organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoIUCrDATA
ISSN: 2414-3146

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

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 19 July 2019; accepted 23 July 2019; online 26 July 2019)

In the title compound, C16H16Cl2N2O2S, the pyrazole ring has an envelope conformation 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 ππ stacking inter­actions link the mol­ecules into a three-dimensional network.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Heterocyclic compounds containing a pyrazole core show various biological properties such as anti-cancer (Sidique et al., 2009[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.]), anti-inflammatory (Viveka et al., 2015[Viveka, S., Dinesha, Shama, P., Nagaraja, G. K., Ballav, S. & Kerkar, S. (2015). Eur. J. Med. Chem. 101, 442-451.]) and anti­oxidant activities (Taj et al., 2011[Taj, T., Kamble, R. R., Gireesh, T. M., Hunnur, R. K. & Margankop, S. B. (2011). Eur. J. Med. Chem. 46, 4366-4373.]). In a continuation of our ongoing research on pyrazoles (Ibrahim et al., 2016[Ibrahim, M. M., Al-Refai, M., Ayub, K. & Ali, B. F. (2016). J. Fluoresc. 26, 1447-1455.]), we now describe the synthesis and structure of the title compound, I (Fig. 1[link]).

[Figure 1]
Figure 1
The mol­ecular structure of I (50% probability displacement ellipsoids) with the short C—H⋯O inter­action shown as a dashed line.

The central pyrazole ring adopts an envelope conformation with the chiral C3 atom as the flap [deviation from the other atoms = 0.363 (3) Å]. C3 has an R configuration in the arbitrarily chosen asymmetric unit but crystal symmetry generates a racemic mixture. 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.

The 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[link]), which closes an S(5) ring.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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.

The extended structure of I (Fig. 2[link]) 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[Riley, K. & Tran, K.-A. (2017). Crystals, 7, 273.]) 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 ππ 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 ππ inter­actions lead to a three-dimensional network.

[Figure 2]
Figure 2
A packing view of I showing layers parallel to bc plane assembled through C—H⋯O (rendered multi-band cylinders), Cl⋯π (gray dashed lines) and ππ (blue dashed lines) inter­actions. Hydrogen atoms not involved in inter­actions are omitted for clarity.

Synthesis and crystallization

3-Acetyl-2,5-di­chloro­thio­phene was prepared via Friedel–Crafts reaction as per the literature procedure (Bachman & Heisey, 1948[Bachman, G. B. & Heisey, L. V. (1948). J. Am. Chem. Soc. 70, 2378-2380.]). 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[Al-Refai, M., Ibrahim, M. M., Alsohaili, S. & Geyer, A. (2017). Phosphorus Sulfur Silicon, 192, 560-564.] 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 refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C16H16Cl2N2O2S
Mr 371.27
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 100
a, b, c (Å) 8.3836 (3), 8.4780 (3), 13.3050 (4)
α, β, γ (°) 97.779 (3), 101.929 (2), 114.967 (2)
V3) 811.94 (5)
Z 2
Radiation type Cu Kα
μ (mm−1) 4.89
Crystal size (mm) 0.17 × 0.14 × 0.12
 
Data collection
Diffractometer Stoe Stadivari
Absorption correction Multi-scan (LANA; Stoe & Cie, 2016[Stoe & Cie (2016). X-AREA software suite. Stoe & Cie, Darmstadt, Germany.])
Tmin, Tmax 0.260, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 21767, 3062, 2794
Rint 0.045
(sin θ/λ)max−1) 0.614
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.050, 0.137, 1.05
No. of reflections 3062
No. of parameters 211
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.79, −0.50
Computer programs: X-AREA and LANA (Stoe & Cie, 2016[Stoe & Cie (2016). X-AREA software suite. Stoe & Cie, Darmstadt, Germany.]), SHELXT2014 (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2017 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]) and DIAMOND (Crystal Impact).

Structural data


Computing details top

Data collection: X-AREA Pilatus3_SV (Stoe & Cie, 2016); cell refinement: 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).

