Synthesis and Characterization of New Nonpolar Substituted Pyridine-Containing Liquid Crystal

• Main Authors: Shen Shih-Wei, 沈世偉
• Other Authors: 賈文隆
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/72873563763668891153

碩士 === 輔仁大學 === 化學系 === 88 === Comparing with 5-CB ,this research has replaced one of benzene by pyridine and changed cyano group to other functional groups. This study describes a novel and efficient synthesis of pyridine-containing liquid crystalline 3-substituted 6-(4-alkylphenyl)pyridines. 4-Alkylphenyl magnesium bromide was reacted with 3-substituted N-ethoxycarbonylpyridinium chloride to give regioselective 1,6-dihydropyridine intermediates, which were subsequently oxidized by o-chloranil. Good yields and high α-regioselectivity on pyridine ring were observed in all cases. Only two of these 3-substituted 6-(4-alkylphenyl)pyridines were found to be liquid crystalline, they were 6-(4-n-butylphenyl)-3-phenylpyridine and 6-(4-n-pentylphenyl)-3-phenylpyridine.