Synthesis of 3,5-disubstituted isoxazolines as a template for liquid-crystalline polymers

SummaryThe synthesis and mesomorphic properties of new polyacrylate liquid crystals 3,5-disubstituted isoxazolines 8a-d are discussed. 1,3-Dipolar cycloadditions of nitrile oxides generated in situ from oximes 2a-b in the presence of 4-substituted styrene 3 (X = Br, Cl and CH3) provided 3,5-disubstituted isoxazolines 5a-d. The monomers 7a-d were submitted to AIBN conditions and all the final polymers showed a stable nematic phase. The mesophase stability was dependent on the spacer length and terminal group at mesogenic core. Also, a small molecular weight effect was observed.