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.
Benzodioxanes are a class of isomeric compounds with the molecular formula C8H8O2. The three isomers of benzodioxane are 1,2-benzodioxane, 1,3-benzodioxane and 1,4-benzodioxane. 1,4-Benzodioxane has long been a versatile template widely used to design molecules with diverse biological activities. Its use spans past decades in medicinal chemistry to today, involving many drug discovery strategies, not excluding the most advanced ones. 1,4-Benzodioxane derivatives have been described as agonists and antagonists of nicotinic, alpha-adrenergic and 5-HT receptor subtypes. 1,4-Benzodioxane derivatives have been also reported as antitumor and antibacterial agents.
Oxazines are heterocyclic compounds containing one oxygen and one nitrogen atom in a diunsaturated six-membered ring. The existence of isomers depends on the relative positions of the heteroatoms and the relative positions of the double bonds.