A Novel and Convenient Preparation of Tropylium Ion Salts

Abstract

Tropylium ion salts are a class of charged, non-benzenoid aromatic compounds possessing 6π electrons and obeying Huckel's rule. The chemistry of these compounds has received considerable attention during the past few years and continues to involve many workers. The synthesis of these compounds by a number of routes has been described in the literature.^1–3 Some of these methods are suitable for small scale laboratory synthesis, while others are unwieldy and inconvenient even for these purposes. To date, the best route for the synthesis of tropylium ion salts has been the oxidation of cycloheptatriene by phosphorous pentachloride.^4,5