Butyraldehydes, from oxidation

Propylene-Based Routes. The strong acid-catalyzed carbonylation of propylene [115-07-1] to isobutyric acid (Koch reaction) followed by oxidative dehydration to methacrylic acid has been extensively studied since the 1960s. The principal side reaction in the Koch reaction is the formation of oligomers of propylene. Increasing yields of methacrylic acid in the oxydehydration step is the current focus of research. Isobutyric acid may also be obtained via the oxidation of isobutyraldehyde, which is available from the hydroformylation of propylene. The -butyraldehyde isomer that is formed in the hydroformylation must be separated. 

Several species of bacteria under suitable conditions cause / -butyraldehyde to undergo the Canni22aro reaction (simultaneous oxidation and reduction to butyric acid and butanol, respectively) this reaction can also be cataly2ed by Raney nickel (7). The direct formation of butyl butyrate [109-21 -7] or isobutyl isobutyrate [97-85-8](Vish.ch.erik.o reaction) from the corresponding aldehyde takes place rapidly with aluminum ethylate or aluminum butyrate as catalyst (8). An essentially quantitative yield of butyl butyrate, CgH2 02, from butyraldehyde has been reported usiag a mthenium catalyst, RuH,[P(C,H,)3], (9). 

Butyric acid is made by air-oxidation of butyraldehyde, which is obtained by appHcation of the oxo synthesis to propylene. Isobutyric acid is made from isobutyraldehyde, a significant product in the synthesis of butyraldehyde (see Butyraldehydes). Butyraldehyde is also used to make 2-ethylhexanoic acid. 

Neo acids are prepared from selected olefins using carbon monoxide and acid catalyst (4) (see Carboxylic Acids, trialkylacetic acids). 2-EthyIhexanoic acid is manufactured by an aldol condensation of butyraldehyde followed by an oxidation of the resulting aldehyde (5). Isopalmitic acid [4669-02-7] is probably made by an aldol reaction of octanal. 

GL 26] [R 3] [P 28] Conversions from 2 to 42% were found for the oxidation of butyraldehyde [10], The highest conversions were obtained for large gas and liquid flows. On increasing the ratio of gas and liquid superficial velocities from 5 to 53, an increase in conversion from 10 to 41% resulted. 

Isobutyraldehyde, 4 459 14 584 animal toxicty, 4 466t effect of unsaturation on toxicity, 2 69t isobutyl alcohol manufacture from, 4 397 oxidative dehydrogenation of, 16 252 physical properties of, 4 459t quality specifications, 4 465t Isobutyraldol, butyraldehyde derivative, 4 461... 

Condensation of butanol has been carried out on alkaline earth metal oxides at 273 K (13,121). This condensation reaction yields 2-ethyl-3-hydroxy-hexanal as a main product other products, such as 2-ethyl-2-hexenal (arising from the dehydration of 2-ethyl-3-hydroxy-hexanal), n-butyl-K-butyrate (arising from the Tishchenko reaction of butyraldehyde), and 2-ethyl-3-hydroxy- -hexyl butyrate (arising from the Tishchenko reaction of 2-ethyl-3-hydroxy-hexanal), are also formed (Scheme 12). 

Under the same reaction conditions, acetaldehyde and butyraldehyde displayed near-complete conversion (greater than 95%). The photocatalytic oxidation of the alcohol 1-butanol displayed similarly high conversion levels, although conversion of methanol was somewhat lower. The oxygenated compounds methyl-t-butyl ether (MTBE), methyl acrylate, 1,4 dioxane, and vinyl acetate displayed conversion levels ranging from 92% to 100%. The lowest conversion levels of the oxygenated compounds studied were seen with the ketones used [acetone and 2-butanone (methylethylketone)], which displayed conversions of approximately 80%. The initial conversion levels seen with -hexane were similar... 

The effect of temperature on the yields of the three addition products, a-butene oxide, n-butyraldehyde, and methyl ethyl ketone, and of a fragmentation product, carbon monoxide, is shown in Figure 3. It is seen that as temperature is increased from 25-200°C. the yields of the... 

Alkoxylation with, for example, propylene oxide (PO). Preferred amine is triethanolamine, or ammonia and other alkanolamines used amine can also be quaternized Best example is triethanol with 14.9 PO units Contains vinyl ester acetal functionalities besides some unreacted vinyl alcohol monomer units. Preferred aldehyde is butyraldehyde Backbone, for example, polyalkylene glycol, polyalkyl-eneimine, polyether, or polyurethane, and active functional side groups made from grafting VP or VCap to backbone using radical initiators TBA (tributylammonium groups)... 

Tetra-n-butyltin is oxidised by chromium trioxide (1 1 molar ratio) to yield tri-n-butyltin acetate and compounds derived from the n-butyl group cleaved from the tin atom (mainly n-butyraldehyde and butyric acid)29. In the initial stages of the oxidation, the reaction follows the simple rate expressions v = k2 [Bu Sn] [Cr03]. Values of the second-order rate coefficient for the oxidation of a number of tetraalkyitins by Cr03 in solvent acetic acid at 20 °C were reported29 to be as follows... 

Several aliphatic carboxylic acids have been known for centuries, and their common names reflect their historical sources. Formic acid was extracted from ants formica in Latin. Acetic acid was isolated from vinegar, called acetum ( sour ) in Latin. Propionic acid was considered to be the first fatty acid, and the name is derived from the Greek protos pion ( first fat ). Butyric acid results from the oxidation of butyraldehyde, the principal flavor of butter butyrum in Latin. Caproic, caprylic, and capric acids are found in the skin secrehons of goats caper in Lahn. The names and physical properties of some carboxylic acids are listed in Table 20-1. 

The synthesis of acetaldehyde by oxidation of ethylene, generally known as the Wacker process, was a major landmark in the application of homogeneous catalysis to industrial organic chemistry. It was also a major step in the displacement of acetylene (made from calcium carbide) as the feedstock for the manufacture of organic chemicals. Acetylene-based acetaldehyde was a major intermediate for production of acetic acid and butyraldehyde. However the cost was high because a large energy input is required to produce acetylene. The acetylene process still survives in a few East European countries and in Switzerland, where low cost acetylene is available. 

The one-step synthesis of isoamyl butyrate from isoamyl alcohol and n-butyral-dehyde, possibly through the formation and subsequent oxidation of an acetal intermediate, could represent a special case in TS-1 catalysis, since the oxidant was molecular oxygen [114]. The authors did not advance any mechanistic hypothesis. -Butyl hydroperoxide, however, produced in situ by the autoxidation of n-butyraldehyde, could have been the true oxidant, by virtue of its dimensional compatibility with the narrow pores of TS-1. 

---