DBU (CAS No. 6674‑22‑2; formula C₉H₁₆N₂; MW 152.24 g/mol) is a colorless, water‑miscible liquid, melting at –70 °C and boiling at ~261 °C. It is a sterically hindered, non‑nucleophilic amidine base, highly soluble in diverse solvents, and commonly used as a strong organic catalyst and reagent.