4-Chloro-o-xylene → 2,2'-Dichloro-4,4',5,5'-tetramethylbenzophenone

Participants

Reaction Steps

Specific benzophenonetetracarboxylic dianhydrides preferred in this invention are readily available from commercial sources or synthesis. For instance, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (D1) is available from Aldrich Chemical Co., Inc. (1001 W. St. Paul Ave., Milwaukee, Wis. 53233), 2,2′-Dichloro-4,4′,5,5′-benzophenone tetracarboxylic dianhydride is available from 4-chloro-o-xylene by Friedel-Crafts acylation with oxalyl chloride to give 2,2′-dichloro-4,4′,5,5′-tetramethylbenzophenone, followed by oxidation with nitric acid and dehydration of the resulting tetracarboxylic acid as described by Falcigno, et al., J. Poly. Sci. 1992, 30, 1433.

Provenance & Evidence