SYNTHESIS, CRYSTAL AND MOLECULAR STRUCTURES OF 2-METHYL-3-CARBOETHOXYQUINOXALINE 1,4-DIOXIDE

Article abstract of DOI:10.1016/0022-2860(87)80046-7

2-Methyl-3-carboethoxyquinoxaline 1,4-dioxide (MCQO) was prepered and single crystals were grown out of the reaction mixture.The structure of MCQO was established by single-crystal X-ray crystallography using a direct method.The crystals are triclinic, space group P<*>, with a = 6.928(1), b = 8.109(1), c = 10.552(1) angstroem, α = 83.445(8), β = 85.681(10), γ = 79.168(8) deg, V = 577.7 angstroem³, Z = 2 and Dc = 1.428 g cm^-3.The structure was refined to R = 0.059 for 1454 reflections.The planar geometry of the parent quinoxaline ring is consistent with the aromaticity of the condensed heterocyclic system in the compound.The average N-O bond length is 1.297(5) angstroem, indicating a certain double-bond character.The X-ray analysis corroborates IR, NMR, and ESR spectroscopic evidence for the structure of this type of heteroaromatic N-oxides.