General Acid - Base Catalysis in the Willgerodt-Kindler Reaction

Abstract

The reaction of acenaphthone with morpholine and sulfur was studied in order to assess the effects of adding a source of acid or base in the Willgerodt-Kindler (WK) reaction. Addition of a strong acid was found beneficial particularly with Montmorillonite K10 which proved to be the best agent for this purpose. As the best conditions involved the use of a strong acid in the presence of an excess of morpholine (acting also as base), it can be inferred that general acid-base catalysis conditions are beneficial in the WK reaction.