Artur Sikorski

X-ray diffraction and high-resolution NMR spectroscopy of methyl 3-azido-2,3-dideoxy-α-d-lyxo-hexopyranoside

The single-crystal X-ray diffraction and high-resolution 1H and 13C NMR spectral data for the title compound are reported. The influence of the ring oxygen atom on the J(1,2e) and J(4,5) coupling constants for 2-deoxy-D-lyxo- and -D-xylo-hexopyranosides is discussed.

Single-crystal X-ray diffraction analysis of designer drugs: hydrochlorides of metaphedrone and pentedrone.

This article, written as a result of cooperation between a police forensic laboratory and an academic institution, outlines the possibility of applying single-crystal X-ray diffraction analysis as an effective method of identifying designer drugs in forensic analysis. This technique allows crystalline samples to be determined with full assurance about their identity, even in the case of new substances for which no reference standards yet exist. Here, single-crystal X-ray diffraction measurements of single-crystal specimens obtained from two samples were performed. Solution and refinement of the structures demonstrated that the target compounds were metaphedrone and pentedrone hydrochlorides - synthetic cathinone derivatives used as recreational stimulants. In addition to the identification of the title compounds, this paper gives a first report on their crystal structures. Once the CIF-files containing the crystal structure data of the title compounds have been deposited in the Cambridge Structural Database - the world repository of small molecule crystal structures - it will be possible to identify single crystals of the title compounds quickly on the basis of simple parameters (lattice parameters a, b, c, α, β, γ and unit cell volume). This description of the relationship between the geometrical parameters of moieties and the analysis of intermolecular interactions occurring in crystals of the title compounds extends knowledge about the synthetic derivatives of cathinone and may play a role in future studies, leading to a better understanding of their characteristic properties.

Solvent-bridged frameworks of hydrogen bonds in crystals of 9-aminoacridinium halides

Crystal structures of eight salts of 9-aminoacridine – chloride monohydrate (1), bromide monohydrate (2), iodide monohydrate (3), chloride methanolate (4), bromide methanolate (5), iodide methanolate (6), fluoride dihydrate (7) and chloride dihydrate (8) – have been studied. The ions and solvent molecules in the crystal structures of 1–8 interact via N–H⋯X, O–H⋯X and C–H⋯X hydrogen bonds (where X = O, F, Cl, Br or I), producing different types of supramolecular synthons consisting of amine groups of 9-aminoacridinium cations, halide anions and solvent molecules. The hybrid dihalide–dihydrate clusters of [X2(H2O)2]2− are observed in compounds 1, 2, 3 and 7. The dichloride–tetrahydrate cluster of [Cl2(H2O)4]2− and (H2O)4 water cluster are present in the crystals of 8.

10-Methyl-9-(2-methylphenoxycarbonyl)acridinium trifluoromethanesulfonate

The crystal structure of the title compound, C21H15N2O4 + CF3O3S , is stabilized by C—H O and C—H F hydrogen bonds, by C—F , N—O and S—O interactions, and by O O [2.70 (4) Å] and O F [2.85 (1) or 2.92 (1) Å] contacts; – interactions are also present. In the packing of the molecules, acridine units are either parallel or inclined at an angle of 12.5 (1) . The nitrophenoxycarbonyl unit is disordered over two position; the site occupancy factors are 0.89 and 0.11.

Differently N-protected 3,4,6-tri-O-acetyl-2-amino-2-deoxy-D-glucopyranosyl chlorides and their application in the synthesis of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside.

Four differently N-protected 3,4,6-tri-O-acetyl-2-amino-2-deoxy-d-glucopyranosyl chlorides were synthesized and used as glycosyl donors in reactions with diosgenin. The following amine group protections were tested: trifluoroacetyl (TFA), 2,2,2-trichloroethoxycarbonyl (Troc), phthaloyl (Phth), and tetrachlorophthaloyl (TCP). Products of glycosylation were deprotected to yield diosgenyl 2-amino-2-deoxy-β-d-glucopyranoside. The efficiency of the procedures is discussed. Additionally, a single-crystal X-ray diffraction analysis for 3,4,6-tri-O-acetyl-2-deoxy-2-tetrachlorophthalimido-β-d-glucopyranosyl chloride is reported. Orientations of the pyranose substituents as well as the planarity of the acetoxy and phthalimide groups in the crystal lattice are discussed. Structural evidence is presented for a mesomeric effect in both groups. The preference of the cis over trans orientation of the acetoxy group is confirmed in the crystal lattice.

