(E)-1-(2-Amino­phen­yl)-3-(thio­phen-2-yl)prop-2-en-1-one

Chantrapromma, S.; Ruanwas, P.; Boonnak, N.; Fun, H.-K.

doi:10.1107/S1600536813014189

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 69| Part 7| July 2013| Pages o1004-o1005

https://doi.org/10.1107/S1600536813014189

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(E)-1-(2-Aminophenyl)-3-(thiophen-2-yl)prop-2-en-1-one

Suchada Chantrapromma,^a ^*‡ Pumsak Ruanwas,^a Nawong Boonnak ^b and Hoong-Kun Fun ^c,^d §

^aDepartment of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, ^bFaculty of Traditional Thai Medicine, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, ^cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^dDepartment of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia
^*Correspondence e-mail: suchada.c@psu.ac.th

(Received 8 May 2013; accepted 22 May 2013; online 8 June 2013)

The molecule of the title heteroaryl chalcone derivative, C₁₃H₁₁NOS, exists in a trans-configuaration and is almost planar with a dihedral angle of 3.73 (8)° between the phenyl and thiophene rings. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, two adjacent molecules are linked into a dimer in an anti-parallel face-to-face manner by a pair of C—H⋯O interactions. Neighboring dimers are further linked into chains along the c-axis direction by N—H⋯N hydrogen bonds.

Related literature

For standard bond lengths, see: Allen et al. (1987 ). For graph-set notation, see: Bernstein et al. (1995 ). For related structures, see: Fun et al. (2011 ); Suwunwong et al. (2009 ). For background to and applications of chalcones, see: Go et al. (2005 ); Liu et al. (2008 ); Molyneux (2004 ); Nerya et al. (2004 ); Ni et al. (2004 ); Shenvi et al. (2013 ); Suwunwong et al. (2011 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer, (1986 ).

Experimental

Crystal data

C₁₃H₁₁NOS
M_r = 229.30
Monoclinic, C 2/c
a = 24.9335 (4) Å
b = 5.0278 (1) Å
c = 18.6813 (3) Å
β = 111.151 (1)°
V = 2184.13 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.27 mm⁻¹
T = 100 K
0.36 × 0.12 × 0.06 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.908, T_max = 0.984
14827 measured reflections
3942 independent reflections
2620 reflections with I > 2σ(I)
R_int = 0.036

Refinement

R[F² > 2σ(F²)] = 0.051
wR(F²) = 0.127
S = 1.04
3942 reflections
153 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.45 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯O1	0.83 (2)	1.97 (2)	2.6253 (18)	135.6 (19)
N1—H2N1⋯N1ⁱ	0.86 (2)	2.34 (2)	3.184 (2)	169 (2)
C11—H11A⋯O1ⁱⁱ	0.95	2.56	3.278 (2)	133
Symmetry codes: (i) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ .

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, PLATON (Spek, 2009 ), Mercury (Macrae et al., 2006 ) and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536813014189/rz5065sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813014189/rz5065Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536813014189/rz5065Isup3.cml

checkCIF report

Comment top

The basic structure of chalcones consists of two aromatic rings bound by an α,β-unsaturated carbonyl group, a unique template associated with various biological activities such as analgesic, anti-inflammatory, antibacterial (Go et al., 2005; Liu et al., 2008; Ni et al., 2004), anticancer and antioxidant (Shenvi et al., 2013) as well as tyrosinase inhibitory (Nerya et al., 2004) and fluorescence (Suwunwong et al., 2011) properties. The title compound (I) was synthesized and studied for antioxidant activity by the DPPH scavenging method (Molyneux, 2004). Our result showed that (I) exhibits a weakly antioxidant activity. It was also tested for antityrosinase activity but found to be inactive. Herein we report the crystal structure of (I).

