Synthesis, characterization and application of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles for the one pot synthesis of triaryl-1H-imidazoles

Abstract

In this investigation, Ni_0.5Zn_0.5Fe₂O₄, as an efficient and heterogeneous catalyst, was prepared and characterized by IR, EDX, XRD and SEM analyses. Ni_0.5Zn_0.5Fe₂O₄ was successfully used for the synthesis of 2,4,5-triaryl substituted imidazoles by the one-pot, three component reaction under solvent-free conditions. Efficiency, generality, high yield, cleaner reaction profiles, ease of product isolation, short reaction times and simplicity are some advantages of this study.

---

In 1858, the synthesis of imidazole as an important compound was first reported by Debus.¹ Imidazoles have various biological roles such as antithrombotic, anti-inflammatory,² fungicidal,³ therapeutic,⁴ antitumor,⁸ and anti-HIV⁹ agents, as well as calcium antagonists; moreover, they act as inhibitors for P38 MAP kinase,⁵ B-Raf kinase,⁶ thromboxane A2 synthesase⁷ and HMG CoA reductase (HMGR).¹⁰ Imidazoles have been used in the synthesis of a large class of compounds such as ionic liquids.^11–13

2,4,5-Triarylimidazoles were first synthesized from 1,2-dicarbonyl compounds, aldehydes and ammonia.¹⁴ Several procedures have been reported for the synthesis of triaryl-1H-imidazoles by the condensation reaction of α-hydroxyketones with ammonium acetate and various aromatic aldehydes in the presence of ionic liquids,¹⁵ HOAc,¹⁶ H₂SO₄,¹⁷ DMSO,¹⁸ H₃PO₄,¹⁹ silica sulfuric acid,²⁰ sulfanilic acid,²¹ NiCl₂·6H₂O,²² iodine,²³ CAN,²⁴ NaHSO₃,²⁵ zeolite HY/silica gel,²⁶ ZrCl₄,²⁷ tetrabutyl ammonium bromide,²⁸ InCl₃·H₂O,²⁹ KMnO₄/CuSO₄ (ref. 30) and microwave irradiation in presence of Al₂O₃ or HOAc.³¹ Some of these synthetic methods suffer from one or more drawbacks such as harsh reaction conditions, poor yields, laborious work-ups and purifications, prolonged reaction times, the use of expensive equipment (microwave or ultrasonic), corrosive reagents, and extensive acid catalysis. Recently, the use of reusable heterogeneous and solid acid catalysts have received considerable importance in organic synthesis due to several advantages, including operational simplicity, low toxicity, low cost, and ease of isolation after the completion of the reaction. The synthesis of magnetic nanoparticles as catalysts has gained considerable interest in recent years due to the magnetic properties of these particles, which leads to easy recovery and recycling of the catalyst.³²

Nanoparticles such as CoFe₂O₄,³³ ZnFe₂O₄,³⁴ Fe₃O₄ ³⁵ with general ferrite formula (MFe₂O₄), are considered due to good magnetic properties, which M is one of the transition elements besides of Fe including Zn, Mn, Ni, Co. In addition, Ni–Zn ferrites are the most versatile magnetic materials as they have high saturation magnetization, high Curie temperature, chemical stability and relatively high permeability.³²

Herein, we have reported a simple and efficient method for the synthesis of 2,4,5-triaryl substituted imidazoles using Ni_0.5Zn_0.5Fe₂O₄ as Fe-based metallic nanoparticles and catalysts with high yields, short reaction times, cleaner reaction profiles and ease of product isolation.

Results and discussion

According to previous literature studies,^32b,c Ni_0.5Zn_0.5Fe₂O₄ nanoparticles as mixed metal oxides have been prepared and characterized using FT-IR, XRD, EDX and SEM analyses. The IR spectrum of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles (Fig. 1) indicates that the prepared ferrite, with a spinel structure, has two principle metal–oxygen bands around 572 cm⁻¹ related to stretching vibrations of the metal at the tetrahedral site (Fe–O). Moreover, the octahedral-metal stretching vibrations, related to Ni–O and Zn–O appear around 419 cm⁻¹.³⁶

Fig. 1 FT-IR spectrum of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles.

