Indolin-5-amine dihydrochloride is primarily used in pharmaceutical research and development. It serves as a key intermediate in the synthesis of various biologically active compounds, particularly those targeting neurological and psychiatric disorders. Its structure is often utilized to develop inhibitors for specific enzymes or receptors involved in disease pathways. Additionally, it is employed in the creation of small molecule drugs for cancer therapy, where it contributes to the design of compounds that can modulate cell proliferation or apoptosis. This chemical is also valuable in organic chemistry studies for exploring novel reactions and mechanisms. Its applications extend to the development of dyes and pigments, where its aromatic amine structure is leveraged for color formation.