99387-18-5Relevant articles and documents
Liquid Crystalline Compounds Bearing Pyridine Ring: 3-(4-Alkoxyphenylazoxy)-6-alkoxypyridines
Kamogawa, Hiroyoshi,Kasai, Tsuneharu
, p. 69 - 78 (2007/10/02)
3-(4-Alkoxyphenylazo)-6-alkoxypyridines (6) with n-alkoxyl (C1-C6) groups were synthesized by the coupling reaction of phenol with 6-alkoxy-3-pyridine diazonium chloride prepared from 2-chloro-5-nitropyridine via 2-alkoxy-5-nitro and 2-alkoxy-5-aminopyridines and subsequent etherification with n-alkyl iodides.Mild oxidation of 6 with hydrogen peroxide in acetic acid provided 3-6-alkoxy-pyridines (7) containing nearly equimolar amounts of ONN (8) and NNO (8') isomers.Centrifugal liquid chromatography satisfactorily separated these two isomers.Mesomorphic behaviors of 8 and 8' are characteristic in that the pyridine ring exerts polar effects and 8 are more balanced in polarity than 8'.Compounds 7 possess rather lower mesomorphic ranges than 8 and 8'.Some of compounds 6 indicate mesomorphic ranges but generally azo compounds are inferior to azoxy ones.