2518-24-3Relevant articles and documents
Method of preparing 2-chlorosulfonylmethyl benzoate from phthalic anhydride and urea
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Paragraph 0029, (2017/01/17)
The invention provides a method of preparing 2-chlorosulfonylmethyl benzoate from phthalic anhydride and urea. The method includes the steps of 1) adding solid phthalic anhydride and urea into a reaction kettle and heating the materials to 135-143 DEG C to carry out a reaction to prepare o-aminobenzene dicarboximide, feeding the o-aminobenzene dicarboximide with water and sodium hydroxide into a first tubular reactor, forcedly cooling the mixture to -12 - -15 DEG C; 2) adding methanol and a sodium hypochlorite solution to perform Hoffman degradation reaction, and separating the reaction product to obtain o-aminomethyl benzoate; 3) according to the same mass ratio, feeding the o-aminomethyl benzoate and a sodium nitrite solution to a second tubular reactor, cooling the reactants to 0 DEG C, and adding sulfuric acid to perform a diazo-reaction for 11.5-11.8 s; and 4) continuously performing a cyclic sulfurization oxidation tubular reaction for 2 h, when the reactants show a dark green color on an benzidine-ethylamine test paper, adding methylbenzene and separating the reactant to obtain the 2-chlorosulfonylmethyl benzoate. The method is safe and simple, is advanced and integrated, is high in synthesis efficiency, has less side reactions and greatly reduces influence due to human factors.