Knoevenagel condensation of acetonedicarboxylates with aldehydes

In this article, a facile method for NH4OAc-promoted synthesis of biscoumarins and 3-arylphenols is described by a straightforward Knoevenagel condensation of 1,3-acetonedicarboxylates with substituted salicyclaldehydes and cinnamaldehydes under the solventfree condition. The structures of the key products were confirmed using X-ray analysis. The plausible mechanisms are proposed and well-discussed. In the overall reaction process, water could be generated as the byproduct. Various reaction conditions are investigated for one-pot condensation.