Ethyl 4-anilino-3-nitro­benzoate

Yoon, Y.K.; Manogaran, E.; Ali, M.A.; Arshad, S.; Razak, I.A.

doi:10.1107/S1600536812019903

organic compounds

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ISSN: 2056-9890

Volume 68| Part 6| June 2012| Page o1684

doi:10.1107/S1600536812019903

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Ethyl 4-anilino-3-nitrobenzoate

Yeong Keng Yoon,^a Elumalai Manogaran,^b Mohamed Ashraf Ali,^a Suhana Arshad ^c and Ibrahim Abdul Razak ^c ^*‡

^aInstitute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden 11800, Penang, Malaysia, ^bFaculty of Pharmaceutical Sciences, UCSI University, Kuala Lumpur, Cheras 56000, Malaysia, and ^cSchool of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
^*Correspondence e-mail: arazaki@usm.my

(Received 24 April 2012; accepted 3 May 2012; online 12 May 2012)

In the title compound, C₁₅H₁₄N₂O₄, the dihedral angle between the benzene and phenyl rings is 73.20 (6)°. An intramolecular N—H⋯O hydrogen bond forms an S(6) ring motif. In the crystal, molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds into a layer parallel to the bc plane.

Related literature

For applications of nitrophenyleneamines, see: Stephane (2006 ); Glebowska et al. (2009 ); Remusat et al. (2004 ). For related structures, see: Mohdaidin et al. (2008 ); Zhang et al. (2009 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₁₅H₁₄N₂O₄
M_r = 286.28
Monoclinic, P 2₁ /c
a = 10.6464 (2) Å
b = 9.9178 (2) Å
c = 14.7885 (2) Å
β = 120.244 (1)°
V = 1348.96 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.35 × 0.20 × 0.16 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.965, T_max = 0.984
17988 measured reflections
4639 independent reflections
3276 reflections with I > 2σ(I)
R_int = 0.040

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.124
S = 1.04
4639 reflections
195 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯O4	0.859 (18)	2.00 (2)	2.6375 (17)	130.6 (17)
N1—H1N1⋯O2ⁱ	0.858 (17)	2.288 (16)	2.9411 (14)	133.0 (14)
C15—H15A⋯O2ⁱⁱ	0.93	2.45	3.342 (2)	160
Symmetry codes: (i) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (ii) -x+1, -y, -z+2.

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812019903/is5128sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812019903/is5128Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812019903/is5128Isup3.cml

checkCIF report

Comment top

In chemistry, nitrophenyleneamines are important building blocks for many pharmaceutical compounds. Phenylenediamine themselves are also used as composition in making dyes (Stephane, 2006), metallomesogens (Glebowska et al., 2009) as well as ligand precursors. Condensation of substituted ο-phenylenediamine with various diketones is then used in the preparation of a variety of pharmaceuticals (Remusat et al., 2004).

In the molecular structure (Fig. 1), an intramolecular N1—H1N1···O4 hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995). The C1–C6 benzene ring [maximum deviation of 0.007 (1) Å at atoms C5 and C6] and C10–C15 phenyl ring [maximum deviation of 0.005 (2) Å at atom C12] make a dihedral angle of 73.20 (6)° with each other. Bond lengths and angles are within normal ranges and are comparable to related structures (Mohd. Maidin et al., 2008; Zhang et al., 2009).

The crystal packing is shown in Fig. 2. The intermolecular N1—H1N1···O2 and C15—H15A···O2 (Table 1) hydrogen bonds linked the molecules into a two-dimensional network parallel to the bc plane.

Related literature top

For applications of nitrophenyleneamines, see: Stephane (2006); Glebowska et al. (2009); Remusat et al. (2004). For related structures, see: Mohd. Maidin et al. (2008); Zhang et al. (2009). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).

