General access to polyamines containing ethane-1,2-diamine units: Synthesis of unnatural homologues and isomeric N-1,4-di(4-coumaroyl)spermines40

The synthesis of the three N,N'-di(4-coumaroyl)tetramines. ie., of (E,E)-N- {3-[(2-aminoethyl)amino]-propyl}-33'-bis(4-hydroxyphenyl)-N,N'-(ethane-1,2d iyl)bis[prop-2-enamide] (1a), (E,E)-N-{4-[(2-aminoethyl)-amino]butyl}-3,3'- bis(4-hydroxyphenyl)-N,N'-(ethane-1,2-diyl)bis[prop-2-enamide] (1b), and (E ,E)-N-(6-[(2-aminoethyl)amino]hexyl)-3,3'-bis(4-hydroxyphenyl)-N,N'-(ethane -1,2-diyl)bis[prop-2-enamide] (1c), is described. It proceeds through stepu vise construction of the symmetric polyamine backbone including protection and deprotection steps of the amino functions. Their behavior on TLC in com parison with that of 1,4-di(4-coumaroyl)spermine (=(E,E)-N-{4-[(3-aminoprop yl)amino]butyl}-3,3'-bis(4-hydroxyphenyl)-N,N'-(propane-1,3-diyl)bis[prop-2 -enamide]; 2) is discussed.