Electrolysis of α-Chloro- and α-Fluorocarboxylic Acids

Abstract

The electrolysis of α-chlorovaleric, α-chlorocaproic, and α-chloroisobutyric acids in methanol gave none of the Kolbe dimer; the main products were chloroester and hydrogen ester with aldehydes and acetals formed in lesser amounts. In water, straight chain α-chloroacids gave dimeric esters as the major product. However, Kolbe dimer was formed in fairly good yields together with small amounts of fluoroester and acetal, when α-fluorocaproic and α-fluoroheptanoic acids were electrolyzed in methanol. No Kolbe dimer was produced from 2-fluoro-2-ethylbutanoic and α-fluorophenylacetic acids; the corresponding ketone or aldehyde was the major product.