CRYSTAL STRUCTURE OF (1R,5S)-9-NITRO- 1,2,3,4,5,6-HEXAHYDRO-1,5-METHANOPYRIDO[1,2-a][1,5] DIAZOCIN-8-ONE (9-NITROCYTISINE), C11H13O3N3

Abstract

The title compound (1, trivial name: 9 (or 3)-nitrocytisine) crystallizes with two independent molecules in the asymmetric unit. In its structure two rings form a bispidine framework that is fused to a 3-nitro-2-pyridone group. The half-normal probability plot reveals that the two molecules do not show any significant geometrical differences, except in conformations of the nitro-group, which is involved in intermolecular interactions. The crystal packing structure of the title compound is described in terms of three-dimensional supramolecular arrays built up from chains of N-H···O (nitro-group), hydrogen bonds and weak intermolecular C-H···O=C interactions, with graph-set descriptors C 2 (6) and C 2 (10) motifs, which together result in R 4 (26) rings motifs. These chains are additionally stabilized by intermolecular NO 2 ···p interactions.

(−)-Cytisine and Derivatives: Synthesis, Reactivity, and Applications

“…The nitration of cytisine was first reported in 1894, and nitrocytisines were isolated a few years later . However, the first and reproducible , preparation of 9-nitro, 11-nitrocytisines 122 , 123 and N -acetyl-9,11-dinitrocytisines 125 was described in 2000 (Scheme ). To obtain the dinitro derivative, protection of the secondary amine function of (−)- 1 was necessary.…”

“…To obtain the dinitro derivative, protection of the secondary amine function of (−)- 1 was necessary. The crystal structure of 9-nitrocytisine, recently described, showed that two independent molecules are linked by intermolecular N–H···ON­(O) hydrogen bonds and weak intermolecular C–H···OC interactions. The chains are additionally stabilized by intermolecular NO 2 ···π interactions.…”