Table 1. Optimization of Reaction Conditions^a.

entry	amount of catalyst (mg)	temperature (°C)	time (min)	yieldb (%)
1	0	50	120	−
2	5	50	120	60
3	10	50	90	75
4	15	50	80	89
5	20	50	30	95
6	20	25	60	78
7	20	40	60	91
8	20	70	30	95
9	30	50	35	95

^aReaction conditions: benzaldehyde (1 mmol), dimedone (2 mmol), catalyst (20 mg), solvent (5 mL).

^bIsolated yields.