Propanediol oxidation

Preparation. The industrial production of malonic acid is much less important than that of the malonates. Malonic acid is usually produced by acid saponification of malonates (9). Further methods which have been recendy investigated are the ozonolysis of cyclopentadiene [542-92-7] (10), the air oxidation of 1,3-propanediol [504-63-2] (11), or the use of microorganisms for converting nitriles into acids (12). 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

The stmcture of individual block polymers is deterrnined by the nature of the initiator (1,2-propanediol above), the sequence of addition of propylene and ethylene oxides, and the percentage of propylene and ethylene oxides in the surfactant. Thus, when the order of addition is reversed, a different stmcture is obtained in which the hydrophobic moieties are on the outside of the molecule. With ethylene glycol as the initiator, the reactions are as foUows ... 

Diaminopropane Processes. 1,2-Propylenediamine can be produced by the reductive amination of propylene oxide (142), 1,2-propylene glycol [57-55-6] (143), or monoisopropanolamine [78-96-6] (144). 1,3-Propanediol [504-63-2] can be used to make 1,3-diaminopropane (143). Various propaneamines are produced by reducing the appropriate acrylonitrile—amine adducts (145—147). Polypropaneamines can be obtained by the oligomerization of 1,3-diaminopropane (148,149). 

Propanediol is a colorless liquid that boils at 210-211°C. It is soluble in water, alcohol, and ether. It is an intermediate for polyester production. It could be produced via the hydroformylation of ethylene oxide which yields 3-hydroxypropionaldehyde. Flydrogenation of the product produces 1,3-propanediol. 

The catalyst is a cobalt carbonyl that is prepared in situ from cobaltous hydroxide, and nonylpyridine is the promotor. Oxidation of the aldehyde produces 3-hydroxypropionic acid. 1,3-Propanediol and 3-hydroxypropi-onic acid could also be produced from acrolein (Chaper 8). ... 

Propylene glycol (1,2-propanediol) is produced by the hydration of propylene oxide in a manner similar to that used for ethylene oxide ... 

Propanediol (1,2-Propylene glycol, 1,2-Dihydroxy propane, Methyl glycol). CH3.CHOH.CH2OH mw 76.09 colorl, viscous, stable, hygr liq bp 187.3°, d 1.0381g/cc at 20/20° RI 1.4293 at 27° fl pt (open cup) 210°F autoignition temp 780°F. Misc with w, ales, and many org solvents in all proportions. Can be prepd by hydration of propylene oxide. On nitration it yields the exp] 1,2-Propanediol Dinitrate (see below)... 

Nearly insoi in w, easily sol in ale, eth, et ac, benz gelatinizes NC. Can be prepd by the nitration of ], 3-propanediol with mixed nitric-sulfuric acid, as described by Naoum (Ref 4) and Blechta (Ref 3). The nitration requires a lower temp than that used for nitrating glycerin, because the central methylene group is readily oxidized at a higher temp. A temp between 0-10° is recommended since decompn is possible even at 15°, while at 20° yel fumes are evolved. Separating the product from the spent acid occurs with ease at 10°. From lOOp of... 

Alcohol oxidoreductases capable of oxidizing short chain polyols are useful biocatalysts in industrial production of chiral hydroxy esters, hydroxy adds, amino adds, and alcohols [83]. In a metagenomic study without enrichment, a total of 24 positive clones were obtained and tested for their substrate specifidty. To improve the detedion frequency, enrichment was performed using glycerol or 1,2-propanediol and further 24 positive clones were deteded in this study. 

Two options are being developed at the moment. The first is to produce 1,2-propanediol (propylene glycol) from glycerol. 1,2-Propanediol has a number of industrial uses, including as a less toxic alternative to ethylene glycol in anti-freeze. Conventionally, 1,2-propanediol is made from a petrochemical feedstock, propylene oxide. The new process uses a combination of a copper-chromite catalyst and reactive distillation. The catalyst operates at a lower temperature and pressure than alternative systems 220°C compared to 260°C and 10 bar compared to 150 bar. The process also produces fewer by-products, and should be cheaper than petrochemical routes at current prices for natural glycerol. The first commercial plant is under construction and the process is being actively licensed to other companies. 

Polypropyleneoxide has a molar mass of 250 to 4000 Dalton. The lower molecular homologues are miscible with water, whereas the higher molecular polypropyleneoxides are sparingly soluble. They are formed by the polyaddition of, for example, propylene oxide to water or propanediol. The simplest examples are di- and tri-u tetrapropyleneglykol. 

The blend is partially crosslinked with a vinyl monomer when dissolved in an organic aprotic solvent and has a pH of 5.0 or lower. The first block copolymer is prepared by polycondensing a bis-hydroxyalkyl ether, such as dipropylene glycol, diethylene glycol, and the like, with propylene oxide. Next, the resulting propoxylated diol is reacted with ethylene oxide to produce the block copolymer. The second copolymer is prepared by polycondensing 2-amino-2-hydroxymethyl-1,3-propanediol, commonly known as TRIS, with... 

Figure 22-4. 2-Amino-2-hydroxymethyl-1,3-propanediol and propylene oxide.

Propylene glycol, i.e., 1,2-propanediol (1,2-PDO), is an important commodity chemical. It is used as biodegradable functional fluids and as precursors for the syntheses of unsaturated polyester resins and pharmaceuticals (9-10). Propylene glycol is currently produced from petroleum-derived propylene via oxidation to propylene oxide and subsequent hydrolysis (9, 11). However, the rising cost of propylene provides an incentive to find a substitute to propylene for this... 

Several methods and reaction pathways have been reported for the conversion of glycerol in the literature, such as etherification, esterification [1], and oxidation [2], Via ionic dehydration acetol [3] and acrolein can be produced. The radical steps result in aldehydes, allyl alcohol, etc. [4], If the dehydration is followed by a hydrogenation step, propanediols (1,2- or 1,3-) can be obtained [5-6]. 

A possible method for producing glycerol derivatives can be the reactive distillation in the presence of various oxide and mixed oxide catalysts, such as copper-chromite [3], In this reaction acetol, 1,2- and 1,3-propanediols may be obtained. 

Alkyldiphosphines turned out to be very useful in a different reaction, namely the carbonylation/hydrogenation of ethylene oxide to give 1,3-propanediol also using cobalt catalysts. Interestingly, the ligand contains two phobane units bridged by 1,2-ethenediyl. The process was commercialised by Shell [18]. 

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