Abstract
2,3-Cycloalkano-3,4-dihydro(5H)-7-benzoyl-1,5-benzodiazepine-4-spirocycloalkanes have been prepared from 4-benzoyl-o-phenylenedi-amine and cycloalkanones in presence of acetic acid. Only in the case of cyclohexanones, dihydrospiro benzimidazoles are formed as coproducts which are absent in others.