Pyrrolidine
= Pyrrolidine
<Pyrrolidine> is a saturated five-membered heterocycle containing one nitrogen atom, with formula $\mathrm{C_4H_9N}$. As a secondary <amine>, it can accept a proton and participate as a nitrogen nucleophile.
Unlike <pyrrole>, its ring has no aromatic pi system tying up the nitrogen lone pair. Distinguishing the saturated and aromatic heterocycles is therefore important when predicting basicity and reactivity.