Optimizing the reaction conditions in the 5-substituted 1H-tetrazoles derivatives through MCRs^a.

Entry	Solvent	Amount of catalyst (mg)	Temp. (°C)	Time (min)	Yieldb (%)
1	Solvent-free	—	r.t.	100	Trace
2	Water	—	r.t.	100	Trace
3	Solvent-free	—	Reflux	100	Trace
4	Ethanol	—	r.t.	100	Trace
5	Ethanol	—	Reflux	100	20
6	Ethanol	30	Reflux	40	38
7	DMF	10	Reflux	40	56
8	DMF	20	Reflux	40	72
9	DMF	30	Reflux	40	97
10	DMF	50	Reflux	40	89

^aReaction conditions: aromatic aldehyde (1 mmol), malononitrile (1 mmol) and sodium azide (1.2 mmol), the CFHT nanocatalyst (10–50 mg).

^bThe yields relate to the isolated product.