Solvent-free and 'on-water' multicomponent assembling of aldehydes, 3-methyl-2-pyrazoline-5-one, and malononitrile: fast and efficient approach to medicinally relevant pyrano[2,3-c]pyrazole scaffold

摘要

Sodium acetate-catalyzed multicomponent reaction of aldehydes, 3-methyl-2-pyrazoline-5-one, and malononitrile initiated by grinding in mortar in the presence of small quantities of water results in the fast (15 min) and efficient formation of substituted pyrano[2,3-c]pyrazoles in 90-95 % yields. The developed fast multicomponent approach to the substituted pyrano[2,3-c]pyrazoles-the known pharmacologically active substances such as antibiotics, enzyme inhibitors, and anticancer drugs--is beneficial from the viewpoint of diversity-oriented large-scale processes and represents fast efficient and environmentally benign synthetic concept for multicomponent reactions strategy.