THE ELECTROCHEMICAL FLUORINATION OF NITROGEN-CONTAINING CARBOXYLIC ACIDS. FLUORINATION OF METHYL ESTERS OF CYCLIC AMINOGROUP SUBSTITUTED CARBOXYLIC ACIDS

Article abstract of DOI:10.1016/S0022-1139(00)80494-7

Nine methyl esters of cyclic amino-group substituted carboxylic acids related to glycine, alanine or β-alanine were subjected to electrochemical fluorination.This afforded the corresponding perfluoroacid fluorides together with cleavage products in fair yields.As cyclic amino-substituents, pyrrolidino-, morpholino-, piperidino-, hexamethyleneimino- and N'-methylpiperazinyl-groups were investigated.The formation of cyclized by-products was not observed, which contrasts with the fluorination of aliphatic dialkylamino-substituted carboxylic acids.From such methyl 2-cyclic amino-propionates (cyclic amino-group: a pyrrolidino, a morpholino or a piperidino-group), the perfluorinated methyl esters were obtained together with the corresponding perfluoroacid fluorides in yields of 1-2percent and 14-29percent, respectively.The formation of the former compounds is ascribed to the blocking effect of the bulky cyclic amino-groups.The physical properties of the new compounds obtained are reported together with their spectral (19F NMR, Mass and IR) data.