Table 3.

Optimizing reaction conditions for oxidation of methyl phenyl sulfide in the presence of ZnFe₂O₄@SiO₂@APTES@DHBS-Cu.

Entrya	Catalyst (g)	Solvent	H2O2 (mg)	Time (min)	Yield (%)b
1	–	Solvent-free	0.3	360	Trace
2	0.003	Solvent-free	0.3	30	75
3	0.007	Solvent-free	0.3	30	85
4	0.01	Solvent-free	0.3	30	87
5	0.02	Solvent-free	0.3	30	97
6	0.03	Solvent-free	0.3	30	97
7	0.02	n-Hexane	0.3	30	58
8	0.02	H2O	0.3	30	Trace
9	0.02	H2O: EtOH	0.3	30	47
10	0.02	EtOAc	0.3	30	92
11	0.02	EtOH	0.3	30	82
12	0.02	Solvent-free	0.1	30	88
13	0.02	Solvent-free	0.2	30	92
14	0.02	Solvent-free	0.3	30	96
15	0.02	Solvent-free	0.4	30	96
16	0.02	Solvent-free	0.3	30	N. Rc
17	0.02	Solvent-free	0.3	30	Traced

^aReaction conditions: sulfide (1 mmol) H₂O₂ (0.3 mL) and ZnFe₂O₄@SiO₂@APTES@DHBS-Cu at 25 °C under solvent-free conditions.

^bIsolated yield.

^cThe reaction was catalyzed by ZnFe₂O₄.

^dThe reaction catalyzed by ZnFe₂O₄@SiO₂@APTES@DHBS.