Attempted synthesis of substituted carbazoles from 1-oxo-1,2,3,4-tetrahydro-carbazoles and 1-hydroxyimino-1,2,3,4-tetrahydrocarbazoles

The reaction of 1-oxo-1,2,3,4-tetrahydrocarbazoles 1 with vinyl acetate in presence of alcoholic KOH affords hitherto Unknown 7-methyl-1-oxo-2-(3'-methyl propan-1'-al)-1,2,3,4-tetrahydrocarbazole 2. Similarly, the reaction of 1-hydroxyimino-1,2,3,4-tetrahydrocarbazoles 3 with vinyl acetate in the presence of p-toulenesulphonic acid results in the formation of a new compound viz., 2-acetoxy-1,2,3,3a,4,5-hexahydropyrrolo[3,4-a]carbazole 4. All the compounds have been characterized by IR, NMR and mass spectra and elemental analysis.