Chlorophenols, acetates

Fig. 5.1. Separation of chlorophenol acetates (2-0.02 ng). Peaks 1 = 2-chloro 2 = 3-chloro 3 = 4-chloro 4 = 2,6-dichloro 5 = 2,5-dichloro 6 = 2,4-dichloio 7 = 3,4-dichloro 8 = 2,3-dichIoro 9 = 3,5-dichloro 10 = 2,4,6-trichloro 11 = 2,4,5-trichloro 12 = 2,3,4,6-tetrachloro 13 = pentachloro-phenol acetates. Conditions Pyrex glass column (25 m X 0.35 mm I.D.), dynamically coated with SE-30 temperature programme, 3°C/min (95-180°C) helium flow-rate, 2-3 ml/min splitting flow-rate, 0-60 ml/min. (Reproduced from J. Chromatogr. 131 (1977) 412.)...

Chem. 60, 1311-14 (1956). NMR effect of concentration, phenol, o-, m-,/>-chlorophenol, acetic acid in CCI4. 

Another appHcation of 4-chlorophenol is in the synthesis of a dmg, ethyl a, a-dimethyl-4-chlorophenoxy acetate [637-07-0] (60), used as a cholesterol-reducing agent. This synthesis involves reaction with acetone and chloroform, followed by ethanol esterification. 

Acetal homopolymer resins show outstanding resistance to organic solvents, no effective solvent having yet been found for temperatures below 70°C. Above this temperature some phenolic materials such as the chlorophenols are effective. Stress cracking has not been encountered in organic solvents. Swelling occurs with solvents of similar solubility parameter to that of the polymer (8 = 22.4 MPa ). 

Dichlorodibenzo- -dioxin. 2-Bromo-4-chlorophenol (31 grams, 0.15 mole) and solid potassium hydroxide (8.4 grams, 0.13 mole) were dissolved in methanol and evaporated to dryness under reduced pressure. The residue was mixed with 50 ml of bEEE, 0.5 ml of ethylene diacetate, and 200 mg of copper catalyst. The turbid mixture was stirred and heated at 200°C for 15 hours. Cooling produced a thick slurry which was transferred into the 500-ml reservoir of a liquid chromatographic column (1.5 X 25 cm) packed with acetate ion exchange resin (Bio-Rad, AG1-X2, 200-400 mesh). The product was eluted from the column with 3 liters of chloroform. After evaporation, the residue was heated at 170°C/2 mm for 14 hours in a 300-cc Nestor-Faust sublimer. The identity of the sublimed product (14 grams, 74% yield) was confirmed by mass spectrometry and x-ray diffraction. Product purity was estimated at 99- -% by GLC (electron capture detector). 

Attention is drawn to the dechlorination by anaerobic bacteria of both chlorinated ethenes and chlorophenolic compounds that serve as electron acceptors with electron donors including formate, pyruvate, and acetate. This is termed dehalorespiration and is important in the degradation of a range of halogenated compounds under anaerobic conditions, and is discussed further in Chapter 3, Part 2 and Chapter 7, Part 3. 

During the degradation of 2-chloroacetophenone by a strain of Alcaligenes sp., one atom of 02 was incorporated into 2-chlorophenol formed from the 2-chlorophenyl acetate that was initially formed by Baeyer-Villiger monooxygenation (Higson and Focht 1990). 

A facultatively anaerobic organism designated Anaeromyxobacter dehalogenans (Sanford et al. 2002) was capable of dechlorinating ortho-chlorinated phenols using acetate as electron donor—2-chlorophenol was reduced to phenol and 2,6-dichlorophenol to 2-chloro-phenol (Cole et al. 1994). A strain of Desulfovibrio dechloracetivorans was also able to couple the dechlorination of ortho-substituted chlorophenols to the oxidation of acetate, fumarate, lactate, and propionate (Sun et al. 2000). 

A spore-forming strain of Desulfitobacterium chlororespirans was able to couple the dechlorination of 3-chloro-4-hydroxybenzoate to the oxidation of lactate to acetate, pyruvate, or formate (Sanford et al. 1996). Whereas 2,4,6-trichlorophenol and 2,4,6-tribro-mophenol supported growth with the production of 4-chlorophenol and 4-bromophenol, neither 2-bromophenol nor 2-iodophenol was able to do so. The membrane-bound dehalogenase contains cobalamin, iron, and acid-labile sulfur, and is apparently specific for ortho-substituted phenols (Krasotkina et al. 2001). 

