A facile microwave assisted synthesis and spectral characterization of substituted benzylidine carbazoles, pyrazolo[3,4-a]carbazoles and isooxazolo[3,4-a]carbazoles.

ABSTRACT

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-2Hpyrazolo[ 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.