organic compounds
3-(2,5-Dichlorothiophen-3-yl)-5-(2,4-dimethoxyphenyl)-1-methyl-4,5-dihydro-1H-pyrazole
aDepartment of Chemistry, Al al-Bayt University, Mafraq 25113, Jordan, and bFaculty of Chemistry, Philipps University Marburg, Hans-Meerwein-Strasse 4, 35032, Marburg, Germany
*Correspondence e-mail: bfali@aabu.edu.jo
In the title compound, C16H16Cl2N2O2S, the pyrazole ring has an with the C atom bearing the phenyl ring being the flap. The dihedral angles between the central pyrazole ring (all atoms) and pendant thiophene and phenyl rings are 2.00 (14) and 81.49 (12)°, respectively. In the crystal, weak C—H⋯O, Cl⋯π and π–π stacking interactions link the molecules into a three-dimensional network.
Keywords: crystal structure; pyrazole; Cl⋯π interactions.
CCDC reference: 1906405
Structure description
et al., 2009), anti-inflammatory (Viveka et al., 2015) and antioxidant activities (Taj et al., 2011). In a continuation of our ongoing research on pyrazoles (Ibrahim et al., 2016), we now describe the synthesis and structure of the title compound, I (Fig. 1).
containing a pyrazole core show various biological properties such as anti-cancer (SidiqueThe central pyrazole ring adopts an R configuration in the arbitrarily chosen but crystal symmetry generates a The C atom of the methyl group attached to N2 of the pyrazole ring deviates significantly by 0.758 (3) Å from the plane of N1/N2/C4/C5 (r.m.s. deviation = 0.025 Å), which suggests that the electronic structure of N2 is well described as being sp3 hybridized.
with the chiral C3 atom as the flap [deviation from the other atoms = 0.363 (3) Å]. C3 has anThe thiophene ring at position C5, and the phenyl ring at position C3 are inclined to the pyrazole ring (all atoms) by dihedral angles of 2.00 (14) and 81.49 (12)°, respectively; the dihedral angle between the pendant rings is 82.76 (11)°. The C atoms of the methoxy groups lie close to the plane of the phenyl ring [deviations for C18 and C19 = −0.081 (2) and 0.045 (2) Å, respectively]. The molecular structure features a short intramolecular C3—H3⋯O1 contact of 2.39 Å (Table 1), which closes an S(5) ring.
|
The extended structure of I (Fig. 2) features very weak C11—H11C⋯O2(x, −1 + y, z) hydrogen bonds, which generate [010] chains of molecules. Adjacent chains in the [001] direction are linked by Cl⋯π interactions (Riley & Tran, 2017) with C9⋯Cg1(−x, −y, 1 − z) = 3.5088 (12) Å, Cl2⋯Cg1(−x, −y, 1 − z) = 4.005 (3) Å and C9—Cl2⋯Cg1 = 93.77 (9)° where Cg1 is the centroid of the thiophene ring. Weak offset face-to-face π–π stacking interactions occur between inversion-related thiophene rings with a centroid–centroid separation Cg1⋯Cg1(−x, 1 − y, 1 − z) of 3.9011 (14) Å. Taken together, the C—H⋯O, Cl⋯π and π–π interactions lead to a three-dimensional network.
Synthesis and crystallization
3-Acetyl-2,5-dichlorothiophene was prepared via Friedel–Crafts reaction as per the literature procedure (Bachman & Heisey, 1948). The corresponding chalcone, (E)-1-(2,5-dichlorothiophen-3-yl)-3-(2,4-dimethoxyphenyl)prop-2-en-1-one, was prepared according to the literature procedure (Al-Refai et al., 2017 and references therein).
