Novel bipodal, tripodal, and tetrapodal 1,4-dihydropyridines — Microwave-assisted synthesis and structural confinements

The one pot, three component reaction of p-hydroxy benzaldehyde, β-ketoester, and ammonium acetate afforded the corresponding monopodal 1,4-dihydropyridines as building blocks, which in turn converted into diversified novel bipodal, tripodal, and tetrapodal 1,4-dihydropyridines with different alkylating agents through conventional as well as microwave assisted reactions. The unambiguous structural confinements of the all the synthesized compounds were drawn out with the help of 2D NMR (H-H COSY and C-H COSY).