Synthesis and Structural Characterization of Substituted 2-Phenacylbenzoxazoles
1 H and 13C NMR spectra of eleven 2-phenacylbenzoxazoles (ketimine form) show that their CDCl3-solutions contains also (Z)-2-(benzo[d]oxazol-2-yl)-1-phenylethenols (enolimine form). Intramolecular hydrogen bonding in the latter tautomer was found to be significantly weaker than that one in respective (Z)-2-(2-hydroxy-2-phenylvinyl)pyridines. Integrals of the 1 H NMR signals were used to evaluate the molar ratio of the tautomers. Strong electron-donating substituents were found to stabilize the ketimine tautomer. pKT (negative logarithm of the equilibrium constant, KT = [ketimine]/[enolimine]) was found to be linearly dependent on the Hammett substituent constant σ. The results of the MP2 ab…
CCDC 922097: Experimental Crystal Structure Determination
Related Article: Agnieszka Skotnicka, Erkki Kolehmainen, Przemysław Czeleń, Arto Valkonen, Ryszard Gawinecki|2013|Int.J.Mol.Sci.|14|4444|doi:10.3390/ijms14034444
CCDC 922098: Experimental Crystal Structure Determination
Related Article: Agnieszka Skotnicka, Erkki Kolehmainen, Przemysław Czeleń, Arto Valkonen, Ryszard Gawinecki|2013|Int.J.Mol.Sci.|14|4444|doi:10.3390/ijms14034444