Pyromellitic Acid → Pyromellitic dianhydride

Participants

Reaction Steps

50.0 g pyromellitic acid were boiled under reflux with 400 ml anisole and 3.0 g activated carbon, Merck Art. No. 2184, under the same conditions as in example 1 and then processed. 4.3 g (60.6% of the theory) water separated in the course of 2.5 hours. 27.3 g (=64% of the theory) pyromellitic acid anhydride were obtained and the remainder of 18.0 g, (36%) was filtered off as unchanged pyromellitic acid, together with the activated carbon.

Provenance & Evidence