SYNTHESIS OF MESOMORPHIC 2-ALKYL-5-(p-CYANOPHENYL)PYRIDINES
A new series of liquid-crystal derivatives of 2-alkyl-5-(p-cyanophenyl)pyridines were obtained by halogenation of 2-alkyl-5-phenylpyridines under the conditions of the Birckenbach-Gubo-Waters reaction with subsequent conversion of the 2-alkyl-5-(p-bromo- or iodophenyl)pyridines to the cyano derivatives.
Pavlyuchenko, A. I.,Kovshev, E. I.,Titov, V. V.
p. 69 - 72
(2007/10/02)
New Heterocyclic Liquid Crystalline Compounds
Mesomorphic derivatives of 2-substituted 5-p-alkyl(alkoxy or cyano)phenylpyridines, 1,4-disubstituted piperidines, and ethyl 5-p-alkylphenylthiophene-2-carboxylates have been synthesised and their liquid crystal properties compared with those of analogous benzene and cyclohexane derivatives.Intermediates in the pyridine derivative synthesis 2-thienyl- and 2-furylpyridines - have been found to be mesomorphic too.Some piperidine compounds containing the cyano group in the benzene ring exhibit a large (over +30) positive dielectric anisotropy.