Paper
RSC Advances
Preparation of lepidocrocite
Notes and references
The lepidocrocite and Fe–CuO were prepared following the
28
1 F. Diederich and A. de Meijere, Metal-Catalyzed Cross-
Coupling Reactions, Wiley-VCH, Weinheim, 2004.
literature. To prepare lepidocrocite, FeSO
4
$7H
2
O (0.13 M) was
OH (10%) was
dissolved in distilled water (100 mL). Then NH
4
2
J. P. Wolfe, S. Wagaw, J. F. Marcoux and S. L. Buchwald, Acc.
Chem. Res., 1998, 31, 805.
added drop wise into the suspension until the pH of the solu-
tion was adjusted to 6.5. The mixture was stirred vigorously for 4
h. The black precipitate was collected from the solution by an
external magnet and washed with double distilled water. Finally
3
G. R. Martinez, K. A. M. Walker, D. R. Hirscheld, J. J. Bruno,
D. S. Yang and P. J. Maloney, J. Med. Chem., 1992, 35, 620.
ꢁ
4 J. Ohmori, M. S. Sasamata, M. Okada and S. Sakamoto, J.
Med. Chem., 1996, 39, 3971.
the black product was dried under vacuum at 80 C.
5
I. Sircar, R. E. Weishaar, D. Kobylarz, H. Moos and
J. A. Bristol, J. Med. Chem., 1987, 30, 1955.
Preparation of Fe–CuO catalyst
4 2
CuSO $5H O (0.005 M), was dissolved in distilled water (50 mL).
6
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.
Y. S. Lo, J. C. Nolan, T. H. Maren, W. J. Welstead Jr,
D. F. Gripshover and D. A. Shamblee, J. Med. Chem., 1992,
g-FeOOH (0.51 g) was then dispersed in the above solution and
sonicated to obtain a uniform suspension. The suspension was
vigorously stirred at room temperature for 50 min to ensure that
7
2
+
enough Cu had been adsorbed on the surface of g-FeOOH.
Then the pH was adjusted to 6.5 by adding 10% NH OH. The
4
35, 4790.
mixture was stirred vigorously for 4 h. The precipitated black
product was collected from the solution using an external
8
9
D. Maiti, B. P. Fors, J. L. Henderson, Y. Nakamura and
S. L. Buchwald, Chem. Sci., 2011, 2, 57.
W. Yi, W. Zhiqing, W. Lixia, L. Zhengkai and Z. Xiangge,
Chem.–Eur. J., 2009, 15, 8971.
magnet (Fig. 1), washed with water, and dried under vacuum at
ꢁ
8
0 C.
1
1
1
1
0 S. G. Babu and R. Karvembu, Ind. Eng. Chem. Res., 2011, 50,
9594.
1 M. L. Kantam, Y. Jagjit, L. Soumi, S. Bojja and J. Shailendra,
Adv. Synth. Catal., 2007, 349, 1938.
2 S. Mandal, D. Roy, R. V. Chaudhari and M. Sastry, Chem.
Mater., 2004, 16, 3714.
3 P. Poisson, J. P. Brunelle and P. Nortier, Catalyst Supports
and Supported Catalysts, ed. A. B. Stiles, Wiley VCH,
Butterworth, Boston, 1987, pp. 11–55.
Procedure for N-arylation of imidazole
In a typical procedure, Fe–CuO catalyst (10 mg) was added into a
mixture of imidazole (1.2 mmol, 81 mg), 4-bromobenzonitrile
(
1 mmol, 182 mg) and K CO (2 mmol, 276 mg) in DMAc (4 mL),
2 3
ꢁ
stirred under air atmosphere at 120 C for 24 h. Aer the
complete consumption of starting materials as monitored by
thin layer chromatography (TLC), the catalyst was separated by
magnetic decantation and washed well with diethyl ether and
ꢁ
14 S. Shylesh, V. Schunemann and W. R. Thiel, Angew. Chem.,
Int. Ed., 2010, 49, 3428.
dried in an oven at 110 C for 3 h. The organic layer was parti-
tioned between 10 mL of ethyl acetate and 5 mL of saturated
aqueous NaCl solution. The product was extracted with ethyl
acetate and dried over anhydrous sodium sulfate. The yield of
product was determined by GC. Finally, the organic layer was
concentrated to obtain N-arylated imidazole.
1
1
5 J. Fan and Y. Gao, J. Exp. Nanosci., 2006, 1, 457.
6 Y. Zhu, J. Shen, K. Zhou, C. Chen, X. Yang and C. Li, J. Phys.
Chem. C, 2011, 115, 1614.
1
1
1
2
2
2
2
2
2
7 S. R. Kale, S. S. Kahandal, M. B. Gawande and R. V. Jayaram,
RSC Adv., 2013, 3, 8184.
8 M. B. Gawande, P. S. Branco and R. S. Varma, Chem. Soc.
Rev., 2013, 42, 3371.
9 R. B. N. Baig and R. S. Varma, Chem. Commun., 2012, 48,
Product analysis
In order to conrm the formation of the product, samples of
both reactants and products were dissolved in ethyl acetate and
analyzed by gas chromatograph (Shimadzu 2010) equipped with
2582.
0 P. H. Li, B. L. Li, Z. M. An, L. P. Mo, Z. S. Cui and Z. H. Zhang,
Adv. Synth. Catal., 2013, 355, 2952.
1 M. J. Aliaga, D. J. Ramon and M. Yus, Org. Biomol. Chem.,
5
% diphenyl and 95% dimethyl polysiloxane, Restek-5 capillary
column (0.32 mm dia, 60 m length and 0.32 mm dia) and a
ame ionization detector (FID). The initial column temperature
2010, 8, 43.
ꢁ
ꢁ
ꢀ1
was increased from 60 to 150 C at the rate of 10 C min and
then to 220 C at the rate of 40 C min . N was used as a
2 M. Liu, X. G. Peng, W. Sun, Y. W. Zhao and C. G. Xia, Org.
Lett., 2008, 10, 3933.
3 S. G. Babu, P. A. Priyadarsini and R. Karvembu, Appl. Catal.,
A, 2011, 392, 218.
ꢁ
ꢁ
ꢀ1
2
carrier gas. During the product analysis the temperatures of the
FID and injection port were kept constant at 150 and 250 C
respectively.
ꢁ
4 S. G. Babu and R. Karvembu, Tetrahedron Lett., 2013, 54,
1677.
5 S. G. Babu, N. Neelakandeswari, N. Dharmaraj, S. David
Acknowledgements
Jackson and R. Karvembu, RSC Adv., 2013, 3, 7774.
One of the authors R.S. is thankful to the Department of Science 26 M. Gopiraman, S. G. Babu, Z. Khatri, W. Kai, Y. A. Kim,
and Technology, Government of India, New Delhi for the award
of research fellowship under the DST PURSE programme.
M. Endo, R. Karvembu and I. S. Kim, Carbon, 2013, 62, 135.
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 8571–8578 | 8577