Propene hydrogen peroxide

CH3CH2OHCH3. B.p. 82 C. Manufactured by hydrolysis of propene. Used in the production of acetone (propanone) by oxidation, for the preparation of esters (e.g. the ethanoate used as a solvent), amines (diisopropylamines, etc.), glycerol, hydrogen peroxide. The alcohol is used as an important solvent for many resins, aerosols, anti-freezes. U.S. production 1978 775 000 tonnes. 

Hydroxyl radicals, generated from hydrogen peroxide and titanium trichloride, add to the sulfur atom of 2-methylthiirane 1-oxide leading to the formation of propene and the radical anion of sulfur dioxide (Scheme 102) (75JCS(P2)308). 

It is possible to obtain anti-Markovnikov products when HBr is added to alkenes in the presence of free radical initiators, e.g. hydrogen peroxide (HOOH) or alkyl peroxide (ROOR). The free radical initiators change the mechanism of addition from an electrophilic addition to a free radical addition. This change of mechanism gives rise to the anh-Markovnikov regiochemistry. For example, 2-methyl propene reacts with HBr in the presence of peroxide (ROOR) to form 1-bromo-2-methyl propane, which is an anh-Markovnikov product. Radical additions do not proceed with HCl or HI. 

Hydroboration-oxidation of alkenes preparation of alcohols Addition of water to alkenes by hydroboration-oxidation gives alcohols via anti-Markovnikov addition. This addition is opposite to the acid-catalysed addition of water. Hydrohoration is regioselective and syn stereospecific. In the addition reaction, borane bonds to the less substituted carbon, and hydrogen to the more substituted carbon of the double bond. For example, propene reacts with borane and THF complex, followed by oxidation with basic hydrogen peroxide (H2O2), to yield propanol. 

A comparative study of nanocomposites (16% Nafion-silica and commercial SAC-13) has been performed by Hoelderich and co-workers169 in the alkylation of isobutane and Raffinate II. Raffinate II, the remaining C4 cut of a stream cracker effluent after removal of dienes, isobutane, propane, and propene, contains butane, isobutylene, and butenes as main components. High conversion with a selectivity of 62% to isooctane was found for Nafion SAC-13 (batch reactor, 80°C). Both the quality of the product and the activity of the catalysts, however, decrease rapidly due to isomerization and oligomerization. Treating under reflux, the deactivated catalysts in acetone followed by a further treatment with aqueous hydrogen peroxide (80°C, 2 h), however, restores the activity. 

The propene oxidation process is globally conducted on a 5 million t/a scale. A new gas-phase oxidation process of propene to propene oxide using hydrogen peroxide would save the use of solvents and is expected to have higher selectivity. 

Isopropanol45 Hydrogen peroxide plus exchange resin Produced by catalytic hydration of propene and contains odorous non-ionic impurities... 

The most convenient route to lluorinatcd epoxides is the direct epoxidation of alkenes. Since first reports of a general method using alkaline hydrogen peroxide at low temperature,- several alternative synthetic approache.s have been developed. Molecular oxygen under free-radical conditions has been used to oxidize alkenes such as tetrafluoroethene or hexafluoro-propene however, internal epoxides are formed most conveniently using hypochlorites. The products, e. g. oxirane 14 from alkene 13, are usually obtained in high... 

Scheme 18.6 Reaction pathways in the oxidation of propene with hydrogen peroxide.

The industrial process for propene oxide manufacture is commonly referred to as the HPPO (hydrogen peroxide propene oxide) process. EniChem set up a prototype plant in 2002 [150]. BASF/Dow Chemicals and Degussa, in turn, have the construction of commercial plants already in progress or at the planning stage [151]. 

Degussa, in turn, has recently announced the commercialization of a HPPO process, jointly developed with the engineering company Uhde. Parallel to this, Degussa with Headwaters is also working on the direct synthesis of H2O2, for which a demonstration plant was completed in 2006 [151]. According to the news release, hydrogen peroxide will be obtained in the new process as a dilute methanol solution to be used directly in the epoxidation of propene. 

The integration of propene oxide and hydrogen peroxide processes appears, from a short-term perspective, a more realistic approach than in situ generation. It is also favored by the location of both facilities at the same chemical site. Basically, process integration envisages a simplification of H2O2 recovery that can even... 

A variant envisages the use of aqueous methanol for both the extraction of hydrogen peroxide and the epoxidation of propene as shown, in a simplified form, by Figure 18.3. Thus, no extra water is added to the epoxidation reactor, which decreases separation and waste-treatment costs. On the laboratory scale, the quantity of methanol dissolving into the working solution is small and apparently does not interfere with the AO cycle of reactions [154, 161]. 

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