Knoevenagel condensation of acetonedicarboxylates with aldehydes.

• Concise, high-yield method for the solventfree synthesis of biscoumarins and 3-arylphenols. • Knoevenagel condensation of 1,3-acetonedicarboxylates with substituted salicyclaldehydes and cinnamaldehydes. • Key products could be confirmed by X-ray crystallography. • One-pot open-vessel process for the formations of C-O and C-C bonds. In this article, a facile method for NH 4 OAc-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. A facile method for NH 4 OAc-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. [Display omitted] [ABSTRACT FROM AUTHOR]