Nucleophilic substitution studies on nitroimidazoles, and applications to the synthesis of biologically active compounds
作者:Gérard Chauvière、Cécile Viodé、Jacques Périé
DOI:10.1002/jhet.5570370120
日期:2000.1
The rationalization of the synthesis of substituted analogs of megazol, a biologically active 5-nitroimidazole at position 4 of the imidazole ring, had led to the study of intermediate steps. The methylation by diazomethane of 2,4-(5)dihalogeno-5-(4)nitroimidazole is regioselective leading to 2,4-dihalogeno-1-methyl-5-nitroimidazole 2. On this compound 2, hard nucleophiles such as cyanide, methoxide
合成的咪唑取代的类似物(咪唑环第4位具有生物活性的5-硝基咪唑)的合理化导致了中间步骤的研究。2,4-(5)二卤代-5-(4)硝基咪唑被重氮甲烷甲基化是区域选择性的,从而导致2,4-二卤代-1-甲基-5-硝基咪唑2。在该化合物2上,硬的亲核试剂如氰化物,甲醇根或氢化物阴离子仅在2位与卤素反应;而来自有机铜物种的柔软亲核试剂(例如胺,硫醇或三氟甲基阴离子)仅与中间体3b或化合物4b中位置4的卤素反应。