A Sustainable, Semi-Continuous Flow Synthesis of Hydantoins

Hydantoins are an important class of heterocycles with applications in pharmacy, agriculture, and as intermediates in organic synthesis. Traditional synthetic procedures to access hydantoins are target oriented with multiple synthetic steps, often use reagents that are not commercially available, and are not sustainable. Herein, an efficient process is described accessing hydantoins starting from commercially available amines using consecutive gas/liquid transformations (oxygen, carbon dioxide). This semi-continuous process produced ten benzylic/aliphatic hydantoins in good overall yields (52-84%)