Experimental top

Ethyl-4-fluro-3-nitro benzoate (1 g) in dichloromethane (20 ml) was added into the solution of aniline (0.51 g) and N,N-diisopropylethylamine (0.72 g) in dichloromethane (20 ml). The reaction mixture was stirred overnight at room temperature. After completion of the reaction, evidenced by TLC analysis. The reaction mixture was washed with water (10 ml × 2) and 10% Na₂CO₃ (10 ml × 2). The dichloromethane layer was collected and dried over Na₂SO₄ and evaporated in vacuo to yield the product. The product was recrystallised from ethyl acetate.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atom-numbering scheme. The intramolecular N—H···O hydrogen bond is shown by a dashed line.
	Fig. 2. A crystal packing diagram of the title compound, viewed along the b axis. The H atoms not involved in the intermolecular interactions (dashed lines) have been omitted for clarity.

Ethyl 4-anilino-3-nitrobenzoate top

Crystal data top

C₁₅H₁₄N₂O₄	F(000) = 600
M_r = 286.28	D_x = 1.410 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3629 reflections
a = 10.6464 (2) Å	θ = 2.9–31.4°
b = 9.9178 (2) Å	µ = 0.10 mm⁻¹
c = 14.7885 (2) Å	T = 100 K
β = 120.244 (1)°	Block, yellow
V = 1348.96 (4) Å³	0.35 × 0.20 × 0.16 mm
Z = 4

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	4639 independent reflections
Radiation source: fine-focus sealed tube	3276 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.040
ϕ and ω scans	θ_max = 31.9°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −15→15
T_min = 0.965, T_max = 0.984	k = −14→14
17988 measured reflections	l = −21→21

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.0561P)² + 0.2709P] where P = (F_o² + 2F_c²)/3
4639 reflections	(Δ/σ)_max = 0.001
195 parameters	Δρ_max = 0.39 e Å⁻³
0 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

C₁₅H₁₄N₂O₄	V = 1348.96 (4) Å³
M_r = 286.28	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 10.6464 (2) Å	µ = 0.10 mm⁻¹
b = 9.9178 (2) Å	T = 100 K
c = 14.7885 (2) Å	0.35 × 0.20 × 0.16 mm
β = 120.244 (1)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	4639 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	3276 reflections with I > 2σ(I)
T_min = 0.965, T_max = 0.984	R_int = 0.040
17988 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	0 restraints
wR(F²) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.39 e Å⁻³
4639 reflections	Δρ_min = −0.26 e Å⁻³
195 parameters

