Comparison of the results obtained from the synthesis of 9-(4-hydroxyphenyl)-6,6-dimethyl-5,6,7,9-tetrahydro-[1,2,4]triazolo[5,1-b]quinazolin-8(4H)-one and 12-(4-hydroxyphenyl)-3,3-dimethyl-3,4,5,12-tetrahydrobenzo[4,5]imidazo[2,1-b]quinazolin-1(2H)-one catalyzed by NGPU with some of the other catalysts.

Product	Catalyst (mol%)	Reaction conditions	Time (min)	Yield (%)
	[DABCO](SO3H)2(HSO4)2 (0.02 mmol)32	Solvent free/100 °C	120	90
	NH2SO3H (50 mol%)56	CH3CN/reflux	60	89
	[C4(H-DABCO)2][HSO4]4 (16 mg)33	Solvent free/90 °C	28	87
	SBA–Pr–SO3H (5 mg)34	Solvent free/r.t	10	85
	[(DABCO)2C3H5OH] 2Cl (5.7 mol%)31	Solvent free/100 °C	40	95
	NGPU (2 : 1 : 5) (4 mol%)a	120 °C	18	95
	[DABCO](SO3H)2(HSO4)2 (0.02 mmol)32	Solvent free/100 °C	120	90
	NH2SO3H (0.05 mmol)56	CH3CN/reflux	20	90
	Na+-MMT-[pmim]HSO4 (50 mg)35	Solvent free/110 °C	60	91
	SBA–Pr–SO3H (5 mg)34	Solvent free/r.t	15	87
	Fe3O4@chitosan (2 mg)36	Ethanol/40 °C	135	95
	NGPU (2 : 1 : 5) (12 mol%)a	120 °C	14	99

^aThis work.