Evaluation of the efficiency of ion exchange zeolite catalysts^a.

Test number	Catalyst	Weight percent (%) of selected metal	Yield (%)
1	Cu/NaY	3.91	97
2	Co/NaY	3.88	51
3	Ni/NaY	3.90	47
4	Mn/NaY	3.81	50

^aReaction conditions: 2 mmol of dimedone, 1 mmol of benzaldehyde, 1 mmol of ammonium nitrate and 2 mg of catalyst, 110 °C.