Efficient and facile ‘on-solvent’ multicomponent synthesis of medicinally privileged pyrano[3,2-c]pyridine scaffold

The new type of ‘on-solvent’ multicomponent reaction was found: transformation of benzaldehydes, malononitrile and 4–hydroxy-6-methylpyridin-2(1H)-one in the presence of sodium acetate as catalyst in a small amount of ethanol results in formation of substituted 2-amino-7-methyl-5-oxo-4-phenyl-5,6-dihydro-4H-pyrano[3,2-c]pyridine-3-carbonitriles in excellent 92–99% yields. This novel ‘one-pot’ process opens an efficient and convenient way to functionalize pyrano[3,2-c]pyridine systems, which are promising compounds for different biomedical applications.