Over the past few years, many pyrazole fused-ring systems, especially with applications in medicinal chemistry, have been published. These include general structures such as pyrazoline, pyrazoline, pyrazoquinoline, pyrazoloisoquinoline, pyrazoline, pyrazolopyrazine, pyrazolopyrazine, pyranopyrazole, pyrano Pyrazoles, pyrazolotriazines and pyrazole fused phosphorus rings.
Fluorine is the most electronegative element in the periodic table, and the fluorine atom has a small atomic radius, so fluorine-containing organic compounds have many wonderful properties. For example, the introduction of fluorine atoms or fluorine-containing groups into drug molecules can improve the permeability to cell membranes, metabolic stability and bioavailability; in addition, the introduction of fluorine atoms will improve the lipid solubility of the compound and promote its absorption in the body. The speed of delivery changes the physiological effect. In the field of medicinal chemistry, the introduction of fluorine atoms into organic molecules is an important direction for the development of new anticancer drugs, antitumor drugs, antiviral agents, anti-inflammatory drugs, and central nervous system drugs.
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.