3-(2,5-Dichlorothiophen-3-yl)-5-(2,4-dimethoxyphenyl)-1-methyl-4,5-dihydro-1H-pyrazole top
Crystal data top
C16H16Cl2N2O2SZ = 2
Mr = 371.27F(000) = 384
Triclinic, P1Dx = 1.519 Mg m3
a = 8.3836 (3) ÅCu Kα radiation, λ = 1.54178 Å
b = 8.4780 (3) ÅCell parameters from 30941 reflections
c = 13.3050 (4) Åθ = 3.5–71.7°
α = 97.779 (3)°µ = 4.89 mm1
β = 101.929 (2)°T = 100 K
γ = 114.967 (2)°Block, yellow
V = 811.94 (5) Å30.17 × 0.14 × 0.12 mm
Data collection top
Stoe Stadivari
diffractometer
3062 independent reflections
Radiation source: GeniX 3D HF Cu2794 reflections with I > 2σ(I)
Detector resolution: 5.81 pixels mm-1Rint = 0.045
rotation method, ω scansθmax = 71.3°, θmin = 3.5°
Absorption correction: multi-scan
(LANA; Stoe & Cie, 2016)
h = 108
Tmin = 0.260, Tmax = 1.000k = 410
21767 measured reflectionsl = 1615
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.137H-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 parametersΔρmax = 0.79 e Å3
0 restraintsΔρmin = 0.50 e Å3
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.0524 (2)0.3616 (2)0.24617 (13)0.0167 (4)
O10.63312 (18)0.79340 (19)0.17276 (12)0.0201 (3)
Cl10.40982 (6)0.63165 (6)0.59685 (4)0.02134 (19)
Cl20.26047 (7)0.01538 (6)0.52260 (4)0.02362 (19)
O20.46909 (19)1.27080 (19)0.12925 (12)0.0202 (3)
N20.1173 (2)0.4670 (2)0.17701 (13)0.0161 (4)
C30.3126 (3)0.6004 (3)0.22968 (15)0.0150 (4)
H30.3946880.5511010.2104160.018*
C40.3262 (3)0.6153 (3)0.34763 (16)0.0163 (4)
H4A0.4423940.6207500.3881010.020*
H4AB0.3158410.7215860.3799230.020*
C50.1609 (3)0.4417 (3)0.34130 (16)0.0153 (4)
C60.1101 (3)0.3698 (3)0.42980 (16)0.0157 (4)
C70.2065 (3)0.4389 (3)0.53541 (16)0.0164 (4)
S80.10142 (7)0.31227 (6)0.61630 (4)0.01945 (19)
C90.0797 (3)0.1644 (3)0.50664 (17)0.0195 (4)
C100.0603 (3)0.2079 (3)0.41399 (17)0.0168 (4)
H100.1477430.1404210.3466840.020*
C110.0802 (3)0.3591 (3)0.07189 (16)0.0199 (4)
H11A0.1147500.4380120.0242260.030*
H11B0.0511750.2737500.0441200.030*
H11C0.1522080.2931020.0766270.030*
C120.3582 (3)0.7768 (3)0.19820 (15)0.0150 (4)
C130.5195 (3)0.8720 (3)0.17247 (15)0.0155 (4)
C140.5623 (3)1.0375 (3)0.14841 (15)0.0165 (4)
H140.6725131.1003350.1306630.020*
C150.4406 (3)1.1093 (3)0.15080 (15)0.0161 (4)
C160.2790 (3)1.0170 (3)0.17691 (16)0.0186 (4)
H160.1965741.0663910.1788510.022*
C170.2401 (3)0.8534 (3)0.19987 (16)0.0183 (4)
H170.1295220.7908380.2173850.022*
C180.7935 (3)0.8799 (3)0.13908 (17)0.0194 (4)
H18A0.8554090.8044490.1366060.029*
H18B0.8776310.9966210.1892890.029*
H18C0.7572390.8976380.0683230.029*
C190.6361 (3)1.3732 (3)0.10549 (18)0.0213 (4)
H19A0.6414551.4869150.0941070.032*
H19B0.6397491.3048780.0411670.032*
H19C0.7415581.3979370.1649240.032*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0173 (8)0.0128 (8)0.0178 (9)0.0038 (7)0.0070 (7)0.0052 (7)
