5-(4-烷基苯基)-2-(4-氰基苯基)-嘧啶的合成

对 5 (4 烷基苯基 ) 2 (4 氰基苯基 ) 嘧啶的合成进行了研究 ,以 5 (4 正己基苯基 ) 2 (4 氰基苯基 ) 嘧啶 (Ⅳ )的合成为例 ,论述了以 4 己基苯乙酸为原料 ,先依次制得 4 己基苯乙酰氯 ,1 二甲氨基 3 二甲亚胺基 2 (4 正己基苯基 ) 丙烯 高氯酸盐 (Ⅰ ) ,得率 84%。进而在甲醇钠存在下与 4 溴苯基脒盐酸盐 (Ⅱ )相对接 ,合成 5 (4 正己基苯基 ) 2 (4 溴苯基 ) 嘧啶 (Ⅲ ) ,得率 87%。最后Ⅲ和CuCN反应合成了液晶化合物Ⅳ ,得率 78%。其结构由1HNMR和IR光谱所证实 ,同时还测定了其DSC。另外在合成Ⅱ时 ,必须在无水条件下进行 ,而且在通入氯化氢气体时 ,反应温度保持 - 5～ 0℃ ,其反应得率 97%。

Synthesis of 5-(4-alkylphenyl)-2-(4-cyanophenyl)-pyrimidines

Synthesis of liquid crystals 5 (4 alkylphenyl) 2 (4 cyanophenyl) pyrimidines was studied,for instance 5 (4 n hexylphenyl) 2 (4 cyanophenyl) pyrimidine(Ⅳ).5 (4 n Hexylphenyl) 2 (4 bromophenyl) pyrimidine(Ⅲ) was prepared in the presence of sodium methoxide by means of cyclization of 4 bromobenzamidine hydrochloride(Ⅱ) with 1 dimethylamino 3 dimethylimino 2 (4 n hexylphenyl) propene perchlorate(Ⅰ) in 87% yield,Ⅰ was in turn prepared via acylchloride with p n hexylphenylacetic acid as starting material in 84% yield.Ⅳ was synthesized by reaction of Ⅲ and cuprous cyanide in 78% yield.The structure of Ⅳ was confirmed by 1 HNMR and IR,and DSC of Ⅳ was measured.The optimum conditions for synthesizing Ⅱ were exclusion of moisture and reaction temperature kept at -5-0℃ when hydrogen chloride gas was led in.Yield of Ⅱ was 97%.