Synthesis of 6,13-difluoropentacene

Abstract

6,13-Difluoropentacene was synthesized from 1,4-difluorobenzene. Friedel–Crafts annulation of the latter with phthalic anhydride and subsequent reduction of the anthraquinone gave 1,4-difluoroanthracene. After ortho-lithiation and reaction with phthalic anhydride a carboxylic acid was obtained whose Friedel–Crafts acylation and subsequent reductive removal of the oxygen-functionalities resulted in the formation of the target compound. The HOMO–LUMO gap of 6,13-difluoropentacene was determined via UV–vis spectroscopy and compared to other fluorinated pentacenes.

Keywords

• fluorinated acenes
• friedel–crafts reaction
• ortho-lithiation
• synthesis