Used primarily as a sulfonylation reagent in organic synthesis, enabling the introduction of the 2,6-difluoro-4-nitrobenzenesulfonyl (DNBS) group to amines and alcohols. This derivatization enhances detection and purification in analytical and medicinal chemistry workflows. The electron-withdrawing fluorine and nitro groups increase the reactivity of the sulfonyl chloride, making it effective under mild conditions. It is particularly useful in peptide chemistry and in the preparation of sulfonamide-based pharmaceuticals, where selective protection or activation is required. The DNBS group can also serve as a chromophore or auxiliary in stereochemical control due to its strong UV absorbance and steric profile.