In another study, the X-ray diffraction (XRD) pattern of the catalyst was studied in a domain of 5–90° (Fig. 2) (JCPDS no. 08-0234). The XRD pattern displayed diffraction lines of a high crystalline nature at 2θ ≈ 30.00°, 35.50°, 43.00°, 53.50°, 57.10°, 62.5°, and several small lines in the 15–90° range, which is in good agreement with previous studies.³⁶

Fig. 2 XRD pattern of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles.

To confirm the nanostructure of Ni_0.5Zn_0.5Fe₂O₄, TEM measurements were performed as showed in Fig. 3. The TEM micrograph confirms the presence of nanoparticles.

Fig. 3 Transmission electron micrographs (TEM) of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles.

Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) are widely used as surface analytical techniques. SEM of the catalyst clearly showed that the particles have not completely agglomerated and formed nanoparticles (Fig. 4). As shown in Fig. 4, the particles are 28–43 nm in size and have a spherical structure with only one type of particle morphology.

Fig. 4 SEM images for Ni_0.5Zn_0.5Fe₂O₄ nanoparticles.

The elements in the Ni_0.5Zn_0.5Fe₂O₄ nanoparticles were studied by energy dispersive X-ray (EDX) spectrometry of the surface of the catalyst. The results of the EDX analysis of the Ni_0.5Zn_0.5Fe₂O₄ nanoparticles revealed the existence of Zn, Fe, Ni and O (Fig. 5). The actual chemical composition of the nanoparticles and the abundance of the elements were determined by ICPOES (inductively coupled plasma optical emission spectroscopy, Yvon-Jobin, France).

Fig. 5 EDX analysis of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles.

To optimize the reaction conditions, as a model reaction, a mixture of benzil (1 mmol), ammonium acetate (2.2 mmol), and benzaldehyde (1 mmol) was stirred in the presence of different amounts of Ni_0.5Zn_0.5Fe₂O₄ under different temperatures and solvent-free conditions. As seen in Table 1, 5 mol% of Ni_0.5Zn_0.5Fe₂O₄ was sufficient to catalyze the reaction at 80 °C under solvent-free conditions.

Table 1 Effect of different amounts of the catalyst and temperatures on the reaction of benzil (1 mmol), ammonium acetate (2.2 mmol) and benzaldehyde (1 mmol) under solvent free conditions

Entry	Catalyst	Catalyst (mol%)	Temp (°C)	Time (min)	Yield^a (%)	TOF^b (min^−1)
a Isolated yield.b Turn over frequency.
1	Ni0.5Zn0.5Fe2O4	3	80	18	77	1.42
2	Ni0.5Zn0.5Fe2O4	4	80	12	81	1.68
3	Ni0.5Zn0.5Fe2O4	5	80	10	88	1.76
4	Ni0.5Zn0.5Fe2O4	6	80	10	88	1.46
5	Ni0.5Zn0.5Fe2O4	5	25	60	25	0.08
6	Ni0.5Zn0.5Fe2O4	5	60	35	60	0.34
7	Ni0.5Zn0.5Fe2O4	5	70	23	70	0.60
8	Ni0.5Zn0.5Fe2O4	5	80	10	80	1.60

---

We also tested this reaction condition (5 mol% of Ni_0.5Zn_0.5Fe₂O₄) using different solvents. As shown in Table 2, solvent-free conditions are better than solvent-based conditions for the synthesis of 2,4,5-triaryl substituted imidazoles.

Table 2 Effects of solvent on the reaction of benzil (1 mmol), ammonium acetate (2.2 mmol) and benzaldehyde (1 mmol) in the presence of Ni_0.5Zn_0.5Fe₂O₄ (5 mol%)

Entry	Solvent	Conditions	Time (min)	Yield^a (%)
a Isolated yield.
1	—	80 °C	10	88
2	Acetonitrile	Reflux	36	58
3	Ethanol	Reflux	25	88
4	Water	Reflux	90	—
5	Dichloromethane	Reflux	100	20
6	Toluene	Reflux	100	10

---

The catalytic activity of Ni_0.5Zn_0.5Fe₂O₄ nanoparticles as an efficient and heterogeneous catalyst was investigated in the synthesis of 2,4,5-triaryl-1H-imidazoles by the one-pot three component condensation reaction of ammonium acetate and aromatic aldehydes with various benzil compounds (Scheme 1 and Table 3).

