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.
Tetrazoles are doubly unsaturated five-membered aromatic heterocycles consisting of one carbon atom and four nitrogen atoms. Tetrazole derivatives are a major class of heterocyclic compounds that are important for medicinal chemistry and drug design because of their not only isosteric properties with carboxylic acid and amide moieties, but also metabolic stability and other beneficial physicochemical properties.