Synthesis and Spectroscopic Characterization of New Double-Armed Benzo-15-Crown-5 Derivatives and Their Sodium Complexes

Double-armed crown ether aldehydes (13) were synthesized from the reaction of 2 equiv salicylaldehyde, 4-hydroxy-3-methoxybenzaldehyde (vanillin), and 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with 4,5-bis(bromomethyl)benzo-15-crown-5. New crown ethers imine compounds (49) were synthesized by the condensation of corresponding crown ether aldehydes (13) with 4-amino-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazole-3-one and 2-furan-2-yl-methylamine. Sodium complexes (1a9a) of the crown compounds form crystalline 1:1 (Na+:ligand) stoichiometries and were also synthesized. The structures of the crown ether aldehydes (13), imine compounds (49), and complexes (1a9a) were confirmed on the basis of elemental analyses, IR, 1H and 13C NMR, and mass spectrometry. (c) 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:100109, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21070