咪唑衍生物的一锅法选择性合成

1-(2-氰乙基)咪唑与α,ω-二卤代烃、二溴苄及三溴苄选择性地发生季铵化反应,继而在碱作用下发生Hoffmann型消去反应,简便而高效地制备了3个系列咪唑衍生物:1-(ω-卤烷基)咪唑3a～3e、含中心功能基的双咪唑5a～5b和三咪唑6a～6b,并类似地制得相应的苯并咪唑衍生物7和8.

Selective One-pot Synthetic Method for Imidazole and Benzimidazole Derivatives

A novel and selective one-pot synthetic method of imidazole and benzimidazole derivatives has been developed. Three series of target compounds, 1-(ω-haloalkyl) imidazoles 3a-3e, bis-imidazoles 5a-5b and tri-imidazoles 6a-6b have been synthesized by the selective quaterisation of 1H-imidazole-1-propanenitrile (1) with α, ω-dihalide, bis(bromomethyl) benzene or tri(bromomethyl) benzene to obtain imidazolium salts, following by Hoffmann-type elimination. Similarly, benzimidazole analogues 7 and 8 were also prepared. It is found that important factors affecting this selective quaterisation are the solvent, temperature, structure and amount of halides.