(E)-1-(2,5-Dichlorothiophen-3-yl)-3-(2,4-dimethoxyphenyl)prop-2-en-1-one (3.0 mmol) and methylhydrazine (4.0 mmol, 1.3 equiv.) were refluxed in 25 ml of ethanol for 5 h until completion of the reaction. The reaction mixture was then cooled, whereupon a solid precipitate was formed. This was filtered off, washed with cold ethanol, and dried. Yellow blocks of I were grown by slow evaporation of an ethanol solution. Yield: 89%. 1H NMR (300 MHz, DMSO-d6, p.p.m.): δ = 7.33 (d, J = 8.27, 1H, H-6"), 7.27 (s, 1H, H-4′), 6.65 (d, J = 8.44, 1H, H-5"), 6.59 (s, 1H, H-3"), 4.39 (dd, J = 14.06, 10.47, 1H, H-5), 3.80, 3.77 (2s, 6H, OCH3-2",4"), 3.58 (dd, J = 16.48, 10.38, 1HA, H-4), 2.76 (m, 1H, HB, H-4), 2.70 (s, 3H, N—CH3).13C NMR (75 MHz, DMSO-d6, p.p.m.): δ = 159.93, 158.12 (Cq-2",4"), 142.86 (Cq-3), 131.45, 125.40, 121.46, 119.80 (Cq-2′, 3′, 5′, 1"), 127.45, 126.37 (CH-4′, 6′′), 105.07 (CH-5′′), 98.50 (CH-3′′), 66.06 (CH-5), 55.57, 55.19 (OCH3-2",4"), 41.86 (CH2-4), 40.88 (NCH3). –(+)-ESIMS m/z 371 ([M+H]+,100), 373 ([M+H+2]+,70), 375 ([M+H+4]+,15), 393([M+Na]+, 20), 395 ([M+Na+2]+, 16), 397 ([M+Na+4]+, 4). -(+)-HRESIMS m/z 371.0383 [M+H]+, 373.0355 [M+H+2]+, (calculated for C16H16Cl2N2O2SH, 371.0382).
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1906405
https://doi.org/10.1107/S2414314619010460/hb4309sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314619010460/hb4309Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314619010460/hb4309Isup3.cml
Data collection: X-AREA Pilatus3_SV (Stoe & Cie, 2016); cell
X-AREA Recipe (Stoe & Cie, 2016); data reduction: X-AREA Integrate and LANA (Stoe & Cie, 2016); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015b); molecular graphics: DIAMOND (Crystal Impact); software used to prepare material for publication: X-AREA (Stoe & Cie, 2016).C16H16Cl2N2O2S | Z = 2 |
Mr = 371.27 | F(000) = 384 |
Triclinic, P1 | Dx = 1.519 Mg m−3 |
a = 8.3836 (3) Å | Cu Kα radiation, λ = 1.54178 Å |
b = 8.4780 (3) Å | Cell parameters from 30941 reflections |
c = 13.3050 (4) Å | θ = 3.5–71.7° |
α = 97.779 (3)° | µ = 4.89 mm−1 |
β = 101.929 (2)° | T = 100 K |
γ = 114.967 (2)° | Block, yellow |
V = 811.94 (5) Å3 | 0.17 × 0.14 × 0.12 mm |
Stoe Stadivari diffractometer | 3062 independent reflections |
Radiation source: GeniX 3D HF Cu | 2794 reflections with I > 2σ(I) |
Detector resolution: 5.81 pixels mm-1 | Rint = 0.045 |
rotation method, ω scans | θmax = 71.3°, θmin = 3.5° |
Absorption correction: multi-scan (LANA; Stoe & Cie, 2016) | h = −10→8 |
Tmin = 0.260, Tmax = 1.000 | k = −4→10 |
21767 measured reflections | l = −16→15 |
