Abstract:
Some imidazoles like 1 methylimiduzole and 1 methyl 2
hydroxymethylimidazole were originally brominated with Br2/DMF/KHCO3 and afford the correspondant 2.4.5-dibromo-1-methylimidazole and 4,5-dibromo-i- methylimidazole.
This reaction is calended to N unprotected imidazoles like 2
methylimidazole, 2 phenylimidazole and imidazole to yied respectively 2 methyl 4,5 dibromoimidazole. 2 phenyl 1.5 dibromoimidazole and 2,1,5 tribromoimidazole in comparative yields with acetic buffer medium.
Protection of this later with dimethylsulfate and 20% NaO land moderate temperature constituted also an original method in this serie.
Quaternisation of this brominated imidazole protected with methyl in position-1 with bromoacetophenone, ethylbromoacetate and chloroacethylchlorid yielded nearly quantitatively corresponding imidazolium salts.
Attempted eyelisation give retroquaternisation, but quaternisation with bromoalcanes afford a serie of fiveteen ionic liquids (reputed as green solvents). Inside we have brominated and quaternised a serie of nitroimidazoles,