• Heiner Fangerau,

  • Cornelius Borck


The pyrano-phenazine derivatives 6 were synthesized by an efficient procedure using the reaction between benzo[a]phenacin-5-ols with the condensation product of an aldehyde with Meldrum's acid in the presence of a catalytic amount of Et3N at ambient temperature. The procedure is very simple, and products could be separated from the reaction media by simple filtration. High functional-group tolerance both in the benzo[a]phenazin-5-ol and aldehyde moieties, facile reaction procedure, medium-to-high yields, and simple separation of the products from the reaction media are the advantages of this route.