Drug synthesis intermediates:
1. Used as a precursor for the production of folic acid (vitamin B9), which is an essential nutrient for cell division and DNA synthesis.
2. Synthesize sulfonamide drugs (such as sulfamethoxazole), which were initially used as antibiotics.
3. Raw materials for local anesthetics (such as benzocaine) (esterified to produce ethyl para aminobenzoate).

Industrial and scientific research purposes:
1. Dye intermediates: used for synthesizing azo dyes or other colored compounds.
2. Chemical reagents: used as amino protecting groups or to construct benzene ring structures in organic synthesis.