Sun B, JR Cole, RA Sanford, JM Tiedje (2000) Isolation and characterization of Desulfobvibrio dechlorace-tivorans sp. nov., a marine dechlorinating hacterium growing hy coupling the oxidation of acetate to the reductive dechlorination of 2-chlorophenol. Appl Environ Microbiol 66 2408-2413. 

Organic carboxylic acids are commonly found in foods, in the adipate process stream, and as pollutants. Fatty acids are the lipophilic portion of glycerides and a major component of the cell membrane. Phenols are widely used in polymers, as wood preservatives, and as disinfectants. Chloro-phenols such as 4-chlorophenol, two isomeric dichlorophenols, 2,4,6-tri-chlorophenol, three isomeric tetrachlorophenols, and pentachlorophenol were separated on a Dowex (The Dow Chemical Co. Midland, MI) 2-X8 anion exchange resin using an acetic acid-methanol gradient.138... 

A number of carboxylic acids other than acetic were investigated as solvents or promoters. All of these acids which were stable to reaction conditions were found to be effective in promoting glycol ester production (e.g., propionic, pivalic, benzoic, etc.). However, other Br nsted acids of non-carboxylic nature were not found to be effective promoters. Thus penta-chlorophenol, although it has a pKa value (4.82) very close to that of acetic acid (4.76), is not a comparable promoter (Table I, reaction 13). Likewise, phosphoric acid (pK 2.15) is not an effective solvent or co-solvent with acetic acid (Table I, reaction 8). Experiments with lower concentrations of these acids in sulfolane solvent also showed that carboxylic acids are unique in promoting glycol formation. The promoter function of carboxylic acids thus appears not to be dependent (only) upon their acidity, but on some other chemical or structural property. 

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. 

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. 

Lee [42] determined pentachlorophenol and 19 other chlorinated phenols in sediments. Acidified sediment samples were Soxhlet extracted (acetone-hexane), back extracted into potassium bicarbonate, acetylated with acetic anhydride and re-extracted into petroleum ether for gas chromatographic analysis using an electron capture or a mass spectrometric detector. Procedures were validated with spiked sediment samples at 100,10 and lng chlorophenols per g. Recoveries of monochlorophenols and polychlorophenols (including dichlorophenols) were 65-85% and 80-95%, respectively. However, chloromethyl phenols were less than 50% recovered and results for phenol itself were very variable. The estimated lower detection limit was about 0.2ng per g. 

Xie [39] determined trace amounts of chlorophenols and chloroguaiacols in marine sediments collected off the Swedish coast. The compounds were desorbed from sediment surfaces by a mixture of acetic anhydride and hexane, after buffering with O.lmol L 1 sodium carbonate. The optimal pH was achieved by a 1 4 ratio of buffer to acetic anhydride. The acetylated extracts were analysed by glass capillary gas chromatography with electron capture detection. The recoveries, at the pg kg-1 level, ranged from 85-100% with standard deviations of 4-11%. 

Chemical/Physical. Wet oxidation of 2-chlorophenol at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). Wet oxidation of 2-chlorophenol at elevated pressure and temperature yielded the following products acetone, acetaldehyde, formic, acetic, maleic, oxalic, muconic, and succinic acids (Keen and Baillod, 1985). 

Bell (1956) reported that the composition of photodegradation products formed were dependent upon the initial 2,4-D concentration and pH of the solutions. 2,4-D undergoes reductive dechlorination when various polar solvents (methanol, butanol, isobutyl alcohol, ferf-butyl alcohol, octanol, ethylene glycol) are irradiated at wavelengths between 254 to 420 nm. Photoproducts formed included 2,4-dichlorophenol, 2,4-dichloroanisole, 4-chlorophenol, 2- and 4-chlorophenoxy-acetic acid (Que Hee and Sutherland, 1981). 

