Syntheses of novel hexahomotrithiacalix[3]arenes

The first synthesis of the C-3-symmetrical p-tert-butylhexahomotrithiacalix[3]arene 7d via one-pot procedure by the reaction of 2,6-bis(chloromethyl)-p-tert-butylphenol 8d with sodium sulfide nanohydrate under high-dilution conditions is reported. Also, hexahomotrithiacalix[3]arenes 7d-f (where d-f designate the type of the substituents R at the p-positions of the phenolic rings: d, R = t-Bu; e, R = CH3; f, R = Cl) were synthesized via a convergent approach in good yield by the [2 + 1] cyclization reaction of 2,6-bis(chloromethyl)phenol monomers 8d-f and bis(chloromethyl)phenol dimers 15d-f in presence of sodium sulfide nanohydrate under high-dilution conditions. The structures of 7d-f were determined by H-1, C-13 NMR, MS and elemental analysis. A preliminary study of the binding properties of 7d with alkali- and heavy metal cations using biphasic picrate extraction method showed only weak abilities to bind the cations examined.