Used in the synthesis of fluorescent dyes and probes due to its reactive chloromethyl group, which readily undergoes substitution with nucleophiles. Commonly employed in labeling biomolecules for imaging applications in biological research. Also serves as an intermediate in the preparation of pharmaceuticals and agrochemicals, where the benzothiazole core contributes to bioactivity. Its ability to form stable conjugates makes it valuable in developing sensors and diagnostic reagents.