Table 5.

Comparison of Fe₃O₄@SiO₂-Im[Br]-SB-Cu (II) with other catalysts in synthesis of tetrazole derivatives.

Entry	Catalyst	Conditions	Time (min)	Yield (%)a	Refs.
1	Cu (OAC)2	EDS (chcl-urea), 100 °C	720	90	51
2	La/THH-CO2H@Fe3O4	PEG-600, 100 °C	300	90	52
3	Pd‐isatin‐boehmite	PEG-400, 120 °C	480	94	53
4	Fe3O4@SiO2-TCT-GA-Cu(II)	Ethylene glycol/H2O (1 : 1), 90 °C	90	97	54
5	PDNPs@CS-Zeo	DMF, 120 °C	720	90	55
6	Zn-CA-MOFs	DMF, 120 °C	480	97	56
7	Cu Nano-catalyst	Solvent-free, 100 °C	85	89	57
8	Nano-Fe3O4/In	Solvent-free, 100 °C	150	90	58
10	Fe3O4@SiO2-Im[Br]-SB-Cu (II)	H2O, 40 °C	20	97	This workb

^aIsolated Yield.

^bAniline (1.0 mmol), Triethyl orthoformate (1.2 mmol), Sodium azide (1.0 mmol) and Fe₃O₄@SiO₂-Im[Br]-SB-Cu (II) (0.6 mol %, 0.008 g). Benzaldehyde (1.0 mmol), hydroxy amine hydrochloride (1.0 mmol), Sodium azide (1.2 mmol) and Fe₃O₄@SiO₂-Im[Br]-SB-Cu (II) (0.9 mol %, 0.012 g).