NMR and DFT study on the prototropic tautomerism of 3-methyl-5-pyrazolone

Authors
Alderete, JB Belmar, J Parra, M Zuniga, C
Citation
Jb. Alderete et al., NMR and DFT study on the prototropic tautomerism of 3-methyl-5-pyrazolone, BOL SOC CH, 45(1), 2000, pp. 85-89
Citations number
9
Categorie Soggetti
Chemistry
Journal title
BOLETIN DE LA SOCIEDAD CHILENA DE QUIMICA
ISSN journal
03661644 → ACNP
Volume
45
Issue
1
Year of publication
2000
Pages
85 - 89
Database
ISI
SICI code
0366-1644(200003)45:1<85:NADSOT>2.0.ZU;2-D
Abstract
The prototropic tautomerism of 3-methyl-5-pyrazolone was studied by using D ensity Functional Theory along with H-1, C-13 and N-15-NMR. The results sho w that for the isolated molecule and low polarity solvent the 5PYR-1 tautom er, a keto form, is the predominant species. In DMSO solution the predomina nt tautomeric form is 5PYR3, a hydroxy tautomeric species. For almost every atom an excellent agreement was found between the experimental and calcula ted NMR spectra using GIAO method at DFT/ B3LYP/6-311+G (2p,d) level.