Amylene oxidation

Higher Olefins. Yapor-phase oxidation of olefins in the presence of vanadium pentoxide catalysts results in substantial yields of maleic anhydride which increase with increase in molecular weight of the olefin. Thus, from pentene-2, trimethylethylene, technical amylene, methyl pen-tene, heptene, and octene, approximate relative conversions of 10, 25, 27, and 30 per cent, respectively, were obtained from 5, 6, 7, and 8 C-atom olefins. Optimum tanperatures of about 425 C were foimd for amylene oxidation. Catalysts used for 250 hr showed no reduction in activity. 

By the action of zinc ethyl on allyl iodide he obtained impure propyl ethylene (C H C H ), an isomer of amylene. (Commercial amylene is a mixture, the chief constituent being trimethylethylene, (CHs)2C CH-CHs). Frankland, in Liebig s laboratory, by heating allyl iodide with zinc obtained amylene and what he described as amyl, ready diamyl or tetramethylhexane, which Wurtz obtained from amyl iodide and sodium it is (CHj)2C,Hxo(CH8)j. Wurtz also obtained new isomers of amyl alcohol, the true constitution of which was established only later. Bauer obtained triamylene (C15H30) as well as di- and tetramylene. He also obtained amylene oxide, corresponding with ethylene oxide. 

Shah et al. (1994) have studied the preparation of a class of compounds called Indans, by cross-dimerization of AMS with amylenes, using an ion-exchange resin and acid-treated clay catalysts (Eqns. (12) and (13)). Indans can be subsequently converted, e.g. by acetylation, into perfumric compounds having mu.sk odour. For example, 1,1,2,3,3-pentamethylindan, the product obtained by cross-dimerization of AMS and wo-amylene (Eqn. (12)), can be reacted with propylene oxide and /7 ra-formaldehyde to give an indan type isochroman musk compound, 6-oxa-l,l,2,3,3,8-hexamethyl-2,3,5,6,7,8-hexahydro-lH-benz(f)-indene, sold as Galaxolide commercially. 

Hexaldehyde has been prepared from caproic acid by passing it over zinc dust at 300°, by reaction with amylene at 300°. in the presence of thorium oxide, by passing it over manganous oxide at 300-360 with two volumes of formic acid, and by distillation of the calcium salt with calcium formate. It has also been prepared by heating a-hydroxyheptoic acid or better a-acetoxyheptoic acid, and by the reaction of ethyl orthoformate with -amylmagnesium bromide. ... 

Impurities are described in many texts on solvents [4, 5]. Many organic impurities can be identified by GC or GC/MS techniques for instance, MIBK can be found to contain mesityl oxide, the precursor to the manufacture of MIBK (Figure 4.6) [20]. Common impurities in solvents include H20, DMF [21], and AcOFl (in EtOAc and other solvents). Some solvents are inhibited with trace amounts of antioxidants, e.g., CH2C12 (stabilized with amylene or cyclohexane) andTFIF and 2-Me-THF (stabilized with BHT, butylated hydroxytoluene ). These impurities can influence the desired chemistry positively [22] and negatively, so and they should be considered. 

Similarly, n-hexane gave formaldehyde, ethylene, propylene, butylenes, amylenes, xylenes, water and carbon dioxide. The presence of butadiene in the products of these two oxidations is questionable. 

AMYLENE DIMER (16736-42-8) Forms explosive mixture with air (flash point 118°F/48°C). Reacts violently with strong oxidizers. Flow or agitation of substance may generate electrostatic charges due to low conductivity ground all equipment containing this material. On small fires, use dry chemical powder (such as Purple-K-Powder), alcohol-resistant foam, or CO2 extinguishers. 

AMYLENE HYDRATE (75-85-4) CsH O Flammable liquid. Forms explosive mixture with air (flash point 105°F/41°C cc Fire Rating 3). Violent reaction with strong oxidizers acetyl bromide alkylaluminums... 

There is a very wide range of inhibitors available to stabilize MDC, but it is best to avoid aluminium as a material of construction when MDC may be processed or stored. Because of MDC s volatility there is always a danger that it will distil away from a less volatile inhibitor and lose its protection. Low-boihng inhibitors such as te/t-butylamine, propylene oxide and amylene (2-methylbut-2-ene) tend to stay with MDC when it is vaporized whereas dioxane, ethanol, THF, N-methyhnorpholine and cyclohexane tend to remain in the liquid phase. The concentrations required for effective inhibition are low (50 ppm to 0.2%) and, if MDC is used as a reaction medium, it is almost always possible to find one that does not become involved in the reaction itself. 

Phosphorus pentachloride and ethylene oxide gave ethylene dichloride, C H CP. Propylene, butylene, and amylene glycols, prepared by exactly the same general reaction as ethylene glycol, showed exactly the same chemical properties, as Wurtz (following the lead of Berthelot s publications on glycerine) showed in tedious detail. It was said also of Hofmann that the mere production appears at all times to have given him infinite pleasure. ... 

---