Access to 4‑((Pyridin-2-yl)amino)quinazolinones\nvia Annulation of 2‑Aminobenzonitriles with <i>N</i>′‑(Pyridin-2-yl)‑<i>N</i>,<i>N</i>‑dimethyl Ureas

We have developed a convenient protocol for synthesizing <i>N</i>-(2-pyridyl)-substituted 4-(amino)quinazolin-2(1<i>H</i>)-ones by reacting <i>N</i>,<i>N</i>-dimethyl-<i>N</i>′-pyridylureas with 2-aminobenzonitriles.\nThe method relies on the ability of <i>N</i>,<i>N</i>-dimethyl-<i>N</i>′-pyridyl/quinolinyl ureas to\nact as masked isocyanates under\nthermal activation, followed by a Dimroth rearrangement of 4-imino-3-(hetaryl)-3,4-dihydroquinazolin-2(1<i>H</i>)-ones. Conducted at 120 °C, either in DMF or under\nsolvent-free conditions, this approach has produced 28 derivatives\nof 4-aminoquinazolinones, featuring pyridine or quinoline substituents,\nwith yields of up to 92%.