Synthesis of 4,5-dihydro-3-(3',4'-methylenedioxy)phenyl-2H-pyrazolino[3,4-a]carbazoles and 3-(3',4'-methylenedioxy)phenylisoxazolo[3,4-a]carbazoles

摘要

2-(3',4'-Methylenedioxy)benzylidene-1-oxo-1,2,3,4-tetrahydrocarbazoles 2 obtained by the mixed aldol condensation of 1-oxo-1,2,3,4-tetrahydrocarbazoles 1 with 3,4-methylenedioxybenzaldehyde on treatment with hydrazine hydrate in ethanol and hydroxylamine hydrochoride in pyridine afford 4,5-dihydro-3-(3',4'-methylenedioxy)phenyl-2H-pyrazolino [3,4-a] carbazoles 3 and 3-(3',4'-methylenedioxy)phenylisoxazolo [3,4-a] carbazoles 4 respectively.