PASE facile and efficient multicomponent approach to the new type of 5-C-substituted 2,4-diamino-5H-chromeno[2,3-b]pyridine scaffold

The new multicomponent reaction comprises the triethylamine catalyzed assembling of salicylaldehydes, 2-aminoprop- 1-ene-1,1,3-tricarbonitrile and 3-methyl-2-pyrazolin-5-one in small amount of propanol, which affords substituted 2,4-diamino-5-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-5Hchromeno[2,3-b]pyridine-3-carbonitriles in 63–98% yields. This process is in agreement with PASE principles and opens the way to new chromeno[2,3-b]pyridine scaffold containing 3-methyl-2-pyrazolin-5-one fragment, which is promising for various biomedical applications.