Synthesis of 2,4,5-trisubstituted imidazoles catalyzed by Fe₃O₄/SO₃H@zeolite-Y^a.

Entry	R	Product	Time (min)	Yieldb (%)	mprep/mplit. (°C)
1	H	4a	45	98	270–272 (271–273)11
2	2-NO2	4b	65	97	226–228 (226–227)37
3	3-NO2	4c	20	85	268–270 (267–268)11
4	3-OH, 4-OMe	4d	45	93	215–217 (215–217)11
5	2-OMe	4e	65	97	200–202 (209–211)38
6	3,4-OMe	4f	45	98	214–216 (214–216)11
7	3-OH	4g	35	97	259–261 (259–260)11
8	4-OMe	4h	60	95	226–228 (230–231)11
9	2-Cl	4i	65	95	168–170 (196–199)37
10	2,3-Cl	4j	50	98	254–256 (194–197)37
11	2,4-Cl	4k	50	98	168–170 (175–178)37
12	4-Cl	4l	35	97	260–262 (260–262)11
13	3-Br	4m	30	98	301–303 (302–303)11
14	4-Me	4n	45	96	231–233 (230–232)11

^aReaction conditions: benzil (1 mmol), aldehyde (1 mmol), ammonium acetate (2 mmol) and Fe₃O₄/SO₃H@zeolite-Y (0.020 g) in EtOH at 80 °C.

^bIsolated yield.