O10.0160 (7)0.0155 (7)0.0316 (8)0.0061 (6)0.0122 (6)0.0105 (6)
Cl10.0178 (3)0.0155 (3)0.0190 (3)0.0003 (2)0.0012 (2)0.0018 (2)
Cl20.0234 (3)0.0144 (3)0.0280 (3)0.0009 (2)0.0143 (2)0.0063 (2)
O20.0196 (7)0.0142 (7)0.0285 (8)0.0066 (6)0.0097 (6)0.0106 (6)
N20.0158 (8)0.0112 (8)0.0158 (8)0.0007 (7)0.0057 (7)0.0041 (6)
C30.0137 (9)0.0110 (9)0.0184 (10)0.0031 (7)0.0059 (8)0.0052 (7)
C40.0155 (10)0.0122 (10)0.0181 (10)0.0030 (8)0.0047 (8)0.0062 (7)
C50.0143 (9)0.0096 (9)0.0200 (10)0.0033 (8)0.0056 (8)0.0039 (7)
C60.0150 (9)0.0106 (10)0.0196 (10)0.0040 (8)0.0060 (8)0.0035 (7)
C70.0157 (10)0.0116 (10)0.0189 (10)0.0025 (8)0.0061 (8)0.0056 (8)
S80.0213 (3)0.0164 (3)0.0162 (3)0.0042 (2)0.0062 (2)0.0050 (2)
C90.0174 (10)0.0117 (10)0.0252 (11)0.0027 (8)0.0078 (8)0.0028 (8)
C100.0157 (9)0.0155 (10)0.0182 (10)0.0048 (8)0.0073 (8)0.0058 (8)
C110.0215 (10)0.0177 (10)0.0164 (10)0.0051 (8)0.0064 (8)0.0046 (8)
C120.0137 (9)0.0125 (10)0.0143 (9)0.0025 (7)0.0028 (8)0.0039 (7)
C130.0142 (9)0.0137 (10)0.0136 (9)0.0026 (8)0.0033 (8)0.0025 (7)
C140.0138 (9)0.0141 (10)0.0165 (9)0.0014 (8)0.0055 (8)0.0036 (7)
C150.0166 (10)0.0114 (10)0.0148 (9)0.0020 (8)0.0026 (8)0.0044 (7)
C160.0174 (10)0.0182 (11)0.0227 (11)0.0088 (8)0.0082 (8)0.0073 (8)
C170.0143 (9)0.0166 (10)0.0204 (10)0.0031 (8)0.0064 (8)0.0056 (8)
C180.0139 (10)0.0159 (10)0.0264 (11)0.0035 (8)0.0097 (8)0.0053 (8)
C190.0201 (10)0.0130 (10)0.0280 (11)0.0032 (8)0.0089 (9)0.0087 (8)
Geometric parameters (Å, º) top
N1—C51.289 (3)C9—C101.355 (3)
N1—N21.400 (2)C10—H100.9500
O1—C131.373 (2)C11—H11A0.9800
O1—C181.433 (2)C11—H11B0.9800
Cl1—C71.719 (2)C11—H11C0.9800
Cl2—C91.713 (2)C12—C131.394 (3)
O2—C151.368 (2)C12—C171.397 (3)
O2—C191.430 (2)C13—C141.394 (3)
N2—C111.457 (3)C14—C151.394 (3)
N2—C31.483 (2)C14—H140.9500
C3—C121.520 (3)C15—C161.393 (3)
C3—C41.534 (3)C16—C171.377 (3)
C3—H31.0000C16—H160.9500
C4—C51.513 (3)C17—H170.9500
C4—H4A0.9900C18—H18A0.9800
C4—H4AB0.9900C18—H18B0.9800
C5—C61.457 (3)C18—H18C0.9800
C6—C71.371 (3)C19—H19A0.9800
C6—C101.453 (3)C19—H19B0.9800
C7—S81.730 (2)C19—H19C0.9800
S8—C91.728 (2)
C5—N1—N2109.43 (16)N2—C11—H11B109.5
C13—O1—C18117.89 (15)H11A—C11—H11B109.5
C15—O2—C19117.63 (15)N2—C11—H11C109.5
N1—N2—C11112.53 (15)H11A—C11—H11C109.5
N1—N2—C3108.77 (15)H11B—C11—H11C109.5
C11—N2—C3115.30 (15)C13—C12—C17117.67 (18)
N2—C3—C12111.22 (15)C13—C12—C3122.64 (17)
N2—C3—C4102.37 (15)C17—C12—C3119.61 (17)
C12—C3—C4113.81 (16)O1—C13—C12116.01 (17)
N2—C3—H3109.7O1—C13—C14122.38 (17)
C12—C3—H3109.7C12—C13—C14121.62 (17)
C4—C3—H3109.7C13—C14—C15118.95 (18)
C5—C4—C3100.78 (16)C13—C14—H14120.5
C5—C4—H4A111.6C15—C14—H14120.5
C3—C4—H4A111.6O2—C15—C16115.63 (17)
C5—C4—H4AB111.6O2—C15—C14123.92 (17)
C3—C4—H4AB111.6C16—C15—C14120.44 (18)
H4A—C4—H4AB109.4C17—C16—C15119.31 (18)
N1—C5—C6119.76 (18)C17—C16—H16120.3
N1—C5—C4113.11 (18)C15—C16—H16120.3