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.28632 (10)	−0.12818 (8)	0.76247 (7)	0.01976 (19)
O2	0.46453 (10)	0.00161 (9)	0.76921 (7)	0.0212 (2)
O3	0.66947 (10)	0.34436 (10)	1.03221 (8)	0.0273 (2)
O4	0.55970 (10)	0.42674 (9)	1.10945 (8)	0.0228 (2)
N1	0.33488 (11)	0.29963 (10)	1.09858 (8)	0.0181 (2)
N2	0.56820 (11)	0.34349 (10)	1.05006 (8)	0.0184 (2)
C1	0.46344 (13)	0.16060 (11)	0.92632 (9)	0.0165 (2)
H1A	0.5353	0.1764	0.9095	0.020*
C2	0.45671 (12)	0.24143 (11)	1.00074 (9)	0.0154 (2)
C3	0.34771 (13)	0.22195 (11)	1.02854 (9)	0.0153 (2)
C4	0.24935 (13)	0.11392 (12)	0.97700 (9)	0.0169 (2)
H4A	0.1767	0.0968	0.9929	0.020*
C5	0.25813 (13)	0.03416 (12)	0.90452 (10)	0.0173 (2)
H5A	0.1924	−0.0362	0.8730	0.021*
C6	0.36523 (13)	0.05748 (11)	0.87723 (9)	0.0161 (2)
C7	0.37913 (13)	−0.02319 (12)	0.79882 (10)	0.0173 (2)
C8	0.29118 (15)	−0.20792 (13)	0.68146 (11)	0.0239 (3)
H8A	0.3826	−0.2563	0.7107	0.029*
H8B	0.2825	−0.1497	0.6259	0.029*
C9	0.16782 (18)	−0.30447 (14)	0.63980 (12)	0.0324 (3)
H9A	0.1677	−0.3582	0.5858	0.049*
H9B	0.0780	−0.2555	0.6114	0.049*
H9C	0.1780	−0.3620	0.6953	0.049*
C10	0.23046 (13)	0.27774 (12)	1.13077 (10)	0.0175 (2)
C11	0.11792 (14)	0.37011 (13)	1.10012 (11)	0.0227 (3)
H11A	0.1090	0.4418	1.0567	0.027*
C12	0.01887 (15)	0.35537 (14)	1.13428 (12)	0.0281 (3)
H12A	−0.0559	0.4176	1.1143	0.034*
C13	0.03126 (15)	0.24804 (14)	1.19810 (12)	0.0287 (3)
H13A	−0.0359	0.2374	1.2202	0.034*
C14	0.14412 (16)	0.15626 (14)	1.22907 (12)	0.0269 (3)
H14A	0.1528	0.0846	1.2724	0.032*
C15	0.24447 (15)	0.17090 (12)	1.19555 (11)	0.0218 (3)
H15A	0.3202	0.1095	1.2165	0.026*
H1N1	0.3899 (19)	0.3693 (16)	1.1227 (13)	0.030 (4)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0247 (5)	0.0208 (4)	0.0188 (5)	0.0008 (3)	0.0147 (4)	−0.0030 (3)
O2	0.0237 (5)	0.0249 (4)	0.0222 (5)	0.0049 (3)	0.0169 (4)	0.0034 (4)
O3	0.0211 (5)	0.0350 (5)	0.0342 (6)	−0.0065 (4)	0.0202 (4)	−0.0053 (4)
O4	0.0259 (5)	0.0229 (4)	0.0250 (5)	−0.0052 (4)	0.0169 (4)	−0.0054 (4)
N1	0.0189 (5)	0.0194 (5)	0.0218 (6)	−0.0037 (4)	0.0146 (4)	−0.0049 (4)
N2	0.0176 (5)	0.0211 (5)	0.0193 (5)	−0.0010 (4)	0.0113 (4)	0.0013 (4)
C1	0.0172 (5)	0.0188 (5)	0.0176 (6)	0.0039 (4)	0.0119 (5)	0.0048 (4)
C2	0.0151 (5)	0.0172 (5)	0.0163 (6)	0.0000 (4)	0.0096 (5)	0.0011 (4)
C3	0.0153 (5)	0.0176 (5)	0.0153 (6)	0.0018 (4)	0.0092 (4)	0.0011 (4)
C4	0.0157 (5)	0.0211 (5)	0.0172 (6)	−0.0009 (4)	0.0107 (5)	−0.0005 (4)
C5	0.0176 (5)	0.0191 (5)	0.0167 (6)	−0.0001 (4)	0.0098 (5)	−0.0005 (4)
C6	0.0182 (5)	0.0187 (5)	0.0146 (6)	0.0036 (4)	0.0107 (5)	0.0025 (4)
C7	0.0195 (6)	0.0183 (5)	0.0162 (6)	0.0050 (4)	0.0106 (5)	0.0037 (4)
C8	0.0314 (7)	0.0249 (6)	0.0208 (7)	0.0044 (5)	0.0171 (6)	−0.0038 (5)
C9	0.0428 (9)	0.0279 (7)	0.0307 (8)	−0.0050 (6)	0.0217 (7)	−0.0078 (6)
C10	0.0157 (5)	0.0222 (5)	0.0183 (6)	−0.0038 (4)	0.0113 (5)	−0.0063 (5)
C11	0.0181 (6)	0.0273 (6)	0.0227 (7)	0.0004 (5)	0.0104 (5)	−0.0031 (5)
C12	0.0181 (6)	0.0356 (7)	0.0334 (8)	−0.0002 (5)	0.0151 (6)	−0.0101 (6)
C13	0.0256 (7)	0.0362 (7)	0.0356 (8)	−0.0118 (6)	0.0239 (6)	−0.0167 (6)
C14	0.0348 (8)	0.0266 (6)	0.0314 (8)	−0.0086 (5)	0.0256 (7)	−0.0073 (6)
C15	0.0245 (6)	0.0217 (6)	0.0259 (7)	−0.0012 (5)	0.0176 (6)	−0.0033 (5)

