Solvent-free and ‘on-water’ multicomponent assembling of salicylaldehydes, malononitrile and 3-methyl-2-pyrazolin-5-one: A fast and efficient route to the 2-amino-4-(1H-pyrazol-4-yl)-4H-chromene scaffold

Sodium acetate-catalyzed multicomponent reaction of salicylaldehydes, malononitrile and 3-methyl-2-pyrazolin-5-one initiated by grinding in mortar in the presence of small quantities of water results in the fast (10 min) and efficient formation of substituted 2-amino-4-(1H-pyrazol-4-yl)-4H-chromenes in 90–96% yields. The developed fast and efficient approach to the substituted 2-amino-4-(1H-pyrazol-4-yl)-4H-chromenes – the promising small-molecule ligands for the treatment of human inflammatory TNFα-mediated diseases and different biomedical applications –, is beneficial from the viewpoint of diversity-oriented large-scale processes and represents fast, efficient and environmentally benign synthetic concept for multicomponent reactions strategy.