Quantum chemical studies on the tautomerism of some potentially tautomeric aminoindazole derivatives

Ogretir C., TAY N. F.

STRUCTURAL CHEMISTRY, vol.17, no.3, pp.263-274, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 17 Issue: 3
  • Publication Date: 2006
  • Doi Number: 10.1007/s11224-006-9019-z
  • Journal Name: STRUCTURAL CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.263-274
  • Eskisehir Osmangazi University Affiliated: Yes

Abstract

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.