Synthesis and characterization of monohydroxylated derivatives of 7H-dibenzo[c,g]carbazole

The synthesis of several monohydroxylated derivatives of the potent carcinogen 7H-dibenzo[c,g]carbazole (DBC), including 1-hydroxy-7H-dibenzo[c,g]carbazole (1-OH-DBC), 13-c-hydroxydibenzo[c,g]carbazole (13-c-OH-DBC), and 5-hydroxy-7H-dibenzo[c,g]carbazole (5-OH-DBC), is described. 1-OH-DBC was prepared from 8-methoxy-2-tetralone and 2-naphthyl-hydrazine via Fischer indole synthesis followed by boron tribromide demethylation. The rearrangement and hydrolysis reactions to give 13-c-OH-DBC from DBC and benzoyl peroxide are discussed. The preparation and isolation of 5-OH-DBC, by hydrolysis of 5-acetoxy-N-acetyl-DBC, and the formation of its intermediate 5-acetoxy-DBC and its byproduct 6,6'-bis-(5-OH-DBC) are described in detail.