A green one-pot synthesis of 5H-Chromeno[4,3-b]pyridin-5-one derivatives which are the main core natural product Polyneomarline C is described by reaction 4-chloro-3-formyl coumarin and different cyclic acyclic compounds having active methylene group in presence Et3N NH4OAc EtOH. The advantages this strategy good yields, no need for chromatographic separation absence heavy metal catalysts toxic...