Refinement on F2 | Primary atom site location: dual |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.117P)2] where P = (Fo2 + 2Fc2)/3 |
3062 reflections | (Δ/σ)max = 0.001 |
211 parameters | Δρmax = 0.79 e Å−3 |
0 restraints | Δρmin = −0.50 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. The H atoms were included at calculated positions and refined using the riding model with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C). Thr CH3 groups were allowed to rotate about the bond to their next atom to best fit the electron density. |
x | y | z | Uiso*/Ueq | ||
N1 | 0.0524 (2) | 0.3616 (2) | 0.24617 (13) | 0.0167 (4) | |
O1 | 0.63312 (18) | 0.79340 (19) | 0.17276 (12) | 0.0201 (3) | |
Cl1 | 0.40982 (6) | 0.63165 (6) | 0.59685 (4) | 0.02134 (19) | |
Cl2 | −0.26047 (7) | −0.01538 (6) | 0.52260 (4) | 0.02362 (19) | |
O2 | 0.46909 (19) | 1.27080 (19) | 0.12925 (12) | 0.0202 (3) | |
N2 | 0.1173 (2) | 0.4670 (2) | 0.17701 (13) | 0.0161 (4) | |
C3 | 0.3126 (3) | 0.6004 (3) | 0.22968 (15) | 0.0150 (4) | |
H3 | 0.394688 | 0.551101 | 0.210416 | 0.018* | |
C4 | 0.3262 (3) | 0.6153 (3) | 0.34763 (16) | 0.0163 (4) | |
H4A | 0.442394 | 0.620750 | 0.388101 | 0.020* | |
H4AB | 0.315841 | 0.721586 | 0.379923 | 0.020* | |
C5 | 0.1609 (3) | 0.4417 (3) | 0.34130 (16) | 0.0153 (4) | |
C6 | 0.1101 (3) | 0.3698 (3) | 0.42980 (16) | 0.0157 (4) | |
C7 | 0.2065 (3) | 0.4389 (3) | 0.53541 (16) | 0.0164 (4) | |
S8 | 0.10142 (7) | 0.31227 (6) | 0.61630 (4) | 0.01945 (19) | |
C9 | −0.0797 (3) | 0.1644 (3) | 0.50664 (17) | 0.0195 (4) | |
C10 | −0.0603 (3) | 0.2079 (3) | 0.41399 (17) | 0.0168 (4) | |
H10 | −0.147743 | 0.140421 | 0.346684 | 0.020* | |
C11 | 0.0802 (3) | 0.3591 (3) | 0.07189 (16) | 0.0199 (4) | |
H11A | 0.114750 | 0.438012 | 0.024226 | 0.030* | |
H11B | −0.051175 | 0.273750 | 0.044120 | 0.030* | |
H11C | 0.152208 | 0.293102 | 0.076627 | 0.030* | |
C12 | 0.3582 (3) | 0.7768 (3) | 0.19820 (15) | 0.0150 (4) | |
C13 | 0.5195 (3) | 0.8720 (3) | 0.17247 (15) | 0.0155 (4) | |
C14 | 0.5623 (3) | 1.0375 (3) | 0.14841 (15) | 0.0165 (4) | |
H14 | 0.672513 | 1.100335 | 0.130663 | 0.020* | |
C15 | 0.4406 (3) | 1.1093 (3) | 0.15080 (15) | 0.0161 (4) | |
C16 | 0.2790 (3) | 1.0170 (3) | 0.17691 (16) | 0.0186 (4) | |
H16 | 0.196574 | 1.066391 | 0.178851 | 0.022* | |
C17 | 0.2401 (3) | 0.8534 (3) | 0.19987 (16) | 0.0183 (4) | |
H17 | 0.129522 | 0.790838 | 0.217385 | 0.022* | |
C18 | 0.7935 (3) | 0.8799 (3) | 0.13908 (17) | 0.0194 (4) | |
H18A | 0.855409 | 0.804449 | 0.136606 | 0.029* | |
H18B | 0.877631 | 0.996621 | 0.189289 | 0.029* | |
