Microwave-assisted synthesis and crystal structure of 1-(4-Chlorophenyl)-4, 5-diphenyl-2-(3,4,5-trimethoxy-phenyl)-1H-imidazole

Article abstract of DOI:10.1080/15421400903291475

The title compound, 1-(4-chlorophenyl)-4,5-diphenyl-2-(3,4,5-trimethoxy- phenyl)- 1H-imidazole, was synthesized using a domestic microwave oven, and the structure of the product obtained was confirmed by X-ray diffraction (XRD) studies. The compound, C30H

Full text of DOI:10.1080/15421400903291475

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Microwave-Assisted Synthesis
and Crystal Structure of 1-(4-
Chlorophenyl)-4,5-diphenyl-2-
(3,4,5-trimethoxy-phenyl)-1H-
imidazole
Ali Saberi a , H. R. Manjunath b , S. Naveen b , T. N.
Mahadeva Prasad b , K. S. Rangappa a , M. A. Sridhar
b & J. Shashidhara Prasad b
a Department of Studies in Chemistry , University of
Mysore , Mysore, India
b Department of Studies in Physics , University of
Mysore , Mysore, India
Published online: 17 Dec 2009.
To cite this article: Ali Saberi , H. R. Manjunath , S. Naveen , T. N. Mahadeva
Prasad , K. S. Rangappa , M. A. Sridhar & J. Shashidhara Prasad (2009) Microwave-
Assisted Synthesis and Crystal Structure of 1-(4-Chlorophenyl)-4,5-diphenyl-2-(3,4,5-
trimethoxy-phenyl)-1H-imidazole, Molecular Crystals and Liquid Crystals, 515:1,
199-206, DOI: 10.1080/15421400903291475
To link to this article: http://dx.doi.org/10.1080/15421400903291475
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Mol. Cryst. Liq. Cryst., Vol. 515, pp. 199–206, 2009
Copyright # Taylor & Francis Group, LLC
ISSN: 1542-1406 print=1563-5287 online
DOI: 10.1080/15421400903291475
Microwave-Assisted Synthesis and Crystal Structure
of 1-(4-Chlorophenyl)-4,5-diphenyl-2-(3,4,5-trimethoxy-
phenyl)-1H-imidazole
Ali Saberi1, H. R. Manjunath2, S. Naveen2,
T. N. Mahadeva Prasad2, K. S. Rangappa1, M. A. Sridhar2,
and J. Shashidhara Prasad2
1Department of Studies in Chemistry, University of Mysore, Mysore,
India
2Department of Studies in Physics, University of Mysore, Mysore, India
The title compound, 1-(4-chlorophenyl)-4,5-diphenyl-2-(3,4,5-trimethoxy-phenyl)-
1H-imidazole, was synthesized using a domestic microwave oven, and the struc-
ture of the product obtained was confirmed by X-ray diffraction (XRD) studies.
The compound, C30H25ClN2O3, crystallizes in the triclinic crystal class in the
˚
˚
ꢀ
space group P1 with cell parameters a ¼ 10.635(15) A, ꢀ b ¼ 12.262(2) A,
ꢀ
ꢀ
˚
c ¼ 11.656(3) A, a ¼ 69.817(15) , b ¼ 64.630(6) , c ¼ 73.503(16) , and Z ¼ 2. The
structure has been solved by direct methods and refined to R1 ¼ 0.0764 for 3078
unique reflections with I > 2r(I). The imidazole ring in the structure adopts a
planar conformation. No classic hydrogen bonds were found in the structure.
Keywords: crystal structure; equatorial confirmation; imidazole ring; microwave oven
INTRODUCTION
Several biologically active synthetic compounds possess five-
membered nitrogen containing heterocycles in their structure [1].
The imidazole core is a common moiety in a large number of natural
products and pharmacologically active compounds [2]. Recently, there
has been considerable amount of progress in imidazole structure in
biological process. Of late in drug therapy, imidazole containing com-
pounds such as etomidate, cimetidine, omeprazole, and lansoprazole
find large applications [3]. On the other hand, microwave assisted
solid phase organic synthesis is a relatively new technique that has
Address correspondence to Prof. K. S. Rangappa, Department of Studies in Chemis-
try, University of Mysore, Mysore 570 006, India. E-mail: rangappaks@gmail.com
199

