Modified and Scalable Synthesis of N-Tosyl-4-Chlorobenzenesulfonimidoyl Fluoride (SulfoxFluor): Direct Imidation of Sulfinyl Chlorides with Chloramine-T Trihydrate

N-Tosyl-4-chlorobenzenesulfonimidoyl fluoride (SulfoxFluor) has emerged as a new fluorination reagent that can be used in the rapid deoxyfluorination of various alcohols. We disclose in this article a general and practical method for the preparation of SulfoxFluor and its adaption to a large scale. Starting from readily available 4-chlorobenzenesulfonyl chloride, chloramine-T trihydrate, and potassium fluoride, SulfoxFluor was prepared on a hectogram scale in 63% overall yield with simple purification techniques. The use of chloramine-T trihydrate (instead of anhydrous chloramine-T) is a significant improvement over previous work, which streamlines the process and avoids the risk of explosion during drying or heating. This research not only establishes a reliable method for the scale-up synthesis of SulfoxFluor but also provides an insight into the imidation of sulfinyl chlorides with chloramine-T in the presence of water.