Document Type: Regular Paper
Institute of Pharmacy and Science, Nirma University of Science and Technology Sarkhej-Gandinagar Highway, Ahmedabad, India, 380 009
Calix(6)arene hydroxamic acids (III) are synthesised for the first time by reacting
calix(6)arene acid chloride(II) with substituted hydroxylamines at low temperature in the presence of
sodium bicarbonate. The p-carboxycalix(6)arene(I) is obtained by an acid catalysed condensation
reaction of p-hydroxybenzoic acid and formaldehyde. These calixarenes are characterised by melting
point, UV, IR, 1H NMR and mass spectra. The thermodynamic ionization constants of calixarene
hydroxamic acids have been determined by a pH titration technique in dioxane-water media.