Fusion heterocyclic compounds have various biological activities, such as anticancer, antibacterial, antifungal and anti-inflammatory, and thus have been widely used in the field of medicinal chemistry. Pyrrolopyrimidines are a major class of fused heterocyclic compounds. Compared with single pyrrole and pyrimidine cores, pyrrolopyrimidines have more diverse and effective pharmacological characteristics as fusion scaffolds.
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 molecular structure of cyclobutane has four carbon atoms, and its four carbon atoms are not in the same plane, which is the folded conformation of cyclobutane. Cyclobutane itself is not of commercial or biological interest, but more complex derivatives are important in biology and biotechnology. Currently, nine FDA-approved drugs contain the cyclobutane structure. From the perspective of therapeutic areas, cyclobutyl drugs are mainly distributed in popular areas such as tumors, neurological diseases, infectious diseases, endocrine and metabolic diseases.