First synthesis of tert-butyl-substituted [1,2,4]triazino[5,6-b]indole-3-thiols and indolo[2,3-b]quinoxalines

In this investigation, the first introduction of a tert-butyl group into [1,2,4]triazino[5,6-b]indole and indolo[2,3-b]quinoxaline systems, leading to a series of structurally novel 8-(t-butyl)-5H-[1,2,4]triazino[5,6-b]indole-3-thiol and 9-(t-butyl)-6H-indolo[2,3-b]quinoxaline derivatives, has been achieved by condensation of tert-butyl-substituted isatins with benzene-1,2-diamine or thiosemicarbazide. The molecular structures of these newly synthesized compounds were elucidated on the basis of elemental analysis and spectral data.