The reactions of 3-phenyl-1-azabicyclo[1.1.0]butane (4) with dimethyl dicyanofumarate ((E)-8) and dimethyl dicyanomaleate ((Z)-8) lead to the same mixture of cisand trans-4-phenyl-1-azabicyclo[2.1.1]hexane 2,3-dicarboxylates (cis-11 and trans-11, resp.; Scheme 3). This result of a formal cycloaddition to the central C-N bond of 4 is interpreted by a stepwise reaction mechanism via a relatively ...

X-ray diffraction, Raman spectroscopy, 3’P MAS-NMR and spin-echo NMR indicated that model vanadium phosphorus oxide (VPO) precursors and catalysts contained various minor phases depending oxboth the synthetic approach and P/V ratios used. Raman spectroscopy revealed the presence of a number of micro-crystalline and amorphous V(W) and V(V) phases not evident by XRD. The presence of VOPO, phases ...

Catalytic performance and formation of carbonaceous deposits were studied simultaneously during alkane isomerization over sulfated zirconia in a fixed bed flow reactor with an optical window for in situ UV–vis diffuse reflectance spectroscopy. The reactions of n-butane (5 kPa) at 358 and 378 K and of n-pentane (0.25 kPa) at 298 and 308 K passed within 5 h or less through an induction period, a ...

Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity...

Iso-butene is an important material for the production of chemicals and polymers. It can take part in various chemical reactions, such as hydrogenation, oxidation and other additions owing to the presence of a reactive double bond. It is usually obtained as a by-product of a petroleum refinery, by Fluidized Catalytic Cracking (FCC) of naphtha or gas-oil. However, an interesting alternative to i...

The application of serpentine ore (brownish colour) as a stationary phase for the separation of hydrocarbons by gassolid chromatography has been tested. Separation of methane, ethane, propane, n-butane, iso-butane and acetylene has been accomplished at room temperature (25°C). The separated components were detected with a flame ionization detector. The peaks of isobutane and n-butane were rathe...

The fluidization characteristics of a prototype-fluidized bed laboratory reactor were understudied in order to investigate the suitable conditions at which the dehydrogenation reaction of butane could be carried out. To achieve this, a reactor with an effective volume of 1100ml was fabricated and coupled with temperature and pressure accessories. Zeolites were obtained from the market and clay ...

The relative and absolute configurations of naphthomycin A were elucidated by an X-ray structural analysis of a methylation product, 25-O-methylnaphthomycin A iminomethyl ether. The absolute configuration was confirmed by degradation (O3, NaBH4) to (S)-butane-1,2,4-triol.