Synthesis, molecular, and crystal structure of a new, unexpected polycyclic system: 5,12:10,12-dimethano-12H-pyrazolo[3,4-b]pyrazolo[4′,3′:6,7]azapino[2,3-f]azocine

Abstract

By reacting 1-phenyl-3-R-5-methylaminopyrazoles (1a, b) and hexane-2,5-dione (2) in acetic acid compounds (4a, b), containing the title system, were obtained. They were characterized by elemental analysis, n.m.r. spectroscopy and, for (4a), X-ray crystallography of a single crystal. The structure is characterized by a fused hexacyclic system which includes two N-phenyl-substituted pyrazole rings adjacent to two azepine ones in the half-chair conformation and, finally, two five-membered fused rings.