The molecular structure of (I) exists in a trans configuration with respect to the C8═C9 double bond [1.340 (2)°] as indicated by the torsion angle C7–C8–C9–C10 = 179.29 (15)° (Fig. 1). The whole molecule is almost planar, the interplanar angle between phenyl and thiophene rings being 3.73 (8)° (Fig. 2). The propenone unit (C7—C9/O1) is almost planar with the torsion angle O1–C7–C8–C9 = -7.8 (2)°. The mean plane through the propenone bridge makes the dihedral angles of 7.37 (10) and 3.66 (10)° with the phenyl and thiophene rings, respectively. Intramolecular N1—H1N1···O1 hydrogen bond between amino and enone groups (Fig. 1 and Table 1) generates S(6) ring motif (Bernstein et al., 1995). This intramolecular hydrogen bond helps to stabilize the planarity of the structure. However it may result in the prohibition of the α,β-unsaturated carbonyl moiety to be reactive. The bond distances in (I) agree with the literature values (Allen et al., 1987) and are comparable with those observed in related structures (Fun et al., 2011; Suwunwong et al., 2009).

In the crystal packing (Fig. 3), two adjacent molecules are linked in an anti-parallel face-to-face manner into a dimer by a pair of C_thiophene—H···O interactions and the neighboring dimers are further linked into chains along the c axis by N—H···N hydrogen bonds (Fig. 4 and Table 1).

Related literature top

For standard bond lengths, see: Allen et al. (1987). For graph-set notation, see: Bernstein et al. (1995). For related structures, see: Fun et al. (2011); Suwunwong et al. (2009). For background to and applications of chalcones, see: Go et al. (2005); Liu et al. (2008); Molyneux (2004); Nerya et al. (2004); Ni et al. (2004); Shenvi et al. (2013); Suwunwong et al. (2011). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer, (1986).

Experimental top

The title compound (I) was prepared by mixing 2-aminoacetophenone (0.40 g, 3 mmol) and 2-thiophenecarboxaldehyde (0.34 g, 3 mmol) in ethanol (30 ml). 30% NaOH aqueous solution (5 ml) was then added and the mixture was stirred at room temperature for 2 hr. The yellow solid formed was filtered and washed with distilled water. Yellow block-shaped single crystals of (I) suitable for x-ray structure determination were recrystallized from ethanol by slow evaporation at room temperature over a few weeks. M.p. 407–408 K.

Structure description top

For standard bond lengths, see: Allen et al. (1987). For graph-set notation, see: Bernstein et al. (1995). For related structures, see: Fun et al. (2011); Suwunwong et al. (2009). For background to and applications of chalcones, see: Go et al. (2005); Liu et al. (2008); Molyneux (2004); Nerya et al. (2004); Ni et al. (2004); Shenvi et al. (2013); Suwunwong et al. (2011). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer, (1986).

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), PLATON (Spek, 2009), Mercury (Macrae et al., 2006) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. The asymmetric unit of the title compound showing 50% probability displacement ellipsoid. Intramolecular N—H···O hydrogen bond is drawn as dashed line.
	Fig. 2. The molecular structure of the title compound showing the approximate planarity of the molecule and the interplanar angle between phenyl and thophene rings.
	Fig. 3. The crystal packing of the title compound viewed along the b axis. Hydrogen bonds are drawn as dashed lines.
	Fig. 4. The crystal packing of the title compound, showing a chain of dimers running along the c axis. Hydrogen bonds are drawn as dashed lines.

(E)-1-(2-Aminophenyl)-3-(thiophen-2-yl)prop-2-en-1-one top

Crystal data top

C₁₃H₁₁NOS	F(000) = 960
M_r = 229.30	D_x = 1.395 Mg m⁻³
Monoclinic, C2/c	Melting point = 407–408 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 24.9335 (4) Å	Cell parameters from 3942 reflections
b = 5.0278 (1) Å	θ = 1.8–32.5°
c = 18.6813 (3) Å	µ = 0.27 mm⁻¹
β = 111.151 (1)°	T = 100 K
V = 2184.13 (7) Å³	Block, yellow
Z = 8	0.36 × 0.12 × 0.06 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	3942 independent reflections
Radiation source: sealed tube	2620 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.036
φ and ω scans	θ_max = 32.5°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −37→37
T_min = 0.908, T_max = 0.984	k = −7→5
14827 measured reflections	l = −28→28

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.0488P)² + 2.0262P] where P = (F_o² + 2F_c²)/3
3942 reflections	(Δ/σ)_max = 0.001
153 parameters	Δρ_max = 0.39 e Å⁻³
0 restraints	Δρ_min = −0.45 e Å⁻³

