13C and 15N NMR spectra of aminobenzimidazoles in solution and in the solid state |
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| Authors: | M Ángeles García Rosa M Claramunt Tomá? Sol?an Viktor Milata Ibon Alkorta José Elguero |
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| Institution: | 1. Departamento de Química Orgánica y Bio‐Orgánica, Facultad de Ciencias, UNED, Senda del Rey 9, E‐28040 Madrid, Spain;2. Department of Organic Chemistry, Faculty of Chemical and Food Technology, STU, Radlinského 9, SK‐812 37, Bratislava, Slovakia;3. Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E‐28006 Madrid, Spain |
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| Abstract: | The 13C hexadeutero‐dimethylsulfoxide (DMSO‐d6), hexamethyl‐phosphoramide (HMPA)‐d18and solid‐state] and 15N (solid‐state) NMR spectra of six C‐aminobenzimidazoles have been recorded. The tautomerism of 4(7)‐aminobenzimidazoles and 5(6)‐aminobenzimidazoles has been determined and compared with B3LYP/6‐311 + + G(d,p) calculations confirming the clear predominance of the 4‐amino tautomer and the slight preference for the 6‐amino tautomer. GIAO‐calculated absolute shieldings compare well with experimental chemical shifts. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | NMR 13C 15N benzimidazoles tautomerism CPMAS DFT GIAO |
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