Rapid and Mild Synthesis of 5-Pyrimidinecarbonitriles by Using a TiO2-CNTs Nanocomposite Catalyst under Solvent-Free Conditions

We report on the preparation of a series of 5-pyrimidinecarbonitriles, a new efficient protocol, via the condensation reaction of aromatic aldehydes, malononitrile, and urea/thiourea using a TiO2-CNTs nanocomposite with a weight ratio of 50:50 as an inexpensive, recoverable, and high yielding heterogeneous catalyst. The use of a low cost and reusable catalyst under mild and solvent-free conditions, and simplicity in operation with easier isolation of the products in high to excellent yields are the main advantages of this highly versatile and eco-friendly protocol.