As we found, simplest pyrazole based aurone analogs could be obtained by Claisen-Shmidt condensation of hydroxylated or alkoxylated benzofuran-3(2H)-ones and 3(5)-pyrazolecarboxaldehyde or 4-pyrazolecarboxaldehyde under action of KOH in EtOH.
For the synthesis of hydroxypyrazole based aurone analogs we choose condensation of masked enaminones as synthetic equivalent of 3-hydroxy-4-formylpyrazoles/4-formylpyrazolin-3-ones. Target aurones were obtained by refluxing of benzofuranones with masked aldehydes in acetic acid
