Table 2.

Optimization of the reaction conditions in the typical reaction.^a

Entry	Solvent	Catalyst loading (g)	Temperature (°C)	Time (min)	Yield (%)b
1	CH3CN	0.01	Reflux	60	51
2	EtOAc	0.01	Reflux	90	Trace
3	n-hexane	0.01	Reflux	120	−
4	C2H5OH	0.01	Reflux	45	70
5	H2O	0.01	Reflux	60	66
6	−	0.01	100	10	85
7	−	−	100	60	−
8	−	0.01	25	90	−
9	−	0.01	50	60	65
10	−	0.01	75	30	76
11	−	0.005	100	60	72
12	−	0.02	100	15	85
13	−	0.03	100	20	85
14c	−	0.01	100	60	35
15d	−	0.01	100	60	54
16e	−	0.01	100	30	61
17f	−	0.01	100	10	85
18g	−	0.01	100	30	83
19h	−	0.01	100	15	80

^aReaction conditions: 3,4-dimethoxybenzaldehyde (1 mmol; 0.166 g), 3-amino-1,2,4-triazole (1 mmol; 0.084 g, 0.014 mL), malononitrile (1 mmol; 0.066 g); ^bIsolated yield; ^cCompound A (in Fig. 3) was used as a catalyst; ^dCompound B (in Fig. 3) was used as a catalyst; ^eCompound C (in Fig. 3) was used as a catalyst; ^f{[VO(TPPA)][C(CN)₃]₄}⁷² was used as a catalyst; ^gChitosan based vanadium oxo (ChVO)⁷⁵ was used as a catalyst; ^h[VO(TPPABr)]CBr₃⁷⁶ was used as a catalyst.