3-Bromo-4-fluorobenzaldehyde is a bifunctional aromatic building block featuring a bromine atom at the 3-position, a fluorine atom at the 4-position, and an aldehyde group. Its molecular formula is C7H4BrFO, with a molecular weight of 203.01 g/mol. The compound is a pale yellow to light brown solid or liquid at room temperature, commonly used in organic synthesis due to its reactive sites. This compound serves as a key intermediate in the pharmaceutical industry, particularly for constructing small-molecule drug fragments targeting neurological disorders and anticancer agents. The aldehyde group enables further functionalization via reductive amination or condensation reactions, while the bromine atom facilitates cross-coupling reactions such as Suzuki or Heck couplings. Additionally, it is widely employed as a versatile synthetic building block in medicinal chemistry for structure-activity relationship (SAR) studies. As a halogenated benzaldehyde derivative, it is also utilized in the synthesis of agrochemicals and functional materials. It should be stored under inert atmosphere and away from strong oxidizing agents to maintain stability.