Selective Ipso-Nitration of tert-Butyl Calix[4]arene Ether Derivatives under Mild and Heterogeneous Conditions

Abstract

Nitration of p-tert-butyl calix[n]arene propyl ethers under variety of reaction conditions has been examined. Ipso-Nitration of tri and tetra propoxy tetra-p-tert-butyl calix[4]arene with silica supported sulfuric acid and nitric acid give best yields of p-nitro calixarenes in simple work up conditions. The obtained nitrated products are key intermediates for construction of molecular receptors based on calixarenes.