This work was supported by the Schweizerische Nationalfonds zur Förderung der Wissenschaftlichen Forschung and by Ciba-Geigy SA. We thank P. Renold and G. Strasser, Basel, for experimental cooperation and Profs. A. J. Kresge, University of Toronto, and J. Liebman, University of Maryland, for helpful suggestions.
Article first published online: 22 DEC 2003
Copyright © 1994 by VCH Verlagsgesellschaft mbH, Germany
Angewandte Chemie International Edition in English
Volume 33, Issue 11, pages 1153–1156, June 22, 1994
How to Cite
Gut, I. G. and Wirz, J. (1994), 3H-Indole. Angew. Chem. Int. Ed. Engl., 33: 1153–1156. doi: 10.1002/anie.199411531
- Issue published online: 22 DEC 2003
- Article first published online: 22 DEC 2003
- Manuscript Received: 27 DEC 1993
Remarkable stability is shown by the recently observed 3H isomer 1 of indole (2) (τ ≅ 100 s at pH ≅ 9 and 25°C). The equilibrium constant pKT of the tautomerization of 2 to 1 is 5.8 ± 0.2; in other words, the equilibrium concentration of 1 lies in the range of 1 to 2 ppm. The tautomerization is catalyzed by acid and—less efficiently—by base.