Scheme 1 The synthesis of 2,4,5-triaryl imidazoles.

Table 3 Synthesis of 2,4,5-triaryl-1H-imidazoles using various benzil, ammonium acetate and aromatic aldehydes in the presence of Ni_0.5Zn_0.5Fe₂O₄ (5% mol) under solvent free conditions

Entry	R1	R2	Time (min)	Yield^a (%)
a Isolated yield.
1	H	H	10	88
2	H	2-Cl	14	89
3	H	4-Cl	12	91
4	H	4-Me	16	86
5	H	4-OMe	25	79
6	H	4-Br	15	90
7	H	2-OMe	15	87
8	H	2,4-Dichloro	18	90
9	H	4-NO2	30	87
10	4-Me	H	16	76
11	4-Me	4-MeO	35	65

---

To study different types of catalysts, we examined the model reaction in the presence of other Lewis acids, such as Fe₃O₄, ZnO and ZnFe₂O₄, in comparison with Ni_0.5Zn_0.5Fe₂O₄ (Table 4). As shown in Table 4, Ni_0.5Zn_0.5Fe₂O₄ is more successful than these catalysts for the synthesis of 2,4,5-triaryl substituted imidazoles.

Table 4 Effects of different catalysts on the synthesis of 2,4,5-triaryl-1H-imidazole

Entry	Catalyst	Catalyst (mol%)	Temp (°C)	Time (min)	Yield^a (%)	TOF^b (min^−1)
a Isolated yield.b Turn over frequency.
1	Fe3O4	5	85	45	87	0.38
2	ZnO	5	95	18	88	0.97
3	ZnFe2O4	5	80	16	87	1.08

---

The ease of recycling of the catalyst is one of the major advantages of this work. For this purpose, the reaction of benzil, ammonium acetate and benzaldehyde was tested with a recycled catalyst. We did not observe significant loss of the yields when Ni_0.5Zn_0.5Fe₂O₄ was reused for four runs. The results are depicted in Table 5.

Table 5 The results of the preparation of 2,4,5-triphenyl-1H-imidazole in the presence of recycled Ni_0.5Zn_0.5Fe₂O₄

Entry	Cycle	Time (min)	Yield^a (%)
a Isolated yield.
1	—	10	88
2	1	10	86
3	2	10	83
4	3	10	80
5	4	10	78

---

Moreover, the results of this study were compared with the previously reported methods in Table 6. As shown in Table 6, our work is superior to some previous studies. The catalytic activity of Ni_0.5Zn_0.5Fe₂O₄ was improved by increasing the catalytic surface of the nanoparticle catalyst.

Table 6 Comparison the results of this work with previously reported catalysts

Entry	Catalyst	Conditions	Time (min)	Yield^a (%) [ref.]
a Isolated yield.b Our work.
1	KH2PO4, (5 mol%)	Ethanol, reflux	40	93 [37]
2	Yb(OPf)3	C10F18, 80 °C	360	80 [38]
3	[EMIM]OAc	EtOH, ultrasonic irradiation, r.t.	45	87 [39]
4	InCl3·H2O	CH3OH, r.t.	492	76 [40]
6	Ni0.5Zn0.5Fe2O4, (5 mol%)	Solvent free, 80 °C	10	88^b

---

In a proposed mechanism supported by the literature,^41,42 ammonia from NH₄OAc attacks the carbonyl group of the activated aldehyde and produces 1,2-diamine (I). In the next step, by the reaction of 1,2-diamine with activated benzil along with the elimination of two molecules of H₂O, II is prepared. A [1,5] hydrogen shift of II resulted in 2,4,5-triaryl imidazoles (Scheme 2).

