Table 2.

Preparation of 1-substituted 1H-1,2,3,4-tetrazoles in the presence of Cu NPs/bentonite by reaction between sodium azide, primary amines and triethyl orthoformate at 120 °C.^a

Entry	Substrate	Product	Yield [%]b
1			93
2			85
3			94
4			87
5			83
6			85
7			87
8			87
9			88
10			92
11			86
12			83

^aReaction conditions: Amine (2.0 mmol), NaN₃ (2 mmol), triethyl orthoformate (2.4 mmol), Cu NPs/bentonite (0.05 g) at 120 °C, 3 h. ^bIsolated yield.