Jain, V.K., Pillai, S.G., Pandya, R.A., Agrawal, Y.K. and Shrivastav, P.S. (2005) Molecular Octopus: Octa Functionalized Calix[4]Resorcinarene-Hydroxamic Acid [C4RAHA] for Selective Extraction, Separation and Preconcentration of U(VI). Talanta, 65, 466-475.
https://doi.org/10.1016/j.talanta.2004.06.033

has been cited by the following article:

• 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.