چكيده فارسي :
Dihydropyridine (DHP) derivatives are important class of organic compounds in view of
its vast application in pharmaceuticals. These derivatives are widely known as calcium
channel blockersand emerge as one of the most substantial classes of drugs for treatment of
cardiovascular diseases including hypertension [1]. Many methods have been reported for the
synthesis of 1,4-dihydropyridine derivatives in view of the biological importance associated
with these compounds. However, many of them suffer from drawbacks such as unsatisfactory
yields, long reaction time and pollution to the environment resulted from the use of organic
solvent and/or acidic or basic promoters [2]. Thus, development of a simple, efficient, and
versatile method for preparation of new derivatives of 1,4-dihydropyridine is a great
challenge.The best known procedure for preparation of symmetrical 1,4-dihydropyridines is
the classical Hantzch synthesis [3].
In the work presented here, an efficient one-step synthesis of 1,4-dihydropyridines in good
to excellent yields via the Al(OAc)3 catalyzed Hantzsch three-component reaction of an
aldehyde, ethyl acetoacetate and ammonium acetate under solvent-free conditions at 80 oC
and in room temperature is described and these different conditions are compared with each
other. The present methodology offers several advantages such as simple procedure, excellent
yields, and short reaction time. It would better to mention that catalyst can be easily separated
from reaction mixture and reused severaltimes in subsequent reactions.
