H. Deligoz et H. Cetisli, The synthesis and properties of some novel azo group containing calix[n]arene derivatives, J CHEM R-S, (10), 2001, pp. 427-429
Two different azo derivatives of p-tert butylcalix[4 and 6]arene 5a, 5b hav
e been synthesised; treatment of the monomers (phenol and p-tert-butyl phen
ol) with diazonium chloride (3) provided corresponding compounds 4a, 4b.