Anodic oxidation of bisamides from diaminoalkanes by constant current electrolysis

In general, bisamides derived from diamines and involving 3 and 4 methylene groups as spacers between the two amide functionalities behave similar to monoamides upon anodic oxidation in methanol/LiClO(4) because both types undergo majorly mono- and dimethoxylations at the α-position to the N atom. However, in cases where the spacer contains two methylene groups only the anodic process leads mostly to CH(2)–CH(2) bond cleavage to afford products of type RCONHCH(2)OCH(3). Moreover, upon replacing LiClO(4) with Et(4)NBF(4) an additional fragmentation type of product was generated from the latter amides, namely RCONHCHO. Also, the anodic process was found to be more efficient with C felt as the anode, and in a mixture of 1:1 methanol/acetonitrile co-solvents.