the study also aimed to examine the catalysts’ reusability in the reaction of benzaldehyde and dimedone. During the work-up procedure, the reaction mixture in each case was cooled to room temperature, diluted with dichloromethane (10 ml) and filtered to isolate the catalyst. The recovered catalyst was washed three times with CH2 Cl2 (5 ml) and then dried. The separated catalyst was applied to the synthesis of1a(Table 3). The results showed that the catalyst can be easily recovered and reused five times without a significant decrease in catalytic activities