Crystal data top

C₁₃H₁₁NOS	V = 2184.13 (7) Å³
M_r = 229.30	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 24.9335 (4) Å	µ = 0.27 mm⁻¹
b = 5.0278 (1) Å	T = 100 K
c = 18.6813 (3) Å	0.36 × 0.12 × 0.06 mm
β = 111.151 (1)°

Data collection top

Bruker APEXII CCD area-detector diffractometer	3942 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	2620 reflections with I > 2σ(I)
T_min = 0.908, T_max = 0.984	R_int = 0.036
14827 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.051	0 restraints
wR(F²) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.39 e Å⁻³
3942 reflections	Δρ_min = −0.45 e Å⁻³
153 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
S1	0.071728 (19)	−0.24213 (9)	0.38943 (3)	0.02647 (13)
O1	0.21891 (5)	0.4157 (2)	0.59945 (7)	0.0243 (3)
N1	0.22281 (6)	0.7977 (3)	0.69701 (8)	0.0196 (3)
H1N1	0.2382 (8)	0.721 (4)	0.6700 (11)	0.021 (5)*
H2N1	0.2361 (9)	0.944 (5)	0.7198 (12)	0.037 (6)*
C1	0.13438 (6)	0.5801 (3)	0.61394 (9)	0.0157 (3)
C2	0.16405 (7)	0.7756 (3)	0.66901 (9)	0.0161 (3)
C3	0.13202 (7)	0.9494 (3)	0.69732 (9)	0.0193 (3)
H3A	0.1516	1.0791	0.7346	0.023*
C4	0.07321 (7)	0.9354 (3)	0.67233 (10)	0.0210 (3)
H4A	0.0526	1.0560	0.6919	0.025*
C5	0.04342 (7)	0.7438 (3)	0.61801 (10)	0.0214 (3)
H5A	0.0027	0.7337	0.6007	0.026*
C6	0.07387 (7)	0.5711 (3)	0.59021 (9)	0.0197 (3)
H6A	0.0535	0.4408	0.5537	0.024*
C7	0.16602 (7)	0.3989 (3)	0.58064 (9)	0.0166 (3)
C8	0.13517 (7)	0.1944 (3)	0.52357 (9)	0.0176 (3)
H8A	0.0955	0.1613	0.5126	0.021*
C9	0.16398 (7)	0.0568 (3)	0.48761 (9)	0.0181 (3)
H9A	0.2034	0.1021	0.5010	0.022*
C10	0.14298 (7)	−0.1511 (3)	0.43121 (9)	0.0186 (3)
C11	0.17609 (7)	−0.3053 (3)	0.40209 (10)	0.0210 (3)
H11A	0.2166	−0.2864	0.4176	0.025*
C12	0.14450 (8)	−0.4928 (4)	0.34746 (10)	0.0267 (4)
H12A	0.1613	−0.6149	0.3228	0.032*
C13	0.08760 (8)	−0.4801 (4)	0.33398 (10)	0.0275 (4)
H13A	0.0596	−0.5897	0.2981	0.033*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0228 (2)	0.0244 (2)	0.0278 (2)	0.00019 (17)	0.00385 (17)	−0.00763 (19)
O1	0.0191 (6)	0.0249 (6)	0.0278 (7)	−0.0020 (5)	0.0071 (5)	−0.0082 (5)
N1	0.0185 (7)	0.0191 (7)	0.0187 (7)	−0.0015 (5)	0.0035 (6)	−0.0039 (6)
C1	0.0186 (7)	0.0133 (6)	0.0144 (7)	−0.0012 (6)	0.0050 (6)	0.0004 (6)
C2	0.0203 (7)	0.0143 (6)	0.0125 (7)	−0.0003 (6)	0.0043 (6)	0.0027 (6)
C3	0.0265 (8)	0.0151 (7)	0.0144 (7)	−0.0006 (6)	0.0054 (6)	−0.0005 (6)
C4	0.0265 (8)	0.0185 (7)	0.0195 (8)	0.0037 (6)	0.0100 (7)	0.0003 (6)
C5	0.0180 (7)	0.0224 (7)	0.0241 (8)	0.0004 (7)	0.0078 (6)	−0.0015 (7)
C6	0.0218 (8)	0.0172 (7)	0.0186 (8)	−0.0024 (6)	0.0056 (6)	−0.0020 (6)
C7	0.0195 (8)	0.0144 (7)	0.0151 (7)	−0.0004 (6)	0.0055 (6)	0.0012 (6)
C8	0.0190 (7)	0.0149 (7)	0.0180 (7)	−0.0012 (6)	0.0057 (6)	0.0003 (6)
C9	0.0201 (8)	0.0163 (7)	0.0172 (7)	−0.0020 (6)	0.0060 (6)	0.0001 (6)
C10	0.0241 (8)	0.0151 (7)	0.0179 (8)	−0.0014 (6)	0.0090 (6)	0.0003 (6)
C11	0.0252 (8)	0.0202 (8)	0.0228 (8)	−0.0027 (6)	0.0148 (7)	−0.0014 (6)
C12	0.0443 (11)	0.0195 (8)	0.0221 (9)	−0.0013 (8)	0.0191 (8)	−0.0029 (7)
C13	0.0384 (10)	0.0205 (8)	0.0192 (8)	−0.0038 (7)	0.0050 (7)	−0.0055 (7)

