2494-89-5Relevant articles and documents
Para-ester synthesis method and para-ester
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Paragraph 0059-0170, (2020/05/05)
The invention discloses a para-ester synthesis method which comprises the following steps: S1, adding a set amount of chlorosulfonic acid and acetanilide into a sulfonation reaction kettle, adding thionyl chloride, and carrying out a reaction to prepare a sulfonated product, wherein the molar ratio of acetanilide to chlorosulfonic acid to thionyl chloride is (0.45-0.46):1:(0.46-0.47); S2, dilutingthe sulfonated substance and then carrying out suction filtration; S3, adding pyronitrite, adjusting a stable pH value, and carrying out a reduction reaction to obtain a reduction solution; S4, taking sodium phosphate as a buffer agent, adding sulfuric acid and ethylene oxide, and carrying out condensation reaction to obtain a condensation product; S5, carrying out suction filtration on the condensation product; S6, adding sulfuric acid into a product obtained after suction filtration, and carrying out an esterification reaction; and S7, crushing and packaging the product obtained after the esterification reaction to prepare the para-ester. The invention also discloses the para-ester. According to the synthetic method disclosed by the invention, the dosage of chlorosulfonic acid is reduced, thionyl chloride is used for replacing part of chlorosulfonic acid, and the para-ester yield is improved by optimizing the ratio.
Preparation method of para-ester
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, (2018/04/01)
The invention provides a preparation method of para-ester. The preparation method of para-ester comprises the following steps: under the existence of phosphorus pentoxide, carrying out chlorosulfonation on N-phenylacetamide and chlorosulfonic acid as well as thionyl chloride, thus obtaining a chlorosulfonation composition; and sequentially carrying out reduction reaction, condensation reaction andesterification reaction on the chlorosulfonation composition, thus obtaining para-ester. Compared with the prior art, the preparation method has the advantages that phosphorus pentoxide is added in chlorosulfonation, a balance state is broken, the balance moves to the direction in which 4-acetamidobenzenesulfonyl azide is generated, the conversion rate of N-phenylacetamide is increased, namely the yield of chlorosulfonation is increased, and meanwhile, excessive chlorosulfonic acid is avoided, so that wastewater pollution is alleviated.
An environment-friendly to-(β-hydroxyethyl sulphone sulfate) method for the synthesis of aniline
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Paragraph 0024-0025, (2017/06/20)
The invention discloses a synthesis method of environmental-friendly p-(beta-sulfatoethylsulfonyl) aniline. The synthesis method comprises the following steps: (1) in the presence of a chlorination inhibitor, carrying out sulfonation reaction on acetanilide and chlorosulfonic acid, and then carrying out chlorination reaction on the obtained product and thionyl chloride, so that a chlorosulfonation substance is obtained; and (2) sequentially carrying out condensation reaction, sulfonating reaction and hydrolysis reaction on the chlorosulfonation substance obtained in the step (1), so that environmental-friendly p-(beta-sulfatoethylsulfonyl) aniline is obtained. According to the preparation method, by changing a production formula, introducing the chlorination inhibitor, and changing the reaction reactivity of reaction raw materials, p-chloroacetanilide byproducts are greatly reduced, so that an effect that a para-ester product parachloroaniline meets the standard is finally achieved.