Multicomponent assembling of isatins, malononitrile and 4-hydroxy-6-methylpyridin-2(1H)-ones: one-pot efficient approach to privileged spiro[indoline-3,4’-pyrano[3,2-c]pyridine]-2,5’(6’H)-dione scaffold

The new one-pot multicomponent assembling of isatins, malononitrile and 4 hydroxy-6-methylpyridin-2(1H)-ones into previously unknown 2’-amino-7’-methyl-2,5’-dioxo-5’,6’-dihydrospiro[indoline-3,4’-pyrano[3,2-c]pyridine]-3’-carbonitriles in 80–98% yields has been accomplished by their reflux in ethanol in the presence of sodium acetate.