Acetamido-4-amino-6-chloro-s-triazine, see Atrazine Acetanilide, see Aniline, Chlorobenzene, Vinclozolin Acetic acid, see Acenaphthene, Acetaldehyde, Acetic anhydride. Acetone, Acetonitrile, Acrolein, Acrylonitrile, Aldicarb. Amyl acetate, sec-Amyl acetate, Bis(2-ethylhexyl) phthalate. Butyl acetate, sec-Butyl acetate, ferf-Butyl acetate, 2-Chlorophenol, Diazinon. 2,4-Dimethylphenol, 2,4-Dinitrophenol, 2,4-Dinitrotoluene, 1,4-Dioxane, 1,2-Diphenylhydrazine, Esfenvalerate. Ethyl acetate, Flucvthrinate. Formic acid, sec-Hexyl acetate. Isopropyl acetate, Isoamyl acetate. Isobutyl acetate, Methanol. Methyl acetate. 2-Methvl-2-butene. Methyl ferf-butvl ether. Methyl cellosolve acetate. 2-Methvlphenol. Methomvl. 4-Nitrophenol, Pentachlorophenol, Phenol. Propyl acetate. 1,1,1-Trichloroethane, Vinyl acetate. Vinyl chloride Acetoacetic acid, see Mevinphos Acetone, see Acrolein. Acrylonitrile. Atrazine. Butane. 

Oxadiazonphenol, see Oxadiazon Oxalic acid, see Acetic acid, 2-Chlorophenol, Cyclohexene, 2,4-D, 2,4-Dinitrophenol, 1,4-Dioxane, Glycine. 2-Methylphenol, Naphthalene, 4-Nitroaniline, 4-Nitrophenol, Parathion, Phenol, Picloram. 2,4,5-T Oxamic acid, see Acetamide 1 -Oxa-2-oxocycloheptane, see Cyclohexane Oxindole, see Indole... 

Figure 2b. Experimental data on the effect of operating pressure and average pore size on membrane surface on solute separation and (PR)/(PWP) ratio for the reverse osmosis system cellulose acetate membrane-p-chlorophenol-water fill...

The preferential sorption-capillary flow mechanism of reverse osmosis does that. In the NaCl-H20-cellulose acetate membrane system, water is preferentially sorbed at the membrane-solution Interface due to electrostatic repulsion of ions in the vicinity of materials of low dielectric constant (13) and also due to the polar character of the cellulose acetate membrane material. In the p-chlorophenol-water-cellulose acetate membrane system, solute is preferentially sorbed at the interface due to higher acidity (proton donating ability) of p-chlorophenol compared to that of water and the net proton acceptor (basic) character of the polar part of cellulose acetate membrane material. In the benzene-water-cellulose acetate membrane, and cumene-water-cellulose acetate membrane systems, again solute is preferentially sorbed at the interface due to nonpolar... 

Typical procedure A mixture of p-chlorophenol (128 mg, 1 mmol), NaOH (40 mg, 1 mmol) and THF (10 mL) was stirred for 10 min allyldiisobutylteUuronium bromide (360 mg, 1 mmol) was then added. The reaction mixture was stirred for another 5 h at room temperature under nitrogen. Aqueous saturated NaHCOj solution was added and extracted with CH2CI2. The extract was dried over anhydrous MgS04 and concentrated in vacuo. The residue was chromatographed on sihca gel with 95 5 hexane-ethyl acetate as eluent to give a colourless oil of allyl p-chlorophenyl ether (145 mg, 86%). 

In the 19th century, various carbons were studied for their ability to decolorize solutions and adsorb compounds from gases and vapors. Commercial applications of activated carbon began early in the 20th century. Solutions containing phenols, acetic acid, herbicides, dyes, chlorophenols, cyanide and chromium have been successfully treated by carbon adsorption ( ). 

Chlorophenol Red [4430-20-0] M 423.3, Xmax573nm. Crystd from glacial acetic acid. 

Note Column headings key 135-TCB 1,3,5-trichlorobenzene 124-TCB 1,2,4-trichlorobenzene TCEE tetrachloroethylene MECL2 methylene chloride CHOL cyclohexanol ACET acetone NO2 benzene nitrobenzene MIBK methyl isobutyl ketone CHONE cyclohexanone DCB 1,2-dichlorobenzene THIQ 1,2,3,4-tetrahydroisoquinoline p-CLPHEN 4-chlorophenol THF tetrahydrofuran 24DCLPHEN 2,4-dichlorophenol 25DCLPHEN 2,5-dichlorophenol. 

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