Synthetic ionophores. Part 8. Amide–ether–amine-containing macrocycles: synthesis, transport and binding of metal cations

Abstract

1,2-Bis(ethoxycarbonylmethoxy)benzene undergoes 1 : 1 stoichiometric condensation with 1,2-diaminoethane, 1,3-diaminopropane, diethylenetriamine and 3,3′-diaminodipropylamine to form the macrocycles 2a, 2b, 3a and 4a respectively. Methyl iodide, ethyl bromoacetate and chloro-N,N-diethylacetamide react with triamines 3a and 4a to give the respective N-substituted macrocycles 3b–d and 4b–d. Among these macrocycles, compounds 3a and 4a selectively extract lead picrate over silver, alkali metal and alkaline earth metal picrates and the former shows a higher order of specificity. IR and ¹³C NMR studies depict a preferential co-ordination of the amide oxygen of these macrocycles with metal ions.