Reaction of 2-methoxy-3H-azepine with NBS: efficient synthesis of 2-substituted 2H-azepines

[reaction: see text] The reaction of 2-methoxy-3H-azepines, in the presence or absence of a nucleophile, with N-bromosuccinimide (NBS) gave a regioselective 1,4-adduct from which the corresponding 2H-azepine derivatives were formed via base-promoted hydrogen bromide elimination, generally in moderate to quantitative yield. Competitive formation of 4-bromo-2-methoxy-3H-azepine by electrophilic substitutuion or 3H-azepin-2-yl 2H-azepin-2-yl ether by transetherification was minimized at lower reaction temperatures. Quantitative substitution of 2-(2',4',6'-trichlorophenoxy)-2H-azepine derivatives, formed in moderate yield from the respective 3H-azepine and NBS in the presence of 2,4,6-trichlorophenol (TCP), by various nucleophiles gave the corresponding 2-substituted 2H-azepine. Among these nucleophiles were alkanethiol and alkylamine that are not tolerated in the reaction of 3H-azepine and NBS.     

A normalization method of input data that conserves the norm information for competitive learning neural network using inner product

Normalization of input vector is essential for a competitive learning neural network using the inner product. In this paper we propose a transformation method of input vector without losing the norm information. To conserve the norm information, an additional vector component concerning the norm is introduced besides the original normalized components of the input vector. By applying the method to Kohonen’s self-organizing feature map, its usefulness is demonstrated. We also propose an optical apparatus for its realization.     

Prospective trial of a navigator setting under left hepatic lobe on magnetic resonance cholangiopancreatography using a free-breathing prospective acquisition correction technique

PURPOSE: To prospectively compare the image acquisition time and image quality obtained by navigator setting under the left hepatic lobe vs. on the right diaphragm on magnetic resonance cholangiopancreatography (MRCP) using a free-breathing navigator-triggered prospective acquisition correction technique (PACE). MATERIALS AND METHODS: Fifty consecutive patients prospectively underwent three-dimensional T2-weighted turbo spin-echo MRCP using PACE with the navigator randomly set either under the left hepatic lobe or on top of the right diaphragm. Image acquisition time and subjective image quality were compared on a five-point scale using Student's t-test and Mann-Whitney's U test, respectively. RESULTS: There was no significant difference for mean acquisition time (6.1+/-1.6 vs. 6.3+/-1.2 min, P=.689) between the left hepatic lobe group and right diaphragm group. Mean subjective image quality was significantly worse in the left hepatic lobe group than in the right diaphragm group (4.1 vs. 4.7, P=.044). CONCLUSION: Setting the navigator under the left hepatic lobe for MRCP using PACE causes the data processing to be more difficult. As well, under current circumstances, it does not contribute to reducing acquisition time or improving the image quality.     

Development of Rapid and Facile Solid-Phase Synthesis of PROTACs via a Variety of Binding Styles

Optimizing linker design is important for ensuring efficient degradation activity of proteolysis-targeting chimeras (PROTACs). Therefore, developing a straightforward synthetic approach that combines the protein-of-interest ligand (POI ligand) and the ligand for E3 ubiquitin ligase (E3 ligand) in various binding styles through a linker is essential for rapid PROTAC syntheses. Herein, a solid-phase approach for convenient PROTAC synthesis is presented. We designed azide intermediates with different linker lengths to which the E3 ligand, pomalidomide, is attached and performed facile PROTACs synthesis by forming triazole, amide, and urea bonds from the intermediates.     

Assembling 100 nm Scale Particles by an Electrostatic Potential Field

The assembly of particles is one of the many methods for the fabrication of organized structures in the range of micro- to nanometer sizes. These structures have potential applications in the electronic, optical and biochemical fields. Recently, many papers have reported the patterning of particles using patterned SAM (self-assembly monolayer) films and micro molding methods. We have been developing a new technique to assemble particles using an electrostatic field. This paper describes a new technique to fabricate two-dimensional microstructures assembled from 100 nm particles. Spherical silica of 900 nm diameter and aluminum of 100 nm diameter were used as the model particles. An electrostatic image was formed on an insulating substrate by drawing a focused electron beam at 10 keV. Both types of particles were deposited on the electrostatic images. In this process, the dielectrophoretic (DEP) force plays an important role in depositing particles on the electrostatic images. The DEP forces for particles in a suspension were calculated using numerical analysis. The result showed that the DEP force above the electrified region on the substrate is larger than disturbing forces, such as Brownian motion.     

Far-infrared spectroscopy by synchrotron radiation at the UVSOR Facility

At the UVSOR Facility, Institute for Molecular Science, the practical use of the synchrotron radiation as a far-infrared light source has started. A spectroscopic system has been constructed at the beam line BL6A1 of UVSOR storage ring, which covers the wavenumber region from 5 to 250 cm^–1. The cross sectional diameter of the light beam at the sample position is as small as 3 mm with the angular divergence of about 100 mrad. The system has been made mainly for the transmission and reflection measurements of small samples with small angular divergence by the use of the high brightness of the synchrotron radiation. Examples of observed transmission and reflectivity spectra are shown.     

Line-Mixing Calculations for the 5.3 μm NO Band

Line-mixing coefficients of the NO-N₂ system are calculated within the infinite-order sudden (IOS) and energy-corrected sudden (ECS) approximations. The so-called sum rule between the line width and the line-mixing coefficients is used for line-mixing calculation. Line widths calculated from the ECS model are in good agreement with experimental data for the 5.3 μm NO band. The band-correction function of NO, which characterizes the deviations from the superposition of Lorentz profiles, is also calculated. The ECS results as well as experimental data indicate strong sub-Lorentzian behavior in the wing of the R branch of the 5.3 μm NO band.     

Band-structure-dependent demagnetization in the Heusler alloy Co₂Mn(1-x)FexSi

We investigate the ultrafast demagnetization for two Heusler alloys (Co?Mn(1-x)FexSi) with a different lineup of the minority band gap and the Fermi level. Even though electronic spin-flip transitions are partially blocked by the band gap in one compound, the respective magnetization dynamics, as measured by the time-resolved Kerr effect, are remarkably similar. Based on a dynamical model that includes momentum and spin-dependent carrier scattering, we show that the magnetization dynamics are dominated by hole spin-flip processes, which are not influenced by the gap.     

Line Shapes in the R-Branch of the 5.3 μm NO Band

The shape of the spectral lines in the 5.3 μm fundamental band of NO perturbed by N₂ was studied by means of an infrared spectrometer. Sub-Lorentzian line profile was observed in the wing of the R -branch. These deviations from the Lorentz shape can be mainly interpreted in terms of line mixing. To calculate line-coupling coefficients, the exponential gap law and the statistical exponential power gap law (SEPG) were used. In the case of the SEPG model the degeneracy factor dependence on the inelastic rate is also discussed. The influence of the slit width on the observed band-correction function was found to be small in the R -branch wing of NO.