L-748,337 is primarily utilized in research settings as a selective antagonist for the beta-2 adrenergic receptor. Its application is significant in studying the role of beta-2 receptors in various physiological processes, including smooth muscle relaxation, bronchodilation, and cardiovascular function. Researchers use this compound to explore the mechanisms underlying asthma, chronic obstructive pulmonary disease (COPD), and other conditions where beta-2 receptors play a critical role. Additionally, it aids in understanding the signaling pathways and potential therapeutic targets for these diseases. Its specificity makes it a valuable tool in pharmacological studies aimed at developing more effective treatments for respiratory and cardiovascular disorders.