Pyrrolidine, also known as tetrahydropyrrole, is a saturated five-membered heterocyclic ring, which is miscible with water. Pyrrolidine exists in many alkaloids and drug molecules, such as kappa opioids, antagonists of dopamine D4 receptors, and HIV reverse transcriptase inhibitors.
The use of azepane as a scaffold for drug discovery remains of interest. The azepane linker is the key to efficient activity. A number of seven-membered ring derivatives have been prepared or investigated for their potential or actual pharmacological properties. Examples include azaalkane derivatives as PKB (protein kinase B) inhibitors.