Oxidation of Propan-2-ol

The main effect of MW irradiation on the graphite and charcoal-supported catalysts is to reduce the average temperature required for reaction to occur. The authors believe this is the result of hot spots formed within the catalyst bed (Section 9.4.2). Graphite-supported catalysts seem, moreover, to be more selective than the equivalent charcoal-supported catalysts, especially under the action of MW irradiation - 3.6-97.7% compared with 68.4-86.3%. This might be because of the hydrophobic nature of the graphite which directs the reaction away from the production of water by dehydration of the alcohol. 

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Table 8 Representative kinetic data for the oxidation of propan-2-ol by ruthenium oxo complexes.

The major products of the photolysis of glycolaldehyde are HCHO and CO, methanol and OH production was also observed. Photolysis of glycolaldehyde was used as the OH source to measure the reaction rate constants of OH with a series of dienes by the relative method and to identify and quantify the oxidation products of the OH-initiated oxidation of propan-2-ol. HCHO is observed to be the major product of the OH-initiated oxidation of glycolaldehyde. The results indicate that the OH reaction and photolysis can compete as tropospheric sinks for glycolaldehyde.218... 

Representative Kinetic Data for the Oxidation of Propan-2-ol by Ruthenium... 

Cundall RB, Rudham R, Salim MS. Photocatalytic oxidation of propan-2-ol in the liquid phase by rutile. J Chem Soc Faraday Trans 1 1976 72 1642-51. 

Before we leave the discussion of industrial processes, it is worth mentioning one other autoxidation process, based on the oxidation of propan-2-ol, developed by Shell Chemicals. The process was employed by Shell in its 15 000 metric tonnes per annum facility at Norco between 1957 and 1980. The process was discovered in 1954 by Harris,25 who showed that the oxidation of primary and secondary alcohols formed hydrogen peroxide, and the corresponding aldehyde or ketone (Figure 1.11). 

Only propan-2-ol has had any industrial use since the aldehydes formed in the reaction with primary alcohols are easily oxidized. The oxidation of propan-2-ol in the liquid phase with oxygen does not require a special catalyst, because it is catalysed by a small amount of hydrogen peroxide, which is added to the feed-stream of the propan-2-ol in order to shorten the induction phase (Figure 1.12). 

Westheimer demonstrated in 1949 [24] that the oxidation of propan-2-ol with chromic acid proceeds through rapid formation of a chromate ester, followed by rate-controlling abstraction of the carbinol proton in an elimination process ... 

In the oxidation of propan-2-ol substantial yields of hydrogen peroxide are obtained. In view of the reported instability of an intermediate believed to be hydrogen trioxide (2, 3), it seems unlikely that the titration for H2O2 at 20 °C. actually represents H0O3 furthermore Reaction R produces HoOa, whose fate must now be considered. Fission to HO and O2H seems probable even at low temperatures, and in 2-propanol some such sequence as... 

CH3-COCH3) A colorless liquid ketone, used as a solvent and in the manufacture of methyl 2-methyl-propanoate (from which polymethylmethacrylate is produced). Propanone is manufactured from propene, either by the air-oxidation of propan-2-ol or, as a by-product from the cumene process. 

The A-chlorosaccharin (CSA) oxidations of propan-2-ol " and malic acid in ACOH-H2O-HCIO4 are first order in CSA and H+ ions, fractional order in alcohol, and of variable order (from one to zero) in malic acid. Added saccharin retards the rate in each case. 

Q11 The oxidation of propan-2-ol, CH3CH(OH)CH3, by sodium dichromate(vi) leads to the formation of ... 

The oxidation of propan-2-ol by chlorine has also been reported, with chloride-ion catalysis of the reaction. The data have been treated to include the two forms of the oxidant. 

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