Synthesis of Some Quaternary N-(1,4-anhydro-5-deoxy-D, L-ribitol-5-yl)ammonium Salts

The successful removal of the isopropylidene-protecting group from 1,4-anhydro-2,3-O-isopropylidene-5-O-tosyl-D,L-ribitol and from quaternary N-(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol-5-yl)ammonium salts is reported. The structures of all isolates were determined by spectral analysis, including extensive 2-D NMR analyses. Single-crystal x-ray diffractions of 1,4-anhydro-5-O-tosyl-D,L-ribitol and its 2,3-O-isopropylidene derivatives are reported.

Influence of the halogen substituent on the formation of halogen and hydrogen bonding in co-crystals formed from acridine and benzoic acids

In order to determine the influence of the ortho- and meta- halogen substituents in the phenyl ring of benzoic acid on the formation of C–H⋯X hydrogen bonds and X⋯O halogen bonds in crystal packing where the halogen (X) is a fluorine, chlorine, bromine or iodine atom, we synthesized and structurally characterized a series of nine co-crystals formed from acridine and benzoic acids: acridine·benzoic acid (1), acridine·2-fluorobenzoic acid (2), acridine·2-chlorobenzoic acid (3), acridine·2-bromobenzoic acid (4), acridine·2-iodobenzoic acid (5), acridine·3-fluorobenzoic acid (6), acridine·3-chlorobenzoic acid (7), acridine·3-bromobenzoic acid (8) and acridine·3-iodobenzoic acid (9). The number, type and strength of the hydrogen and halogen bonds, and the melting points of co-crystals 1–9 were compared. Systematic analysis of the intermolecular interactions taking place in the co-crystals of the title compounds indicates that competition between halogen and hydrogen bonding depends on the position and type of halo-substituent.

9-(2-tert-Butylphenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonate

The crystal structure of the title compound, C25H24NO2+·CF3SO3−, is stabilized by C—H...O, C—H...F and C—H...π hydrogen bonds, and by O...F [2.94 (1) A] and O...N [2.87 (1) A] interactions. In the packing of the molecules, acridine groups are either parallel or inclined at an angle of 5.4 (1)°. Similarly, the benzene rings are either parallel or lie at an angle of 72.4 (1)°.

2,3,4,6-tetra-O-Acetyl-D-Gluconic Acid: Crystal Structure and Application in the Synthesis of N-(D-gluconyl) Derivatives of D-Glucosamine

2,3,4,6-tetra-O-Acetyl-D-gluconic acid was synthesized and coupled with 1,3,4, 6-tetra-O-acetyl-2-amino-2-deoxy-β-D-glucopyranose and diosgenyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-β-D-glucopyranoside to afford N-gluconyl derivatives of diosgenyl 2-amino-2-deoxy-D-glucopyranoside using the methods of solution-phase peptide synthesis. Both coupling reactions suffered from acetyl O→N migration, which caused the N-acetyl derivatives to be formed together with the N-(D-gluconyl) derivatives of D-glucosamine. Additionally, single-crystal X-ray diffraction and high-resolution NMR spectral data for 2,3,4,6-tetra-O-acetyl-D-gluconic acid were analyzed to reveal that this acyclic carbohydrate has adopted the 2G− conformation instead of a typical zigzag conformation. The planarity and cis geometry of the acetoxyl groups are demonstrated.

Potassium trans-(bis(oxalato)diaquacobaltate(II)) tetrahydrate: synthesis, structure, potentiometric and thermal studies

The title compound, trans-K2[Co(C2O4)2(H2O)2]·4H2O, was synthesised, and characterised by elemental analysis. Acid dissociation constants for the complex were determined by potentiometric titration and calculated by STOICHIO program. The crystal structure of trans-K2[Co(C2O4)2(H2O)2]·4H2O was determined by X-ray diffraction studies. The asymmetric part of the unit cell contains one symmetric anion of oxalate and water molecule bound with Co(II) ion in crystallographic special position, one potassium cation and two molecules of water. Thermal properties of the complex were examined by thermogravimetric analysis (TGA). A decomposition mechanism is proposed on the basis of the results.