The new acetylene-terminated monomers i, l'-(1-methylethylidene)bis [4-(4-ethynylphenyl)methoxy] benzene and 1,3-bisl'(4-ethynylphenoxy)methyl]benzene (VI) were prepared in 50% and 60% overall yield, respectively. The three-step synthesis involved: (a) a Williamson reaction between ~,4-dibromotoluene and bisphenol A, or ~,~'-dichloro-m-xylene and 4-bromophenol, giving the bromo-terminated compounds 1,1'-(1-methylethylidene)bisl'4-(4-bromophenyl)methoxy]benzene or 1,3-bis[(4-bromophenoxy)methyl]benzene, respectively; (b) palladium-catalysed cross-coupling with 2-methyl-3-butyn-2-ol, affording the corresponding alkynyl tertiary alcohols from which catalyst residues were removed by treatment with diaminoethane; and (c) removal of the acetone protecting group in the presence of KOH. The low melting point of VI (102-104°C) makes it suitable for catalysed cure studies
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Synthesis of acetylene-terminated monomers: 1,1 '- (1 - methylet hyl idene) bis [4- (4- ethynylphenyl) methoxy] benzene and 1,3-bis[(4-ethynylphenoxy)methyl] benzene / William E. Douglas* and Andrew S. Overend // Polymer. – 1994. – Vol 35. – P. 4462-4464.