Electrochemical fluorination of aromatic compounds in liquid R4NF·mHF—part I. Basic properties of R4NF·mHF and the fluorination o

✍ Scribed by Kunitaka Momota; Masayuki Morita; Yoshiharu Matsuda

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 712 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)80222-l

✦ Synopsis

A series of new electrolytes, R,NF.mHF (R: CH,, C,H, and n-C,H,, m > 34, has been utilized for electrochemical fluorination of organic compounds. These electrolytes are non-viscous liquids at room temperature, and have high electrolytic conductivity and high electrochemical stability. The electrolysis gave high current densities and high current efficiencies for the fluorination without any film formation at the anode. Benzene, fluorobenzene and l&difluorobenzene were electrochemically fluorinated on a platinum anode at 2.5 V (vs. Ag/Ag+ (0.01 mol dm-3)) in (C,H,),NF . mHF. Electrochemically stable 3,3,6trifluoro-l,&yclohexadiene(I) and 3,3,6,6-tetrafluoro-l&cyclohexadiene(II) were obtained as the final products for the fluorination of benzene and fluorobenzene. The electrolysis of l&difluorobenzene gave II in ca. 90% yield. The current efficiency for the fluorination was su!liciently high; benzene, fluorobenzene and l&difluorobenzene were fluorinated in 66-70%, 71-76% and 8840% current efliciences, respectively.