Geometric parameters (Å, º) top

S1—C13	1.7195 (19)	C5—C6	1.373 (2)
S1—C10	1.7245 (17)	C5—H5A	0.9500
O1—C7	1.2392 (19)	C6—H6A	0.9500
N1—C2	1.371 (2)	C7—C8	1.481 (2)
N1—H1N1	0.83 (2)	C8—C9	1.340 (2)
N1—H2N1	0.86 (2)	C8—H8A	0.9500
C1—C6	1.412 (2)	C9—C10	1.442 (2)
C1—C2	1.422 (2)	C9—H9A	0.9500
C1—C7	1.481 (2)	C10—C11	1.380 (2)
C2—C3	1.409 (2)	C11—C12	1.404 (2)
C3—C4	1.371 (2)	C11—H11A	0.9500
C3—H3A	0.9500	C12—C13	1.350 (3)
C4—C5	1.402 (2)	C12—H12A	0.9500
C4—H4A	0.9500	C13—H13A	0.9500

C13—S1—C10	91.94 (9)	O1—C7—C1	120.84 (14)
C2—N1—H1N1	113.2 (13)	O1—C7—C8	118.34 (14)
C2—N1—H2N1	115.3 (14)	C1—C7—C8	120.82 (14)
H1N1—N1—H2N1	122 (2)	C9—C8—C7	119.10 (15)
C6—C1—C2	117.86 (14)	C9—C8—H8A	120.4
C6—C1—C7	121.29 (14)	C7—C8—H8A	120.4
C2—C1—C7	120.81 (14)	C8—C9—C10	128.46 (15)
N1—C2—C3	118.61 (14)	C8—C9—H9A	115.8
N1—C2—C1	122.50 (14)	C10—C9—H9A	115.8
C3—C2—C1	118.88 (14)	C11—C10—C9	125.77 (15)
C4—C3—C2	121.45 (15)	C11—C10—S1	109.74 (12)
C4—C3—H3A	119.3	C9—C10—S1	124.49 (12)
C2—C3—H3A	119.3	C10—C11—C12	113.91 (16)
C3—C4—C5	120.26 (15)	C10—C11—H11A	123.0
C3—C4—H4A	119.9	C12—C11—H11A	123.0
C5—C4—H4A	119.9	C13—C12—C11	112.33 (16)
C6—C5—C4	119.19 (15)	C13—C12—H12A	123.8
C6—C5—H5A	120.4	C11—C12—H12A	123.8
C4—C5—H5A	120.4	C12—C13—S1	112.06 (13)
C5—C6—C1	122.36 (15)	C12—C13—H13A	124.0
C5—C6—H6A	118.8	S1—C13—H13A	124.0
C1—C6—H6A	118.8

