The effect of various solvents, temperature and catalyst loadings for the synthesis of substituted coumarins through Pechmann condensation.

Entry	Catalyst loading	Solvent	T (°C)	Time (min)	Yield (%)
1	—	—	120	360	No reaction
2	Fe3O4 NPs (6.5 mol%)	—	120	360	No reaction
3	CCMNPs (Fe3O4@C) (6.5 mol%)	—	120	360	No reaction
4	SCCMNPs (Fe3O4@C@OSO3H) (3.25 mol%)	—	120	30	86
5	SCCMNPs (Fe 3 O 4 @C@OSO 3 H) (6.5 mol%)	—	120	20	98
6	SCCMNPs (Fe3O4@C@OSO3H) (13 mol%)	—	120	20	98
7	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	—	100	30	87
8	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	—	90	40	83
9	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	H2O	Reflux	360	Trace
10	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	Toluene	Reflux	360	No reaction
11	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	CH2Cl2	Reflux	360	No reaction
12	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	EtOH	Reflux	360	No reaction
13	SCCMNPs (Fe3O4@C@OSO3H) (6.5 mol%)	CH3CN	Reflux	360	No reaction