O-Bromobenzaldehyde is an ortho-substituted aromatic aldehyde featuring a bromine atom at the 2-position of the benzaldehyde ring. Its molecular formula is C7H5BrO, and it exists as a pale yellow to light brown liquid or low-melting solid. The compound is characterized by the presence of both a reactive aldehyde group and a labile bromine atom, making it a versatile bifunctional building block in organic synthesis. As a key synthetic intermediate, o-Bromobenzaldehyde is widely employed in the construction of complex molecules via cross-coupling reactions, such as Suzuki, Heck, and Sonogashira couplings, where the bromine serves as an excellent leaving group. The aldehyde moiety allows for further transformations including reductive amination, Grignard addition, and condensation reactions. In the pharmaceutical industry, it serves as a crucial precursor for the synthesis of various drug candidates, including heterocyclic compounds, anti-inflammatory agents, and central nervous system (CNS) active molecules. It is also utilized in the preparation of ligands for metal catalysts and functional materials. The compound should be stored in a cool, dry, well-ventilated area away from strong oxidizing agents and light to prevent degradation. It is classified as an irritant and requires standard laboratory safety precautions, including the use of gloves and eye protection during handling.