1-Alkyl- and azeto[1,2-alpha][1,5]benzodiazepine derivatives in the reaction of o-Phenylenediamine with 3-(dimethylamino)propiophenones

The reaction of o-phenylenediamine (4) with one, two or three equivalents o f p-substituted 3-dimethylaminopropiophenone hydrochlorides 5a-e was studie d. 4-Aryl-2,3-dihydro-1H-1,5-benzodiazepine derivatives 6a-e were obtained in good yields, along with the 1:2-adducts 7c-e and the unexpected 1:3-addu cts rac-8c-e, The type of adduct formed is determined by the molar ratio of the reactants 4 and 5 and by the nature of the substituent in the para pos ition of the propiophenone 5.