Chemical modification of plant alkaloids. 6. T-reactions of anabasine derivatives

T-reactions of anabasine derivatives were performed for the first time. Condensation of 5-nitro-2-[2-(3pyridyl)piperidino]benzaldehyde with 1,3-dimethylbarbituric acid formed an annelated tetrahydroquinoline system containing a spiropyrimidine moiety as the T-reaction product. Condensation of this same aldehyde with Meldrum’s acid was accompanied by recyclization that led to opening of the piperidine ring and closing of the tetrahydroquinolone system. A third version of the T-reaction that also led to opening of the piperidine ring but without recyclization was the condensation with dimedone.