But-3-en-2-amine hydrochloride is primarily used in organic synthesis as a building block for the preparation of more complex chemical compounds. It serves as a key intermediate in the production of pharmaceuticals, particularly in the development of drugs that target the central nervous system. The compound's structure allows it to participate in various chemical reactions, such as nucleophilic additions and polymerizations, making it valuable in creating polymers and specialty chemicals. Additionally, it is utilized in research settings for the study of amine chemistry and the development of novel organic molecules with potential therapeutic applications.