloses a method for purifying bi(trichloromethyl)phenyl, in which a molecular distillation and purification technology is introduced. The method comprises the following steps of: firstly, pre-processing crude bi(trichloromethyl)phenyl, and eliminating light components in the bi(trichloromethyl)phenyl; carrying out primary molecular distillation of the pre-processed bi(trichloromethyl)phenyl, thus obtaining a distillate, namely high-purify bi(trichloromethyl)phenyl; and optionally, further carrying out secondary molecular distillation on the distilled residues obtained in primary molecular distillation. According to the invention, the problems of being easy to polymerize and coke in the purification process of the bi(trichloromethyl)phenyl are solved; and the method has the advantages of being high in yield and purity, energy-saving, environmentally friendly and the like.
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Paragraph 0034; 0035; 0036
(2017/01/02)
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- METHOD FOR THE PREPARATION OF TRICHLOROMETHYL-GROUP-SUBSTITUTED BENZENE
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The present application relates to a method for photochlorination, and specifically to photochlorination by a photochemical reaction of an aromatic compound with gaseous chlorine so as to prepare a trichloromethyl-substituted benzene, and to a method using bis-(trichloromethyl)-benzene as the trichloromethyl-substituted benzene to prepare by further reaction bis-(chloroformyl)-benzene. Through the control of temperature, illuminance and consumption of gaseous chlorine, the method of this application can greatly improve the purity of trichloromethyl-substituted benzene and further prepare polymer-grade bis-(chloroformyl)-benzene with low cost. The present application also relates to a method for purifying trichloromethyl-substituted benzene, and specifically to a method for purifying trichloromethyl-substituted benzene via molecular distillation. The present application further relates to a photochlorination reactor for use in photochlorination reactions (such as those of the present application).
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Paragraph 0140
(2016/06/28)
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