4-Chlorobenzenesulfonic acid NEW

Production method: 

(1) By the p-aminobenzenesulfonic acid through diazotization, elimination of p-aminobenzenesulfonic acid, hydrochloric acid added to water, cooling to 20℃ below, drop sodium nitrite solution, reaction to the end point to obtain diazo solution. In addition, add copper sulfate and sodium chloride to water at about 80℃, and then add basic sodium sulfite solution after all dissolution. Add the reaction for 20 min, cool to room temperature, let it stand, clean the precipitation by pouring method, dissolve it with hydrochloric acid, cool to below 0℃, drop the above diazo solution, that is, p-chlorobenzenesulfonic acid is generated. The reaction solution was heated to 80℃, salted out with salt and filtered to obtain sodium p-chlorobenzenesulfonate. 

(2) The sulfonated chlorobenzene was obtained by adding 98% concentrated sulfuric acid and 10% fuming sulfuric acid into the reaction pot, stirring for 15min, gradually adding dry chlorobenzene, stirring at 95-100℃ for 5h, and checking the sulfonation end point. At the end, the acidity of the reactant is not more than 70%, and it can be completely dissolved in water.

Chemical properties: acicular crystal. The melting point is 67 ° C (68 ° C) and the boiling point is 147-148 ° C (3.33kPa). Soluble in water and ethanol.