Simple and efficient procedures for selective preparation of 3-haloindoles and 2,3-dihaloindoles by using 1,3-dibromo-5,5-dimethylhydantoin and 1,3-dichloro-5,5-dimethylhydantoin
作者:Jianwei Yan、Tianjun Ni、Fulin Yan
DOI:10.1016/j.tetlet.2015.01.080
日期:2015.2
Simple and efficient synthetic procedures for the selective preparation of 3-bromo/3-chloroindoles and 2,3-dibromo/2,3-dichloroindoles by using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) and 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) were developed. Using 1,4-dioxane as the solvent, a variety of indoles, treated with 0.55 equiv DBDMH/DCDMH, afford the corresponding 3-bromo/3-chloroindoles selectively in 82-99% yield. In 1,2-dichloroethane (DCE), a series of 2,3-dichloro/2,3-dibromoindoles were selectively obtained in 84-95% yield by treating with DBDMH/DCDMH. All the processes do not need extra catalysts, dry solvents, or harsh reaction conditions. (C) 2015 Elsevier Ltd. All rights reserved.