Functionalization at the upper rim aromatic nuclei

Caution Carry out all procedures in a well-ventilated hood, and wear disposable vinyl or latex gloves and chemical-resistant goggles. HCL is produced in this reaction. 

The following de-f-butylation procedure is representative of all the calix[n]arene series. 

Clamp the hot flask to a support and allow to cool to room temperature in a nitrogen atmosphere and equip it with a mechanical stirrer. 

Fill the vacuum adaptor with calcium chloride and position it to a neck of the flask connect it to the water aspirator (gentle flow) to trap HCI produced during the reaction. 

with vigorous stirring, to the colourless heterogeneous mixture, aluminium trichloride (10 g) at once and continue to stir the mixture, which rapidly turns deep red. Within 30 min a viscous deep-red sticky phase separates on the walls of the flask. 

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