5-Ethynylpyrazin-2-amine is used in pharmaceutical research as a building block for kinase inhibitors, particularly in the development of anticancer agents. The ethynyl group and pyrazine core enable selective interactions with biological targets and versatile derivatization, making it valuable for synthesizing compounds that modulate cell signaling pathways. It is also employed in medicinal chemistry for structure-activity relationship (SAR) studies, enhancing binding affinity and metabolic stability in drug candidates. Additionally, the terminal alkyne facilitates click chemistry reactions to form triazole-linked conjugates for biolabeling and diagnostic applications.