The Thermal Rearrangement of Dipotassium Salicylate under Increasing Gaseous Pressure

Abstract

The rearrangement of dipotassium salicylate (SA-K₂) under active or inert gaseous pressure was studied by using the micro thermal analyses and UV.
Under N₂, an exothermic peak is attributed to the formation of p-hydroxy benzoic acid, the second endothermic peak is attributed to that of intermediate (4-hydroxy isophthalic acid), and the first endothermic peak is attributed to evolved gases (phenol + CO₂) owing to the fusion of SA-K₂.
Under Co₂, the above reactions proceeded vigorously, and two endothermic peaks overlapped. Though both the period and the amount of evolved gases vary with the pressure and the rearrangement rate increases with the pressure, two rearrangements were similar in the higher temperature range.