Crystal structure of 2-azaniumyl-3-bromo-6-oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium dibromide

Abstract

The title salt, C12H10BrN3O2+·2Br−, was synthesized from the reaction of N 1,N 4-bis­(pyridin-2-yl­methyl­idene)benzene-1,4-di­amine and bromine in a methanol solution. All non-H atoms of the 2-aza­niumyl-3-bromo-6-oxo-5,6-di­hydro­pyrido[1,2-a]quinoxalin-11-ium cation are nearly coplanar, the maximum deviation being 0.114 (4) Å. In the crystal, the cations and anions are linked through N—H⋯Br hydrogen bonds and weak C—H⋯Br inter­actions, forming a three-dimensional supra­molecular architecture. A short Br⋯Br contact [3.3088 (9) Å] is observed in the crystal.

Crystal structure of 2-amino-1,3-dibromo-6-oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium bromide monohydrate

“…1). The cation is non-planar compared to the previously reported structure (Faizi et al, 2015). The mean plane of the pyridine ring forms a dihedral angle of 24.2 (4) with the benzene ring and 14.6 (4) with the pyrazine ring of the fused system while the dihedral angle between the pyrazine and the benzene ring is 11.5 (4) .…”

“…Previously, we have reported new methods for the preparation of substituted quinoxaline derivatives together with their crystallographic characterization. However, there are very few reported structures of compounds similar to the title compound, one being the doubly protonated dibromide salt 2-azaniumyl-3-bromo-6oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium dibromide (Faizi et al, 2015).…”

“…There are very few examples of similar compounds in the literature, a search of the Cambridge Structural Database (Version 5.35, May 2014; Groom & Allen, 2014) revealing the structure of 2-azaniumyl-3-bromo-6-oxo-5,6-dihydropyrido-[1,2-a]quinoxalin-11-ium dibromide (Faizi et al, 2015), in which the 2-amino-1,2-dibromide ring in the title compound is replaced by a 2-azaniumyl-3-bromo ring. Other similar structures have been reported (Faizi & Sen, 2014;Koner et al, 2008).…”