5,7-Dihydropyrrolo[3,4-<Emphasis Type="Italic">d</Emphasis>][1,2]diazepin-1(2<Emphasis Type="Italic">H</Emphasis>)-ones. Synthesis and transformations

A preparative procedure has been developed for the synthesis of substituted 5,7-dihydropyrrolo-3,4-d]1,2]diazepines by recyclization of 6-phenylpyrano3,4-c]pyrrol-4(2H)-one with hydrazine hydrate. The stability of the seven-membered ring in the products under acidic conditions, alkylation, and heteroring fusion to the diazepine ring have been studied.