A FACILE MICROWAVE ASSISTED SYNTHESIS AND SPECTRAL CHARACTERIZATION OF SUBSTITUTED BENZYLIDINE CARBAZOLES, PYRAZOLO(3,4-a)CARBAZOLES AND ISOOXAZOLO(3,4-a)CARBAZOLES

Aldol condensation between 1-oxo-1,2,3,4-tetrahydrocarbazole 1 and benzaldehyde yielded 2-benzylidine-1-oxo-1,2,3,4-tetrahydrocarbazole 2. Which on treatment with hydrazine hydrate in ethanol afforded substituted 4,5-dihydro-3-phenyl-2H- pyrazolo(3,4-a)carbazoles 3. The compound 2 on treatment with hydroxylamine hydrochloride in ethanol yielded 3-phenyl isooxazolo(3,4-a)carbazoles 4. Microwave irradiation of 2 with hydrazine hydrate and hydroxylamine hydrochloride in ethanol separately yielded the same products 3 and 4 respectively.