Condensation of dithioanilin with β-ketoesters in xylol, gave 2-acetyl (benzoyl)-3-oxo- l,4-benzothiazines and 2-ethoxycarbonyl-3-methyl (phenyl)-1,4-benzothiazines. In the case of ethyl acetoacetate, two others products have been isolated: 2-methyl benzothiazole and 2-dihydro-3-oxo-1,4-benzothiazine. The sulfurization of 2-acetyl (benzoyl) 3-oxo-1,4-benzothiazines by phosphorus pentasulfide or lawesson reagent, lead to 1-methyl (phenyl)-2,3-dithiolo[4,3-b]-1,4-benzothiazines .
A. Keita, E.M. Essassi, M. Salem
dithioanilin, β-ketoesters, 1,4-benzothiazine, sulfurization 1,2-dithiols