Tetrazole

Tetrazoles are cyclic chemical compounds having a base structure (C₁N₄H₂) in which four nitrogen atoms and one carbon atom form a 5-atom heterocycle. They can be synthesized by click chemistry, reacting a cyanide with an azide, as depicted below. The base tetrazole compound (R₁ = R₂ = H) is commonly used as a base in chemical reactions. Some tetrazoles are angiotensin receptor antagonists used to treat high blood pressure (hypertension).

© Image: David E. Volk
Tetrazole formed by cyclization of a cyanide and an azide.