220698-60-2Relevant academic research and scientific papers
Synthesis of a new class of difunctional tetraphenylene crown ethers
Gibson, Harry W.,Nagvekar, Devdatt S.,Delaviz, Yadollah,Bryant, William S.
, p. 1429 - 1436 (2007/10/03)
Three new substituted tetraphenylene crown ethers have been made. Bis(5- carbomethoxy-1,3-phenylene)-bis(p-phenylene)-(3x + 6)-crown-x, where x = 12, 16, and 20 (11b-11d) were synthesized via [1 + 1] cyclization of methyl 3,5- bis[ω-chloro(oligoethyleneoxy)]benzoates (13b-3d) with methyl 3,5-bis[ω- (p-hydroxyphenoxy)(oligoethyleneoxy)]benzoates (16b-6d) using K2CO3 as base and tetrabutylammonium iodide as a phase transfer agent in dimethylformamide (DMF). The corresponding 30-membered (x = 8) macrocycle 11a could not be made by this approach; only the elimination product, 3,5-bis(vinyloxy)benzoic acid (19), was isolated. 16a-16d were made via alkylation of p-benzyloxyphenol (14) with 13a-13d, respectively, followed by hydrogenolysis with Pd/C as catalyst. No complexation of these macrocycles with dibenzylammonium ions was detected by NMR spectroscopy, but weak complexation of 11d with a paraquat derivative was observed.
