An Expedient Dehomologative Annulation Synthesis of Pyrazole‐4‐Azetone Under Mild Condition

ABSTRACT A mild and efficient method has been developed for the synthesis of pyrazole‐4‐azetones from pyrazole‐4‐carbazaldehyde and 4‐amino‐thiazole under mild conditions. Herein, we represent the first report that enables access directly to the core structure of pyrazole‐4‐azetone using 2‐amino‐thiazole. It is presumably acts as a nitrogen source proceeding via the formation of a Schiff base as an intermediate followed by a dehomologative annulation process. The present method has been generalized to a broad range of functional groups with good to excellent yields.