2-Furylmethylene-2,3,4,9-tetrahydrocarbazol-1-ones were obtained from the mixed aldol condensation of 2,3,4,9-tetrahydrocarbazole-1-ones and furan-2-carbaldehyde (furfural). The corresponding enones were utilised as the synthons to prepare various heteroannulated pyrazolo[3,4-a]-, isoxazolo[3,4-a]-, pyrido[2,3-a]-, and pyrimido[4,5-a] carbazoles under different conditions using various reagents. Single crystal X-ray diffraction studies of 2-furylmeth-ylene-6-methyl-2,3,4,9-tetrahydrocarbazol-1-one are discussed.
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