STRUCTURAL CHEMISTRY, cilt.17, sa.3, ss.263-274, 2006 (SCI-Expanded)
The aqueous phase AM1, PM3, and PM5 calculation data had indicated that when a potentially tautomeric amino group is placed at 3C position of the indazole ring the ring-chain tautomerism becomes feasible. However, when the amino group is placed at 4-7C of the indazole ring only the annular tautomerism was found to be feasible and no effect of amino group to provoke a ring chain tautomerism was observed. On the other hand amino form of 3 amino substituted indazole was found to be predominant over imino forms whereas for the 4-7 amino substituted indazoles imino forms were found to be predominant over amino forms. The attempt to apply soft-hard base and soft nucleophile-electrophile criteria to protonation and tautomerism phenomena was successful.