Electrochemical studies on 3,3′-methylenebis-(4-hydroxycoumarin) (dicoumarol) in dimethylformamide

✍ Scribed by A. Inesi; L. Rampazzo

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 573 KB
• Volume: 16
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(71)80017-8

✦ Synopsis

The electrochemical behaviour of 3,3'-methylenebis-(4-hydroxycoumarin) (Dicoumarol, H,A) and of 4-hydroxycoumarin (HR) has been studied in DMF-O.5 F (EtdN)ClO. solutions. H,A is reduced in two steps at the dme, the solvated proton originating from the dissociation of HpA is the electro-active species involved in the f&t stage of reduction. The wave corresponds to the wave of solvated proton from HCIO, in the same base solution [El,, = -1.23 V&e)]. The second step of HIA reduction corresponds to hydrogen discharge from the undissociated HA-. 4-Hydroxycoumarin behaves like HA-. Coulometric and controlled-potential electrolysis experiments substantiate the mechanism previously described. HIA, a weak acid in hydroxylic solvents, exhibits an enhanced strength in the aprotic solvent DMF; this is consistent with current ideas about anion solvation in DMF.