Phenoxy acetic acid

Chemical Name [2,3-dichloro-4-(2-methvlene-1-oxobutvl)phenoxy] acetic acid... 

Hansch C, Maloney PP, Fujita T. Correlation of biological activity of phenoxy-acetic acids with Hammett subsistent constants and partition coefficients. Nature 1962 194 178-80. 

Other blockers of epithelial Cl -channels are of the aryl-amino-benzoate type or phenoxy-acetic-acid type [70]. Very few systematic surveys comparing different classes of blockers in one type of Cl -channel are available at this stage. One such study has been performed in membrane vesicles from kidney cortex [80]. In this study IAA-94 and NPPB (cf. Fig. 2) turned out to be the most potent blocker of conductive Cl -flux. In another systematic survey the Cl -conductance of the sweat duct was examined, and it was found that dichloro-DPC (Fig. 2) was the most potent inhibitor of the transepithelial Cl -conductance [90]. 

This technique has also been coupled with mass spectrometry for the partial identification of organic compounds eluted from the column, e.g. the determination of phenoxy acetic acid herbicides in soil and non-saline sediments. 

In sludge anionic and non-ionic surfactants carboxylic acids hhydroxybutyrate hydroxy valerate chloroaliphatic compounds chlorophenols polychlorobiphenyls 4-nitrophenol mixtures of organic compounds chlorinated insecticides, phenoxy acetic acid type herbicides and organotin compounds. 

Another growing technique is super-critical fluid chromatography. Recent references to soil analysis include the following applications aliphatic hydrocarbons, polyaromatic hydrocarbons, polychlorobiphenyls, dioxins, alkyl and aryl phosphates, chloro, organophosphorus, triazine, substituted urea, phenoxy acetic acid, Dacthal herbicides and insecticides and mixtures of herbicides and pesticides and mixtures of organic compounds. 

Renberg [35] used an ion-exchange technique for the determination of chlorophenols and phenoxy acetic acid herbicides in soil. In this method the soil extracts are mixed with Sephadex QAE A-25 anion exchanger and the adsorbed materials are then eluted with a suitable solvent. The chlorinated phenols are converted into their methyl ethers and the chlorinated phenoxy acids into their methyl or 2-chloroethyl esters for gas chromatography. 

Chau and Terry [146] reported the formation of penta-fluorobenzyl derivatives of ten herbicidal acids including 4-chloro-2-methyl-phenoxy acetic acid [145]. They found that 5h was an optimum reaction time at room temperature with pentafluorobenzyl bromide in the presence of potassium carbonate solution. Agemian and Chau [147] studied the residue analysis of 4-chloro-2-methyl phenoxy acetic acid and 4-chloro-2-methyl phenoxy butyric acid from water samples by making the pentafluorobenzyl derivatives. Bromination [148], nitrification [149] and esterification with halogenated alcohol [145] have also been used to study the residue analysis of 4-chloro-2-methyl phenoxy acetic acid and 4-chloro-2-methyl phenoxybutyric acid. Recently pentafluorobenzyl derivatives of phenols and carboxylic acids were prepared for detection by electron capture at very low levels [150, 151]. Pentafluorobenzyl bromide has also been used for the analytical determination of organophosphorus pesticides [152],... 

Saltar and Paasivirta [155] have described a method for the analysis in soils of MCPA (4-chloro-2-methyl phenoxy acetic acid) and two of its main metabolites, 4-chloro-o-cresol and 6-chloromethyl catechol by gas chromatography of their pentafluorobenzyl derivatives (Fig. 9.12). After derivitization of the residue extract, a clean-up procedure was applied. The best recoveries of compounds from soil were obtained when the extraction was performed by shaking with ether-acetone-heptane-hexane (2 1 1 1) from acidified soil and when the clean-up was done by thin layer chromatography (Table 9.17). Detection limits were in the range 20-25ng absolute. 

Waliszewski and Szynczynski [158] have described a gas chromatographic method for the determination of 4-chloro-2-methyl phenoxy acetic acid (MCPA) and 2.4 chloro phenoxy acetic acid (2.4D) herbicides in soils. The chlorophenoxy acetic acid herbicides were extracted from soil... 

A dendrimer containing a dye as core was synthesized by Zhang and coworkers (Fig. 7.7) [39, 40]. The feoc-protected amine endgroups of this [Gl] dendrimer were equipped with a 4-(hydroxymethyl)phenoxy acetic acid (HMPA) linker performing several reaction steps to obtain the red colored dendritic support (14). 

