Hydrochloric Acid → HCID 53652618, compound

Participants

Reaction Conditions

Reaction Steps

44.0 gm (0.157 mol) of the above 2-carboxy-benzo[b]thiophene-3-sulfonic acid mono sodium salt were suspended in 200 cc of phosphorus oxychloride and admixed with 65.4 gm (0.314 mol) of phosphorus-(V)-chloride. To complete the reaction which was exothermic in the beginning accompanied by evolution of hydrogen chloride, the reaction mixture was heated to 100° C. for 2 hours, cooled and the inorganic salts were filtered off. After evaporation in vacuo, the residue was taken up in 300 cc of dry chloroform, the solution was filtered and again evaporated. The oily residue, consisting of 27 gm (58% of theory) of raw 2-chlorocarbonyl-benzo[b]thiophene-3-sulfonic acid chloride, crystallized upon cooling (m.p. 45°-47° C.) and was used without further purification in the next step.

Provenance & Evidence