Phenoxyacetic acids, oxidation

Irradiation of at longer wavelengths (>280 nm) provided phenyl formate (6) as a major volatile product, together with minor amounts of phenol and phenoxyacetone (4), as well as other products. A possible pathway for formation of phenyl formate by oxidation and subsequent cleavage is provided in Scheme III. Phenoxyacetic acid (7) was also identified as a minor product by mass-gc analysis. Photolysis of phenoxyacetone ( ) and phenoxyacetic acid (7)12 yields phenol together with photo-Fries products (also shown in Scheme III). 

Steric effects dominate in the oxidation of dialkyl, alkyl phenyl and benzal methyl phenyl sulfides to their sulfoxides by quinolinium fluorochromate (QFC) in aqueous acetic acid. QFC oxidation of phenoxyacetic acids has been smdied. Imidazolium dichromate oxidations of a-hydroxy acids have been smdied. ... 

The substituted phenoxyacetic acids are used as herbicides. If Fe oxide anodes are used in the electrochemical oxidation of diethylene glycol, l,4-dioxan-2-ol is initially formed... 

The reverse situation - selective bioactivation in the uneconomic species — is realized in the selectively acting weedkillers of the phenoxybutyric acid type (Fig. 8). The butyric acid derivatives, as such, are inactive they have to be converted by 0-oxidation to the corresponding phenoxyacetic acid derivatives, which have the required auxin and hence weedkiller action. Since plant species... 

Fig. 2. Relative Peroxisome Proliferative Activity of Chlorinated Phenoxyacetic Acids and Related Compounds in Cultured Rat Hepatocytes. ( R.P. = Relative potency for induction of palmitoyl CoA oxidation. Data summarized from Lewis et al. [20])...

Ferric oxide Guanidine hydrochloride Heparin ammonium Heparin lithium Hexane Hydrochloric acid Hydrocinnamic alcohol Hydrocinnamyl acetate Hydrogen sulfide Isophthaloyl dichloride Manganese dioxide a-Methylbenzyl alcohol Myrtrimonium bromide Nickel oxide (ic) Oxalic acid dihydrate o-Phenetidine Phenolsulfonic acid Phenoxyacetic acid Phenylacetaldehyde Phenylacetaldehyde dimethyl acetal Phenyl acetate Phenylacetic acid ... 

The rate of oxidation of chalcones in ACOH-H2O has first order in imidazolium dichromate (INDC) and H+ ion and fractional order in the chalcones decreased with decreasing dielectric constant." The oxidation of phenoxyacetic acids in ACOH-H2O-HCIO4 is first order in nicotinium dichromate (NDC) and substrates, and second order in H+ ion. The electron-releasing substituents and increased percentage of AcOH increased the rate, which was decreased by electron-attracting substituents. The rate correlated with the Hammett relation, and Mn + ions exhibited noticeable catalytic effect." ... 

The rates of oxidation of p- and m-substituted phenoxyacetic acids in ACOH-H2O-HCIO4 by TPCC increase with increasing AcOH%. The rate is accelerated by electronreleasing substituents and subject to catalysis by Al + ions." ... 

C13H8CI2O4S, 2,3-Dichloro-4-(2-thionyl)-phenoxyacetic acid, 46B, 360 C13H8O2S, Thioxanthone 10-oxide, 42B, 262 C13H10O2S, Thioxanthen-9-ol-lO-oxide, 32B, 187 C,3H,oS, Thioxanthene, 39B, 240... 

We proposed a metabohc pathway of phosphonates with structure lo in plants when these compounds lo were initially designed. lo might be metabolized to substituted phenoxyacetic acids (lo-a) as auxin-type herbicide and acylphospho-nates (lo-c) as PDHc El inhibitors after the hydrolysis and oxidation by esterases and oxidases took place in plants (Scheme 1.21). 

---