Production propyl propionate

Reaction of acetic acid solutions of Ru3(CO)i2 with mixtures of CO and R2 under pressure produces substantial amounts of methyl acetate and smaller quantities of ethylene glycol diacetate/ as shown in Table I. Other products observed in these reactions are traces of glycerine triacetate and small amounts of ethyl acetate. (The ethanol is apparently derived largely from acetic acid by catalytic hydrogenation, since reactions in propionic acid solvent yield similar quantities of propyl propionate and only traces of ethyl propionate.)... 

Pyrolysis of the crude Ci-C3 alkyl propionate distillate fraction from Table VI, expt. 1 yields ethylene, propylene and propionic acid as the principal products (see Table VIII, expt. 17) where the ethyl and propyl propionate conversions are 53 and 41%, respectively. The methyl propionate passes through the thermolysis unit unchanged. 

Figure 10. Alkyl propionates from synthesis gas. Effect of ruthenium to quaternary phosphonium salt molar ratio (RUO2 HpPh3PBr). Operating conditions RuOjxHgO, 2.0 mmole C2H5COOH, 25.0 g CO/Hj, 1 1 220 C 18 hr 430 atra constant pressure. Product profile ethyl propionate, methyl propionate A n-propyl propionate, .

The mechanism and end products of the reaction of OH with DnPE have been studied by Sempeles and Andino (2000). Reported products, with molar yields in parentheses, were as follows propyl formate (61 4%), acetaldehyde (60 6%), propanal (15 6%), and propyl propionate (4.3 1.5%). Reaction of OH with DnPE is predicted to occur predominantly ( 85-90%) at the CH2 group adjacent to the O-atom of the ether, and all observed products arise from the ensuing chemistry (Sempeles and Andino, 2000). Decomposition of the resultant alkoxy radical, CH3CH2CH(0 )0C3H7, via C—C bond cleavage yields the major products, propyl formate and acetaldehyde ... 

Buchaly et al propose a hybrid process combining reactive distillation and pervaporation for the propionic add/propanol esterification. The membrane module equipped with a commercial PVA membrane is located in the distillate stream in order to selectively remove the produced water. The desired product, n-propyl propionate is removed at the bottom of the distillation column, which is packed with Amberlyst 46 as catalyst, in a reactive zone. 

Jso-propyl lactate has been prepared by heating iso-propyl alcohol and lactic acid in a sealed tube at 1700,1 2 and from silver lactate and iso-propyl iodide, together with the iso-propyl ester of a-iso-propoxy-propionic acid.3 Direct esterification of the acid with the alcohol, with sulfuric acid, has failed to give a yield greater than 20 per cent of the theoretical amount, and the product has been less pure. 

If esters arc perfluorinated the main products are perfluoroalkanes or perfluoroacyl fluorides byproducts are carbon dioxide and oxygen difluoride. The acyl and the alkyl groups in the ester give perfluorocarboxylic acids.41 A comparison of the results obtained from butyl acetate and ethyl butyrate, and from butyl propionate and propyl butyrate, indicates that perfluoro-butanoic acid is obtained in better yield from ethyl and propyl butyrate than from butyl acetate and butyl propionate. Thus, perfluorocarboxylic acids are formed more readily from the acyl than from the alkyl group of the ester. 

Propyl alcohol1 shows a somewhat greater resistance to oxidation. Propionic acid is the chief product, and a good yield is obtained at platinum or lead peroxide anodes in sulphuric acid. Iso-propyl alcohol which is more easily oxidised gives a 70 per cent, yield of acetone. 

Propyl Alcohol.—n-Propyl alcohol offers a considerably greater resistance to electrical oxidation than methyl or ethyl alcohol, according to experiments made by Elbs and Brunner.1 Propionic acid is formed as the principal product, with a current yield of over 90%, at bright (polished) and platinized platinum anodes, as well as at lead peroxide anodes when the alcohol is electrolyzed in sulphuric-acid solution. A little propionic aldehyde also occurs at lower current densities. The formation of carbon mon- and dioxides is likewise very insignificant. 

If butyric acid is electrolyzed with perchlorate, according to the procedure of Hofer and Moest,2 hexane is the preponderating product there are also obtained propyl alcohol and its oxidation product, propionic aldehyde ... 

After 9 hr nearly equal amounts of butyric and isobutyric acid are formed (90-99% yield). The major by-product formed is propyl acetate, especially at higher temperatures. At 250°C, ethylene in an acetic acid solvent, gives an equimolar mixture of propionic anhydride and the mixed anhydride of acetic and propionic acid. The activity of the Pd on carbon catalyst drops slowly through repeated usage owing to slight but continuous solubilization of the palladium. The problem of long-term activity remains unsolved. 

Factors affecting the accumulation of ansamitocins P-2, P-3, and P-4 in Nocardia sp. C-15003 have been studied (246) the addition of isoleucine, propionate, propionaldehyde, or -propyl alcohol to the fermentation medium resulted in the increased production of P-2 the addition of valine, isobutyrate, isobutyraldehyde, or isobutyl alcohol increased the production of P-3, reaching more than 90% of the total ansamitocins produced and the addition of leucine, isovalerate, isovaleraldehyde, or isoamyl alcohol increased the production of P-4. 

In conclusion, CO hydrogenation catalyzed by Ru-Co bimetallic melt catalysis may lead to the formation of four classes of product (a) alcohols, including methanol, ethanol and propanol, (b) esters, mainly methyl acetate and ethyl acetate plus smaller quantities of propyl acetate and propionate esters, (c) acids, acetic acid, and (d) hydrocarbons, methane. 

Compared to the aldol addition, the stereochemical scheme is complicated by the fact that the Michael acceptor may not always and not exclusively adopt the -configuration as shown in 421 but also as Z-diastereomer. The effect of this isomerism has been addressed in a fundamental contribution of Corey and Peterson, which is also one of the first applications of an auxiliary-based stereoselective Michael addition. The chiral lithium enolate 425 that was generated from the propionic ester 424 of phenylmenthol by deprotonation was assumed to adopt the enolate in fcr /is-configuration, in accordance with Ireland s model (cf Section 2.1). The reaction of the enolate with ( )- and (Z)-methyl crotonate led to the Michael products sy/i-426 and a f/-427, respectively. The Michael addition to ( )-crotonate was faster at low temperatures than that of the (Z)-diastereomer and provided higher chemical yields as well as syw-anti-selectivity and induced stereoselectivity. A closed, eight-membered transition state model 428 has been proposed that plausibly explains the opposite stereochemical outcome depending on the double-bond configuration of the Michael acceptor. As the rear side is shielded by the bulky 2-phenyl-2-propyl substituent, the attack of both croto-nates occurs at the Si-face of the enolate 425. Whereas Si-face of ( )-crotonate is selected for the addition of the enolate, the attack to (Z)-crotonate occurs predominantly from the e-face (Scheme 4.92) [206]. 

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