Copper-catalyzed tandem aryl–halogen hydroxylation and CH2Cl2-based N,O-acetalization toward the synthesis of 2,3-dihydrobenzoxazinones

Abstract

The concise synthesis of 2,3-dihydro-4H-benzo[e][1,3]oxazin-4-ones has been accomplished by copper-catalyzed tandem reactions of o-halobenzamides, LiOH and dichloromethane. The aryl–halogen bond hydroxylation and subsequent N,O-acetalization on CH₂Cl₂ are enabled under catalytic conditions which allows the generation of C(sp²)–O, C(sp³)–O and C(sp³)–N bonds to give the target products.