Scheme 2 The proposed mechanism for the synthesis of 2,4,5-triaryl imidazoles.

Experimental

Synthesis of nano Ni_0.5Zn_0.5Fe₂O₄

In order to obtain the desired compositions, stoichiometric amounts of NiCl₂·6H₂O, ZnCl₂ and FeCl₃·6H₂O were dissolved in ultra-pure water. The solutions of NiCl₂·6H₂O, ZnCl₂ and FeCl₃·6H₂O in their stoichiometry (100 ml of 0.05 M NiCl₂·6H₂O, 100 ml of 0.2 M FeCl₃·6H₂O, 100 ml of 0.05 M ZnCl₂) were dissolved in distilled water with a constant stirring. The neutralization was carried out with 1.5 M sodium hydroxide solution. The reaction temperature was kept at 85 °C for 45 min. The pH of the reaction was kept at 12. The precipitates were thoroughly washed with distilled water until the washings were free from sodium and chloride ions. The product was dried in an electric oven at a temperature of 120 °C for overnight to remove water contents. The dried powder was mixed homogeneously in a cleaned agate mortar and pestle.

General procedure for the synthesis of 2,4,5-triaryl-1H-imidazoles

To a mixture of benzil (1 mmol), ammonium acetate (2.2 mmol) and aromatic aldehyde (1 mmol) in a test tube Ni_0.5Zn_0.5Fe₂O₄ nanoparticles (0.0118 g, 5 mol%) was added and the resulting mixture was stirred in an oil-bath at 80 °C for the appropriate time. After completion of the reaction, as monitored by TLC, ethanol was added and the mixture stirred for 5 min. The magnetic Ni_0.5Zn_0.5Fe₂O₄ nanoparticles were separated from the products using an external magnet and then washed twice with acetone, dried in a desiccator and stored for another subsequent reaction runs (the catalyst reused seven times in subsequent reaction without any significant changes in the yield and reaction times). The mixture was poured in cold water (50 ml), the precipitated solid was filtered, washed several times with water, dried and recrystallized from EtOH or acetone : water (9 : 1) to get the corresponding 2,4,5-triaryl-1H-imidazoles. The pure products (compounds 1–11) were identified by IR, ¹H, ¹³C NMR and mass spectra.

2,4,5-Triphenyl-1H-imidazole: (1). Mp: 275–276 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.24 (t, 1H, J = 7.2 Hz), 7.32 (t, 2H, J = 7.2 Hz), 7.39 (t, 2H), 7.44–7.53 (m, 6H), 7.57 (d, 2H, J = 7.6 Hz), 8.10 (d, 2H, J = 7.2 Hz), 12.76 (1H, br) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 125.66, 127.03, 127.55, 128.28, 128.66, 128.76, 128.9, 128.95, 129.18, 129.2, 130.74, 131.47, 135.6, 137.57, 145.85 ppm; IR (KBr, cm⁻¹): 3433, 3029, 1598, 1499, 1453, 1199, 1128, 964, 766, 734, 696.

2-(2-Chlorophenyl)-4,5-diphenyl-1H-imidazole: (2). Mp: 198–200 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.24 (t, 1H, J = 7.1 Hz), 7.31–7.39 (m, 3H), 7.42–7.53 (m, 6H), 7.57 (d, 2H, J = 7.2 Hz), 7.61–7.64 (m, 1H), 7.81–7.83 (m, 1H), 12.69 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 127.08, 127.7, 128.24, 128.39, 128.7, 129.18, 130.46, 130.68, 130.73, 131.31, 132.02, 132.07, 135.5, 137.37, 143.8 ppm; IR (KBr, cm⁻¹): 3446, 3061, 1599, 1501, 1478, 1321, 1203, 1068, 762, 692, 604.

2-(4-Chlorophenyl)-4,5-diphenyl-1H-imidazole: (3). Mp: 262–264 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.22–7.57 (m, 12H), 8.11 (d, 2H, J = 8.4 Hz), 12.81 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 127.12, 127.41, 127.59, 128.42, 128.71, 128.89, 129.27, 129.31, 129.47, 131.33, 133.31, 135.42, 137.78, 144798 ppm; IR (KBr, cm⁻¹): 3439, 3060, 1599, 1498, 1485, 1451, 1325, 1130, 1090, 971, 829, 765, 731, 696, 601.

