A Conceptual Approach to the Synthesis of Bifunctional EDTA Analogs: EDTA-Extended Polyamides
作者:N. Kahana、R. Arad-Yellin、A. Warshawsky
DOI:10.1021/jo00096a025
日期:1994.8
A conceptual approach to the synthesis of epsilon-carboxyl and epsilon-amino polyamide-linked EDTAs is proposed (Scheme 1), starting from epsilon-carboxy vicinal diamine blocked by Cbz or Boc groups (A, Scheme 1), followed by extension along the chain to form polyamides with epsilon-carboxy groups (A(2),A(3),..., A(n)) or amine groups (B-1, B-2,..., B-n). The A(n) series can be converted to acidic EDTAs (AE(n) series) or basic EDTAs (BE(n) series). This depends on the selection of the protecting groups to offer exclusive protection of the amine and acid functions. The choice of the protecting groups (three categories a-c in Scheme 1) provides an exclusive synthetic methodology. This is further exploited for conversion of acidic polyamide-linked EDTA (AE(n)) to either acidic or basic EDTA homologs (see Scheme 2). Scheme 4 proposes methodology for synthesis of terminally blocked bis-EDTA polyamides.