4-Aminobut-2-yn-1-ol is a versatile bifunctional intermediate featuring a primary amine, an internal alkyne, and a primary alcohol. It serves as a key building block in the synthesis of pharmaceuticals and biologically active compounds, particularly kinase inhibitors and antitumor agents. The combination of its functional groups enables diverse reactivity, including nucleophilic substitutions, alkyne functionalizations (e.g., via metal-catalyzed couplings), and alcohol modifications, making it valuable in medicinal chemistry for constructing complex heterocycles and enzyme inhibitors. It is also utilized in bioconjugation strategies and the preparation of specialty polymers and functional materials requiring precise molecular architectures.