2-p-Tolyl-4,5-diphenyl-1H-imidazole: (4). Mp: 236–237 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 2.36 (s, 3H), 7.23 (t, 1H, J = 7.4 Hz), 7.31 (t, 4H, J = 7.2 Hz), 7.38 (t, 1H, J = 7.2 Hz), 7.45 (t, 2H, J = 7.4 Hz), 7.51 (d, 2H, J = 7.2 Hz), 7.56 (d, 2H, J = 7.6 Hz), 7.99 (d, 2H, J = 8.0 Hz), 12.63 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 55.67, 114.57, 123.53, 126.92, 127.55, 128.1, 128.82, 129.12, 131.63, 135.77, 137.24, 145.19, 146.13, 159.9 ppm; IR (KBr, cm⁻¹): 3419, 3029, 1598, 1497, 1449, 1130, 1067, 970, 823, 765, 729, 693, 671.

2-(4-Methoxyphenyl)-4,5-diphenyl-1H-imidazole: (5). Mp: 232–235 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 3.82 (s, 3H), 7.06 (d, 2H, J = 6.8 Hz), 7.23–7.58 (m, 10H), 8.05 (d, 2H, J = 7.2 Hz), 12.56 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 55.7, 114.6, 123.5, 126.9, 127.2, 127.5, 128.0, 128.1, 128.6, 128.8, 129.1, 131.6, 131.7, 135.8, 137.2, 146.0, 146.1, 159.9 ppm; IR (KBr, cm⁻¹): 3431, 3060, 1614, 1493, 1293, 1249, 1177, 1030, 968, 829, 765, 695.

2-(4-Bromophenyl)-4,5-diphenyl-1H-imidazole: (6). Mp: 264–266 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.25 (t, 1H, J = 7.4 Hz), 7.33 (t, 2H, J = 7.0 Hz), 7.40 (t, 1H, J = 7.8 Hz), 7.46 (t, 2H, J = 7.2 Hz), 7.51–7.58 (m, 6H), 8.12 (d, 2H, J = 7.2 Hz), 12.82 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 127.12, 127.44, 127.59, 128.42, 128.71, 128.91, 129.59, 129.63, 129.59, 131.33, 133.31, 135.42, 137.78, 144.79 ppm; IR (KBr, cm⁻¹): 3447, 3030, 1598, 1499, 1482, 1450, 1431, 1131, 1071, 825, 765, 730, 693, 501.

2-(2-Methoxyphenyl)-4,5-diphenyl-1H-imidazole: (7). Mp: 208–210 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 3.93 (s, 3H), 7.08 (t, 1H, J = 7.2 Hz), 7.17–7.24 (m, 2H), 7.30 (t, 2H, J = 7.2 Hz), 7.38–7.50 (m, 6H), 7.54 (d, 2H, J = 7.2 Hz), 8.06 (d, 1H, J = 7.6 Hz), 11.93 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 56.02, 112.12, 119.3, 121.07, 126.9, 127.55, 127.7, 128.11, 128.03, 129.06, 129.1, 129.32, 130.28, 131.64, 135.7, 136.87, 143.99, 156.47 ppm; IR (KBr, cm⁻¹): 3448, 3063, 1603, 1587, 1478, 1469, 1445, 1249, 1101, 1020, 764, 747, 694, 613.

2-(2,4-Dichlorophenyl)-4,5-diphenyl-1H-imidazole: (8). Mp: 178–180 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.26–7.59 (m, 11H), 7.79 (d, 1H, J = 7.6 Hz), 7.86 (d, 1H, J = 7.6 Hz), 12.76 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 127.15, 127.68, 127.95, 128.34, 128.73, 129.17, 129.31, 130.22, 131.2, 132.92, 133.06, 134.37, 135.39, 142.76 ppm; IR (KBr, cm⁻¹): 3446, 3070, 1595, 1550, 1503, 1476, 1426, 1323, 1135, 1099, 881, 770, 698, 498.

