I. INTRODUCTION
2-(Methylamino)-2-phenylcyclohexan-1-one (deschloroketamine) belongs by its structure among arylcyclohexylamines. Arylcyclohexylamines are typical representative of dissociative anesthetics (Frison et al., Reference Frison, Zamengo, Zancanaro, Tisato and Traldi2016). Deschloroketamine is a structural analogue of ketamine, which is still used in healthcare as an anesthetic and recently it has been tested also for its long-lasting antidepressant effects (Dolgin, Reference Dolgin2013; Frison et al., Reference Frison, Zamengo, Zancanaro, Tisato and Traldi2016). Deschloroketamine was originally designed for the treatment of bacterial, fungal and viral diseases, but it did not find any pharmaceutical application (Preiss and Tatar, Reference Preiss and Tatar1995, Reference Preiss and Tatar2000). It started to appear on the black market with New Psychoactive Substances (NPS) as a substitute for methoxetamine, which was listed among prohibited substances by law by the Member States of the European Union (Frison et al., Reference Frison, Zamengo, Zancanaro, Tisato and Traldi2016; Jurásek and Kuchař, Reference Jurásek and Kuchař2016). Here, we present powder data for deschlorketamine hydrochloride.
We have inspected the CSD database (Allen, Reference Allen2002) and the PDF4+ database (ICDD, 2015) and have not found any entry for this organic substance C13H18ClNO in the mentioned databases. Therefore we have decided to characterize this compound by X-ray powder diffraction technique.
II. EXPERIMENTAL
A. Synthesis
Synthesis of deschloroketamine hydrochloride was carried out according to Lambdasyn instructions (Lambdasyn, 2015) and Stevens patents (Stevens and Parke, Reference Stevens and Parke1966; Stevens et al., Reference Stevens, Hanson and Taylor1966). (1-Hydroxycyclopentyl)phenyl-N-methylketimine was dissolved in decalin (10 ml) and stirred 4 h at 190 °C in a microwave reactor. Then the reaction mixture was cooled down and treated with a solution of hydrogen chloride in diethylether. The precipitated solid (title compound, Figure 1) was filtered, washed with acetone and recrystallized from a methanol/diethyl ether mixture. Deschloroketamine hydrochloride was isolated as a white solid polycrystalline material. The structure was confirmed by NMR analysis.
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Figure 1. (Color online) Structural formula of (S)-2-(Methylamino)-2-phenylcyclohexan-1-one hydrochloride..
Deschloroketamine was prepared as racemate. We used chiral separation to obtain (S)-deschloroketamine.
B. Specimen preparation
Sample was prepared by careful grinding in an agate mortar and front-loaded into the specimen holder.
C. Diffraction data collection and reduction
The diffraction pattern for the title compound was collected at room temperature with an X'Pert PRO θ–θ powder diffractometer with parafocusing Bragg-Brentano geometry using CuKα radiation (λ = 1.5418 Å, Ni filter, generator setting: 40 kV, 30 mA). An ultrafast X'Celerator detector was employed to collect XRD data over the angular range from 4° to 70°2θ with a step size of 0.017°2θ and a counting time of 81.28 s step−1.
The software package HighScore Plus V 3.0e (PANalytical, Almelo, Netherlands) was used to smooth the data, to fit the background and the top of smoothed peak method was used to determine the peak positions and intensities of the diffraction peaks.
III. RESULTS AND DISCUSSION
The experimental powder diffraction pattern is depicted in Figure 2. Automatic indexing of results obtained using DICVOL04 (Boultif and Louër, Reference Boultif and Louër2004) show that title compound C13H18ClNO is monoclinic with space group P21 and unit-cell parameters: a = 6.578 (1) Å, b = 13.250 (2) Å, c = 15.096 (2) Å, β = 91.619 (3)°, unit-cell volume V = 1315(1) Å3, and Z = 4. The figures of merits are F20 = 124.8(0.0050, 32) (Smith and Snyder, Reference Smith and Snyder1979) and M20 = 45.5 (de Wolff, Reference de Wolff1968). All measured lines (Table 1) were indexed and are consistent with the P21 space group.
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Figure 2. (Color online) X-ray powder diffraction pattern of title compound using CuK α radiation (λ = 1.5418 Å).
Table I. Indexed X-ray powder diffraction data for C13H18ClNO. Only the peaks with I rel of 1 or greater are presented [a = 6.578 (1), b = 13.250 (2), c = 15.096 (2) Å, β = 91.619 (3)°, unit-cell volume V = 1315(1) Å3, Z = 4, and space group P21]. All lines were indexed and are consistent with the P21 space group. The d-values were calculated using CuKα radiation (λ = 1.5418 Å).
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SUPPLEMENTARY MATERIAL
The supplementary material for this article can be found at https://doi.org/10.1017/S0885715617000586.
ACKNOWLEDGEMENTS
Financial support from specific university research (MSMT No 20-SVV/2016), Ministry of Interior of the Czech Republic (MV0/VI20152020048), the Czech Science Foundation (grant no 16-17689Y), the National Programme for Sustainability (NPU I LO1215) Ministry – 34870/2013) and GACR project 16-25747S.