200
A. Saberi et al.
shown significant improvement in the generation of combinatorial
libraries of small molecules [4]. Various types of thermally conducted
organic reactions have been accelerated by microwave irradiation [5].
Microwave irradiation has been demonstrated to dramatically acceler-
ate many organic reactions and improves the yields and selectivity [6].
These advantage offer an opportunity for a convenient and rapid
library synthesis of substituted imidazoles.
EXPERIMENTAL
All the chemicals and solvents used in this work were obtained from
E-Merck, Ltd., Mumbai and S.D. Fine Chem., Ltd., Mumbai, and were
used without further purification. Kenstar microwave system (OM
9925-E) was used, and the output of microwave power is mentioned
as percent intensity (20%, 40%, 60%, 80%, 100%). The elemental ana-
lysis (CHNS analysis) was done on a CHNS rapid analyzer. Purity of
the compounds was checked by thin layer chromatography (TLC).
Synthesis of 1-(4-Chlorophenyl)-
4,5-diphenyl-2(3,4,5-trimethoxy-phenyl)-1H-imidazole
A mixture of 5 g silica gel, Benzil (631 mg, 3 m mol), 3,4,5-trimethoxy-
benzaldehyde (589 mg, 3 m mol), p-chloroaniline (391 mg, 3 m mol),
and ammonium acetate (232 mg, 3 m mol) was ground in a mortar
until a fine powder was formed. The reaction mixture was then trans-
ferred into an open beaker (250 ml) and irradiated with microwaves for
9 minutes at 70% power. The progress of the reaction was monitored
by thin layer chromatography (TLC) using C6H14:EtOAc. (90:10) as
the eluent. The mixture was extracted with CH2Cl2 (3 ꢁ 30 cm3), fil-
tered and washed with water. The organic phase was removed under
reduced pressure. Further purification by column chromatography
(eluent C6H14:EtOAc. (90:10)) on silica gel gave the desired product
[7]. Schematic diagram of the molecule is as shown in the Fig. 1.
Crystal Structure Determination
A single crystal of the title compound with dimensions 0.3 ꢁ 0.27 ꢁ
0.25 mm was chosen for X-ray diffraction (XRD) study. The data were
collected on a DIPLabo Image Plate system equipped with a normal
focus, 3 kW sealed X-ray source (graphite monochromated MoKa).
The crystal to detector distance is fixed at 120 mm with a detector area
of 441 ꢁ 240 mm2. Thirty-six frames of data were collected at room
temperature by the oscillation method. Each exposure of the image

Microwave-Assisted Synthesis
201
FIGURE 1 Schematic diagram of the molecule.
plate was set to a period of 400 s. Successive frames were scanned in
steps of 5ꢀ per minute with an oscillation range of 5ꢀ. Image processing
and data reduction were done using Denzo [8]. The reflections were
merged with Scalepack [9]. All the frames could be indexed using pri-
mitive triclinic lattice. The structure was solved by direct methods
using SHELXS-97. All of the non-hydrogen atoms were revealed in
the first Fourier map itself. Full-matrix least squares refinement
using SHELXL-97, with isotropic temperature factors for all the atoms
converged the residuals to R1 ¼ 0.1577. Refinement of the
non-hydrogen atoms with anisotropic thermal parameters was started
at this stage. The hydrogen atoms were placed at chemically accepta-
ble positions and were allowed to ride on the parent atoms; 329 para-
meters were refined with 3078 unique reflections which saturated the
residuals to R1 ¼ 0.0764. The details of the crystal data and refinement
are given in Table 1.1
Table 2 gives the list of atomic coordinates and equivalent thermal
parameters. Tables 3 and 4 give the list of bond lengths and bond
angles, respectively, which are in good agreement with the standard
values. An ORTEP diagram of the molecule with thermal ellipsoids
drawn at 50% probability is shown in Fig. 2.
The molecule consists of two phenyl rings, one chlorophenyl ring,
and one trimethoxyphenyl ring. The imidazole ring is planar with a
˚
maximum deviation of ꢁ0.008(5) A for the atom C5. The formal single
1CCDC 730169 consists the supplementary crystallographic data for this paper.
These data can be obrained free of charge via http://www.ccdc.cam.ac.uk/conts/
retrieving.html (or from the Cambridge Crystallographic Data Center, 12 Union Road,
Cambridge CB21EZ, UK; Fax: þ45(0)1233-336033). E-mail: deposit@ccdc.cam.ac.uk