2-(4-Nitrophenyl)-4,5-diphenyl-1H-imidazole: (9). Mp: 240–242 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 7.27–7.75 (m, 10H), 7.90–8.37 (m, 4H), 13.17 (br, 1H), ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 124.74, 126.21, 127.68, 128.96, 136.51, 143.76, 146.99 ppm; IR (KBr, cm⁻¹): 3392, 3078, 1598, 1579, 1513, 1442, 1336, 1246, 1111, 970, 853, 763, 6954.

2-Phenyl-4,5-di-p-tolyl-1H-imidazole: (10). Mp: 269–271 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 2.30 (s, 3H), 2.36 (s, 3H), 7.12 (d, 2H, J = 8.0 Hz), 7.25 (d, 2H, J = 8.0 Hz), 7.38–7.50 (m, 7H), 8.09 (d, 2H, J = 7.6 Hz), 12.61 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 21.25, 21.33, 125.6, 127.49, 128.22, 128.62, 128.7, 129.14, 129.24, 129.67, 130.84, 132.88, 136.02, 137.37, 137.50, 145.53 ppm; IR (KBr, cm⁻¹): 3436, 3029, 1519, 1500, 1478, 1412, 1322, 1124, 816, 719, 690.

2-(4-Methoxyphenyl)-4,5-dip-tolyl-1H-imidazole: (11). Mp: 258–260 °C; ¹H NMR (400 MHz, DMSO-d₆): δ = 2.36 (s, 6H), 3.82 (s, 3H), 7.11–7.13 (d, 2H, J = 8.0 Hz), 7.23–7.30 (dd, 4H, J = 8.0 Hz), 7.38–7.40 (d, 2H, J = 8.0 Hz), 7.44–7.45 (d, 2H, J = 7.8 Hz), 8.06–8.08 (d, 2H, J = 8.0 Hz), 12.54 (br, 1H) ppm; ¹³C NMR (100 MHz, DMSO-d₆): δ = 21.33, 55.77, 124.40, 127.48, 127.89, 128.29, 128.44, 129.10, 129.22, 129.65, 129.72, 133.10, 136.02, 137.57, 137.79, 138.13, 148.73 ppm; IR (KBr, cm⁻¹): 3441, 3018, 1523, 1498, 1429, 1321, 1126, 970, 820, 728.

Conclusions

In this study, 2,4,5-triaryl-1H-imidazole has been synthesized in the presence of a catalytic amount of Ni_0.5Zn_0.5Fe₂O₄, as a recyclable and heterogeneous catalyst. Ni_0.5Zn_0.5Fe₂O₄ nanoparticles were synthesized and characterized by IR, EDX, XRD and SEM analyses. Green reaction conditions, good yields, easy work-up, short reaction times and efficiency of the catalyst are some of the advantages of this study.^41,42

Acknowledgements

We gratefully acknowledge the support of this work by the Research Council of Bu-Ali Sina University.

