The Structure and Tautomerism of Cyameluric Acid*
نویسندگان
چکیده
The single crystal X-ray structure of the DMSO solvate of cyameluric acid C6N7O3H3 · 3DMSO, 2b’ has been determined. The results show that the most stable tautomer of solid cyameluric acid is the tri-keto form 2b with C3h symmetry. 1H and 13C NMR data indicate that this isomer is also present in solution, with slow interchange of the N-H protons. This confirms previous theoretical results although almost all derivatives reported in the literature are derivatives of the tri-hydroxy tautomer 2a.
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