Used as a key building block in medicinal chemistry, particularly in the design of bioisosteres. Its rigid, three-dimensional structure makes it ideal for replacing phenyl rings or tert-butyl groups in drug molecules, improving pharmacokinetic properties such as metabolic stability and solubility. Commonly employed in the development of CNS drugs, agrochemicals, and PET tracers due to its ability to modulate lipophilicity and enhance target selectivity. The carboxylic acid functionality allows for easy derivatization, enabling rapid incorporation into complex molecules through standard coupling reactions.