4',4''(5'')-Di-tert-butyldibenzo-18-crown-6

4′,4″(5″)-Di-tert-butyldibenzo-18-crown-6 is a hydrophobic crown ether compound. This crown ether is potentially useful in studies of ion transport through non-polar regions and membranes, and has been described in the design of microsensor devices for ammonia determination based upon ammonia-mediated deprotonation of a pH indicator followed by sequestering of ammonium within the 4′,4″(5″)-Di-tert-butyldibenzo-18-crown-6 sphere.

Off-white powder

4'',4''''(5'''')-Di-tert-butyldibenzo-18-crown-6 is a hydrophobic crown ether compound..

4',4''(5'')-Di-tert-butyldibenzo-18-crown-6 (DTBB18C6) was synthesized using 4-tert-butyl catechol (TBC) as starting material, 2,2′-diethylene glycol di(p-touenesulfonate) as cyclization reagent, Cs2CO3 as template, and tetrahydrofuran (THF) as solvent. The reaction was carried out in a sealed environment with nitrogen, and Cs2CO3 was supplemented in three steps. Moreover, it could also be synthesized by improving the electrophilic aromatic substitution of dibenzo-18-crown-6 (DB18C6) using tert-butyl alcohol (TBA) as alkylation reagent, H3PO4 (85 wt %) as catalyst and CH2Cl2 as solvent[1-2].

[1] Juan Fan. “Preparation of 4′,4′′(5′′)-Di-tert-butyldibenzo-18-crown-6 Based on Electrophilic Aromatic Substitution.” Chemistry Letters 41 1 (2012): 274–276.
[1] Jun Fan. “Optimization of Synthetic Strategy of 4′4″(5″)-Di-tert-butyldibenzo-18-crown-6 Using Response Surface Methodology.” Organic Process Research & Development 17 3 (2013): 368–374.