Reaction of N-aminophthalimide derivatives with aluminum chloride in benzene

The reaction of N-aminophthalimide derivatives with AlCl3 in benzene has been investigated. From N-amino- and N-benzamidophthalimide (1a and 1b), N-amino- and N-benzamido-3,3-diaryl-2,3-dihydroisoindol-1-ones (2) are obtained in high yield by initial attack of benzene on the imide carbonyl, assisted by the neighboring nitrogen atom. From N-arylaminophthalimide derivatives (4), the N-N bond is cleaved heterolytically to give an arylnitrenium ion and canonical forms involving the arene which are trapped by benzene to give aminobiaryls and N-arylanilines.