4-Bromobutyryl chloride（Cat No.:R030432）is a reactive acyl halide featuring a four-carbon butyryl chain with a bromine atom at the terminal (4-) position and an acyl chloride group at the 1-position. This bifunctional molecule is widely used in organic synthesis for introducing both acyl and haloalkyl functionalities. The acyl chloride group readily undergoes nucleophilic substitution with amines, alcohols, or thiols to form amides, esters, and thioesters, while the bromo group enables further derivatization through substitution or elimination reactions. It is commonly employed in pharmaceutical, polymer, and agrochemical intermediate synthesis.