Synthesis and Structural Characterization of 2-(Hydroxyethoxy Substituted)phenyl Benzimidazoles
摘要:
本文以邻苯二胺、羟基取代的苯甲醛和氯海德林为起始原料,通过两种不同的路线合成了四种 2-(羟乙氧基取代)苯基苯并咪唑。在路线 I 中,羟乙基取代的苯甲醛首先与邻苯基苯二胺反应,得到 2-(羟乙基取代)苯基苯并咪唑中间体,然后利用这些中间体与氯醇进行邻羟乙基化反应合成最终产物。在路线 II 中,首先通过邻羟乙基反应合成羟乙基取代的苯甲醛,然后与邻苯二胺反应。结果表明,路线 I 只适用于羟乙氧基位于苯环中苯并咪唑的对位和元位的目标化合物。对于 2-(邻羟乙氧基)苯基苯并咪唑的合成,路线 II 是唯一的选择,因为它具有很强的立体阻碍。通过元素分析、红外光谱、1H NMR、13C NMR 和单晶 X 射线衍射分析,对这四种新化合物的结构进行了表征和确认。
In this paper, using o-phenylendiamine, hydroxyl substituted benzaldehyde and chlorohydrin as starting materials, four 2-(hydroxyethoxy substituted)phenyl benzimidazoles were synthesized by two different routes. In route I, the hydroxyl substituted benzaldehyde firstly reacted with o-phenylendiamine to get the intermediates 2-(hydroxyl substituted)phenyl benzimidazoles which then were used to synthesize the final products by the o-hydroxyethylation reaction with chlorohydrin. In route II, the hydroxyethoxy substituted benzaldehyde was firstly synthesized through the o-hydroxyethylation reaction and then reacted with o-phenylendiamine. Results show that route I is suitable only for the target compounds in which hydroxyethoxy group is located in para- and meta-position of benzimidazole in the benzene ring. For the synthesis of 2-(o-hydroxyethoxy)phenyl benzimidazole, route II is the only choice because of its strong steric hindrance. The structures of the four new compounds were characterized and confirmed by elemental analysis, IR, 1H NMR, 13C NMR and single-crystal X-ray diffraction analysis.
本文以邻苯二胺、羟基取代的苯甲醛和氯海德林为起始原料,通过两种不同的路线合成了四种 2-(羟乙氧基取代)苯基苯并咪唑。在路线 I 中,羟乙基取代的苯甲醛首先与邻苯基苯二胺反应,得到 2-(羟乙基取代)苯基苯并咪唑中间体,然后利用这些中间体与氯醇进行邻羟乙基化反应合成最终产物。在路线 II 中,首先通过邻羟乙基反应合成羟乙基取代的苯甲醛,然后与邻苯二胺反应。结果表明,路线 I 只适用于羟乙氧基位于苯环中苯并咪唑的对位和元位的目标化合物。对于 2-(邻羟乙氧基)苯基苯并咪唑的合成,路线 II 是唯一的选择,因为它具有很强的立体阻碍。通过元素分析、红外光谱、1H NMR、13C NMR 和单晶 X 射线衍射分析,对这四种新化合物的结构进行了表征和确认。