[5+1] Annulation of Aza‐o‐quinone Methides with Primary Amines: Construction of 3,4‐Dihydroquinazolin‐2(1H)‐one Derivatives"

A [5+1] annulation between in situ generated aza‐o‐quinone methides and primary amines has been developed. This methodology offers efficient access to diverse 3,4‐dihydroquinazolin‐2(1H)‐one derivatives with yields ranging from 45 to 99%. The significance of this methodology is highlighted by its application to the synthesis of a potential CDK5 inhibitor, a bioactive compound.