H18C | 0.757239 | 0.897638 | 0.068323 | 0.029* | |
C19 | 0.6361 (3) | 1.3732 (3) | 0.10549 (18) | 0.0213 (4) | |
H19A | 0.641455 | 1.486915 | 0.094107 | 0.032* | |
H19B | 0.639749 | 1.304878 | 0.041167 | 0.032* | |
H19C | 0.741558 | 1.397937 | 0.164924 | 0.032* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0173 (8) | 0.0128 (8) | 0.0178 (9) | 0.0038 (7) | 0.0070 (7) | 0.0052 (7) |
O1 | 0.0160 (7) | 0.0155 (7) | 0.0316 (8) | 0.0061 (6) | 0.0122 (6) | 0.0105 (6) |
Cl1 | 0.0178 (3) | 0.0155 (3) | 0.0190 (3) | −0.0003 (2) | 0.0012 (2) | 0.0018 (2) |
Cl2 | 0.0234 (3) | 0.0144 (3) | 0.0280 (3) | 0.0009 (2) | 0.0143 (2) | 0.0063 (2) |
O2 | 0.0196 (7) | 0.0142 (7) | 0.0285 (8) | 0.0066 (6) | 0.0097 (6) | 0.0106 (6) |
N2 | 0.0158 (8) | 0.0112 (8) | 0.0158 (8) | 0.0007 (7) | 0.0057 (7) | 0.0041 (6) |
C3 | 0.0137 (9) | 0.0110 (9) | 0.0184 (10) | 0.0031 (7) | 0.0059 (8) | 0.0052 (7) |
C4 | 0.0155 (10) | 0.0122 (10) | 0.0181 (10) | 0.0030 (8) | 0.0047 (8) | 0.0062 (7) |
C5 | 0.0143 (9) | 0.0096 (9) | 0.0200 (10) | 0.0033 (8) | 0.0056 (8) | 0.0039 (7) |
C6 | 0.0150 (9) | 0.0106 (10) | 0.0196 (10) | 0.0040 (8) | 0.0060 (8) | 0.0035 (7) |
C7 | 0.0157 (10) | 0.0116 (10) | 0.0189 (10) | 0.0025 (8) | 0.0061 (8) | 0.0056 (8) |
S8 | 0.0213 (3) | 0.0164 (3) | 0.0162 (3) | 0.0042 (2) | 0.0062 (2) | 0.0050 (2) |
C9 | 0.0174 (10) | 0.0117 (10) | 0.0252 (11) | 0.0027 (8) | 0.0078 (8) | 0.0028 (8) |
C10 | 0.0157 (9) | 0.0155 (10) | 0.0182 (10) | 0.0048 (8) | 0.0073 (8) | 0.0058 (8) |
C11 | 0.0215 (10) | 0.0177 (10) | 0.0164 (10) | 0.0051 (8) | 0.0064 (8) | 0.0046 (8) |
C12 | 0.0137 (9) | 0.0125 (10) | 0.0143 (9) | 0.0025 (7) | 0.0028 (8) | 0.0039 (7) |
C13 | 0.0142 (9) | 0.0137 (10) | 0.0136 (9) | 0.0026 (8) | 0.0033 (8) | 0.0025 (7) |
C14 | 0.0138 (9) | 0.0141 (10) | 0.0165 (9) | 0.0014 (8) | 0.0055 (8) | 0.0036 (7) |
C15 | 0.0166 (10) | 0.0114 (10) | 0.0148 (9) | 0.0020 (8) | 0.0026 (8) | 0.0044 (7) |
C16 | 0.0174 (10) | 0.0182 (11) | 0.0227 (11) | 0.0088 (8) | 0.0082 (8) | 0.0073 (8) |
C17 | 0.0143 (9) | 0.0166 (10) | 0.0204 (10) | 0.0031 (8) | 0.0064 (8) | 0.0056 (8) |
C18 | 0.0139 (10) | 0.0159 (10) | 0.0264 (11) | 0.0035 (8) | 0.0097 (8) | 0.0053 (8) |
C19 | 0.0201 (10) | 0.0130 (10) | 0.0280 (11) | 0.0032 (8) | 0.0089 (9) | 0.0087 (8) |
N1—C5 | 1.289 (3) | C9—C10 | 1.355 (3) |
N1—N2 | 1.400 (2) | C10—H10 | 0.9500 |
O1—C13 | 1.373 (2) | C11—H11A | 0.9800 |
O1—C18 | 1.433 (2) | C11—H11B | 0.9800 |
Cl1—C7 | 1.719 (2) | C11—H11C | 0.9800 |
Cl2—C9 | 1.713 (2) | C12—C13 | 1.394 (3) |
O2—C15 | 1.368 (2) | C12—C17 | 1.397 (3) |
O2—C19 | 1.430 (2) | C13—C14 | 1.394 (3) |
