Determination of pKa values of benzimidazole derivatives from mobility obtained by capillary electrophoresis

Microwave assisted synthesize of new some benzimidazole derivatives and determination of protonation constant of these compounds in non-aqueous media

“…Because, relationships between acidity constant, pKa and structure may behelpful in drug design studies and in explaining solubility, absorption, distribution, metabolism and elimination [35]. The structure of all synthesized compounds was confirmed by 1 H-NMR and elemental analysis.…”

Simultaneous determination of anthelmintic drugs by capillary electrophoresis using cyclodextrins as buffer additives

“…The pK a value (ABZ-6.9; FBZ-7.4; FLZ-7.1; MBZ-6.6; LEV-6.9) of the drugs serves as a guideline that shows the extent of ionization at different pH levels [16]. In our case all substances have almost similar pKa values and will be ionized at the imidazole ring, in an acidic background electrolyte (BGE).…”

Synthesis, Characterisation and Molecular Recognition of Novel Zn(II) Macrocyclic Complexes with Imidazole or Benzimidazole Pendants

“…18 For this reason, we propose that hydrogen bonds are formed between a cyclen ligand and a guest at pH 7.5. The schematic diagrams of 9a-dT and 9a-Cyt are shown in Scheme 4, and only one hydrogen bond is formed between complex 9a and Cyt.…”

“…There are a few articles reporting on the protonation constants (pK a values) of the four amino groups in cyclen, which are known to be 10.5, 9.5, 1.6 and 0.8 respectively, 17 and the pKa 1 of benzimidazole in IDB is around 5.5. 18 For this reason, we propose that hydrogen bonds are formed between a cyclen ligand and a guest at pH 7.5. The schematic diagrams of 9a-dT and 9a-Cyt are shown in Scheme 4, and only one hydrogen bond is formed between complex 9a and Cyt.…”