A Practical Oxone®-Mediated,High-Throughput, Solution-Phase Synthesis of Benzimidazolesfrom 1,2-Phenylenediamines and Aldehydes and its Application toPreparative Scale Synthesis
作者:Pierre Beaulieu、Bruno Haché、Elisabeth von Moos
DOI:10.1055/s-2003-40888
日期:2003.8
Addition of oxone® to a mixture of a 1,2-phenylenediamine and an aldehyde in wet DMF at room temperature results in rapid formation of benzimidazoles under very mild conditions. The reaction is applicable to a wide range of substrates including aliphatic, aromatic and heteroaromatic aldehydes, and is not significantly affected by steric or electronic effects. In most cases, crude products are isolated in good to excellent yields (59-95%) and homogeneities (86-99%) by simple precipitation or extraction from the reaction mixture and do not require additional purification. Limitations to the scope of this methodology were encountered in cases where aldehydes were sensitive to oxone® under the acidic reaction conditions. The features of this methodology make it particularly well suited for the high-throughput, solution-phase synthesis of benzimidazole libraries. The low cost and simplicity of this procedure makes it equally attractive for preparative-scale syntheses where safety and environmental issues are of greater concern.
在室温下,将oxone®添加到1,2-苯二胺和醛的湿DMF混合物中,可以在非常温和的条件下快速形成苯并咪唑。该反应适用于多种底物,包括脂肪族、芳香族和杂芳香族醛,并且不受立体或电子效应的显著影响。在大多数情况下,粗产物通过简单的沉淀或从反应混合物提取,得到了良好至优异的产率(59-95%)和均匀性(86-99%),且不需要额外的纯化。该方法的适用范围在某些对oxone®在酸性反应条件下敏感的醛的情况下受到限制。这种方法的特点使其特别适合于苯并咪唑库的高通量溶液相合成。该程序的低成本和简单性也使其在对安全和环境问题更为关注的制备规模合成中同样具有吸引力。