Efficient Synthesis of Spirooxindole‐Pyrrolo[1,2‐a]Pyrazin‐2‐ones via Ionic Liquid‐Ultrasonication

Abstract A sustainable and efficient synthesis of new spiro[pyrrolo[1,2 ‐a ]pyrazin]‐2‐ones was developed using N ‐protected isatins, N ‐substituted piperazines, and chalcones under ultrasonic conditions in [C 12 C 12 BIm]Br, a green ionic liquid. The reaction proceeds through a 1,3‐dipolar cycloaddition between an in situ generated azomethine ylide and chalcone. This approach offers several advantages, including its environmental friendliness, mild reaction conditions, and the recyclability of the ionic liquid.