C4H5NO3

C4H5NO3 is a chemical compound with the molecular formula C4H5NO3. It is a derivative of acetic acid, specifically an ester of acetic acid with an amino group. The compound is commonly known as para-aminobenzoic acid or pABA. It is a white crystalline powder that is soluble in water and has a melting point of approximately 250°C. pABA is used in the synthesis of various pharmaceuticals and dyes. It is also a precursor in the production of certain antibiotics and antimalarial drugs. In biological systems, pABA serves as an intermediate in the synthesis of folic acid, which is essential for DNA synthesis and repair. The compound is classified as a weak acid and has a pKa value of around 4.2. Its chemical structure includes a benzene ring with an amino group (-NH2) and a carboxyl group (-COOH) attached to it. pABA is also known to have antioxidant properties and is sometimes used in skincare products for its potential benefits in protecting against oxidative stress.