Synthesis of novel dihydropyridine, fused dihydropyridines, hexahydrobenzo[4,5]imidazo[2,1-b]quinazolines, and fused-pyrans linked to piprazine core via benzoyloxyacetyl likages as new hybrid molecules utilizing Michael, and Hantzsch reaction

Abstract

The precursor, piperazine-1,4-diylbis(2-oxoethane-2,1-diyl) bis(4-formylbenzoate) was prepared by reacting 1,1’-(piperazine-1,4-diyl)bis(2-chloroethan-1-one) with the potassium salt of 4-formylbenzoic acid in DMF at reflux. A new series of 1,4-dihydropyridin-3,5-dicarbonitrile, hexahydroacridine-1,8-diones, decahydropyrimido[4,5-b]quinoline, and hexahydrobenzo[4,5]imidazo[2,1-b]quinazolines which are linked to piperazine-1,4-diylbis(2-oxoethane-2,1-diyl) dibenzoate were obtained through the Hantzsch reaction. Besides, the Michael addition reaction of the piperazine-bis-aldehyde with malononitrile and active methylene containing reagents in the presence of catalytic amounts of a basic catalyst yielded the corresponding fused pyrans. The constitutions of novel compounds were confirmed using the different spectral tools.

Graphical Abstract

Keywords:

• Bis-aldehyde
• 1,4-dihydropyridines
• fused pyrans
• Hantzsch reaction
• Michael addition
• piperazine