ELECTROPHILIC SUBSTITUTION-REACTIONS OF BENZ[A]INDENO[1,2,3-CD]AZULENE

The title compound (2) was prepared through the photochemical transformation of several triptycene derivatives. Electrophilic substitution reactions of 2 took place primarily at the 6-position: the Vilsmeier reaction gave the 6-formyl derivative in good yield; bromination afforded the 6-bromo derivative, accompanied by a small amount of the 6,11-dibromo compound; nitration yielded mainly the 6-nitro compound, with the 8-nitro derivative as a minor product. However, Friedel-Crafts type reactions did not give any acyl derivatives. Structures of the reaction products were confirmed by their NMR spectra. © 1990, American Chemical Society. All rights reserved.