202
A. Saberi et al.
TABLE l Crystal Data and Structure Refinement Table
CCDC Deposition number
Empirical formula
Formula weight
Temperature
Wavelength
Crystal system
Space group
CCDC 730169
30H25CIN2O3
496.97
C
293(2)K
0.71073 A
Triclinic
˚
ꢀ
P1
˚
˚
Cell dimensions
a ¼ 10.635(3) A
b ¼ 12.262(2) A
˚
c ¼ 11.656(3) A
a ¼ 69.817(15)ꢀ
b ¼ 64.630(6)ꢀ
c ¼ 73.503(16)ꢀ
3
˚
Volume
Z
Density (calculated)
Absorption coefficient
F000
1272.4(5) A
2
1.297 Mg=m3
0.185 mmꢂ1
520
Crystal size
Theta range for data collection
Index ranges
0.3 ꢁ 0.27 ꢁ 0.25 mm
2.2ꢀ to 23.3ꢀ
ꢂ11 ꢃ h ꢃ 11
ꢂ12 ꢃ k ꢃ 12
ꢂ12 ꢃ l ꢃ 12
3078 [R(int) ¼ 0.056]
None
Independent reflections
Absorption correction
Refinement method
Data=parameters
Goodness-of-fit on F2
Final R indices
Full-matrix least-squares on F2
3078=329
1.056
R1 ¼ 0.0764
ꢂ3
˚
Largest diff. peak, and hole
0.88 and ꢂ0.32 e A
˚
˚
bonds C2ꢂN3 (1.372(4) A) and N3ꢂC4 (1.394(5) A) have a partial
double bond character, and are significantly shorter than the Csp2ꢂN
bond distance. The bond angle values of 117.3(4)ꢀ and 118.2(4)ꢀ about
C25 and C31 are relatively smaller compared to the standard value,
which can be attributed to the steric hindrance between the imidazole
ring and the respective phenyl rings. The two phenyl rings are equa-
torial to each other as the dihedral angle between the two rings is
67.8(2)ꢀ. The rings C25ꢂC30 and C31ꢂC36 are twisted by the angles
15.2(3)ꢀ and 68.2(3)ꢀ, respectively, with respect to the imidazole ring,
which are different from the values of 31.5(1)ꢀ, 41.7(1)ꢀ reported for
2-(2-methylphenyl)-4,5-diphenyl-1H-imidazole [10]. The dihedral angle
between the imidazole ring and the chlrophenyl ring is 71.4(2)ꢀ which
deviates from the value of 40.74(8)ꢀ reported earlier for 1-benzyl-2-
(4-chlorophenyl)-4,5-diphenyl-1H-imidazole [11]. The torsion angles

Microwave-Assisted Synthesis
203
TABLE 2 Atomic Coordinates and Equivalent Thermal Parameters of the
Non-Hydrogen Atoms
Atom
x
y
z
Ueq
C2
N1
C5
C4
N3
C6
C7
C8
0.4248(4)
0.3381(3)
0.2490(4)
0.2848(4)
0.3979(3)
0.4647(4)
0.5495(5)
0.6161(5)
0.5970(5)
0.5112(4)
0.4459(4)
0.6767(2)
0.5389(4)
0.6611(4)
0.7633(4)
0.7469(4)
0.6263(4)
0.5218(4)
0.8858(3)
0.9173(5)
0.8514(3)
0.8236(6)
0.6198(3)
0.4992(5)
0.1345(4)
0.1334(5)
0.0260(6)
ꢂ0.0841(5)
ꢂ0.0848(5)
0.0222(5)
0.2314(4)
0.2537(4)
0.2049(5)
0.1366(5)
0.1167(5)
0.1614(5)
0.8574(3)
0.9523(3)
0.9815(3)
0.9033(3)
0.8229(3)
0.7226(3)
0.7394(4)
0.6414(4)
0.5304(4)
0.5145(4)
0.6106(4)
0.4108(1)
0.7966(3)
0.7301(3)
0.6767(3)
0.6911(3)
0.7608(3)
0.8121(3)
0.6079(3)
0.6032(5)
0.6394(3)
0.5329(5)
0.7711(3)
0.8452(4)
1.0824(3)
1.1648(4)
1.2602(5)
1.2744(5)
1.1934(5)
1.0985(4)
0.8967(3)
0.9814(4)
0.9778(5)
0.8858(5)
0.8003(4)
0.8063(4)
ꢂ0.1056(3)
ꢂ0.1360(3)
ꢂ0.0206(4)
0.0828(4)
0.0268(3)
0.1010(3)
0.1525(4)
0.2238(4)
0.2394(4)
0.1867(4)
0.1171(4)
0.3302(2)
ꢂ0.2026(3)
ꢂ0.1844(4)
ꢂ0.2794(4)
ꢂ0.3958(3)
ꢂ0.4156(3)
ꢂ0.3195(4)
ꢂ0.2675(3)
ꢂ0.1600(5)
ꢂ0.4919(3)
ꢂ0.4916(5)
ꢂ0.5335(3)
ꢂ0.5603(4)
ꢂ0.0184(4)
ꢂ0.1357(5)
ꢂ0.1372(6)
ꢂ0.0206(7)
0.0937(6)
0.0960(5)
0.2244(4)
0.2645(4)
0.3949(5)
0.4883(4)
0.4512(4)
0.3204(4)
0.0543(1)
0.0584(9)
0.0571(1)
0.0565(1)
0.0550(9)
0.0549(1)
0.0668(1)
0.0733(1)
0.0671(1)
0.0645(1)
0.0611(1)
0.0999(6)
0.0537(1)
0.0567(1)
0.0542(1)
0.0566(1)
0.0571(1)
0.0574(1)
0.0736(9)
0.0891(2)
0.0709(9)
0.0935(2)
0.0746(9)
0.0774(1)
0.0584(1)
0.0770(1)
0.0962(2)
0.0948(2)
0.0851(2)
0.0745(1)
0.0578(1)
0.0642(1)
0.0779(1)
0.0796(1)
0.0795(1)
0.0703(1)
C9
C10
C11
C112
C13
C14
C15
C16
C17
C18
O19
C20
O21
C22
O23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
C35
C36
about N1ꢂC2ꢂC13ꢂC14 and N3ꢂC2ꢂC13ꢂC18 are 153.0(4)ꢀ and
156.5(4)ꢀ, respectively, which determines the conformation of the
junction between the imidazole and trimethoxyphenyl rings. The
chlorophenyl and trimethoxyphenyl rings are in the –synperiplanar
conformation as indicated by the torsion angle value of ꢂ3.2(7)ꢀ about
the atoms C6ꢂN3ꢂC2ꢂC13. No classic hydrogen bonds were found in
the molecule.

