I. INTRODUCTION
The title compound DCT (C12H12Cl2N6O4S2 • C6H15N) (Figure 1), systematic name 5-Thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid, 7-[(2, 2- dichloroacetyl) amino]-3-[[(1-methyl-1H-tetrazol-5-yl) thio] methyl]-8-oxo-,(6R, 7R)-, compd. with N, N-diethylethanamine (1:1), is one of the most important intermediates in semi-synthetic β-lactam antibiotic cefmetazole sodium (Tang et al., Reference Tang, Zhang and Zhang2014). The CAS register number of DCT is 1597415-32-1.
Figure 1. Structural formula of DCT.
Presently, the crystal structure of DCT has not been reported in the literature.
II. EXPERIMENTAL
A. Sample preparation
The title compound DCT, with the melting point ranging from 142 to 145°C was obtained from Harbin Pharmaceutical Group Holding Co., Ltd., Harbin, Heilongjiang, China, the purity was more than 98%. Its structure was characterized by IR (Thermo Nicolef 6700) and high-performance liquid chromatography (Agilent 1200). The sample was screened by 200-mesh test sieve to get suitable particle size. The optical photomicrograph was showed in Figure 2.
Figure 2. The optical photomicrograph of DCT.
B. Diffraction data collection and reduction
The diffraction pattern for the title compound was collected at room temperature using an X'Pert PRO diffractometer (PANalytical Co., Ltd., Netherlands) with an X'celerator detector and CuKα radiation (generator setting: 40 kV, 40 mA). The diffraction data were collected over the angular range from 5° to 50°2θ with a step size of 0.013 13°2θ and a counting time of 60 ms step−1. Data evaluation was performed using the software package Material Studio 4.2 (Accelrys Co. Ltd., San Diego, CA).
The first stage of structure determination involves pretreatment of the powder diffraction pattern by subtracting the background, smoothing, and eliminating the Kα 2 component (Li et al., Reference Li, Wu, Pan, Cheng and Li2014). The task named “indexing” where the X-ray powder diffraction data (XRD) pattern was carried out using peak positions obtained from the powder diffraction profiles by the X-Cell method (Neumann, Reference Neumann2003; Wu et al., Reference Wu, Tang, Li, Zhang and Li2014) and then the indexing result was refined using Pawley refinement. After Pawley refinement of the unit cell, the final R wp and R p of the structure were converged at 5.48 and 4.09%, respectively.
III. RESULTS
The experimental powder diffraction pattern is depicted in Figure 3. Indexing results show that DCT is orthorhombic with the space-group P212121 and unit-cell parameters: a = 18.991(9) Å, b = 19.057(2) Å, c = 7.346(8) Å, α = β = γ = 90°, unit-cell volume V = 2659.05 Å3, and Z = 4. The values of 2θ obs, d obs, I obs, h, k, l, 2θ cal, d cal, I cal, and Δ2θ are listed in Table I.
Figure 3. XRD pattern of DCT using CuKα radiation.
Table I. XRD data of DCT (C12H12Cl2N6O4S2 • C6H15N). The d-values were calculated using CuKα 1 radiation (λ = 1.540 56 Å).
