Imidazole and benzimidazole addition to quinones. Formation of meso and d,l isomers and crystal structure of the d,l isomer of 2,3-Bis(benzimidazol-1'-yl)-1,4-dihydroxybenzene
作者:Consuelo Escolástico、María Dolores Santa María、Rosa María Claramunt、María Luisa jimeno、Ibon Alkorta、Concepción Foces-Foces、Félix Hernández Cano、José Elguero
DOI:10.1016/s0040-4020(01)89555-7
日期:1994.1
4-dihydroxybenzene (2c) and 2,3-bis(benzimidazol-1′-yl)-1,4-dihydroxynaphthalene (5c) exist as mixtures of meso and d,l isomers. NMR spectroscopy (n.O.e. experiments in 1H NMR and solid-state 13C CPMAS spectra) and AM1 semiempirical calculations have been used to establish the structure of the isomers both in the solid state and in solution as well as their interconversion pathways. Compound 2c-d,l crystallizes
分离并鉴定了通过将咪唑,2-甲基咪唑和苯并咪唑加到1,4-苯醌和1,4-萘醌中获得的对苯二酚。在1,4-苯醌的情况下,它们是单取代的氢醌1a - 1e,在邻位的氢醌2a - 2c和对二取代的衍生物3a - 3c,而在1,4-萘醌的情况下,只有二取代的衍生物5a和5c已被隔离。在溶液中,2,3-双(2'-甲基咪唑-1'-基)-1,4-二氧苯甲酮(2b),2,3-双(苯并咪唑-1'-基)-1,4-二羟基苯(2c)和2,3-双(苯并咪唑-1'-基)-1,4-二羟基萘(5c)以内消旋异构体和d,l异构体的混合物形式存在。NMR光谱法(在1 H NMR和固态13 C CPMAS光谱中进行的nOe实验)和AM1半经验计算已用于建立固态和溶液中异构体的结构以及它们的相互转化途径。化合物2c - d,1以两个甲醇溶剂化物分子作为客体结晶,并且具有穿过中间的结晶学双轴。主体分子通过OH = O / N氢键通