I<sub>2</sub> mediated synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones via sequential condensation/oxidative cyclization and rearrangement
作者:Shyam Sunder Patel、Nisha Chandna、Shreemoyee Kumar、Nidhi Jain
DOI:10.1039/c5ob02667a
日期:——
A simple and efficient iodine-assisted protocol for the synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones has been developed. The reaction involves a sequential condensation followed by tandem oxidative cyclization and rearrangement of readily available methyl/benzyl carbazates and aldehydes as starting substrates. The presence of iodine and base promotes intramolecular C–O bond
已经开发了一种简单有效的碘辅助方案,用于合成5-取代的3-甲基/苄基-1,3,4-恶二唑-2(3 H)-ones。该反应包括顺序缩合,然后串联氧化环化,以及容易获得的甲基/苄基氨基甲酸酯和醛作为起始底物进行重排。碘和碱的存在会促进分子内C–O键的形成,然后在90°C时在缩合步骤形成的intermediate中间体中,甲基/苄基的Chapman式重排。已采用这种无过渡金属的方法,可在温和条件下以高至优异的收率生成各种恶二唑酮。