Comparison of efficiency ZrO₂–TiO₂ with reported catalysts.

Entry	Catalyst	Time (min)	Temperature (°C)	Solvent	Yield	References
1	Zeolite BEA	240	130	PhNO2	63	42
2	PFPAT	180	110	Toluene	90	43
3	MFRH	50	80	Solvent-free	65	43
4	Nanoreactors	60	130	Solvent-free	30	43
5	CMK-5-SO3H	20	130	Solvent-free	95	44
6	CMK-5	60	130	Solvent-free	10	44
7	ZrO 2 –TiO 2	180	RT	Solvent-free	97	41
8	ZrO 2 –TiO 2	110	60	Toluene	95	41
9	ZrO 2 –TiO 2	150	60	Ethanol	92	41