Synthesis and Reactions of Some New Benzo[a]phenothiazine-3,4-dione Derivatives

The reaction of 2,3-dihydro-2,3-epoxy-1,4-naphthoquinone () with substituted anilines furnished the corresponding benzo[fused]heterocyclic derivatives . Furthermore, treatment of benzo[a]phenothiazine derivative with halo compounds, namely, ethyl bromoacetate, phenacyl bromide, dibromoethane, or chloroacetone afforded ether derivatives , respectively. Moreover, the reaction of with o-substituted aniline gave the corresponding benzo[a]phenothiazin-5-one derivatives and benzo[d][1,3]oxazin-4-one, respectively. Finally, the chromenone derivative was synthesized via the reaction of ester derivative with salicyaldhyde in refluxing pyridine. The newly synthesized compounds were characterized by spectroscopic measurements (IR, 1H NMR, 13C NMR, and mass spectra).