Table 2. Optimizing the reaction conditions for synthesis of 2-amino-7-hydroxy-4-phenyl-4H-chromene-3-carbonitrile using Arg@ZY-Fe₃O₄ nanocatalyst^a.

Entry	Catalyst loading, (wt/wt%)	Solvent	Temperature (°C)	Time (min)	Yieldb (%)
1	—	Ethanol	80	24 h	—
2	10	Ethanol	25	60	25
3	10	Ethanol	80	20	88
4	10	H2O/EtOH (1 : 1 ratio)	80	16	90
5	10	H2O	80	10	92
6	10	H 2 O	90	5	97
7	10	H2O	100	5	97
8	10	H2O	25	60	55
9	15	H2O	90	4	97
10	5	H2O	90	15	65
11	10	CH3OH	80	15	73
12	10	CH3–CN	80	20	65
13	10	CH2Cl2	40	30	10
14	—	H2O	90	30	30
15	10	—	90	20	65
16	10 (zeolite-NaY)	H2O	90	30	20
17	10 (l-arginine)	H2O	90	15	30
18	10 (Arg@ZY)	H2O	90	8	89
19	10 (Fe3O4)	H2O	90	15	25

^aReaction condition: resorcinol (1 mmol), benzaldehyde (1 mmol) and malononitrile (1 mmol).

^bIsolated yield.