Cascade Wolff Rearrangement and Double <i>N</i>‐Acylation: A Cyclization of <i>α</i>‐Diazoketones with 2‐aminopyridines or 3‐aminopyrazoles to Synthesize Fused Pyrimidinediones
A cascade Wolffrearrangement and double N-acylation reaction has been developed for the synthesis of fused pyrimidinediones in one-pot under air. These reactions were performed with α-diazoketones and 2-aminopyridines or 3-aminopyrazoles under catalyst- and additive-free conditions. The protocol avoided traditional purification procedures, such as organic solvent extraction and column chromatography