1373025-18-3Relevant academic research and scientific papers
Palladium and copper catalyzed cyclizations of hydrazine derived Ugi products: Facile synthesis of substituted indazolones and hydroxytriazafluorendiones
Welsch, Sebastian J.,Kalinski, Cédric,Umkehrer, Michael,Ross, Günther,Kolb, Jürgen,Burdack, Christoph,Wessjohann, Ludger A.
, p. 2298 - 2301 (2012)
Indazolones are medicinally relevant targets. Herein we disclose an improved synthesis to N'-(acetamido-2-yl)-substituted indazolones with four points of diversity introduced by Ugi-[M]-amination and -amidation. The ring closure can be achieved by either conventional palladium catalysis or with a ligandless copper protocol. When α-unbranched isocyanides were employed the sole cyclization products of the copper catalyzed reactions are the hitherto undescribed 2-hydroxy-3H-3,4a,9a-triaza-fluorene-4,9-diones.
