Silica-Supported Ferric Chloride (FeCl₃-SiO₂): An Efficient and Recyclable Heterogeneous Catalyst for the Preparation of Arylaminotetrazoles

Abstract

An efficient method for preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using FeCl₃-SiO₂ as an effective heterogeneous catalyst. Generally, when the substituent in arylcyanamide is a strongly electron-withdrawing group, the position of the equilibrium would shift toward 5-arylamino-1H-tetrazole, whereas with an electron-releasing substituent, the position of the equilibrium would shift toward 1-aryl-5-amino-1H-tetrazole.

Keywords:

• 1-Aryl-5-amino-1H-tetrazole
• 5-arylamino-1H-tetrazole
• arylcyanamide
• FeCl₃-SiO₂
• heterogeneous catalyst

ACKNOWLEDGMENT

We are thankful to the Bu-Ali Sina University, Hamedan, Iran, for partial support of this work.

Notes

^a Yield refer to the pure isolated product.

^b Determined by ¹H NMR analysis.

^c Yield after the third cycle.

^a Reaction was carried out at 120 °C.

^b In the absence of catalyst at 110 °C, no reaction occurred after 120 min.