 The reaction conditions for the Kröhnke synthesis are generally facile and the reactions often proceed in high yields with reaction temperatures generally not exceeding 140 °C.The Kröhnke synthesis is generally performed in either glacial acetic acid or methanol, but it can also be done under aqueous conditions, and more recently under solvent-free conditions.1,3-dicarbonyl compounds have also been shown to be viable starting materials in place of the α-pyridinium methyl ketone salts.