4-aminobenzoic acid

4-Aminobenzoic acid (CAS 150-13-0), commonly known as PABA or para-aminobenzoic acid, is an aromatic amino acid derivative used as a key building block in pharmaceutical synthesis. Its bifunctional structure, carrying both an amine and a carboxylic acid group, makes it a reactive intermediate for producing dyes, UV absorbers, and active pharmaceutical ingredients.

In pharmaceuticals, PABA serves as a precursor in the synthesis of local anesthetics such as benzocaine and procaine, as well as folate-class compounds for various medical uses. Textile and leather processors use it as an intermediate in azo dye production, where it contributes to colorfast, high-affinity dye systems for natural and synthetic fibers.

In sunscreen and personal care formulations, PABA derivatives function as UV-B absorbing agents, though demand has shifted toward its ester forms in recent years. It also acts as a crosslinking and surface-modifying agent in specialty polymer and coating applications, providing versatility across multiple industrial chemical sectors.

4-Aminobenzoic acid is supplied as a white to off-white crystalline powder. Standard commercial grades include technical and pharmaceutical-grade material for diverse needs. The pharmaceutical supply conforms to USP and BP specifications. Bulk quantities are available for industrial synthesis, with smaller quantities offered for R&D use.