苯並咪唑

苯並咪唑是一個多環芳香雜環化合物，由苯和咪唑併合而成，分子式為C₇H₆N₂。維生素B12分子中，5,6-二甲基苯並咪唑為鹼基與鈷中心相連。^[1]

苯並咪唑與咪唑類似，也是製備氮雜環卡賓的常用原料。此類卡賓由N,N'-二取代的苯並咪唑用鹼在2-位去質子化製得，用於製取過渡金屬卡賓配合物。^[2]^[3]

製備[編輯]

苯並咪唑由鄰苯二胺與甲酸^[4] 或等量原甲酸三甲酯縮合製得：

C₆H₄(NH₂)₂ + HC(OCH₃)₃ → C₆H₄N(NH)CH + 3 CH₃OH

2-取代的苯並咪唑可由此法用其他羧酸製備。^[4]

^ H. A. Barker, R. D. Smyth, H. Weissbach, J. I. Toohey, J. N. Ladd, and B. E. Volcani. Isolation and Properties of Crystalline Cobamide Coenzymes Containing Benzimidazole or 5,6-Dimethylbenzimidazole. Journal of Biological Chemistry. 1960, 235 (2): 480–488 [2008-07-02]. （原始內容存檔於2009-02-11）.
^ R. Jackstell, A. Frisch, M. Beller, D. Rottger, M. Malaun and B. Bildstein. Efficient telomerization of 1,3-butadiene with alcohols in the presence of in situ generated palladium(0)carbene complexes. Journal of Molecular Catalysis A: Chemical. 2002, 185 (1-2): 105–112. doi:10.1016/S1381-1169(02)00068-7.
^ H. V. Huynh, J. H. H. Ho, T. C. Neo and L. L. Koh. Solvent-controlled selective synthesis of a trans-configured benzimidazoline-2-ylidene palladium(II) complex and investigations of its Heck-type catalytic activity. Journal of Organometallic Chemistry. 2005, 690 (16): 3854–3860. doi:10.1016/j.jorganchem.2005.04.053.
^ ^4.0 ^4.1 E. C. Wagner and W. H. Millett (1943). "Benzimidazole". Org. Synth.; Coll. Vol. 2: 65.

Grimmett, M. R. Imidazole and benzimidazole synthesis. Boston: Academic Press. 1997. ISBN 0-12-303190-7.