Abstract: | During attempts to prepare the tricyclic ring system of type III by cyclization of N-methyl-N-(1-phenyl-3-methylpyrazol-5-yl)-2-acetamido benzamide (Ib) under Bischler-Napieralski reaction conditions, the formation of the macro-heterocycle IV was observed, whose structure was determined on the basis of analytical and spectroscopic data as well as on some transformation products. |