Pyrrolines, also called dihydropyrroles, are obtained from aromatic pyrroles by hydrogenation. 1-pyrroline is a cyclic imine, while 2-pyrroline and 3-pyrroline are cyclic amines.
Thiazolidine is a heterocyclic organic compound, which is a five-membered saturated ring with a thioether group and an amine group. It is the sulfur analog of oxazolidine. Thiazolidine derivatives have many uses and have a broad spectrum of biological activities. For example, the drug pioglitazone contains a thiazolidine ring. Thiazolidine has three isomers, 2-, 3-, and 4-. Derivatives with a 2-thiazoline ring are the most common.