Geometric parameters (Å, º) top

O1—C7	1.3470 (15)	C6—C7	1.4764 (16)
O1—C8	1.4582 (14)	C8—C9	1.485 (2)
O2—C7	1.2165 (13)	C8—H8A	0.9700
O3—N2	1.2325 (12)	C8—H8B	0.9700
O4—N2	1.2415 (13)	C9—H9A	0.9600
N1—C3	1.3518 (14)	C9—H9B	0.9600
N1—C10	1.4293 (14)	C9—H9C	0.9600
N1—H1N1	0.858 (17)	C10—C15	1.3852 (17)
N2—C2	1.4468 (15)	C10—C11	1.3904 (17)
C1—C6	1.3789 (17)	C11—C12	1.3875 (17)
C1—C2	1.3923 (15)	C11—H11A	0.9300
C1—H1A	0.9300	C12—C13	1.384 (2)
C2—C3	1.4262 (15)	C12—H12A	0.9300
C3—C4	1.4218 (16)	C13—C14	1.388 (2)
C4—C5	1.3727 (16)	C13—H13A	0.9300
C4—H4A	0.9300	C14—C15	1.3935 (17)
C5—C6	1.4071 (15)	C14—H14A	0.9300
C5—H5A	0.9300	C15—H15A	0.9300

C7—O1—C8	115.13 (9)	O1—C8—H8A	110.2
C3—N1—C10	124.35 (10)	C9—C8—H8A	110.2
C3—N1—H1N1	117.8 (11)	O1—C8—H8B	110.2
C10—N1—H1N1	117.8 (11)	C9—C8—H8B	110.2
O3—N2—O4	122.02 (11)	H8A—C8—H8B	108.5
O3—N2—C2	118.75 (10)	C8—C9—H9A	109.5
O4—N2—C2	119.23 (9)	C8—C9—H9B	109.5
C6—C1—C2	121.06 (10)	H9A—C9—H9B	109.5
C6—C1—H1A	119.5	C8—C9—H9C	109.5
C2—C1—H1A	119.5	H9A—C9—H9C	109.5
C1—C2—C3	121.55 (11)	H9B—C9—H9C	109.5
C1—C2—N2	116.46 (10)	C15—C10—C11	120.29 (11)
C3—C2—N2	121.97 (10)	C15—C10—N1	121.04 (11)
N1—C3—C4	120.59 (10)	C11—C10—N1	118.58 (11)
N1—C3—C2	123.68 (11)	C12—C11—C10	120.00 (13)
C4—C3—C2	115.72 (10)	C12—C11—H11A	120.0
C5—C4—C3	122.11 (10)	C10—C11—H11A	120.0
C5—C4—H4A	118.9	C13—C12—C11	120.03 (13)
C3—C4—H4A	118.9	C13—C12—H12A	120.0
C4—C5—C6	120.86 (11)	C11—C12—H12A	120.0
C4—C5—H5A	119.6	C12—C13—C14	119.90 (11)
C6—C5—H5A	119.6	C12—C13—H13A	120.0
C1—C6—C5	118.69 (10)	C14—C13—H13A	120.0
C1—C6—C7	117.78 (10)	C13—C14—C15	120.36 (13)
C5—C6—C7	123.53 (11)	C13—C14—H14A	119.8
O2—C7—O1	122.94 (11)	C15—C14—H14A	119.8
O2—C7—C6	124.18 (11)	C10—C15—C14	119.41 (12)
O1—C7—C6	112.88 (9)	C10—C15—H15A	120.3
O1—C8—C9	107.49 (10)	C14—C15—H15A	120.3

