Synthesis of condensed heteroaromatics: novel synthesis of aminoquinolizinone derivatives as anti-HIV agents

New routes for the synthesis of aminoquinolizinone derivatives with interesting biological activities are reported. Reactions enaminones 2 and 9 with malononitrile affords aminoquinolizinone derivatives 7a and 7b. Fusion of acetylcyclohexanone (1) with DMF DMA and ethyl cyanoacetate affords only product 11. Treatment of the latter product with malononitrile affords the aminoquinolizinone derivative 15. Reaction of chalcone 17 with malononitrile furnished the product 22. Condensation of (1) with arylidenemalononitrile 23a,b affords compounds 28a,b, respectively. The structure of the newly synthesized compounds was elucidated by elemental analyses and 1H NMR spectra and in some cases by 13C NMR investigation.