TITLE:
Alternative and Eco-Friendly Synthesis of Tetrakis(Aminomethyl)Calix-[4]-Resorcinarene
AUTHORS:
S. Ali Moussaoui, Ziad Damaj, Moheddine Wehbie, Stéphane Pellet Rostaing, Iyad Karamé
KEYWORDS:
Bridged Calix-[4]-Resorcinarene, Eco-Friendly Synthesis, Catalytic Hydrogenation, Atom Economy, Radical Substitution, Nucleophilic Substitution, CH2Cl2
JOURNAL NAME:
International Journal of Organic Chemistry,
Vol.7 No.4,
December
15,
2017
ABSTRACT: A cleaner and eco-friendly method was developed for the preparation of
tetrakis(aminomethyl)calix-[4]-resorcinarene via a synthetic pathway of five steps starting from
methylresorcinol. This alternative methodology is firstly based on avoiding the
use of CH2BrCl, which is a non-eco-friendly substance with high
ozone depletion potential, and on replacing it by CH2Cl2 as a readily available reagent with much less dangerous effects. Secondly, this
method engages acetone or CH2Cl2 as the solvent
of the bromination step in the place of the very toxic CCl4, leading
to tetrakis(bromomethyl)calix-[4]-resorcinarene. The brominated intermediate
has been reacted with sodium azide in acetone instead of the high-boiling
solvent DMSO to produce tetrakis(azidomethyl) calix-[4]-resorcinarene without the
need of tedious purification. Lastly, this work reports an efficient
hydrogenation method of the versatile azido adduct employing Pt/C (5%) as the
catalyst for the preparation of the amino cavitand as an alternative route with
high atom economy that can replace the classical methods used currently.