This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4]arenes were obtained as main product respectively by diazo-coupling in different molar ratio to calix[4]arene in non-aqueous solution at 0-5℃.
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