4-Aminoantipyrine is widely used in biochemical and clinical laboratories as a reagent for the determination of phenolic compounds. It is particularly employed in colorimetric assays to detect the presence of phenols in water, biological fluids, and environmental samples. The chemical reacts with phenols in the presence of an oxidizing agent to form a colored complex, which can be measured spectrophotometrically, allowing for quantitative analysis. Additionally, it is utilized in the synthesis of various pharmaceutical compounds, including antipyretics and analgesics, due to its structural properties. In industrial settings, it serves as an intermediate in the production of dyes and other organic chemicals. Its role in enzymatic assays, such as the detection of hydrogen peroxide, also highlights its importance in biochemical research and diagnostics.