Notes and references

1. H. Debus, Liebigs Ann. Chem., 1858, 107, 199–208.
2. J. G. Lombardino and E. H. Wiseman, J. Med. Chem., 1974, 17, 1182–1188.
3. A. F. Pozherskii, A. T. Soldatenkov and A. R. Katritzky, Heterocycles in Life Society, Wiley, NewYork, 1997.
4. J. Heeres, L. J. J. Backx, J. H. Mostmans and J. Vancustem, J. Med. Chem., 1979, 22, 1003–1005.
5. J. C. Lee, J. T. Laydon, P. C. McDonnell, T. F. Gallagher, S. Kumar, D. Green and D. McNulty, Nature, 1994, 372–739, 739–746.
6. A. K. Takle, M. J. B. Brown, S. Davies, D. K. Dean, G. Francis, A. Gaiba, A. W. Hird, F. D. King, P. J. Lovell, A. Naylor, A. D. Reith, J. G. Steadman and D. M. Wilson, Bioorg. Med. Chem. Lett., 2006, 16, 378–381.
7. P. Cozzi, G. Carganico, D. Fusar, M. Grossoni, M. Menichincheri, V. Pinciroli, R. Tonani, F. Vaghi and P. Salvati, J. Med. Chem., 1993, 36, 2964–2972.
8. L. Wang, K. W. Woods, Q. Li, K. J. Barr, R. W. McCroskey, S. M. Hannick, L. Gherke, R. B. Credo, Y. H. Hui, K. Marsh, R. Warner, J. Y. Lee, N. Zielinsky-Mozng, D. Frost, S. H. Rosenberg and H. L. Sham, J. Med. Chem., 2002, 45, 1697–1711.
9. C. Chuen, E. J. Bailey, H. David, F. H. David, L. H. Julie, G. A. I. Graham, S. J. Paul, E. K. Suzanne and E. K. Barrie, J. Med. Chem., 1996, 36, 3646–3657.
10. P. Renukadevi, J. S. Biradar, S. P. Hiremath and S. Y. Manjunath, Indian J. Heterocycl. Chem., 1997, 6, 277–280.
11. T. Welton, Chem. Rev., 1999, 99, 2071.
12. S. Chowdhury, R. S. Mohan and J. L. Scott, Tetrahedron, 2007, 63, 2363–2389.
13. (a) J. Dupont, R. F. de Souza and P. A. Z. Suarez, Chem. Rev., 2002, 102, 3667–3691; (b) M. A. Zolfigol, A. Khazaei, A. R. Moosavi-Zare and A. Zare, Org. Prep. Proced. Int., 2010, 42, 95–102; (c) M. A. Zolfigol, A. Khazaei, A. R. Moosavi-Zare and A. Zare, J. Iran. Chem. Soc., 2010, 7, 646–651; (d) A. Khazaei, M. A. Zolfigol, A. R. Moosavi-Zare and A. Zare, Sci. Iran., Trans. C, 2010, 17, 31–36; (e) M. A. Zolfigol, A. Khazaei, A. R. Moosavi-Zare, A. Zare, H. G. Kruger, Z. Asgari, V. Khakyzadeh and M. Kazem-Rostami, J. Org. Chem., 2012, 77, 3640–3645; (f) M. A. Zolfigol, A. Khazaei, A. R. Moosavi-Zare, A. Zare and V. Khakyzadeh, Appl. Catal., A, 2011, 400, 70–81.
14. B. Radziszewski, Chem. Ber., 1882, 15, 1493–1496.
15. S. A. Siddiqui, U. C. Narkhede, S. S. Palimkar, T. Daniel, R. J. Lahoti and K. V. Srinivasan, Tetrahedron, 2005, 61, 3539–3546.
16. S. Sarshar, D. Siev and M. M. Mjalli, Tetrahedron Lett., 1996, 37, 835–838.
17. H. Weinmann, M. Harre, K. Koeing, E. Merten and U. Tilestam, Tetrahedron Lett., 2002, 43, 593–595.
18. N. G. Clark and E. Cawkill, Tetrahedron Lett., 1975, 16, 2717–2720.
19. J. Liu, J. Chem, J. Zhao, Y. Zhao, L. Li and H. Zhang, Synthesis, 2003, 17, 2661–2666.
20. A. Shaabani and A. Rahmati, J. Mol. Catal. A: Chem., 2006, 249, 246–248.
21. A. F. Mohammed, N. D. Kokare, J. N. Sangshetti and D. B. Shinde, J. Korean Chem. Soc., 2007, 51, 418–422.
