2,5-dibromopyridine as a key building block in the synthesis of 2,5-disubstituted pyridine-based liquid crystals

Fifteen 2,5-disubstituted pyridine based liquid crystals were synthesized exploiting the different reactivities of the bromine atoms in 2,5-dibromopyridine under Negishi coupling conditions. Convenient approaches to both 2-iodo-5-alkyl-pyridines and 2-alkyl-5-bromopyridines were also developed. The liquid crystalline behaviour of the synthesized materials was investigated using DSC and polarizing microscopy. The charge mobility of 2-(4-heptyloxyphenyl)- 5-heptylpyridine was measured using the time of flight technique.