The Knoevenagel condensation reaction of aromatic aldehydes with malononitrile by grinding in the absence of solvents and catalysts

An improved Knoevenagel condensation reaction of aldehydes and malononitrile can be achieved by grinding at room temperature in the absence of solvents and catalysts. This process is simple, efficient, economical, and environmentally benign. Compared to reactions carried out by microwave irradiation, this procedure is completely free from organic solvents during both the reaction and separation of the product.