A Scalable Preparation and Thermal Analysis of Pentafluorophenyl Iodine(III) Diacetate

Pentafluorophenyl iodine(III) diacetate (F5-PIDA) is an electron-deficient hypervalent iodine(III) reagent with growing utility in modern synthetic methodology, including iodine(III)-mediated ring-expansion chemistry. However, its application as a stoichiometric reagent requires reliable access to preparative amounts. This article describes a practical chromatography-free protocol for the preparation of F5-PIDA on a ca. 300 g scale by the oxidation of pentafluoroiodobenzene with sodium hypochlorite pentahydrate in acetic acid. The product was isolated by a simple slurry trituration in the hexane/MTBE mixture giving F5-PIDA in the yield of 65% and the purity of ≥ 98%. The thermogravimetry-differential thermal analysis has shown that F5-PIDA is stable up to approximately 100-110 °C, while the rapid decomposition occurs above this temperature range. The protocol developed provides a reliable preparative access to high-purity F5-PIDA and practical thermal data for its safe use.