✦ LIBER ✦
Heterocyclic β-enamino esters 43—easy 13C NMR distinction between aryl-substituted dimroth isomers of the 1,2,3-triazole series
✍ Scribed by H. Wamhoff; J. Bohlen; S. Y. Yang
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 313 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
5-Amino
-1-aryl-1,2,3-triazoles and 5-anilino-1,2,3-triazoles can be easily distinguished by their "C N M R spectra. Thus, C-4 and C-5 of some studied 5-anilino isomers are deshielded by 2-5 ppm in comparison with the corresponding 5-amino-1-aryl isomers. From the 13C N M R signals of the aryl carbons in the same ~-anilino isomers, C-6 is shifted downfield (cu 9 ppm; -I effect), whereas C-7 and C-9 are shifted upfeld (cu 7 and 10 ppm, respectively; +M effect). This allows a fast and easy assignment of both Dimroth isomers.