- Method for synthesizing disperse red 92
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The invention relates to the field of fine chemical engineering, in particular to a method for synthesizing disperse red 92. The method comprises the following steps: dissolving disperse red 60 solidin an inert solvent for dissloving; adding chlorosulfonic acid and thionyl chloride into an obtained disperse red 60 solution, and carrying out thermal-insulation sulfonylation reaction; after the sulfonylation reaction is finished, adding sodium carbonate until a reaction solution is neutral; adding sodium carbonate and ethoxypropylamine for thermal insulation reaction; after the reaction is finished, distilling and recycling the solvent, and carrying out filter pressing and washing on an obtained material to obtain a disperse red 92 finished product. Compared with the prior art, the method has the advantages that the use amount of chlorosulfonic acid is greatly reduced, waste acid emission is reduced, and emission of a large amount of hydrogen chloride gas generated in the dilution process of excessive chlorosulfonic acid is reduced; an original two-step operation is changed into one-step operation, so that the production process is simplified; a filter pressing and washing process is omitted, so that the loss of materials in an intermediate operation process is reduced, and the yield of the product is increased.
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Paragraph 0032-0046
(2020/02/10)
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