Deep eutectic solvent as a highly efficient reaction media for the one-pot synthesis of benzo-fused seven-membered heterocycles

摘要

The combination of choline chloride and urea as a deep eutectic solvent has been applied to the synthesis of benzo-fused seven-membered heterocycles, including tricyclic 1,4-benzodiazepines and 1,4-benzoxazepines, via a one-pot, three-component reaction. The reaction conditions are relatively mild and do not require additional metals, acid catalysts, or organic solvents. The protocol has the advantages of excellent yields in short reaction times, an easy workup procedure, and being environmentally friendly. (C) 2016 Elsevier Ltd. All rights reserved.