Bromination of 5‐Methoxyindane: Synthesis of New Benzoindenone Derivatives and Ready Access to 7H‐Benzo[c]fluoren‐7‐one Skeleton

Abstract

The photobromination of 5‐methoxyindane and 5‐methoxyindanone was studied at both high and low temperatures. 1,2,3‐Tribromo‐6‐methoxyindene was easily synthesized by photolytic bromination of 5‐methoxyindane at low temperature. 1,1,2,3‐Tetrabromo‐6‐methoxyindene was obtained from the photobromination of 5‐methoxyindan at 77 °C, which could then be easily converted to the 2,3‐dibromo‐6‐methoxyindene by silver‐supported hydrolysis. Photochemical bromination of 5‐methoxy‐1‐indanone with N‐bromosuccinimide (NBS) gave 3‐bromo‐6‐methoxyindene, which upon thermolysis gave a benzo[c]fluorenone derivative.

Keywords:

• Benzo[c]fluorenone
• indenone
• photobromination

Acknowledgments

The authors are indebted to the Department of Chemistry at Middle East Technical University, Research Foundation (Gaziosmanpaşa University, Project Nos. 30/2001 and 18/2002); Juniata College, TUBITAK (Scientific and Technological Research Council of Turkey, Project No. 104T397); and TUBA (Turkish Academy of Sciences) for their financial support of this research.