Spectroscopic Determination of Acid Dissociation Constants of Some Novel Drug Precursor 6-Acylbenzothiazolon Derivatives

• Published in: Journal of chemical and engineering data Vol. 55; no. 11; pp. 4752 - 4756
• Main Authors: Sıdır, Yadigar Gülseven, Sıdır, İsa, Berber, Halil, Taşal, Erol, Öğretir, Cemil
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 11.11.2010; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Engineering; Engineering, Chemical; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; Technology; Thermodynamics; PROTEASE INHIBITOR; L-735,524; ANTIINFLAMMATORY ACTIVITY; DESIGN; POTENT; CHLOROPHENYLPIPERAZINE; RATS; Drug; Dissociation constant; Protonation; Piperazine derivatives; Chemical properties; Benzothiazole derivatives; Precursor; Ultraviolet visible spectrometry
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/je100378t

The acid dissociation constants, as pK a values, of eight drug precursor 6-acylbenzothiazolon derivatives were determined using UV−vis spectroscopic technique. The protonation and deprotonation behaviors of the investigated molecules were studied from super basic to super acid regions (i.e., 8 mol·L−1 KOH to 98 % H2SO4) including the pH region. It was observed that protonation occurs only at the amid group in the super acid region. By validating the obtained acid dissociation constants, elucidation of the structure and protonation mechanisms of the studied molecules was attempted.