C6—C1—C2—N1	178.64 (14)	C2—C1—C7—C8	179.69 (14)
C7—C1—C2—N1	−3.6 (2)	O1—C7—C8—C9	−7.8 (2)
C6—C1—C2—C3	0.2 (2)	C1—C7—C8—C9	171.71 (14)
C7—C1—C2—C3	177.97 (14)	C7—C8—C9—C10	179.29 (15)
N1—C2—C3—C4	−179.23 (15)	C8—C9—C10—C11	−172.66 (17)
C1—C2—C3—C4	−0.7 (2)	C8—C9—C10—S1	7.8 (3)
C2—C3—C4—C5	0.7 (2)	C13—S1—C10—C11	−0.44 (13)
C3—C4—C5—C6	−0.1 (3)	C13—S1—C10—C9	179.13 (15)
C4—C5—C6—C1	−0.5 (3)	C9—C10—C11—C12	−179.72 (16)
C2—C1—C6—C5	0.4 (2)	S1—C10—C11—C12	−0.15 (18)
C7—C1—C6—C5	−177.38 (15)	C10—C11—C12—C13	0.9 (2)
C6—C1—C7—O1	176.95 (15)	C11—C12—C13—S1	−1.2 (2)
C2—C1—C7—O1	−0.8 (2)	C10—S1—C13—C12	0.96 (15)
C6—C1—C7—C8	−2.6 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O1	0.83 (2)	1.97 (2)	2.6253 (18)	135.6 (19)
N1—H2N1···N1ⁱ	0.86 (2)	2.34 (2)	3.184 (2)	169 (2)
C11—H11A···O1ⁱⁱ	0.95	2.56	3.278 (2)	133

Symmetry codes: (i) −x+1/2, y+1/2, −z+3/2; (ii) −x+1/2, −y+1/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₃H₁₁NOS
M_r	229.30
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	100
a, b, c (Å)	24.9335 (4), 5.0278 (1), 18.6813 (3)
β (°)	111.151 (1)
V (Å³)	2184.13 (7)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.27
Crystal size (mm)	0.36 × 0.12 × 0.06

Data collection
Diffractometer	Bruker APEXII CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.908, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	14827, 3942, 2620
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.756

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.127, 1.04
No. of reflections	3942
No. of parameters	153
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.45

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009), Mercury (Macrae et al., 2006) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O1	0.83 (2)	1.97 (2)	2.6253 (18)	135.6 (19)
N1—H2N1···N1ⁱ	0.86 (2)	2.34 (2)	3.184 (2)	169 (2)
C11—H11A···O1ⁱⁱ	0.95	2.56	3.278 (2)	133

Symmetry codes: (i) −x+1/2, y+1/2, −z+3/2; (ii) −x+1/2, −y+1/2, −z+1.

Footnotes

‡Thomson Reuters ResearcherID: A-5085-2009.

§Additional correspondence author, email: hkfun@usm.my. Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

Financial support from the Thailand Research Fund through the Royal Golden Jubilee PhD Program (grant No. PHD/0314/2552) is gratefully acknowledged. The authors extend their appreciation to Prince of Songkla University, the Deanship of Scientific Research at King Saud University and Universiti Sains Malaysia for the APEX DE2012 grant No. 1002/PFIZIK/910323.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CSD CrossRef Web of Science Google Scholar
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). APEX2, SAINT and SADABS, 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
Fun, H.-K., Suwunwong, T., Anantapong, T., Karalai, C. & Chantrapromma, S. (2011). Acta Cryst. E67, o3074–o3075. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Go, M.-L., Wu, X. & Liu, X.-L. (2005). Curr. Med. Chem. 12, 483–499. CrossRef CAS Google Scholar
Liu, X. L., Xu, Y. J. & Go, M. L. (2008). Eur. J. Med. Chem. 43, 1681–1687. Web of Science CrossRef PubMed CAS Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Molyneux, P. (2004). Songklanakarin J. Sci. Technol. 26, 211–219. CAS Google Scholar
Nerya, O., Musa, R., Khatib, S., Tamir, S. & Vaya, J. (2004). Phytochem. 65, 1389–1395. Web of Science CrossRef CAS Google Scholar
Ni, L., Meng, C. Q. & Sikorski, J. A. (2004). Expert Opin. Ther. Pat. 14, 1669–1691. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shenvi, S., Kumar, K., Hatti, K. S., Rijesh, K., Diwakar, L. & Reddy, G. C. (2013). Eur. J. Med. Chem. 62, 435–442. Web of Science CrossRef CAS PubMed Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Suwunwong, T., Chantrapromma, S. & Fun, H.-K. (2011). Chem. Pap. 65, 890–897. Web of Science CSD CrossRef CAS Google Scholar
Suwunwong, T., Chantrapromma, S., Pakdeevanich, P. & Fun, H.-K. (2009). Acta Cryst. E65, o1575–o1576. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar