Crystal structure of 2-hydroxy-2-phenylacetophenone oxime

The title compound [systematic name: 2-(N-hydroxyimino)-1,2-diphenylethanol], C14H13NO2, consists of hydroxy phenylacetophenone and oxime units, in which the phenyl rings are oriented at a dihedral angle of 80.54 (7)°. In the crystal, intermolecular O—HOxm...NOxm, O—HHydr...OHydr, O—H′Hydr...OHydr and O—HOxm...OHydr hydrogen bonds link the molecules into infinite chains along the c-axis direction. π–π contacts between inversion-related of the phenyl ring adjacent to the oxime group have a centroid–centroid separation of 3.904 (3) Å and a weak C—H...π(ring) interaction is also observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (58.4%) and H...C/C...H (26.4%) contacts. Hydrogen bonding and van der Waals contacts are the dominant interactions in the crystal packing.

Synthesis of functionalized by an oxime group surfactants on the basis of imidazole, pyridine and alkylamines

Methods have been developed for the synthe-sis of a series of monomeric and dimeric surfactants functionalized by an oxime group based on imid-azole, pyridine and alkylamines. Alkyl radicals of varying degrees of branching were used, both as sub-stituents at the nitrogen atom of the head group and as spacers in the formation of dimeric products. This allowed to create a whole spectrum of supramo-lecular systems with different physicochemical pro-perties and reactivity.Methods of obtaining a number of intermedi-ate products were improved, primarily for the reac-tion of the imidazole alkylation using interphase ca-talysis conditons — solid phase-liquid. The method of obtaining surfactants based on imidazole consisted in the interaction of alkylimidazoles with chloro-acetaloxime in a suitable solvent or with chloro-acetone and subsequent reaction with a hydroxyla-mine solution. In the preparation of pyridine-based surfactants, the corresponding oxo-substituted pyri-dine was reacted with a hydroxylamine solution, fol-lowed by reaction of the obtained product with al-kyl halide. A method has been developed for the syn-thesis of functionalized surfactants based on alipha-tic amines, where for monomeric products a path is chosen that is associated with the sequential alkyla-tion of 1-chloroacetoxime with dimethylamine and dodecyl bromide, and for dimeric ones, the direct interaction of 1,3-dichloroacetoxime with 1,1-dime-thyl-1-dodecylamine.The composition, structure and purity of the obtained compounds were confirmed by NMR spec-troscopy, thin-layer chromatography and elemental analysis. NMR spectra were recorded on a BRUKER Avance II 400 instrument (400 MHz), TMS was used as an internal standard. Chromatography in a thin layer of silica gel was performed on Merck Si-licaGel 60 F254 plates (eluent — chloroform: meth-anol = 10:1).The data presented by us testify to the pro-spects of the chosen pathway for structural modifica-tion of surfactants functionalized by the oxime group, and give direction for the further design of such microheterogeneous systems.

Different substituent effects on the supramolecular arrays in some (E)-halo- and nitro-benzaldehyde oximes: confirmation of attractive π(C=N)···π(phenyl) interactions

The crystal structures and Hirshfeld surface analyses are reported for four aldoximes, (E)-X–C6H4CH=N–OH [X = 3-Cl (1), 4-F (2), 2-O2N (3) and 4-O2N (4)]. The strong classical O–H · · · N hydrogen bonds involving the oxime group generate C(3) chains in compound 1, in contrast to the R22(6) dimers formed in compounds 2–4; such arrangements have been shown to be the most frequently found for oximes other than salicylaldoximes (2-hydroxybenzaldehyde oximes). In general, weaker intermolecular interactions involving the X substituents, as well as C–H · · · O and π · · · π interactions have significant effects on the supramolecular arrays generated in the aggegation. A further important interaction in compound 1, and to a lesser extent in compound 4, is a π(C=N) · · · π(phenyl) molecular stacking. A data base search has indicated that short Cg(C=N) · · · Cg(phenyl) distances, <3.3 Å (Cg = centre of gravity), have been found in various compounds, including other oximes. A theoretical study was carried out starting from the crystal structure data of compound 1, with optimisation at the BLYP-D3/def2-DZVP level, as well as at the higher PBE0/ma-def2-TZVP level. Breakdown of the interaction energy into separate contributions was achieved using SAPT (using the jun-cc-pvdz basis set). Overall, the calculations indicate that the π(C=N) ·· · π(phenyl) interaction is attractive, with a magnitude of 14–18 kJ mol−1.

Unidirectional complexation of pillar[4]arene[1]benzoquinoneoxime with alkyl alcohols

Unidirectional binding between a pillar[4]arene[1]benzoquinoneoxime host and n-alkyl alcoholic guests was realized with the hydroxy heads of the guests in direct contact with the oxime group of the macrocyclic host.

Steroidal Oximes: Useful Compounds with Antitumor Activities

Background: Steroids play an important role in life because they can regulate a variety of biological processes and have been widely used in medicine namely as antiinflammatory, anabolic, contraceptives and anticancer drugs. In recent years, there has been an increasing interest in the introduction of the oxime group in a large variety of molecules in order to increase their biological effects. This review highlights steroidal oximes with anticancer properties and their potential mechanisms of action, as well as data on their relative potencies reported in literature in the last few years. Methods: To prepare this review, an extensive literature search was performed on three databases, PubMed, ISI Web of Knowledge and Science Direct, to generate a critical but comprehensive overview of the potential antitumor activities of steroidal oximes. The main keywords used for the search consisted of combinations of the following terms or their synonyms: steroidal oximes, anticancer activity and enzymatic inhibitory activity. The abstracts and full texts were evaluated for their clarity and scientific merit and to further help on the selection of other articles. Results: Over the last decades the introduction of oxime groups in the steroid scaffold is originating molecules with relevant antitumor activities, as well as steroid sulfatase, aromatase, 17α-hydroxylase-17,20-lyase, 5α-reductase and 17β-hydroxysteroid dehydrogenase type 1 inhibitory activities. As relevant examples, pregnenolone 20-oximes showed high activity as 17α-hydroxylase-17,20-lyase and 5α-reductase inhibitors and the introduction of an oxime group at C-6 in androstane series also led to relevant results as aromatase inhibitors. Interestingly, the introduction of this functional group frequently improves the bioactivity when compared with non-oxime analogous compounds, which can be due to extra interactions with biological targets. In addition, it has been observed that varying the position of the hydroximino group on the parent skeleton leads to remarkable changes in the antitumor activity. Conclusion: The recent advances in synthesis and in vitro bioactivity studies of steroidal oximes contributed to understand the potential interest of the introduction of this functional group in the steroidal nucleus in the development of anticancer molecules. Moreover, the cytotoxic/enzyme inhibitory activity usually depends on the position of the oxime group in different steroid scaffolds. However, despite the promising results, it is necessary to perform more in vitro and in vivo assays not only to better explore the mechanisms of action but also to confirm the potential effectiveness and safety of this interesting family of compounds in clinical practice.

Crystal structure of (E)-2-hydroxy-1,2-diphenylethan-1-one oxime

The title compound, C14H13NO2, is a commercially available material and can be used as a multidentate ligand. The molecule of the asymmetric unit has anRconfiguration, while the correspondingS-configured molecule of the racemic mixture is generated by a crystallographic centre of symmetry. Both hydroxy groups (the H atom of the oxime group is equally disordered over two positions) are involved in hydrogen bonding, leading to the formation of chains extending parallel to [001].