Comparison of the current method with other reported strategies for synthesizing 2-amino-4-(4-chlorophenyl)-3-cyano-pyrano[3,2-c] chromene-5(4H)-one.

Entry	Catalyst	Catalyst loading	Solvent	Temp (°C)	Time (min)	Yield (%)	Ref.
1	SDS	20 mol%	H2O	60	150	88	17
2	CuO nanoparticles	15 mol%	H2O	100	6	93	31
3	MNP@AVOPc	20 mg	—	25	15	94	27
4	Urea	10 mol%	H2O/EtOH	25	420	93	59
5	POPINO	5 mol%	H2O	Reflux	10	96	30
6	MNPs@Cu	10 mg	—	90	8	95	This work
7	DAHP	10 mol%	H2O/EtOH	25	240	85	26
8	[Sipim]HSO4	0.08 mmol	—	100	30	90	28
9	Nano Al2O3	25 mol%	EtOH	25	300	89	29
10	TBBDA	0.18 mmol	H2O/EtOH	Reflux	170	91	32
11	DBU	10 mol%	H2O	100	5	94	60
12	t-ZrO2 NPs	10 mol%	H2O	80	38	89	61
13	ZnO NPs	10 mol%	EtOH	Reflux	10	80	62 a
14	Sodium alginate	10 mol%	EtOH	Reflux	50	93	63 a
15	KF/Al2O3	250 mg	DMF	25	60–180	81	64 a

^aReaction conditions: dimedone (1 mmol), 4-chlorobenzaldehyde (1 mmol), malononitrile (1 mmol).