Propane-1,2-diol. oxidation

Some more recent processes have been developed which involve direct hydrogenation of the oil to the fatty acid and 1,2-propane diol. These high-temperature (>230 °C) and high-pressure processes generally use a copper chromium oxide catalyst. 

Molinari, F., Gandolfi, R., Villa, R., Urban, E. and Kiener, A. (2003) Enantioselective oxidation of prochiral 2-methyl-l, 3-propan diol by Acetobacter pasteurianus. Tetrahedron Asymmetry,... 

Also in the case of the C3-diol catalytic oxidation there is a lack of literature concerning the selective oxidation of the hydroxyl groups. According to a recent patent the selective oxidation of propane-1,2-diol has been claimed for either the primary or the secondary hydroxyl group, but no examples were reported for primary ones [6b]. Palladium on carbon has been reported to oxidize propane-1,2-diol in a non selective maimer [12] whereas a patent claims 86% selectivity in propane-1,3-diol oxidation to 3-hydroxy-propanoic acid using a commercial Pd/C catalyst [6a]. 

As an extension of the ethane-l,2-diol oxidation, we investigated the catalytic oxidation of propane-1,2-diol. In this case the problem of chemoselectivity, arising from the presence of a primary and a secondary alcoholic function, is of great interest as both hydroxyacetone and lactic acid are products of synthetic importance (Fig. 1)... 

By using palladium on carbon, from previous studies on C3-diol oxidation, poor selectivity can be expected in the case of propane-1,2-diol [12] and good selectivity in the case of propane-1,3-diol (86% of 3-hydroxy-propanoate) [6a],... 

The PTT is aromatic polyester prepared by the melt polycondensation of 1,3-propanediol (1,3-PDO) with either TPA or dimethyl terephthalate (DMT). The PTT is synthesized by the transesterification of propanediol with dimethylene terephthalate or by the esterification of propane diol with TPA. The reaction is carried out in the presence of hot catalyst like titanimn butoxide (Ti(OBu) ) and dibutyl tin oxide (DBTO) at a temperature of 260°C. The important by-products of this reaction include acrolien and allyl alcohol (Chuah, 2001). Direct esterification of propane diol and TPA is considered as the least economic and industrial method. The reaction is carried out in the presence of a heel imder a pressure of 70-150 kPa at a temperature of 260°C. The heel is usually referred to the added PTT oligomers which act as a reaction mediiun and increase the solubility of TPA (Chuah, 2001). Recent studies by different groups show that the selection of the catalyst plays a major role on the reaction rate and PTT properties. Commonly used catalysts like titanium (Doerr et al., 1994), tin (Kurian and Liang, 2001 Fritz et al., 1969) and antimony (Karayannidis et al., 2003 Fitz et al., 2000) compounds have their own limitations. Titanimn-based catalysts are active but the PTT is discolored, antimony-based catalysts are toxic and only active in polycondensation while tin-based compounds have lower catalytic activity. Karayannidis and co-workers (2003) reported the use of stannous oetoate ([CHj(CH2)3CH(C2Hj)COO]jSn) as the catalyst for PTT synthesis but its catalytic activity is poor, resulting in a low molecular weight PTT which was confirmed... 

Compound (6.973b) can be obtained from 2-hydroxymethyl-l,3 propane diol and trimethyl phosphite, and (6.973c) from P (CH20H)3 and the latter. Compounds (6.973a-c) each form an oxide and a... 

A solid phosphite anti-oxidant has been developed, introduced by GE Specialty Chemicals, in its Ultranox range. Designed to meet the demand for a high-activity stabilizer with superior hydrocarbon stability and Improved handling characteristics, it is based on butyl ethyl propane diol chemistry, rather than the usual pentaerythritol. It has been granted FDA approval for food contact in certain applications and is expected to find applications in polyolefins, styrenics. PVC, engineering thermoplastics, elastomers, and adhesives. 

The Cr /l-propanol, Cr /l,2-propane diol, Cr /phenyl tert-h xXy alcohol, Cr /thiourea, and Cr /ethylene thiourea systems have been studied in the polymerization of acrylonitrile [194,195]. These studies furnished information on polymerization kinetics and the general mechanism of chromic acid oxidations. The mechanism involves the formation of unstable species such as and Cr ". ... 

In another patent, very high propane-1,2-diol yields were obtained with a multi-component oxide catalyst consisting of the metals Co, Cu, Mn and Mo, and P. At 523 K under 25 MPa, glycerol is almost quantitatively converted into propane-1,2-diol. In contrast to most studies, the reactions were performed with pure (99.5%) glycerol instead of aqueous dilutions [123],... 

H, Cl, Br, NO2, Me, MeO) by bromamine-B, catalysed in the presence of HCl in 30% aqueous methanol by RuCls have been smdied and a biphasic Hammett a-relationship derived. A kinetic study of the ruthenium(in)-catalysed oxidation of aliphatic primary amines by sodium A-bromo-j -toluenesulfonamide (bromamine-T, BAT) in hydrochloric acid medium has been undertaken and the mechanism of the reaction discussed. A concerted hydrogen-atom transfer one-electron transfer mechanism is proposed for the ruthenium(in)-catalysed oxidation of 2-methylpentane-2,4-diol by alkaline hexacyanoferrate(III). The kinetics of the oxidation of propane-... 

This heme-dependent enzyme [EC 1.11.1.14], also known as diarylpropane peroxidase, diarylpropane oxygenase, and ligninase I, catalyzes the reaction of 1,2-bis(3,4-dimethoxyphenyl)propane-l,3-diol with hydrogen peroxide to produce veratraldehyde, l-(3,4-dimeth-ylphenyl)ethane-l,2-diol, and four water molecules. The enzyme brings about the oxidative cleavage of C—C bonds in a number of model compounds and also oxidizes benzyl alcohols to aldehydes or ketones. 

---