Used as a key intermediate in the synthesis of pharmaceutical compounds, particularly in the development of antimalarial drugs. Its sulfonyl chloride group readily reacts with amines and alcohols, making it valuable for constructing sulfonamide and sulfonate ester derivatives. It is also employed in the preparation of biologically active molecules in medicinal chemistry research, where the quinoline scaffold contributes to target binding and pharmacokinetic properties. Additionally, it serves as a building block in agrochemicals and dyes due to its aromatic and reactive functional group.