N2—C11 | 1.457 (3) | C14—C15 | 1.394 (3) |
N2—C3 | 1.483 (2) | C14—H14 | 0.9500 |
C3—C12 | 1.520 (3) | C15—C16 | 1.393 (3) |
C3—C4 | 1.534 (3) | C16—C17 | 1.377 (3) |
C3—H3 | 1.0000 | C16—H16 | 0.9500 |
C4—C5 | 1.513 (3) | C17—H17 | 0.9500 |
C4—H4A | 0.9900 | C18—H18A | 0.9800 |
C4—H4AB | 0.9900 | C18—H18B | 0.9800 |
C5—C6 | 1.457 (3) | C18—H18C | 0.9800 |
C6—C7 | 1.371 (3) | C19—H19A | 0.9800 |
C6—C10 | 1.453 (3) | C19—H19B | 0.9800 |
C7—S8 | 1.730 (2) | C19—H19C | 0.9800 |
S8—C9 | 1.728 (2) | ||
C5—N1—N2 | 109.43 (16) | N2—C11—H11B | 109.5 |
C13—O1—C18 | 117.89 (15) | H11A—C11—H11B | 109.5 |
C15—O2—C19 | 117.63 (15) | N2—C11—H11C | 109.5 |
N1—N2—C11 | 112.53 (15) | H11A—C11—H11C | 109.5 |
N1—N2—C3 | 108.77 (15) | H11B—C11—H11C | 109.5 |
C11—N2—C3 | 115.30 (15) | C13—C12—C17 | 117.67 (18) |
N2—C3—C12 | 111.22 (15) | C13—C12—C3 | 122.64 (17) |
N2—C3—C4 | 102.37 (15) | C17—C12—C3 | 119.61 (17) |
C12—C3—C4 | 113.81 (16) | O1—C13—C12 | 116.01 (17) |
N2—C3—H3 | 109.7 | O1—C13—C14 | 122.38 (17) |
C12—C3—H3 | 109.7 | C12—C13—C14 | 121.62 (17) |
C4—C3—H3 | 109.7 | C13—C14—C15 | 118.95 (18) |
C5—C4—C3 | 100.78 (16) | C13—C14—H14 | 120.5 |
C5—C4—H4A | 111.6 | C15—C14—H14 | 120.5 |
C3—C4—H4A | 111.6 | O2—C15—C16 | 115.63 (17) |
C5—C4—H4AB | 111.6 | O2—C15—C14 | 123.92 (17) |
C3—C4—H4AB | 111.6 | C16—C15—C14 | 120.44 (18) |
H4A—C4—H4AB | 109.4 | C17—C16—C15 | 119.31 (18) |
N1—C5—C6 | 119.76 (18) | C17—C16—H16 | 120.3 |
N1—C5—C4 | 113.11 (18) | C15—C16—H16 | 120.3 |
C6—C5—C4 | 126.93 (18) | C16—C17—C12 | 122.01 (18) |
C7—C6—C10 | 110.74 (18) | C16—C17—H17 | 119.0 |
C7—C6—C5 | 127.51 (18) | C12—C17—H17 | 119.0 |
C10—C6—C5 | 121.75 (18) | O1—C18—H18A | 109.5 |
C6—C7—Cl1 | 129.46 (16) | O1—C18—H18B | 109.5 |
C6—C7—S8 | 113.62 (15) | H18A—C18—H18B | 109.5 |
Cl1—C7—S8 | 116.90 (12) | O1—C18—H18C | 109.5 |
C9—S8—C7 | 90.03 (10) | H18A—C18—H18C | 109.5 |
C10—C9—Cl2 | 126.69 (17) | H18B—C18—H18C | 109.5 |
C10—C9—S8 | 113.60 (16) | O2—C19—H19A | 109.5 |
Cl2—C9—S8 | 119.71 (13) | O2—C19—H19B | 109.5 |
C9—C10—C6 | 112.00 (19) | H19A—C19—H19B | 109.5 |
C9—C10—H10 | 124.0 | O2—C19—H19C | 109.5 |
C6—C10—H10 | 124.0 | H19A—C19—H19C | 109.5 |
N2—C11—H11A | 109.5 | H19B—C19—H19C | 109.5 |
C5—N1—N2—C11 | 146.57 (17) | S8—C9—C10—C6 | 0.1 (2) |
C5—N1—N2—C3 | 17.5 (2) | C7—C6—C10—C9 | −1.0 (2) |
N1—N2—C3—C12 | −145.62 (15) | C5—C6—C10—C9 | 179.62 (17) |
C11—N2—C3—C12 | 86.9 (2) | N2—C3—C12—C13 | −136.48 (18) |
N1—N2—C3—C4 | −23.72 (19) | C4—C3—C12—C13 | 108.5 (2) |
C11—N2—C3—C4 | −151.19 (16) | N2—C3—C12—C17 | 46.9 (2) |
N2—C3—C4—C5 | 20.12 (18) | C4—C3—C12—C17 | −68.1 (2) |
