Determination and evaluation of acid dissociation constants of some substituted 2-aminobenzothiazole derivatives

Ogretir C., DEMİRAYAK Ş., TAY N. F., Duran M.

JOURNAL OF CHEMICAL AND ENGINEERING DATA, vol.53, no.2, pp.422-426, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 53 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1021/je700515k
  • Journal Name: JOURNAL OF CHEMICAL AND ENGINEERING DATA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.422-426
  • Anadolu University Affiliated: Yes

Abstract

The acid dissociation constants of some 4- and/or 6-substituted 2-aminobenzothiazole and 4-substituted thiazole derivatives were determined spectroscopically. With the exception of a few, the first protonation was found to occur on the amino group. In some molecules where prototropic tautomerism is possible, a change-over in the protonation mechanism was observed. The first protonation under these circumstances was found to occur on the imino nitrogen atom. The second protonation takes place on the thiazole ring nitrogen atom.