THE SYNTHESIS OF FUNCTIONALIZED PYRROLO-[2,1-C][1,4]-BENZODIAZEPINES

Two concise and high yielding routes to the antitumour antibiotic pyrr olo-[2,1-c][1,4]-benzodiazepine ring system are described. Thus, conde nsation of prolinol with 2-azidobenzoylchloride gives the tertiary ami de (3). Oxidation to the aldehyde (4) followed by generation of the ph osphoroimine by Staudinger reaction results in ring closure via an aza -Wittig reaction to yield the desired ring system. Alternatively, coup ling of prolinol with the appropriate isatoic anhydride yields the cor responding amino alcohol. Oxidation with Dess-Martin periodinane yield s the PBDs in moderate to good yield.