Novel synthesis of liquid crystalline compounds of 5-substituted 2-(4-alkylphenyl)pyridines

This study describes a novel and efficient synthesis of pyridine-containing liquid crystalline 5-substituted 2-(4-alkylphenyl)pyridines. 4-Alkylphenylmagnesium bromide was reacted with 3-substituted N-ethoxycarbonylpyridinium chloride to give regioselective 1,2-dihydropyridine intermediates, which were subsequently oxidized by o-chloranil. Good yields and high α-regioselectivity on the pyridine ring were observed in all cases.