Title:An Efficient Propylphosphonic Anhydride (T3P®)-Mediated MW-induced
Solvent-free Rapid Synthesis of Enamino Esters and Ketones including 5,
5-Dimethyl-3-aminocyclohex-2-enones
Volume: 21
Issue: 6
Author(s): Omid Marvi*, Sattar Arshadi and Bita Baghernejad
Affiliation:
- Department of Chemistry, Payam Noor University, P.O. Box 19395-3697, Tehran, Iran
Keywords:
T3P®, dimedone, 5, 5-dimethyl-3-aminocyclohex-2-enone, enaminone, solvent-free, microwave.
Abstract: This work presents a clean and convenient synthesis of various β-enaminones including 5,5-
dimethyl-3-aminocyclohex-2-enones, in satisfactory to excellent yields from the condensation reaction
of primary amines with β -dicarbonyls by employing T3P® as a catalyst and performing the reaction
under microwave irradiation and solvent-free conditions. These rapid reactions launched readily and
stood a diversity of organic functional groups. A mixture of 1,3-dicarbonyl compound, primary amine
and T3P® (50% in AcOEt) was irradiated for an appropriate time under microwave at 80°C. After
completing the reaction (TLC) and cooling to r.t., ethyl acetate and saturated aqueous NaHCO3 solution
were added. The aqueous phase was extracted ethyl acetate. The combined organic layer was
washed with brine, dried over Na2SO4, and filtered, and the solvent was removed under reduced pressure
to afford the product, which was recrystallized from diisopropyl ether. The presented results exhibit
a better catalytic activity of T3P in the synthesis of enaminones. It could be concluded that T3P is
the best catalyst as it took only a few minutes for the completion of the reaction with an excellent yield
of product, which indicates T3P is more efficient, compared to other catalysts. A comparison of the efficiency
of the present procedure with some heterogeneous solid catalysts was evaluated as well.
Clearly, a higher yield was established in this procedure compared to other catalysts. Furthermore, the
reaction of amines with dimedone was investigated as well, delivering excellent yields. The reaction
catalyzed by T3P under microwave irradiation supplies a comprehensive method for the synthesis of
enaminones. In this work, T3P is an effective, efficient and green catalyst, which forms the procedure
economic, suitable, and safe with widespread application in the synthesis of enaminones.
