Potassium fluoride catalysed multicomponent approach to medicinally privileged 5-[3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl] substituted chromeno[2,3b]pyridine scaffold

Abstract

The new efficient and facile multicomponent reaction was found: transformation of salicylaldehydes, kojic acid, and malononitrile dimer in the presence of potassium fluoride as catalyst in small amount of i-propanol results in formation of substituted 2,4-diamino-5-(3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitriles in 56-93% yields. This complex “domino” transformation includes Knoevenagel condensation of salicylaldehyde with malononitrile dimer, Michael addition of kojic acid, double Pinner type reaction cyclization, and isomerization with following protonation. The novel ‘one-pot’ process opens an efficient and convenient way to functionalized 5H-chromeno[2,3-b]pyridine systems, which are promising compounds for different biomedical applications.