Concise synthesis of 3,4-dihydro-1,4-benzoxazines by three-component reactions of acyl chlorides, o-aminophenols and 1,2-dichloroethane

The Cu(OAc)(2)-catalyzed three-component reactions of o-aminophenols, acyl chlorides and 1,2-dichloroethane (DCE) have been established for the efficient synthesis of 3,4-dihydro-2H-benzo[b][1,4] oxazines (3,4-dihydro-1,4-benzoxazines). This method features advantages of the one-pot operation enabling N-acylation, C-Cl bond amidation and etherification, as well as the structural divergence of the synthesized products. (C) 2018 Elsevier Ltd. All rights reserved.