Used as a reagent in analytical chemistry for the detection and determination of certain ions, particularly in colorimetric methods. It serves as a coupling component in diazo coupling reactions, aiding in the formation of azo dyes for use in spectrophotometric analysis. Also employed in the synthesis of dyes and fluorescent compounds due to its aromatic structure and reactivity. Its derivatives are found in some agrochemicals and pharmaceutical intermediates. Additionally, it has been used in research settings for studying reaction mechanisms involving amines and electrophilic aromatic substitution.