FACILE SYNTHESIS OF A SERIES OF LIQUID CRYSTALLINE 2-(4'-ALKOXYPHENYL)-5-CYANOPYRIDINES

摘要

The invention relates to a facile synthesis of a series of 2-(4′-alkoxyphenyl)-5-cyanopyridine liquid crystal compounds which are represented by the following formula (I):; ;wherein C_nH_2n+1 is a linear alkyl group having 2-12 carbon atoms. The synthesis of the liquid crystalline 2-(4′-alkoxyphenyl)-5-cyanopyridine is completed in a two-step reaction. First, a Grignard reagent (such as 4-alkoxyphenylmagnesium bromide) is added to a 3-cyanopyridinium salt (such as N-phenyloxycarbonyl-3-cyanopyridinium chloride) to get a 1,2-dihydropyridine. Then, the 1,2-dihydropyridine is oxidized with o-chloronil to obtain the 2-(4′-alkoxyphenyl)-5-cyanopyridine.