Preparation of quinazolin-4(3H)-one derivatives in the presence of γ-Fe₂O₃@CPTMS–guanidine@SO₃H (0.05 g) as catalyst under microwave irradiation (180 W, max. 70 °C) conditions in solvent-free condition.

Entry	Name	RNH2	Time (h)	Yielda (%)	Mp (obs) (°C)	Mp (lit) (°C)
1	4a	NH4OAC	15	92	287–289 °C	230–232 °C (ref. 29)
2	4b	Propyl amine	20	92	81–83 °C	82–83 °C (ref. 30)
3	4c	Butyl amine	20	90	88–90 °C	89 °C (ref. 31)
4	4d	Cyclohexyl amine	20	92	289–291 °C	>300 °C (ref. 32)
5	4e	Benzyl amine	15	55	220–223 °C	230–231 °C (ref. 34)
6	4f	Aniline	15	68	145–146 °C	147–148 °C (ref. 33)
7	4g	4- Chloro aniline	20	70	154–155 °C	156–158 °C (ref. 33)
8	4h	4- Nitro aniline	20	80	193 °C	190–193 °C (ref. 33)
9	4i	4-Methoxy aniline	20	62	173 °C	169–171 °C (ref. 33)
10	4j	4-Methyl aniline	20	40	153–155 °C	149–150 °C (ref. 33)
11	—	3- Nitro aniline	20	35	170–173 °C	171–172 °C (ref. 32)
12	4k	4-Bromo aniline	15	90	159–161 °C	159–161 °C (ref. 35)
13	4l	2,5-Dimethoxy aniline	15	70	170–173 °C	171–172 °C (ref. 33)
14	4m	n-Phenylsulfonyl amine	20	50	138–139 °C	138–139 °C (ref. 35)
15	4n	Triflouromethoxy aniline	20	35	223.0 °C	223 °C (ref. 36)
16	4o	3-Aminophenol	20	65	114.5 °C	115 °C (ref. 36)
17	4p	2-Methyl-4-phenyl-1H-imidazole	15	91	257–259 °C	Present work
18	4q	2-(Benzo[d]thiazol-2-yl)phenol	15	92	280–282 °C	Present work

^aIsolated yields.