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Abstract
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The 1,4-dihydropyridine nucleus is a privileged scaffold since, when appropriately
substituted, it can selectively modulate diverse receptors, channels and enzymes.1
Pyrazolopyridines and their derivatives have a wide range of biological activities.2-4 For
example, a number of pyrazolo[3,4-b]pyridines exhibit anxiolytic (e.g., tracazolate),
antiallergic, antiherpetic, antitubercular, antibacterial, antihypertensive and antifungal
activities.
In this work, in continuation of our interest in multicomponent reactions, we performed
the three-component reaction of easily accessible 3-methyl-1H-pyrazol-5(4H)-one 1, ethyl 2-
benzylidenacetoacetates 2 and ammonium acetate in refluxing ethanol, but dipyrazolo-1,4-
dihydropyridine d. erivatives 3 were obtained instead of expected fused pyrazolo-1,4-
dihydropyridines 4 (Scheme 1). The structure of synthesized compounds was confirmed by
spectroscopic methods.
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