The crystal structures of 6'-(4-chloro-phen-yl)- and 6'-(4-meth-oxy-phen-yl)-6a'-nitro-6a',6b',7',9',10',12a'-hexa-hydro-2H,6'H,8'H-spiro-[ace-naphthyl-ene-1,12'-chromeno[3,4-a]indolizin]-2-one.

S Syed Abuthahir,M Nizammohideen,D Velmurugan,J Nagasivarao,V Viswanathan

doi:10.1107/s2056989019000422

Abstract

In the title compounds, C32H25ClN2O4 (I) and C33H28N2O5 (II), the six-membered pyran and piperidine rings adopt envelope and chair conformations, respectively. The five-membered pyrrolidine rings adopt twist conformations. Compound (II) crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In all three mol-ecules there is a C-H⋯O intra-molecular hydrogen bond present enclosing an S(7) ring motif. In (I), both oxygen atoms of the nitro group are disordered, while in (II) the meth-oxy-benzene group is disordered in mol-ecule B. The geometries were regularized by soft restraints. In the crystal of (I), mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains along [010]. The chains are linked by C-H⋯Cl hydrogen bonds, forming layers parallel to (10). Within the layer there are C-H⋯π inter-actions present. In the crystal of (II), the A and B mol-ecules are linked via C-H⋯O hydrogen bonds, forming a square four-membered A-B-A-B unit. These units are linked by a number of C-H⋯π inter-actions, forming a three-dimensional supra-molecular structure.

Highlights

In the title compounds, C32H25ClN2O4 (I) and C33H28N2O5 (II), the sixmembered pyran and piperidine rings adopt envelope and chair conformations, respectively
In the crystal of (I), molecules are linked by C—HÁ Á ÁO hydrogen bonds, forming chains along [010]
These units are linked by a number of C—HÁ Á Á interactions, forming a three-dimensional supramolecular structure

Summary

Chemical context

Nitrogen-containing heterocyclic compounds are reported to possess a diverse range of biological activities such as antimicrobial, antitumor and anti-inflammatory (Thirunavukkarsu et al, 2017) properties. Spiro compounds are encountered in many pharmacologically active alkaloids (NizamMohideen et al, 2009c; Cravotto et al, 2001). The cornerstone for cycloaddition reactions, nitrones, are excellent spin-trapping and highly versatile synthetic intermediates (Bernotas et al, 1996; NizamMohideen et al, 2009b). Substituted spiro compounds result from the 1,3-dipolar cycloaddition of exocylic olefins with nitrones and these spiro compounds have been transformed into complex heterocycles (Hossain et al, 1993; NizamMohideen et al, 2009a). Recognizing the importance of such compounds in drug discovery and our ongoing research on the construction of novel heterocycles has prompted us to investigate the title compounds and we report on their synthesis and crystal structures

Structural commentary

Supramolecular features

Database survey

Synthesis and crystallization