Methyl 3-(4-aminophenyl)propanoate is a key aromatic amino ester intermediate with both amino and ester functional groups, enabling diverse synthetic transformations. Its primary application lies in pharmaceutical synthesis, serving as a critical building block for developing anti-inflammatory, analgesic, and anti-cancer drug candidates. It undergoes diazotization, acylation, and condensation reactions to construct complex drug skeletons, particularly for molecules targeting inflammatory pathways or tumor cells. In organic chemistry research, it acts as a standard substrate for studying aromatic substitution and ester hydrolysis mechanisms, supporting the development of novel synthetic methodologies. Additionally, it is utilized in the production of fine chemicals, such as azo dyes and fluorescent pigments, where the amino group facilitates colorant conjugation. It also serves as a precursor for polymer additives, enhancing the compatibility of polymers with organic fillers. With high purity and good chemical stability, it is widely used in laboratory-scale synthesis and industrial fine chemical manufacturing, playing a vital role in the pharmaceutical and advanced materials sectors.

This compound is classified as a mild irritant with low acute toxicity. Inhalation of dust may cause slight irritation to the respiratory tract; thus, wear a dust-proof mask and ensure adequate ventilation during handling. Direct skin contact may lead to local redness, itching, or dryness; operators must wear nitrile gloves and wash skin thoroughly with soap and water after contact. Eye contact causes stinging and discomfort; immediately flush eyes with plenty of running water for over 15 minutes and seek medical attention if irritation persists. Accidental ingestion in small doses may cause mild gastrointestinal discomfort (nausea, vomiting); do not induce vomiting and seek medical treatment promptly. It is chemically stable under normal conditions but incompatible with strong oxidants and strong bases; avoid high temperature (over 150 °C) to prevent decomposition. Store sealed in a cool, dry, dark place. Dispose of waste in accordance with local hazardous waste regulations; do not discharge arbitrarily to avoid environmental pollution.