1-Benzotriazol-1-yl-3-chloropropan-2-one is a key intermediate and reactive reagent in organic synthesis, particularly for pharmaceuticals, agrochemicals, and fine chemicals. The benzotriazol-1-yl group serves as an effective leaving group, while the 3-chloropropan-2-one moiety enables nucleophilic substitutions, facilitating the formation of carbon-carbon and carbon-heteroatom bonds. It is widely used in the preparation of heterocyclic compounds, functionalized ketones, and complex molecular architectures for drug discovery and medicinal chemistry.