Novel heterocyclic Trِgerʹs base derivatives containing N-methylpyrrole units

Novel analogues of Trögerʹs base were prepared regioselectively from 4-amino-N-methylpyrrole carboxylates in good yield. Catalytic hydrogenation of dibenzyl-4,9-methano-1,6-dimethyl-4,5,9,10-tetrahydro-1H,6H-dipyrrolo-[3,2-b:3′,2′-f][1,5]diazocin-2,7-dicarboxylate 2b led to 4,9-methano-1,6-dimethyl-4,5,9,10-tetrahydro-1H,6H-dipyrrolo-[3,2-b:3′,2′-f][1,5]diazocin-2,7-dicarboxylic acid 3 which was used for the preparation of Trögerʹs base derivatives of natural antibiotics via an amide protocol. The novel heterocyclic Trögerʹs bases were characterized by a variety of spectroscopic techniques and compound 2b by X-ray crystallography. Incorporation of guanidine as the terminal group in the N-methylpyrrole Trögerʹs base skeleton opens the possibility for preparation of water soluble derivatives.