Synthesis of mesomorphic aryl esters bearing a pyridine ring

Aryl carboxylic esters bearing disubstituted pyridine rings were synthesized starting with various pyridine mono- or dicarboxylic acids by means of reactions, principally, with phenolic compounds. Some of the pyridine monocarboxylates thus synthesized exhibited clear nematic phases at relatively low temperatures, whereas most of the 2,5-pyridine dicarboxylates bearing two benzene rings provided nematic phases, the ranges of which were some times wider and/or lower than those of the corresponding aryl esters bearing benzene rings alone.