A Facile Method for the Synthesis of Acetylcarbazoles and Carbazole Aldehydes
作者:Rajagopal Nagarajan、Paramasivan T. Perumal
DOI:10.1081/scc-120038488
日期:2004.12.31
Abstract Acetylation of 9‐alkylcarbazoles with acetic anhydride catalyzed by PPh3 · HClO4 was reported to give acetylcarbazoles. Carbazolealdehydes were easily synthesized by the Vilsmeier reaction of 9‐alkylcarbazoles under microwave condition in good yields.
A Short Route to Heteroarylcarbazoles: Synthesis of New Pyrazolylcarbazoles and Carbazolylquinolines
作者:Paramasivan T. Perumal、Rajagopal Nagarajan
DOI:10.1055/s-2004-822353
日期:——
A short synthesis of pyrazolylcarbazoles from 9-alkylcarbazoles in three steps is reported. The acetylcarbazoles prepared by the acetylation of carbazoles with acetic anhydride catalyzed by BiCl3 were converted into chloroaldehydes with Vilsmeier reagent. Condensation of chloroaldehydes with hydrazine followed by cyclization yield the pyrazolylcarbazoles. Carbazolyl chalcones were prepared by the condensation of carbazole-3-aldehyde with o-aminoacetophenone and cyclized to carbazolylquinolone using several catalysts. Cyclization of carbazolyl chalcones with the Vilsmeier reagent yields a mixture of carbazolylquinoline carbaldehydes.