Used as an intermediate in the synthesis of pesticides, dyes, and pharmaceuticals. Commonly employed in the production of parathion, an organophosphate insecticide. Serves as a precursor in the manufacture of certain analgesics and antipyretics. Utilized in biochemical assays as a chromogenic substrate to measure enzyme activity, particularly in studies involving phosphatases and esterases, due to its distinct color change upon reaction. Also applied in environmental studies to monitor degradation processes and assess the efficiency of wastewater treatment methods.