Heptanes, reaction

Catalyst Dihydrogen Reaction Order n-Heptane Reaction Order... 

In Table 5.3 data are presented for the conversion of methylcyclopentane at 500°C and 14.6 atm over the same catalysts for which data on n-heptane reactions are presented in Table 5.2, and also for a rhenium on alumina catalyst (33). The selectivity to benzene and to C,-C6 alkanes, expressed as percentages of the total conversion of methylcyclopentane to all products, is shown after 0.5 hour and after 24 hours on stream. The methylcyclopentane weight hourly space velocity was 40 grams per hour per gram of catalyst. The inlet stream to the reactor contained five moles of hydrogen per mole of methylcyclopentane. The methylcyclopentane contained 1 ppm sulfur, and the catalysts were pretreated in the same manner as they were in the n-heptane conversion studies. 

Coke deposited on HY zeolite during n-heptane reaction at 450°C, was completely dissolved by CI2CH2 after dissolution of the support with HF . This is not usual, since in most studies there is a fraction of insoluble coke. The coke formed on PtUSHY and PtHMOR catalysts during benzene hydrogenation at 80°C was also completely solubilized in CI2CH2 after support dissolution with 40% HF °. In this case, since the coke was deposited at low temperature, such a high solubility could be expected. 

Figure 2. Solid-state C NMR (75.47 MHz) spectrum for poly(e-CL) obtained with crude Y.lipolytica lipase in the presence of n-heptane. Reaction conditions 3 mmol s-CL/lOO mg lipase. T= 60 °C, t= 360 h reaction time, Mw(NMR)=975 Da. (A) CPMAS spectrum, contact time 1 ms, repetition time 3 s (B) MAS spectrum with a repetition time of 20 s. Spinning sidebands are indicated by an asterisk (top) [5], Expanded zone for carbon/(MAS spectrum) is shown in the...

Compared to an aqueous mediiun, an increased thermostability in heptane for an enriched and freeze-dried EH preparation from A. niger TCP 521 was reported. An initial water activity (a ) of 0.9 for the heptane reaction medium was determined to be optimal in terms of enzyme activity and E-value. On the other hand, the use of heptane greatly increased the apparent value of the enzyme for para-chlorostyrene oxide by a factor of 460, thereby reducing the catalytic efficiency of the enzyme [79]. 

The dicarboxylation of cyclic alkenes is a useful reaction. All-c.vo-methyl-7-oxabicyclo(2.2.1]heptane-2,3,5,6-tetracarboxylate (233) was prepared from the cyclic alkene 232 using Pd on carbon and CuCh in MeOH at room temperature with high diastereoselectivity[216]. The dicarbonylation of cyclopentene... 

In order to faciUtate heat transfer of the exothermic polymerization reaction, and to control polymerizate viscosity, percent reactives are adjusted through the use of inert aromatic or aUphatic diluents, such as toluene or heptane, or higher boiling mixed aromatic or mixed aUphatic diluents. Process feed streams are typically adjusted to 30—50% polymerizable monomers. 

Styrene is a colorless Hquid with an aromatic odor. Important physical properties of styrene are shown in Table 1 (1). Styrene is infinitely soluble in acetone, carbon tetrachloride, benzene, ether, / -heptane, and ethanol. Nearly all of the commercial styrene is consumed in polymerization and copolymerization processes. Common methods in plastics technology such as mass, suspension, solution, and emulsion polymerization can be used to manufacture polystyrene and styrene copolymers with different physical characteristics, but processes relating to the first two methods account for most of the styrene polymers currendy (ca 1996) being manufactured (2—8). Polymerization generally takes place by free-radical reactions initiated thermally or catalyticaHy. Polymerization occurs slowly even at ambient temperatures. It can be retarded by inhibitors. 

This reaction is generally conducted in a hydrocarbon solvent such as heptane, and an aqueous solution of CaCl2, with good mixing, resulting in a brine layer that is subsequentiy separated for disposal. 

The reaction can be driven to the tetraalkoxide stage by addition of an amine or ammonia to scavenge the Hberated hydrochloric acid. The amine or ammonium hydrochloride that forms can be filtered from the reaction mass and the tetraalkyl titanate purified by distillation. If the reaction is mn in the starting alcohol as solvent, the chloride salts formed are in a finely divided state and difficult to filter. When the reaction is mn in the presence of an inert hydrocarbon solvent such as heptane or toluene, a much more readily filterable salt is obtained. The solution of cmde tetraalkyl titanate can be distilled to remove solvent and give a pure product (1,2). 

Sohd, water-soluble a-hydroxycarboxyhc acid and oxaUc acid titanium complexes can be formed by reaction of the acid and a tetraaLkyl titanate in an inert solvent, such as acetone or heptane. The precipitated complex is filtered, rinsed with solvent, and dried to give an amorphous white soHd, which is water- and alcohol—water-soluble (81,82). 

Titanium Phosphorous Containing Chelates. The reaction of a mixture of mono (alkyl) diacid orthophosphate, di(alkyl)monoacid orthophosphate, and TiCl in a high boiling hydrocarbon solvent such as heptane, with nitrogen-assisted evolution of Hberated HCl, gives a mixture of titanium tetra(mixed alkylphosphate)esters, (H0)(R0)0=P0) Ti(0P=0(0R)2)4 in heptane solution (100). A similar mixture can be prepared by the addition of two moles of P2O5 to mole of TiCl in the presence of six moles of alcohol ... 

The reaction can be conveniently monitored by TLC using silica plates and eluting with 1 4 ethyl acetate-heptane. 

This catalyst precursor (5 g.) in 140 ml. of heptane was heated in the autoclave at 160 with a mixture of COiH (1 1) at 150 atm. for 2 hours. The vessel was cooled, the gas released, 1 mole of cyelohexene was charged, and the reaction was carried out according to the usual procedure. 

Another system in which the factors constrolling the direction of reagent approach has been studied systematically is the bicyclo[2.2.1]heptane ring system. The stereochemistry of a number of reactions of the parent system and the 7,7-dimethyl derivative have been examined.Some of the results are given in Table 3.13. These reactions reveal... 

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