Used as a reagent in analytical chemistry for the detection and determination of primary aromatic amines and indoles. It forms intensely colored condensation products, making it valuable in colorimetric assays. Commonly employed in the Ehrlich’s reagent for identifying indoles in urine, drugs, and biological samples. Also applied in the development of dyes and in organic synthesis as an intermediate for pharmaceuticals and agrochemicals. Its strong electron-donating group enhances reactivity in electrophilic substitution reactions.