The dibenzoazepine-5-carbonitrile (I) is converted to its 11-cyano isomer (II) in the presence of potassium tert-butoxide in dichloroethane. Alkylation of the keto nitrile (II) with ethyl bromoacetate leads to the dibenzoazepine derivative (III). Rearrangement of (III) under basic conditions affords the indoloquinazoline (IV). Finally, alkaline hydrolysis of methyl ester (IV) provides the corresponding carboxylic acid.