Used primarily as an intermediate in the synthesis of sulfa drugs and other pharmaceuticals. It plays a key role in the preparation of sulfonamide-based compounds, which exhibit antibacterial, antifungal, and anti-inflammatory properties. Its reactivity allows for the introduction of sulfonamide groups into complex molecules, making it valuable in medicinal chemistry for drug development. Also utilized in the production of agrochemicals and dyes due to its ability to form stable aromatic sulfonate esters and amides.