Quinoline hydrochloride is widely used in the pharmaceutical industry as an intermediate in the synthesis of various drugs, particularly antimalarial medications like chloroquine and quinine. It also plays a role in the production of antiseptics and antimicrobial agents. In the chemical industry, it serves as a catalyst or reagent in organic synthesis, aiding in the creation of dyes, pigments, and other complex compounds. Additionally, it is utilized in research laboratories for studying chemical reactions and developing new compounds due to its versatile properties.