Domagalina E, Zawisza P
Acta Pol Pharm. 1989;46(1):19-26.
Either the alkylation of 5(6)-nitro-benzimidazoles (R = H, CH3) or the nitration of 1-alkyl-benzimidazoles afforded corresponding mixtures of 1-alkyl-5-nitro- and 1-alkyl-6-nitro-benzimidazoles (III, IV, VII, VIII, XI). Fractional crystallization from water was employed for isolation of 6-nitro isomers V, VI and IX from mixtures III, IV and VII. On the other hand, application of this isolation method to mixtures VIII and XI proved unsuccessful. 6-Nitro-compound X and 5-nitro derivatives XIII and XV were obtained by direct syntheses. From calibration curves depicting dependence of absorbance of the mixtures upon their composition, percentage ratios of 5-nitro to 6-nitro isomers in the mixtures were estimated. Usefulness of thin-layer chromatography, and UV and IR spectrometry for identification of 5-nitro and 6-nitro isomers was stated; e. g. 5-nitro isomers have higher epsilon values, while 6-nitro isomers exhibit two vmax values of the benzene ring. Compounds IV, IX and X proved to exert antihelminthic, antibacterial and antiphlogistic activities.
5(6)-硝基苯并咪唑（R = H，CH₃）的烷基化反应或1-烷基苯并咪唑的硝化反应均得到了相应的1-烷基-5-硝基苯并咪唑和1-烷基-6-硝基苯并咪唑的混合物（III、IV、VII、VIII、XI）。采用水相分步结晶法从混合物III、IV和VII中分离出6-硝基异构体V、VI和IX。另一方面，将这种分离方法应用于混合物VIII和XI时却未成功。通过直接合成得到了6-硝基化合物X以及5-硝基衍生物XIII和XV。根据描述混合物吸光度与其组成关系的校准曲线，估算了混合物中5-硝基异构体与6-硝基异构体的百分比比例。阐述了薄层色谱法、紫外光谱法和红外光谱法在鉴定5-硝基和6-硝基异构体方面的实用性；例如，5-硝基异构体具有较高的ε值，而6-硝基异构体呈现出苯环的两个vmax值。已证明化合物IV、IX和X具有抗蠕虫、抗菌和抗炎活性。
