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.
Cyclopropane is the smallest cyclic compound with unique structural features and physicochemical properties, which is widely used in the design of small molecule drugs. In drug design, it is often used to increase activity, fix conformation and improve PK and water solubility. The introduction of cyclopropyl groups into drugs can change various properties of molecules, such as improving metabolic stability; increasing biological activity; enhancing drug efficacy; limiting polypeptide conformation and slowing down its hydrolysis; reducing plasma clearance; improving drug dissociation and many more. Cyclopropane rings are widely found in marketed drugs, including cardiovascular drugs, central nervous system (CNS) drugs, anticancer drugs, autoimmune and anti-inflammatory drugs.
Pyrrole is a five membered heterocyclic compound with the molecular formula of C4H5N. Pyrrole has a ring composed of four carbon atoms and one nitrogen atom. Pyrrole is easy to polymerize in the air. Pyrrole is the parent compound of many important biological substances (such as bile pigment, porphyrin and chlorophyll). Pyrrole scaffolds are widely used in biological and pharmaceutical fields. Pyrrole is a special heterocyclic scaffold, which exists in many natural products, drug molecules and pesticides, and has shown its application in materials science.