New tricyclic systems of biological interest. Annelated 1,2,3-triazolo[1,5-a]pyrimidines through domino reaction of 3-azidopyrroles and methylene active nitriles

Anionic hetero-domino reaction of 3-azidopyrroles and acetonitriles constitutes the synthetic entry to annelated 1,2,3-triazolo[1,5-a]pyrimidines. Upon slight variations of the experimental conditions the method is of general application either with 2 or 4 substituted pyrroles. Thus derivatives of the new ring system pyrrolo[2,3-e][1,2,3]triazolo[1,5-a]pyrimidine, isomers of the previously synthesized pyrrolo[3,4-e][1,2,3]triazolo[1,5-a]pyrimidine, were prepared in high yields. The condensed pyrrolo-triazolo-pyrimidines, although only moderately active, can be used as model for the design of DNA-interactive compounds.