204
A. Saberi et al.
˚
TABLE 3 Bond Length (A)
Atoms
Length
Atoms
Length
C2ꢂN1
1.309(5)
1.373(4)
1.483(5)
1.371(5)
1.381(5)
1.468(5)
1.393(5)
1.477(5)
1.435(5)
1.368(6)
1.381(6)
1.403(6)
1.371(6)
1.383(6)
1.728(4)
1.374(6)
1.384(5)
1.392(5)
1.379(5)
1.371(5)
C15ꢂC16
C16ꢂO21
C16ꢂC17
C17ꢂO23
C17ꢂC18
O19ꢂC20
O21ꢂC22
O23ꢂC24
C25ꢂC30
C25ꢂC26
C26ꢂC27
C27ꢂC28
C28ꢂC29
C29ꢂC30
C31ꢂC32
C31ꢂC36
C32ꢂC33
C33ꢂC34
C34ꢂC35
C35ꢂC36
1.385(5)
1.384(4)
1.386(5)
1.367(5)
1.381(5)
1.408(5)
1.417(6)
1.433(5)
1.387(6)
1.394(6)
1.385(7)
1.390(8)
1.358(8)
1.380(6)
1.386(6)
1.391(6)
1.369(6)
1.387(7)
1.360(7)
1.371(6)
C2ꢂN3
C2ꢂC13
N1ꢂC5
C5ꢂC4
C5ꢂC25
C4ꢂN3
C4ꢂC31
N3ꢂC6
C6ꢂC7
C6ꢂC11
C7ꢂC8
C8ꢂC9
C9ꢂC10
C9ꢂC112
C10ꢂC11
C13ꢂC14
C13ꢂC18
C14ꢂC15
C15ꢂO19
FIGURE 2 ORTEP of the molecule with thermal ellipsoids drawn at 50%
probability.

