150919-08-7

Basic information

• Product Name: 1,3,5,7-tetrakis(p-methylbenzyl)-p-tert-butylcalix[8]arene
• Synonyms: 1,3,5,7-tetrakis(p-methylbenzyl)-p-tert-butylcalix[8]arene
• CAS NO: 150919-08-7
• Molecular Weight: 1714.46
• Mol File: 150919-08-7.mol
• Article Data: 3

Chemical Properties

• CAS DataBase Reference: 1,3,5,7-tetrakis(p-methylbenzyl)-p-tert-butylcalix[8]arene(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3,5,7-tetrakis(p-methylbenzyl)-p-tert-butylcalix[8]arene(150919-08-7)
• EPA Substance Registry System: 1,3,5,7-tetrakis(p-methylbenzyl)-p-tert-butylcalix[8]arene(150919-08-7)

Safety Data

• Hazardous Substances Data: 150919-08-7(Hazardous Substances Data)

Upstream product

• 104-81-4 4-Methylbenzyl bromide 
• 68971-82-4 5,11,17,23,29,35,41,47-octakis(tert-butyl)-49,50,51,52,53,54,55,56-octakis(hydroxy)calix[8]arene 

Relevant articles and documents

Alkylation Products of a Calix[8]arene Trianion. Effect of Charge Redistribution in Intermediates

The behavior of a well-defined calix[8]arene trianion under alkylation conditions was investigated by reacting the tetraethylammonium salt of p-tert-butylcalix[8]arene trianion with p-methylbenzyl bromide. Chromatography of the reaction mixture afforded the following derivatives in order of decreasing yields: 1,3,5,7-tetrakis-, 1,3-bis-, 1,3,5-tris-, 1,2,4-tris-, and mono(p-methylbenzyl)-p-tert-butylcalix[8]arene, besides trace amounts of 1,4- and 1,5-disubstituted compounds. Comparable results were obtained using p-tert-butylbenzyl bromide. The observed regioselectivity has been explained by assuming that after each alkylation step the left negative charge is redistributed, by exchange equilibria, over the remaining phenolic groups with preferential localization at those positions where contiguous H-bond stabilization is possible and the electrostatic repulsion is minimized. The occurrence of protonation/deprotonation equilibria allows the formation of 1,3,5,7-tetrasubstituted calix[8]arene.

Tetra-O-benzylated Calixarenes with C4 Symmetry

The first procedure for the selective partial O-alkylation of p-tert-butylcalixarene 1 affording well defined products is described.Treatment of 1 with p-X-benzyl bromides (X = H, Me, tert-Bu, NO2, CN) and K2CO3 in THF/DMF gives the corresponding 1,3,5,7-tetrabenzyl ethers 2-6 having C4 symmetry.Their structures were firmly established by FAB(+) MS, 1H- and 13C-NMR.Variable temperature NMR studies evidenced conformational flexibility for 2-6.A possible rationale is proposed in order to explain the origin of the 1,3,5,7-substitution pattern. Key words: calixarenes, tetraalkylation, 1,3,5,7-tetrabenzyl ethers, C4 symmetry.