Comparison of catalytic activity of SD-SO₃H with some other catalysts.

Entry	Catalyst	Temperature (°C)	Time (min)	Yield (%)	References
1	SD-SO3H	110	9	98	91
2	m-ZrP	160	240	94	92
3	SCZ	120	143	87	93
4	ASA	100	30	98	94
5	CMK-5-SO3H	130	20	95	95
6	H6P2W18O62·24H2O	130	42	87	96
7	Zeolite-E4a	110	180	97	97
8	HClO4·SiO2	130	35	95	98