Crystal structure of 6-(4-chlorophenyl)-6a-nitro-6a,6b,8,9,10,12a-hexahydro-6H,7H-spiro[chromeno[3,4-a]indolizine-12,11′-indeno[1,2-b]quinoxaline]

Abstract

The title compound, C35H27ClN4O3, crystallized with two independent molecules (A and B) in the asymmetric unit. In both molecules, the pyran and pyridine rings adopt envelope and chair conformations, respectively. The conformation of the pyrrolidine and cyclopentene rings differ in the two molecules; twisted and flat, respectively, in molecule A, but envelope and twisted, respectively, in molecule B. In both molecules, there is a C—H...N intramolecular hydrogen bond present. In both molecules, the oxygen atoms of the nitro groups are disordered as is the chlorine atom in molecule B. In the crystal, the B molecules are linked by C—H...O hydrogen bonds, forming –B–B–B– chains along [010], and by C—H...π interactions. The A and B molecules are also linked by a number of C—H...π interactions, resulting in the formation a supramolecular three-dimensional structure. In molecule A, the nitro group oxygen atoms are disordered over two positions with refined occupancy ratios of the nitro group oxygen atoms O3A and O4A in 0.59 (2):0.41 (2) while in molecule B one of the nitro O atoms is disordered over two positions with a refined occupancy ratio of 0.686 (13):0.314 (13) and the chlorine atoms is disordered over two positions with a refined occupancy ratio of 0.72 (3):0.28 (3).

Keywords

• crystal structure
• spiro compounds
• cycloaddition
• piperidine
• pyran
• pyrrolidine
• cyclopentene
• hydrogen bonding
• C—H...π interactions