Synthesis, IR and NMR studies of zwitterionic ω-(1-pyrrolidine)alkanocarboxylic acids and their N-methyl derivatives

Article abstract of DOI:10.1016/S0022-2860(97)00119-1

Six ω-(1-pyrrolidine)alkanocarboxylic acid hydrohalides [C₄H₈N⁺H(CH₂)(n)COOH · X^-] and 1-(ω-carboxyalkyl)-1-methyl-pyrrolidinium hydrohalides [C₄H₈N⁺CH₃(CH₂)(n)COOH · X^- (n = 1,2,3,4,5,10)] and their sodium and inner salts were synthesized, respectively. IR, ¹H and ¹³C NMR spectra were analyzed with regard to the increasing distance effect on the interaction between the positive nitrogen atom with the negative carboxylic group. The configuration of the pyrrolidine ring was also discussed.