Calcium channel antagonist chemistry

In carbon-14 chemistry, Knoevenagel-Michael sequences with alkyl acetoacetates have found widest application in the synthesis of labeled 1,4-dihydropyridines (Hantzsch dihydropyridine synthesis). 4-Aryl-l,4-dihydro[ C]pyridine derivatives constitute a class of calcium antagonists and calcium channel blockers that play an important role in the treatment of cardiovascular diseases. The basic sequence, depicted in Figure 6.90, involves first the Knoevenagel condensation of an aromatic aldehyde with an alkyl... 

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