Microwave-assisted selective and efficient synthesis of 1,3,5-triazinyl mono and bisureas

Abstract An efficient and sustainable microwave-assisted approach for the one-step preparation of a wide range of 1,3,5-triazinyl mono- and bisureas has been developed, combining solvent-free conditions and microwave irradiation. In these conditions the very unreactive amino groups of 1,3,5-triazine-2,4-diamines successfully react with phenylisocyanate to yield selectively mono and bisureas. This protocol resulted in the shortest reaction times reported so far and is generally applicable for the preparation of these valuable heterocyclic systems.