C12—C3—C4—C5 | 140.24 (16) | C18—O1—C13—C12 | 175.41 (17) |
N2—N1—C5—C6 | 172.21 (17) | C18—O1—C13—C14 | −4.8 (3) |
N2—N1—C5—C4 | −3.1 (2) | C17—C12—C13—O1 | 179.32 (16) |
C3—C4—C5—N1 | −11.6 (2) | C3—C12—C13—O1 | 2.7 (3) |
C3—C4—C5—C6 | 173.50 (18) | C17—C12—C13—C14 | −0.4 (3) |
N1—C5—C6—C7 | −178.71 (18) | C3—C12—C13—C14 | −177.10 (17) |
C4—C5—C6—C7 | −4.1 (3) | O1—C13—C14—C15 | −179.39 (17) |
N1—C5—C6—C10 | 0.6 (3) | C12—C13—C14—C15 | 0.3 (3) |
C4—C5—C6—C10 | 175.16 (16) | C19—O2—C15—C16 | 177.97 (18) |
C10—C6—C7—Cl1 | −177.09 (14) | C19—O2—C15—C14 | −1.6 (3) |
C5—C6—C7—Cl1 | 2.3 (3) | C13—C14—C15—O2 | 179.59 (17) |
C10—C6—C7—S8 | 1.5 (2) | C13—C14—C15—C16 | 0.0 (3) |
C5—C6—C7—S8 | −179.20 (16) | O2—C15—C16—C17 | −179.91 (18) |
C6—C7—S8—C9 | −1.20 (16) | C14—C15—C16—C17 | −0.3 (3) |
Cl1—C7—S8—C9 | 177.54 (12) | C15—C16—C17—C12 | 0.2 (3) |
C7—S8—C9—C10 | 0.60 (17) | C13—C12—C17—C16 | 0.2 (3) |
C7—S8—C9—Cl2 | −179.08 (13) | C3—C12—C17—C16 | 176.92 (18) |
Cl2—C9—C10—C6 | 179.76 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3···O1 | 1.00 | 2.39 | 2.817 (3) | 105 |
C11—H11C···O2i | 0.98 | 2.70 | 3.600 (3) | 153 |
C18—H18C···O2ii | 0.98 | 2.68 | 3.517 (2) | 144 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+2, −z. |
Funding information
The authors thank Al al-Bayt University for financial support. Thanks are also due to the DFG (Deutsche Forschungsgemeinschaft) for financial support (research visit fellowship to Dr Mahmoud Al-Refai).
References
Al-Refai, M., Ibrahim, M. M., Alsohaili, S. & Geyer, A. (2017). Phosphorus Sulfur Silicon, 192, 560–564. CAS Google Scholar
Bachman, G. B. & Heisey, L. V. (1948). J. Am. Chem. Soc. 70, 2378–2380. CrossRef CAS Google Scholar
Ibrahim, M. M., Al-Refai, M., Ayub, K. & Ali, B. F. (2016). J. Fluoresc. 26, 1447–1455. CrossRef CAS PubMed Google Scholar
Riley, K. & Tran, K.-A. (2017). Crystals, 7, 273. CrossRef Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sidique, S., Ardecky, R., Su, Y., Narisawa, S., Brown, B., Millán, J. L., Sergienko, E. & Cosford, N. D. P. (2009). Bioorg. Med. Chem. Lett. 19, 222–225. Web of Science CrossRef PubMed CAS Google Scholar
Stoe & Cie (2016). X-AREA software suite. Stoe & Cie, Darmstadt, Germany. Google Scholar
Taj, T., Kamble, R. R., Gireesh, T. M., Hunnur, R. K. & Margankop, S. B. (2011). Eur. J. Med. Chem. 46, 4366–4373. Web of Science CrossRef CAS PubMed Google Scholar
Viveka, S., Dinesha, Shama, P., Nagaraja, G. K., Ballav, S. & Kerkar, S. (2015). Eur. J. Med. Chem. 101, 442–451. Web of Science CrossRef CAS PubMed Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.