22. M. M. Heravi, K. Bakhtiari, H. A. Oskooie and S. Taheri, J. Mol. Catal. A: Chem., 2007, 263, 279–281.
23. M. Kidwai, P. Mothsra, V. Bansal and R. Goyal, Monatsh. Chem., 2006, 137, 1189–1194.
24. J. N. Sangshetti, N. D. Kokare, S. A. Kotharkara and D. B. A. Shinde, J. Chem. Sci., 2008, 120, 463–467.
25. J. N. Sangshetti, N. D. Kokare, S. A. Kothakar and D. B. Shinde, Monatsh. Chem., 2008, 139, 125–127.
26. S. Balalaie, A. Arabanian and M. Hashtroudi, Monatsh. Chem., 2000, 131, 945–948.
27. G. V. M. Sharma, Y. Jyothi and P. S. Lakshmi, Synth. Commun., 2006, 36, 2991–3000.
28. M. M. Heravi, K. Bakhtiari and H. A. Oskooie, J. Mol. Catal. A: Chem., 2007, 263, 279–281.
29. S. D. Sharma, P. Hazarika and D. Konwar, Tetrahedron Lett., 2008, 49, 2216–2220.
30. A. Khorramabadi-zad, M. Azadmanesh and S. Mohammadi, S. Afr. J. Chem., 2013, 66, 244–247.
31. A. Y. Usyatinsky and Y. L. Khmelnitsky, Tetrahedron Lett., 2000, 41, 5031–5034.
32. (a) A. Goldman, Modern Ferrite Technology, Van Nostrand Reinhold, New York, 1990; (b) H. T. Jiang, X. F. Wang and C. L. Yu, et al., Mater. Manuf. Processes, 2010, 25, 1489–1493; (c) S. Dey, R. Gomes, R. Mondal, S. K. Dey, P. Dasgupta, A. Poddar, V. R. Reddy, A. Bhaumik and S. Kumar, RSC Adv., 2015, 5, 78508–78518.
33. A. Chaudhuri, M. Mandal and K. Mandal, J. Alloys Compd., 2009, 487, 698–702.
34. (a) S. A. Shah, M. U. Hashmi, S. Alam and A. Shamim, J. Magn. Magn. Mater., 2010, 322, 375–381; (b) A. Khazaei, A. Ranjbaran, F. Abbasi, M. Khazaei and A. R. Moosavi-Zare, RSC Adv., 2015, 5, 13643–13647.
35. (a) H. M. Fan, J. B. Yi and Y. Yang, ACS Nano, 2009, 3, 2798–2808; (b) A. Khazaei, A. R. Moosavi-Zare, H. Afshar-Hezarkhani and V. Khakyzadeh, RSC Adv., 2014, 4, 32142–32147; (c) M. A. Zolfigol, A. R. Moosavi-Zare, P. Moosavi, V. Khakyzadeh and A. Zare, C. R. Chim., 2013, 16, 962–966; (d) M. A. Zolfigol, V. Khakyzadeh, A. R. Moosavi-Zare, A. Zare, P. Arghavani-Hadi, Z. Mohammadi and M. H. Beyzavi, S. Afr. J. Chem., 2012, 65, 280–285.
36. N. M. Deraza and O. H. Abd-Elkaderb, J. Anal. Appl. Pyrolysis, 2014, 106, 171–176; K. H. Wu, Y. M. Shin, C. C. Yang, W. D. Ho and J. S. Hsu, J. Polym. Sci., Part A: Polym. Chem., 2006, 44, 2657–2664.
37. R. S. Joshi, P. G. Mandhane, M. U. Shaikh, R. P. Kale and C. H. Gill, Chin. Chem. Lett., 2010, 21, 429–432.
38. M. Shen, C. Cai and W. Yi, J. Fluorine Chem., 2008, 129, 541–544.
39. H. Zang, Q. Su, Y. Mo, B. W. Cheng and S. Jun, Ultrason. Sonochem., 2010, 17, 749–751.
40. S. D. Sharma, P. Hazarika and D. Konwar, Tetrahedron Lett., 2008, 49, 2216–2220.
41. M. A. Zolfigol, V. Khakyzadeh, A. R. Moosavi-Zare, A. Zare, P. Arghavani-Hadi, Z. Mohammadi and M. H. Beyzavi, S. Afr. J. Chem., 2012, 65, 280–285.
42. K. F. Shelke, S. B. Sapkal, S. S. Sonar, B. R. Madje, B. B. Shingate and M. S. Shingare, Bull. Korean Chem. Soc., 2009, 30, 1057–1060.

---

Footnote

† Electronic supplementary information (ESI) available: Including H NMR and C NMR spectral data. See DOI: 10.1039/c6ra05158h

---