Synthesis of 5-substituted 6-methoxy-1,2,3,4-tetrahydro-β-carbolin-1-ones

The nitration and bromination of 6-methoxy-1,2,3,4-tetrahydro--carbolin-1-one were studied. 5-Nitro and 5-bromo derivatives were obtained. 5-Acetyl-1,2,3,4-tetrahydrocarbolin-1-one oxime was obtained, and its Beckmann rearrangement was studied. The use of lithium aluminum hydride leads to reduction of the 5-acetyl group to give an alcohol group, whereas reduction of the acetyl group to an ethyl group occurs in the case of reduction with a palladium catalyst. Saponification of 5-substituted carbolin-1-ones with alcoholic alkali makes it possible to obtain 4-substituted tryptamines with a carbonyl group in the 2 position. The structures of the compounds were established by means of the PMR and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 80–85, January, 1979.