Formation of substituted N-oxide hydroxyquinolines from o-nitrophenyl Baylis-Hillman adduct: a new key intermediate intercepted by ESI-(+)-MS(/MS) monitoring

Data collected from ESI-(+)-MS(/MS) monitoring and probed by experiments in solution reveals the participation of a new key intermediate (4) in the mechanism of formation of N-oxide hydroxyquinolines (3) from o-nitrophenyl Baylis-Hillman adducts (1).