Strontium arsenate and Sr2As2EuxO7+δ pyrochlores as reusable heterogeneous catalysts in one-pot, three-component synthesis of 2-amino-4H-chromene derivatives under microwave irradiation

Document Type : Research Article

Authors

1 Department of Inorganic Chemistry, Faculty of Chemistry, Semnan University, Semnan, Iran

2 Department of Organic Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran

Abstract

In this research work, a highly efficient procedure for the synthesis of 2-amino-4H-chromene derivatives by a one-pot, three component condensation of aromatic aldehydes, malononitrile and β-naphtol in water as the eco-friendly solvent and under microwave irradiation using Sr2As2O7 or Sr2As2EuxO7+δ as catalyst is described. It is the first report of using such catalysts in this field. The catalysts were synthesized via solvothermal method at 180 oC for 24 h and characterized by PXRD, FTIR, FESEM, EDX, UV-Vis techniques. For the catalytic performance, the reaction conditions was optimized and found that in the case of 15 mg of catalyst, water as solvent and 6 min microwave irradiation time, higher efficiency is obtained for the model reaction. The results show that aromatic aldehydes containing electron-donating or electron-withdrawing groups could produce the corresponding products, but higher efficiency was obtained with electron-withdrawing groups. Synthesized catalysts can be recycled very easily and reused for 4 runs without substantial loss in activity. Environment friendly solvent, short reaction times, easy isolation and high yield products are the advantages of presented research.

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