A traceless solid-supported synthesis of novel pyrazinediazepinedione derivatives

A simple, convenient, six-step synthesis of novel, tricyclic pyrazinebenzodiazepinedione derivatives has been described. The strategy is based on the use of the orthogonally-protected, optically pure, (S)-piperazine-2-carboxylic acid, in a Petasis reaction, followed by coupling with anthranilic acid and finally cyclizing cleavage. The investigated method was applied for the synthesis of novel bicyclic pyrazinediazepinedione derivatives. This traceless, solid-supported approach allows the preparation of a wide variety of compounds in moderate yields from commercially available or easily obtainable reagents.