Optimization of the model reaction conditions for the three-component condensation of benzil (2a), 4-chlorobenzaldehyde (3a), and ammonium acetate (4) in the presence of PMAMOSa (1)^a.

Entry	Conditions	Catalyst	Catalyst loading (mg)	Time (min)	Yield (%)
1	Solvent-free/r.t	—	—	300	Trace
2	H2O/r.t	—	—	300	Trace
3	EtOH/r.t	—	—	300	Trace
4	EtOH/50 °C	—	—	300	Trace
5	EtOH/reflux	—	—	300	20
6	H2O/reflux	—	—	300	Trace
7	EtOH/r.t	PMAMOSa (1)	5	300	32
8	EtOH/50 °C	PMAMOSa (1)	5	240	54
9	EtOH/ultrasonic bath/60 °C	PMAMOSa (1)	5	180	68
10	EtOH/reflux	PMAMOSa (1)	5	120	83
11	H2O/reflux	PMAMOSa (1)	5	120	28
12	EtOH/reflux	PMAMOSa (1)	3	120	70
13	EtOH/reflux	PMAMOSa (1)	8	120	78
14	EtOH/reflux	PMAMOSa (1)	10	90	86
15	EtOH/reflux	PMAMOSa (1)	15	40	98

^aReaction conditions: benzil (2a, 1 mmol), 4-chlorobenzaldehyde (3b, 1 mmol), ammonium acetate (4, 2.5 mmol), and PMAMOS (1) unless otherwise noted.