Preparation of Tetramethylphthalic Anhydride

Abstract

Nitration of hexamethylbenzene with benzoylnitrate by Willsttitter's method gave bis(nitromethyl) prehnitene. And, an aquedus alkaline solution of this bis(nitromethyl)prehnitene was poured into a hot dilute solution of hydrochloric acid, stirred for several hours under air or nitrogen atmosphere, and filtered to afford tetramethylphthalic anhydride in good yield.