SYNTHESIS AND IDENTIFICATION OF THE 3 ISOMERS OF BIS(3,3-DIPHENYLPHTHALIDYL) KETONE

The three Isomers of bis (3, 3-dfphenylphthalidyl) ketone have been synthesized and identified. The starting material 3, 3ʹ,4ʹ4ʹ-benzophenonetetracarboxyllc acid dianhydride (BTDA) was subjected to a Friedel-Crafts reaction with benzene to produce the three Isomers of benzophenonedlbenzoyldlcarboxylic acid. One of these was separated owing to its insolubility in chloroform. This Isomer and the mixture of the other twoisomers were then treated with thionyl chloride to yield the pseudoacid chlorides which were subsequently treated again with Friedel-Crafts conditions with benzene to yield the desired products. The mixture of the two isomers was separated by elution chromatography on silica gel. The overall yields for the isomers ranged from 13 to 19% for a total product yield of 45 %. Properties and NMR spectral data are given. © 1979, American Chemical Society. All rights reserved.