Anodic oxidation of selenadiazoloquinolones in alkaline media

✍ Scribed by Andrej Staško; Michal Zalibera; Zuzana Barbieriková; Ján Rimarčík; Vladimír Lukeš; Maroš Bella; Viktor Milata; Vlasta Brezová

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 573 KB
• Volume: 49
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.2716

✦ Synopsis

Abstract

Newly synthesized derivatives of 6‐oxo‐6,9‐dihydro[1,2,5]selenadiazolo[3,4‐h]quinoline variously substituted at position 7 (R = H, COOH, COCH~3~, CN, COOC~2~H~5~ and COOCH~3~) are established in strongly alkaline aqueous solutions (0.1 M NaOH; pH ∼ 13) as N(9)‐deprotonated structures, but in less alkaline solutions (0.001 M NaOH; pH ∼ 11) the N(9)‐protonated oxo tautomeric forms dominate. Upon their anodic oxidation in alkaline solutions, the selenadiazole ring is replaced, forming instead the paramagnetic species analogous to the ortho semiquinone radical anions as monitored by in situ EPR spectroscopy. The quantum chemical calculations for two representative selenadiazoloquinolones (R = H and COOH) and their anodic oxidation products presented are in agreement with experiments. Copyright © 2011 John Wiley & Sons, Ltd.