Table 1.

Screening of conditions for the Aldol-Michael addition reaction of model substrate ^a.

Entry	Condition	Time (h)	Yield (%) b
1	Et2NH/H2O	1	99
2	iPr2NH/H2O	5	85
3	(Cyclohexyl)2NH/H2O	4	82
4	Morpholine/H2O	3	78
5	NaOH/H2O	8	65
6	Et2NH	12	10
7	H2O	12	0

^aAll reactions were carried out with 1,3-dimethylbarbituric acid 1a (3 mmol), benzaldehyde 2a (1.5 mmol) and amine (1.5 mmol) in water (1.5 mL) for the specified time;

^bYield of isolated product.