dihydropyridiner

Dihydropyridines are heterocyclic compounds derived from pyridine by partial reduction, resulting in a six-membered 1,4-dihydropyridine ring that is not aromatic. They are synthetic in origin and serve as an important structural scaffold in organic and medicinal chemistry.

The core structure is a non-aromatic, nitrogen-containing ring with various substituents. A common representation features ester groups at positions 3 and 5 and an aryl substituent at position 4, though substituent patterns vary widely. The dihydropyridine framework can be further modified to tune electronic properties, lipophilicity, and metabolic stability.

In medicinal chemistry, the most well-known subclass of dihydropyridines are the dihydropyridine calcium channel blockers (DHP-CCBs). These compounds act as antagonists of L-type calcium channels, promoting relaxation of vascular smooth muscle and resulting in vasodilation. They are widely used to treat hypertension and angina, with varying onset and duration of action depending on the specific drug. Not all dihydropyridines function as calcium channel blockers; many others are explored as synthetic intermediates or have distinct pharmacological activities.

Synthesis of 1,4-dihydropyridines often employs the Hantzsch reaction, which combines an aldehyde, a β-dicarbonyl compound, and ammonia or an ammonium salt to form the dihydropyridine ring. Beyond pharmaceuticals, dihydropyridines appear as intermediates in organic synthesis and, in some cases, as redox-active or antioxidant agents in research contexts.

Representative examples of DHP-CCBs include nifedipine, amlodipine, felodipine, nimodipine, nisoldipine, nitrendipine, and lercanidipine. Side effects of DHP-CCBs commonly involve headaches, flushing, edema, and palpitations.