C6—C1—C2—C3	−0.58 (18)	C4—C5—C6—C7	−179.04 (11)
C6—C1—C2—N2	177.85 (11)	C8—O1—C7—O2	−2.29 (17)
O3—N2—C2—C1	−7.34 (16)	C8—O1—C7—C6	177.49 (10)
O4—N2—C2—C1	173.15 (11)	C1—C6—C7—O2	−5.67 (18)
O3—N2—C2—C3	171.07 (11)	C5—C6—C7—O2	174.66 (12)
O4—N2—C2—C3	−8.44 (17)	C1—C6—C7—O1	174.56 (10)
C10—N1—C3—C4	3.33 (18)	C5—C6—C7—O1	−5.11 (17)
C10—N1—C3—C2	−177.07 (11)	C7—O1—C8—C9	−171.43 (11)
C1—C2—C3—N1	−178.51 (11)	C3—N1—C10—C15	72.36 (17)
N2—C2—C3—N1	3.15 (18)	C3—N1—C10—C11	−110.92 (14)
C1—C2—C3—C4	1.12 (17)	C15—C10—C11—C12	−0.1 (2)
N2—C2—C3—C4	−177.22 (10)	N1—C10—C11—C12	−176.86 (12)
N1—C3—C4—C5	179.17 (12)	C10—C11—C12—C13	−0.6 (2)
C2—C3—C4—C5	−0.47 (17)	C11—C12—C13—C14	0.9 (2)
C3—C4—C5—C6	−0.72 (19)	C12—C13—C14—C15	−0.5 (2)
C2—C1—C6—C5	−0.65 (18)	C11—C10—C15—C14	0.49 (19)
C2—C1—C6—C7	179.67 (11)	N1—C10—C15—C14	177.15 (12)
C4—C5—C6—C1	1.29 (18)	C13—C14—C15—C10	−0.2 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O4	0.859 (18)	2.00 (2)	2.6375 (17)	130.6 (17)
N1—H1N1···O2ⁱ	0.858 (17)	2.288 (16)	2.9411 (14)	133.0 (14)
C15—H15A···O2ⁱⁱ	0.93	2.45	3.342 (2)	160

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, −y, −z+2.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₄N₂O₄
M_r	286.28
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	10.6464 (2), 9.9178 (2), 14.7885 (2)
β (°)	120.244 (1)
V (Å³)	1348.96 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.35 × 0.20 × 0.16

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.965, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	17988, 4639, 3276
R_int	0.040
(sin θ/λ)_max (Å⁻¹)	0.744

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.124, 1.04
No. of reflections	4639
No. of parameters	195
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.26

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O4	0.859 (18)	2.00 (2)	2.6375 (17)	130.6 (17)
N1—H1N1···O2ⁱ	0.858 (17)	2.288 (16)	2.9411 (14)	133.0 (14)
C15—H15A···O2ⁱⁱ	0.9300	2.4500	3.342 (2)	160.00

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, −y, −z+2.

Footnotes

‡Thomson Reuters ResearcherID: A-5599-2009.

Acknowledgements

The authors thank the Malaysian Government and Universiti Sains Malaysia for the Research University grants Nos. 1001/PFIZIK/811151 and 1001/PSK/8620012. The authors also thank Pharmacogenetic and Novel Therapeutic Research, Institute for Research in Molecular Medicine, Universiti Sains Malaysia.

References

Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Glebowska, A., Przybylski, P., Winek, M., Krzyczkowska, P., Krowczynski, A., Szydlowska, J., Pociecha, D. & Gorecka, E. (2009). J. Mater. Chem. 19, 1395–1398. CAS Google Scholar
Mohd. Maidin, S. M., Abdul Rahim, A. S., Abdul Hamid, S., Kia, R. & Fun, H.-K. (2008). Acta Cryst. E64, o1501–o1502. Web of Science CSD CrossRef IUCr Journals Google Scholar
Remusat, V., Terme, T., Gellis, A., Rathelot, P. & Vanelle, P. (2004). J. Heterocycl. Chem. 41, 221–225. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stephane, S. (2006). US Patent 20060005323. Google Scholar
Zhang, G.-H., Wu, Y.-Z., Li, H.-Y., Liu, B.-N. & Guo, C. (2009). Acta Cryst. E65, o1380. Web of Science CSD CrossRef IUCr Journals Google Scholar