Ionic Liquid Promoted Synthesis of β-Enamino Ketones at Room Temperature

Abstract

β-Enamino ketones have been synthesised in excellent yield at room temperature in the absence of any added catalyst by the reaction of aromatic or aliphatic amines with 1,3-dicarbonyl compounds in ionic liquid. The ionic liquid is recycled and reused several times.

Key words

amination - ionic liquid - 1,3-dicarbonyl compounds - β-enaminone

References and Notes

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16

General Experimental Procedure for the Synthesis of β-Enamino Ketones: A mixture of 1,3-diketones 1 (2 mmol) and amine 2 (2 mmol) in ionic liquid [EtNH₃]NO₃ (4 mmol) was stirred at r.t. The progress of the reaction was monitored by TLC. After completion of reaction, the reaction mixture was diluted with EtOAc and extracted with H₂O and brine. The organic layer was dried over MgSO₄, filtered and the solvent was removed under reduced pressure. The products obtained were purified using column chromatography on SiO₂ and identified by comparing with authentic samples by TLC, ¹H NMR and IR spectra.