Autoxidation of Aldehydes in Acetic Acid Solution

Abstract

chemical engineering since Decem.ber 1969. He studied at the same Uniuersity and obtained the degree in chemical engineering i n 1955: in 1960 he receiued the emee of doctor of tech-Zd,, , nical sciences on the subject: fading by light of anthraquinoid mordant dyes. He authored several papers, for example, in the fields ofphotoreduction of azo dyes and fading by light of organic dyes o f textiles. He is a member of the Royal Dutch Chemical Society. Pieter M. Heertjes studied at the Uniuersity of Technology, Delft, obtained the degree in chemical engineering in 1932 and the degree of doctor of technical sciences in 1938. I n 1973 h e became Doctor H.C. o f Loughborough Uniuersity of Technology. After a short period as a lecturer he took the chair o f ordinary Professor in chemical engineering at the Uniuersity of Technology, Delft, i n 1946. He was President of the Roval Dutch Chemical Societv and is a member of several societies including The Institution of Chemical Engineers and the Chemical Society. His scientific field.? of interest are chemical engineering and dyestuffs. 270 Ind. Eng. Chem.. Prod. Res. De"., VoI. 16, No. 4, 1977The initiation of aldehyde autoxidations in acetic acid has been investigated under circumstances where the radical chain processes were inhibited. Phenol, 4-methylphenol, and 2,6-di-feff-butyl-4-methylphenol were used as inhibitors. It was found that the initiation reactions were combinations of a photochemical and, particularly at higher temperatures, a bimolecular thermal process. The thermal reaction is responsible for the influence of oxygen on the overall autoxidation rates. Oxidation of benzaldehyde in the presence of 2,6-di-tert-butyl-4-methylphenol led to the conversion of the latter into its hydroperoxy-and benzoylperoxy derivatives, thus confirming its activity as scavenger of peroxy chain radicals. Uninhibited autoxidations were second order in the aldehyde concentrations for cyclohexanecarboxaldehyde and halogen substituted aldehydes. Other aldehydes gave firstorder reactions. These results, together with those obtained for the initiation reaction, give information regarding the nature of the chain termination reactions.

Conversion of Cobalt(II) Acetate into Cobalt(III) Acetate by Autoxidizing Benzaldehyde

“…For autoxidations of benzaldehyde inhibited by phenols the same kinetics and the same rate constant were found (Hendriks et al, 1977). However, it was found that at ratios of the initial Co" acetate and benzaldehyde concentrations with values >0.030 the initial oxidation rates were linear with the benzaldehyde concentration and independent of the Co" acetate and oxygen concentrations.…”

Formation of phenylacetic acid and benzaldehyde by degradation of phenylalanine in the presence of lipid hydroperoxides: New routes in the amino acid degradation pathways initiated by lipid oxidation products

“…Once they have been formed, phenylpyrucic acid ( 2 ) can be decarboxylated to produce the benzycarbonyl radical ( 8 ) in the presence of free radicals. This radical has been observed in the photolysis of dibenzylketone (Grissom, 1995), and similar radicals are produced from aldehydes during their free radical oxidation (Hendriks, van Beek, & Heertjes, 1977). The benzylcarbonyl radical ( 8 ) would then react with oxygen to produce the corresponding peroxyacid radical ( 9 ) and later the peroxyacid ( 10 ).…”

The catalytic and radical mechanism for ethanol oxidation to acetic acid

“…14 The well-established literature indicates that a formyl group readily oxidises to the corresponding carboxyl group in oxygen/ air or other oxidants, in an autoxidation cycle initiated by a radical initiator. [15][16][17][18][19][20] Benzaldehyde is one of the most common examples and more extensively studied. The autoxidation cycle is initiated by a radical initiator, which breaks the relatively weak aldehyde C-H bond (86 kcal).…”