TheElbs Reaction

Abstract

Diaryl ketones having a methyl or methylene substituent adjacent to the carbonyl group often suffer cyclodehydration when submitted to pyrolysis and afford a certain amount of the corresponding anthracene derivative. The reaction is usually carried out by heating the ketone without catalyst or solvent at the reflux temperature or at a temperature in the range of 400‐450 degrees until the water is no longer evolved. The main hydrocarbon reaction product may not be that normally expected based on the starting material. A product of the Elbe condensation usually require extensive purification. The mechanism of the condensation is not known.

Recent advances in the syntheses of anthracene derivatives

“…Despite some difficulties and limitations, a number of synthetic methods for preparing anthracene derivatives has been reported over the years. The most familiar methods to obtain substituted anthracenes include Friedel-Crafts reactions [17], Elbs reaction [18], aromatic cyclodehydration [19,20], Bradsher-type reactions from diarylmethanes [21][22][23], and, more recently, metalcatalyzed reactions with alkynes [24,25]. Numerous synthetic routes have also been reported for the synthesis of anthraquinones [26][27][28][29].…”