CGS 21680 HCl is primarily utilized in research settings to study adenosine receptor activity, particularly the A2A subtype. It is widely used in pharmacological studies to investigate the role of adenosine receptors in various physiological processes, such as cardiovascular function, inflammation, and neuroprotection. This compound is also employed in experiments exploring its potential therapeutic effects in conditions like Parkinson's disease, where A2A receptor modulation is of interest. Additionally, it serves as a valuable tool in understanding the mechanisms of adenosine signaling in the central nervous system and its implications for drug development.