Microwave-Assisted Synthesis
TABLE 4 Bond Angles (ꢀ)
205
Atoms
Angle
Atoms
Angle
N1ꢂC2ꢂN3
N1ꢂC2ꢂC13
N3ꢂC2ꢂC13
C2ꢂN1ꢂC5
111.3(3)
124.2(3)
124.5(3)
106.7(3)
110.0(3)
121.1(3)
128.8(4)
105.1(3)
133.1(4)
121.7(3)
106.8(3)
129.3(3)
123.8(3)
120.7(4)
119.2(4)
120.2(4)
119.2(4)
119.8(4)
120.5(4)
119.3(4)
120.2(4)
119.6(4)
120.2(4)
119.4(3)
123.5(3)
117.0(3)
120.3(4)
123.7(3)
O19ꢂC15ꢂC16
C14ꢂC15ꢂC16
O21ꢂC16ꢂC15
O21ꢂC16ꢂC17
C15ꢂC16ꢂC17
O23ꢂC17ꢂC18
O23ꢂC17ꢂC16
C18ꢂC17ꢂC16
C17ꢂC18ꢂC13
C15ꢂO19ꢂC20
C16 O21ꢂC22
C17ꢂO23ꢂC24
C30ꢂC25ꢂC26
C30ꢂC25ꢂC5
C26ꢂC25ꢂC5
C27ꢂC26ꢂC25
C26ꢂC27ꢂC28
C29ꢂC28ꢂC27
C28ꢂC29ꢂC30
C29ꢂC30ꢂC25
C32ꢂC31ꢂC36
C32ꢂC31ꢂC4
C36ꢂC31ꢂC4
C33ꢂC32ꢂC31
C32ꢂC33ꢂC34
C35ꢂC34ꢂC33
C34ꢂC35ꢂC36
C35ꢂC36ꢂC31
115.7(3)
120.6(4)
120.3(4)
120.8(3)
119.0(3)
124.2(4)
114.9(3)
120.8(3)
119.8(4)
118.1(3)
113.6(3)
117.0(3)
117.3(4)
123.0(4)
119.7(4)
121.2(5)
120.0(5)
119.1(5)
121.1(5)
121.3(5)
118.2(4)
119.6(3)
122.1(4)
120.9(4)
119.5(5)
120.6(4)
119.8(4)
120.9(5)
N1ꢂC5ꢂC4
N1ꢂC5ꢂC25
C4ꢂC5ꢂC25
C5ꢂC4ꢂN3
C5ꢂC4ꢂC31
N3ꢂC4ꢂC31
C2ꢂN3ꢂC4
C2ꢂN3ꢂC6
C4ꢂN3ꢂC6
C7ꢂC6ꢂC11
C7ꢂC6ꢂN3
C11ꢂC6ꢂN3
C6ꢂC7ꢂC8
C9ꢂC8ꢂC7
C8ꢂC9ꢂC10
C8ꢂC9ꢂC112
C10ꢂC9ꢂC112
C11ꢂC10ꢂC9
C10ꢂC11ꢂC6
C14ꢂC13ꢂC18
C14ꢂC13ꢂC2
C18ꢂC13ꢂC2
C15ꢂC14ꢂC13
O19ꢂC15ꢂC14
ACKNOWLEDGMENTS
The authors are grateful to DST and Government of India for financial
assistance under the projects SP=I2=FOO=93 and UGC-SAP (Phase-I),
No. F.540=10=DRS=2004(SAP-I).
REFERENCES
[1] Gilchrist, T. L. (1992). Heterocyclic Chemistry: Longman Scientific and Technical,
England; Joule, J. A., Mills, K., & Smith, G. F. (1995). Heterocyclic Chemistry,
Chapman and Hall: London; Coffey, S., Ansell, M. F., & Rodd’s (1986). Chemistry
of Carbon Compounds, IV, 199–196.
[2] Pozherskii, A. F., Soldatenkov, A. T., & Katritzky, A. R. (1997). Heterocycles in
Life and Society, Wiley: New York; Grimment, M. R. (1997). In: Comprehensive
Heterocyclic Chemistry, Katritzky, Rees, C. W. (Ed.), Pergamon: New York.

206
A. Saberi et al.
[3] Grimment, M. R. (1997). Imidazole and Benzimidazole Synthesis, Academic Press,
Inc.: San Diego, California.
[4] Niknam, K., & Fatehi-Raviz, A. (2007). J. Iran. Chem. Soc., 4, 438–443.
[5] Mobinikhaledi, A., Zendehdel, M., & Hasanvand Jamshidi, F. (2007). Synthesis and
Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry, 37, 175.
[6] Balalaiel, S., Arabanian, A., & Hashtroudi, M. S. (2000). Monatshefte fur Chemistry,
131, 945.
[7] Balalaiel, S., Arabanian, A., & Hashtroudi, M. S. (2000). Green Chemistry, 2, 274.
[8] Otwinowski, Z., Minor, W., Carter, Jr., & Sweet, R. M. (1997). Macromolecular
Crystallography, 276, 307.
[9] Mackay, S., Gillmore, C. J., Edwards, C., & Shankland, K. (1999). maXus Computer
Programme for the Solution and Refinement of Crystal Structures, Bruker Nonius,
The Netherlands.
[10] Seethalakshmi, T., Puratchikody, A., Daniel, E., Lynch, Kaliannan, P.,
&
Thamotharan, S. (2006). Acta Cryst., E62, 2803.
[11] Ghoranneviss, M., Ziarani, G. M., Abbasi, A., Hantehzadeh, M. R., & Farahni, Z.
(2008). Acta Cryst., E64, 1233.