Synthesis of 6-Hydroxy-12-methyl-7,12-dihydrobenzo[6,7]cyclohept[1,2-b]indol-7-one

Abstract 5,6,7,12-Tetrahydrobenzo[6,7]cyclohept[1,2-b]indol-7-ones were obtained by the oxidation of 5,6,7,12-tetrahydrobenzo[6,7]cyclohept[1,2-b]indoles with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in wet dioxane. The α,α-dibromo compound, obtained by bromination of 12-methyl-5,6,7,12-tetrahydrobenzo[6,7]cyclohept[1,2-b]indol-7-one with phenyltrimethylammonium tribromide (PTAB), was hydrolyzed to give the diketone (5). By treatment with alkali, compound 5 was converted to 6-hydroxy-12-methyl-7,12-dihydrobenzo[6,7]cyclohept[1,2-b]indol-7-one.