Clar Reaction of 7H-benz[de]anthracen-7-one: Isolation and Identification of Tetrabenzo[a,cd,lm,o]perylene

Abstract

The Clar reaction of 7H-benz[de]anthracen-7-one (20) was reinvestigated as a source for C₃₄H₁₈ polycyclic aromatic hydrocarbons (PAH). The utilization of a ternary sodium chloride/potassium chloride/zinc chloride melt with zinc dust as reducing agent yielded tetrabenzo[a,cd,j,lm]perylene (11) (10.7% yield), dibenzo[a,cd]naphtho[1,8-jk]perylene (16) (10.2% yield), and dibenzo[a,cd]naphtho[3,2,1-lm]perylene (14) (7.4% yield) as main products. Tetrabenzo[a,cd,lm,o]perylene (26) as a minor product of the Clar reaction was purified via semi-preparative high performance liquid chromatography, and its unequivocal identification was demonstrated through NMR data and a microscale-cyclization reaction.

Key Words:

• C₃₄H₁₈ PAH
• Clar reaction of 7H-benz[de]anthracen-7-one
• identification
• synthesis
• tetrabenzo[a,cd,lm,o]perylene
• UV spectrum

Acknowledgments

The authors would like to thank the Air Force Office of Scientific Research (DURIP Grants FA9550-05-1-0253 and FA9550-08-1-0281) for providing funding for the HPLC instruments. The authors are also grateful for funding provided through a Coates Research Grant. The authors wish to thank Dr. Dale Treleaven and Dr. Thomas Weldegheorgis for conducting the NMR experiments. The authors are grateful for reference standards and UV spectra from Dr. John Fetzer, Chevron Research and Fetzpahs Consulting.