Chemicals processed. Waste pesticide solutions were collected after spray operations during late May, June, and July of 1983, and consisted primarily of three compounds 2,4-D [(2,4-dichloro-phenoxy)acetic acid], atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)- -triazine) and paraquat (1,1 -dimethyl-4,4 -bipyridinium dichloride). Our efforts were primarily directed at these pesticides, which are shown in Table I together with their formulations and concentrations. 

Schugerl 115] has recently furnished a detail analysis of the reactive extraction of penicdlin-G and V and precursors like phenyl and phenoxy acetic acids. Thirty different amines have been studied for reactive extraction of penicillins 116] in various solvents such as butyl acetate, chloroform, di-isopropyl ether, kerosene, dioctyl ether, etc. Tertiary amines in n-butyl acetate were found to be advantageous because of their low reactivity with solvent but the distribution coefficients of their complexes are significantly lower than those of secondary amines. While using quaternary ammonium salts for ion-exchange extraction, re-extraction is difficult and very large amounts of anion (e.g.. Cl ) are needed to recover penicillins. The basic relationship for distribution coefficient and extraction kinetics have now been fairly developed for amine-penicillin systems. 

Amine extraction of penicillins has been examined in a pilot scale extractor and its performance has been analyzed through suitable mathematical models 117-19]. Extraction efficiency as high as 90% was achieved under suitable conditions. The procedure for selection of volume ratios of the aqueous to organic phase and concentration ratio of carrier (Amberlite LA-2) to penicillin-G at a desired degree of extraction and enrichment has recently been described [20]. Ion-pair extraction of penicillin-V and phenoxy acetic acid with Amberlite LA-2 hydrochloride and tetrabutyl ammonium hydrogen sulfate can be effective in... 

Since the same effects occurred with the non-herbicidal (2,6-dichloro-phenoxy) acetic acid as with toxic compounds, glucose metabolic changes are not the important singular effects of auxin herbicides. 

Two essentially different views of the metabolism of (2,4-dichloro-phenoxy) acetic acid have been presented. The first12 -124 was based on a 3tudy with bean stems, which converted 42% of (2,4-dichlorophenoxy)-acetic acid-l4C into acidic, water-soluble substances. Two ether-soluble metabolites were formed, and the same two metabolites could be recovered,... 

In Jamaica,302 no effect was found from (2,4-dichlorophenoxy)acetic acid, but positive responses were obtained from low rates of application (less than 0.009 lb. per acre) of (2,4,5-trichlorophenoxy)acetic acid and 2-(2,4,5 trichlorophenoxy)propionic acid. Louisiana sugarcane failed to respond to the low rates of (2,4-dichloro- or (2,4,5-trichloro-phenoxy)-acetic acid, but (2,4-dichlorophenoxy)acetic acid at one and three lb. per acre increased the sugar yield significantly at eight days, although not at 25 or 39 days.31 ... 

Many other compounds have been included in studies on sucrose response. Most of these have been herbicides or enzyme poisons. None of the common herbicides had any positive effect on sucrose at rates up to that causing severe foliar injury. Earlier reports of response from 2-(2,4,5-trichlorophenoxy)propionic acid and 2,2-dichloropropionic acid could not be substantiated in British Guiana and Queensland. 27 Some compounds, such as 3-(p-chlorophenyl)-l,l-dimethylurea (monuron), (2,4-dichloro-phenoxy) acetic acid in soil, ethylenediaminetetraacetic acid, and leaf desiccants decreased sucrose and juice solids content. 20 Field trials with several chemicals in Trinidad showed enhanced sucrose at 14 to 28 days before harvest resulting from the application of 8 and 12 lb. (per acre) of... 

Some support for this mechanism derives from our observation of benzyl radical from phenylacetic acid, phenoxymethyl radical from phenoxy-acetic acid, and possibly the phenyl radical from benzoic acid. Radical spectra were not found for several aryl acids with longer side chains but this is not inconsistent because the 0-phenylethyl and higher radicals are not expected to absorb strongly above 300 m/z. The case of the heterocyclics is complicated by the possibility of excitation either via the 7r-system or a lone pair electron on the heteroatom, and discussion of this group will be deferred until additional experimental data are obtained. 

Dichloro-phenoxy acetic acid, 2,4,5- trichlorophenoxy acetic acid Herbicide derivatised to its methyl or 2-chlororethyl ester, then gas chromatography. 70 - 74% recovery [169]... 

However, the phenoxy acetic acids, 2,4-D and 2,4,5-T, were by far the most widely used, being employed for stand thinning, control of brushy species in reforestation, and control of brush and trees in rights of way (11). 

Liljebris et al. synthesized 2-[4-[(2amino)propyl]-2-(l(2)7/-tetrazol-5-yl)phenoxy]acetic acid 606, peptidomimetic inhibitors of protein tyrosine phosphatase IB <2002JME1785>. 

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