I. INTRODUCTION
Apixaban (Eliquis®) is a novel oral pyrazole-based direct FXa inhibitor; this drug was developed by Bristol-Myers Squibb and Pfizer to treat and prevent thrombotic disorder (Watson et al., Reference Watson, Whiteside and Perry2011). Since May 2011, apixaban has been approved for venous thrombus embolism prevention in adult elective hip or knee replacement patients in various countries, such as the USA, China, Brazil, Australia, New Zealand, and some European countries (Deeks, Reference Deeks2012). The title compound is an intermediate in the synthesis of the anticoagulant, apixaban (Jiang and Ji, Reference Jiang and Ji2013).
The single crystallographic data of the title compound [a = 4.7480(2) Å, b = 9.9256(4) Å, c = 13.3084(4) Å, α = 90°, β = 91.468(3)°, γ = 90°, unit-cell volume V = 626.98(4) Å3, Z = 2, ρ cal = 1.360 g cm−3, and space group P21] was obtained by Asiri et al. (Reference Asiri, Arshad, Zayed, Alamrya and Shafiq2012). To date, the detailed X-ray powder diffraction (XRD) data for the title compound have not been reported.
II. EXPERIMENTAL
A. Sample preparation
The sample (Figure 1) was prepared using 4-methoxyaniline (Ji et al., Reference Ji, Jiang, Liu, Yu, Wang, Liu and Wang2011). The melting point and measured density of the title compound are 101–102 °C and 1.355 g cm−3, respectively. Crystallization of the title compound at room temperature was successful using methanol as solvent. Then, part of crystals were dried and ground into powder.
B. Diffraction data collection and reduction
Powder XRD measurement was performed at room temperature using an X'Pert PRO diffractometer (PANalytical Co., Ltd., The Netherlands) with a PIXcel 1D detector and CuKα radiation (generator setting: 40 kV and 40 mA). The diffraction data were collected over the angular range from 4° to 50° 2θ with a step size of 0.01313° 2θ and a counting time of 50 ms step−1 (Figure 2).
The software package Material Studio 8.0 (Accelrys Co. Ltd., CA, USA) was used to process the data in the Analytical & Testing Center (Sichuan University, Chengdu, China). The powder XRD pattern was pre-treated by subtracting the background, smoothing, and stripping off the Kα 2 component. Automatic indexing results were obtained by the DICVOL91 method (Boultif and Louër, Reference Boultif and Louër1991). The following figures of merit were achieved: F 18 = 75.0 (0.0071, 34) (Smith and Snyder, Reference Smith and Snyder1979) and M 18 = 40 (de Wolff, Reference de Wolff1968). The indexing results were then refined using Pawley (Pawley, Reference Pawley1981), which involves assigning the Miller indices (h, k, l) to each observed peak in the experimental powder XRD pattern.
C. Single-crystal XRD
XRD data for the title compound were collected on an Xcalibur, Eos diffractometer. The crystal was kept at 293.15 K during data collection. The structure was solved with olex2 (Dolomanov et al., Reference Dolomanov, Bourhis, Gildea, Howard and Puschmann2009), a structure solution program using charge flipping and refined with the ShelXL (Sheldrick, Reference Sheldrick2008) refinement package using least-squares minimization.
III. RESULTS
Pawley refinement results confirmed that the title compound is monoclinic with space group P21 and unit-cell parameters: a = 13.308(4) Å, b = 9.908(5) Å, c = 4.753(4) Å, α = 90°, β = 91.510(8)°, γ = 90°, unit-cell volume V = 626.64 Å3, Z = 2, and ρ cal = 1.361 g cm−3. The values of 2θ obs, d obs, I obs, h, k, l, 2θ cal, d cal, and Δ2θ are listed in Table I. The results were in good agreement with the single crystallographic data of Asiri et al. and ours [a = 4.7454(3) Å, b = 9.8938(7) Å, c = 13.3001(7) Å, α = 90°, β = 91.605(5)°, γ = 90°, unit-cell volume V = 624.19(7) Å3, Z = 2, and ρ cal = 1.366 g cm−3] (CCDC:1505270). The detail single crystallographic data of the title compound and the experimental data were listed in Table SI. The comparison of the experimental powder XRD pattern with the simulated patterns of Asiri et al. and ours is shown in Figure 2. Results showed that both single-crystal and powder diffraction methods can get the similar structure data.
The d-values were calculated using CuKα 1 radiation (λ = 1.54056 Å).
SUPPLEMENTARY MATERIAL
The supplementary material for this article can be found at https://doi.org/10.1017/S0885715616000695
Acknowledgements
This work was supported by the Applied Basic Research Project of Sichuan Province (Grant no. 2014JY0042) and the National Development and Reform Commission and Education of China (Grant no. 2014BW011).