Synthesis of triazolo[2,1-b]quinazolinone derivatives catalyzed by NGPU^a.

Entry	Ar	R	Product	Time (min)	Yieldb (%)	M.p. (°C)
						Found	Reported
1	C6H5	CH3	1a	22	96	254–257	252–254 (ref. 26)
2	4-Cl-C6H4	CH3	2a	20	94	300–303	304–305 (ref. 44)
3	2-Cl-C6H4c	CH3	3a	14	88	286–290	288–290 (ref. 45)
4	2,4-Cl2-C6H3	CH3	4a	20	90	>300	>300 (ref. 46)
5	4-Br-C6H4	CH3	5a	30	85d	292–295	287–288 (ref. 44)
6	4-NO2-C6H4	CH3	6a	20	91	291–293	290–294 (ref. 47)
7	3-NO2-C6H4	CH3	7a	22	93	292–294	290–293 (ref. 46)
8	4-OCH3-C6H4	CH3	8a	20	95	233–235	231–233 (ref. 46)
9	4-OH-C6H4	CH3	9a	18	97	>300	>300 (ref. 31)
10	4-OH-3-OCH3-C6H3	CH3	10a	25	85d	272–277	287–290 (ref. 48)
11	4-CH3-C6H4	CH3	11a	20	93	262–266	265–267 (ref. 45)
12	2-CH3-C6H4	CH3	12a	16	97	305–306	299–300 (ref. 28)
13	C6H5	H	13a	24	98	298–299	296–300 (ref. 32)
14	4-Cl-C6H4	H	14a	60	80d	294–295	294–296 (ref. 32)
15	3,4,5-(OCH3)3–C6H2	H	15a	4	98	>300	297–299 (ref. 49)
16	4-Br-C6H4	H	16a	27	98	>300	306–308 (ref. 32)
17	4-CH3-C6H4	H	17a	7	97	>300	316–318 (ref. 50)
18	3-NO2-C6H4	H	18a	16	90	298–300	292–296 (ref. 32)
19	2-CH3-C6H4	H	19a	5	98	>300	New
20	2-Br-C6H4	H	20a	5	97	>300	New
21	4-SCH3-C6H4	H	21a	3	95	>300	New

^aReaction conditions: aldehyde (1 mmol), 1,3-diketones (dimedone and/or 1,3-cyclohexanediones) (1 mmol) and 3-amino-1,2,4-triazole (1 mmol).

^bIsolated yields.

^c8 mol% NGPU (2 : 1 : 5).

^dIsolated yields after recrystallization.