6533b870fe1ef96bd12cef9f

RESEARCH PRODUCT

Complex tauto- and rotamerism of 2-(R-phenyl)-1,2,3,4-tetrahydroquinazolines

Erkki KolehmainenBorys OśmiałowskiKalevi PihlajaRyszard GawineckiAgnieszka Kuczek

subject

chemistry.chemical_compoundAnilinechemistryStereochemistryHydrogen bondOrganic ChemistrySpectral analysisPhysical and Theoretical ChemistryRing (chemistry)Conformational isomerismTautomerMedicinal chemistryEndothermic process

description

Detailed NMR spectral analysis of CDCl3 solutions of 2-(R-phenyl)-1,2,3,4-tetrahydroquinazolines reveals three or four tautomeric forms. Apart from 2-[(benzylideneamino)methyl]aniline, the other chain tautomeric forms are present only in minor quantities. In general, electron-donating substituents increase the contribution of all chain forms. Lowering the temperature of the CDCl3 solution of 2-(R-phenyl)-1,2,3,4-tetrahydroquinazolines decreases the content of the 2-[(benzylideneamino)methyl]aniline form. At the same time, the amount of the ring form increases. Opening of the tetrahydropyrimidine ring in 2-(R-phenyl)-1,2,3,4-tetrahydroquinazolines was found to be an endothermic process especially for less electron-donating substituents. Copyright © 2005 John Wiley & Sons, Ltd.

yearjournalcountryeditionlanguage
2005-04-19Journal of Physical Organic Chemistry
https://doi.org/10.1002/poc.927