A kind of method for preparing p-toluenesulfonic acid by toluene sulfonation

A technology of p-toluenesulfonic acid and toluene, which is used in the preparation of sulfonic acid, chemical recovery, organic chemistry, etc., can solve the problems of sulfonation microreactor technology, such as the lack of data to check, and achieve the effect of process safety and continuity

Active Publication Date: 2016-05-25
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] By searching the prior art literature, toluene liquid phase SO 3 The high-selectivity technology of sulfonation (the selectivity of the product p-toluenesulfonic acid is more than 95%) has not been reported yet, and the toluene liquid phase SO 3 Sulfonated microreactor technology also has no information to check

Method used

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  • A kind of method for preparing p-toluenesulfonic acid by toluene sulfonation
  • A kind of method for preparing p-toluenesulfonic acid by toluene sulfonation

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Embodiment 1

[0021] Embodiment 1: low concentration, equimolar reaction process

[0022] Reaction operating conditions: the initial concentration of toluene is 10wt% (the solvent is 1,2-dichloroethane), the initial concentration of sulfur trioxide is 5wt% (the solvent is 1,2-dichloroethane), and the reactant toluene and three The flow rate of sulfur oxide solution, make toluene and sulfur trioxide mol ratio be 1:1, the ratio of the total volume flow sum of both and reaction microchannel volume is 13000 hours -1 (that is, the apparent residence time is 0.28s), and reacted at a reaction temperature of 28°C, the product was separated by filtration, and the separated solid was dried in an oven at 50°C until constant weight. A certain mass of solid product was weighed and dissolved in triethyl orthoformate, and esterified at 115° C. for 1 h, and the esterified product was analyzed by gas chromatography. Gas chromatography conditions: nitrogen as carrier gas, hydrogen flame ionization detector ...

Embodiment 2

[0024] Embodiment 2: Equal volume, circulation reflux process

[0025] With reference to Example 1, it can be seen that at a toluene concentration of 10wt.%, SO 3 Concentration 5wt.%, temperature of reaction are close to under normal temperature, p-toluenesulfonic acid content is nearly 95% in the product, according to this result, improve reactant toluene concentration, make it excessive, react and filter the toluene concentration in the mother liquor to reduce according to the reaction rate, can Reflux continues to react as a reactant without affecting product concentration, so the present invention proposes a mother liquor circulation and low-temperature micro-reaction process.

[0026] The operating conditions are: the initial concentration of toluene is 50wt% (the solvent is 1,2-dichloroethane), the initial concentration of sulfur trioxide is 5wt% (the solvent is 1,2-dichloroethane), and the reaction temperature is 28°C. The residence time is 0.28s, feed and react at the...

Embodiment 3

[0029] Embodiment 3: high concentration, equal volume, circulation reflux process

[0030] With reference to Example 2, it can be seen that at a toluene concentration of 50wt.%, SO 3 Concentration of 5wt.%, reaction temperature close to normal temperature, and under the operating conditions of three cycles of reflux, the content of p-toluenesulfonic acid in the product reaches 96.36%, and the analysis shows that the by-product sulfone circulates with the mother liquor as a reaction material, which inhibits the formation of phenylsulfone. The p-toluenesulfonic acid product concentration can be increased. According to this result and deduction, continue to improve reactant toluene concentration, make it excessive, reduce solvent consumption, toluene concentration in filter mother liquor after reaction reduces successively according to reaction rate, repeatedly reflux continues reaction as reactant and does not affect product concentration, therefore It is expected to further in...

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Abstract

The invention discloses a method for preparing p-toluenesulfonic acid through toluene sulfonation in a micro-reactor. The method is characterized in that a low-concentration liquid SO3 is taken as a sulfonating agent, an excess feeding ratio of toluene to SO3 is employed, and in the sulfonation technology, a high-concentration toluene is used for feeding and a product mother liquor (filtrate) is cycled. Also, a micro-channel in-situ heat exchange technology is employed for precisely regulating the sulfonation reaction temperature. The method has the advantages that liquid sulfur trioxide is taken as the sulfonating agent, no waste acid is basically generated in products, separation is easy to operate, the concentration of the main product p-toluenesulfonic acid is 97%, and the micro-reaction sulfonation technology is safe and continuous in process and high in efficiency.

Description

technical field [0001] The invention belongs to the technical field of synthesis of fine chemical raw materials, and in particular relates to a method for preparing p-toluenesulfonic acid through liquid-phase sulfonation of toluene in a microreactor. Background technique [0002] Sulfonation reaction occupies an important position in the field of modern chemical industry, and is an important step in the synthesis of various organic products. It is widely used in industries such as medicine, pesticides, dyes, detergents and petroleum. Sulfonation reaction is a kind of reaction that introduces sulfonic acid groups into aromatic hydrocarbon compounds. After the introduction of sulfonic acid groups, organic compounds have specific functions such as water solubility, easy transformation, and hydrolysis. Correspondingly, sulfonated products can be directly used as surfactants Product application, or continue to convert as an intermediate product into intermediates or products cont...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C309/30C07C303/06
CPCY02P20/582
Inventor 陈光文陈彦全焦凤军韩梅
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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