Condensation of anthranilic acids with pyridines to furnish pyridoquinazolones via pyridine dearomatization.

The unprecedented carbodiimide-mediated condensation between pyridines and anthranilic acids via pyridine dearomatization at room temperature has been developed to provide a straightforward approach to pyridoquinazolones. The value of this approach has further been demonstrated by its application to one-step, gram-scale syntheses of a series of pyridoquinazolone-based natural products and their analogues from readily available starting materials.