C6—C5—C4126.93 (18)C16—C17—C12122.01 (18)
C7—C6—C10110.74 (18)C16—C17—H17119.0
C7—C6—C5127.51 (18)C12—C17—H17119.0
C10—C6—C5121.75 (18)O1—C18—H18A109.5
C6—C7—Cl1129.46 (16)O1—C18—H18B109.5
C6—C7—S8113.62 (15)H18A—C18—H18B109.5
Cl1—C7—S8116.90 (12)O1—C18—H18C109.5
C9—S8—C790.03 (10)H18A—C18—H18C109.5
C10—C9—Cl2126.69 (17)H18B—C18—H18C109.5
C10—C9—S8113.60 (16)O2—C19—H19A109.5
Cl2—C9—S8119.71 (13)O2—C19—H19B109.5
C9—C10—C6112.00 (19)H19A—C19—H19B109.5
C9—C10—H10124.0O2—C19—H19C109.5
C6—C10—H10124.0H19A—C19—H19C109.5
N2—C11—H11A109.5H19B—C19—H19C109.5
C5—N1—N2—C11146.57 (17)S8—C9—C10—C60.1 (2)
C5—N1—N2—C317.5 (2)C7—C6—C10—C91.0 (2)
N1—N2—C3—C12145.62 (15)C5—C6—C10—C9179.62 (17)
C11—N2—C3—C1286.9 (2)N2—C3—C12—C13136.48 (18)
N1—N2—C3—C423.72 (19)C4—C3—C12—C13108.5 (2)
C11—N2—C3—C4151.19 (16)N2—C3—C12—C1746.9 (2)
N2—C3—C4—C520.12 (18)C4—C3—C12—C1768.1 (2)
C12—C3—C4—C5140.24 (16)C18—O1—C13—C12175.41 (17)
N2—N1—C5—C6172.21 (17)C18—O1—C13—C144.8 (3)
N2—N1—C5—C43.1 (2)C17—C12—C13—O1179.32 (16)
C3—C4—C5—N111.6 (2)C3—C12—C13—O12.7 (3)
C3—C4—C5—C6173.50 (18)C17—C12—C13—C140.4 (3)
N1—C5—C6—C7178.71 (18)C3—C12—C13—C14177.10 (17)
C4—C5—C6—C74.1 (3)O1—C13—C14—C15179.39 (17)
N1—C5—C6—C100.6 (3)C12—C13—C14—C150.3 (3)
C4—C5—C6—C10175.16 (16)C19—O2—C15—C16177.97 (18)
C10—C6—C7—Cl1177.09 (14)C19—O2—C15—C141.6 (3)
C5—C6—C7—Cl12.3 (3)C13—C14—C15—O2179.59 (17)
C10—C6—C7—S81.5 (2)C13—C14—C15—C160.0 (3)
C5—C6—C7—S8179.20 (16)O2—C15—C16—C17179.91 (18)
C6—C7—S8—C91.20 (16)C14—C15—C16—C170.3 (3)
Cl1—C7—S8—C9177.54 (12)C15—C16—C17—C120.2 (3)
C7—S8—C9—C100.60 (17)C13—C12—C17—C160.2 (3)
C7—S8—C9—Cl2179.08 (13)C3—C12—C17—C16176.92 (18)
Cl2—C9—C10—C6179.76 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O11.002.392.817 (3)105
C11—H11C···O2i0.982.703.600 (3)153
C18—H18C···O2ii0.982.683.517 (2)144
Symmetry codes: (i) x, y1, 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

First citationAl-Refai, M., Ibrahim, M. M., Alsohaili, S. & Geyer, A. (2017). Phosphorus Sulfur Silicon, 192, 560–564.  CAS Google Scholar
First citationBachman, G. B. & Heisey, L. V. (1948). J. Am. Chem. Soc. 70, 2378–2380.  CrossRef CAS Google Scholar
First citationIbrahim, M. M., Al-Refai, M., Ayub, K. & Ali, B. F. (2016). J. Fluoresc. 26, 1447–1455.  CrossRef CAS PubMed Google Scholar
First citationRiley, K. & Tran, K.-A. (2017). Crystals, 7, 273.  CrossRef Google Scholar
First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSidique, 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
First citationStoe & Cie (2016). X-AREA software suite. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationTaj, 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
First citationViveka, 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.

Journal logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds