This compound, known as 3,4-bis((((9H-fluoren-9-yl)methoxy)carbonyl)amino)benzoic acid or Fmoc-protected 3,4-diaminobenzoic acid, serves as a building block in peptide synthesis. The fluorenylmethoxycarbonyl (Fmoc) groups protect the amino groups at the 3 and 4 positions of the benzoic acid scaffold, preventing unwanted reactions and enabling precise stepwise assembly of peptide chains via solid-phase synthesis. The carboxylic acid group allows for coupling to growing peptide chains, while the Fmoc protections are orthogonally removed under mild basic conditions. This bifunctional linker is essential for incorporating aromatic diamine moieties into complex peptides, proteins, and peptidomimetics used in pharmaceutical development, biotechnology, and biochemical research.