Catalytic activity of tungstophosphoric acid supported on carriers of diverse acidity in the synthesis of enaminones Original Research Article

Tungstophosphoric acid (PW), supported on different metal oxide (TiO2, γ-Al2O3, K 10 and KSF) and activated carbon were used in the condensation of aniline with ethylacetoacetate to afford the corresponding β-enaminone. Catalytic activity was discussed in relation with the acid strength of catalysts. The best catalytic activity was obtained with PW/TiO2. Effect of PW loading, solvent and catalyst reusability was studied to introduce the best reaction conditions. Based on the above experimental findings, various β-enaminones were synthesized in excellent yield within a few minutes under solvent free condition.