2006-12-13 to 2026-12-13
The invention relates to a facile synthesis of a series of 2-(4'-alkylphenyl)-5-cyanopyridine liquid crystal compounds which are represented by the following formula (I): ##STR00001## wherein C.sub.n is a linear alkyl having 1-12 carbon atoms. The synthesis of the liquid crystalline 2-(4'-alkylphenyl)-5-cyanopyridine is completed in a two-step reaction. First, a Grignard reagent (such as 4-alkylphenylmagnesium 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'-alkylphenyl)-5-cyanopyridine.