Sodium trichlorophenolate

Under forcing conditions chlorine can be displaced by nucleophiles according to the mechanism described in this chapter also in compounds with fewer or weaker electron accepting substituents than hitherto mentioned. This explains the formation of tetrachlorodibenzodioxin ( dioxin ) from sodium trichlorophenolate in the well-known Seveso accident ... 

C12H4CI4O2. A by-product in the preparation of 2,4,5-trichlorophenol from 1,2,4,5-tetrachlorobenzene, sodium hydroxide and ethylene glycol. Causes chloracne in humans. 

Several antimicrobials have been banned or severely restricted by the EPA based on documented or suspected toxicity or environmental problems. Others have been discontinued in the face of testing costs required by the EPA reregistration program mandated by the Pederal Insecticide, Pungicide, and Rodenticide Act (PIPRA) of 1988 (10). Some of the significant products that have become obsolete are 2,4,5-trichlorophenol/P3 -5 3 -47, sodium... 

Oxidation of saligenin with chromic acid or silver oxide yields saUcyladehyde as the first product. Further oxidation results in the formation of sahcyhc acid, which is also obtained when saligenin is heated with sodium hydroxide at 200—240°C. Chlorination of an aqueous solution of the alcohol gives 2,4,6-trichlorophenol, and bromination in an alkaline medium yields 2,4,6-tribromophenol and tribromosaligenin. When saligenin is heated with one mole of resorcinol in the presence of anhydrous zinc chloride, 3-hydroxyxanthene forms. 

A mixture of 198 grams of 2,4,5-trichlorophenol and 1B.B grams of paraformaldehyde was heated to 65°C and well stirred. 65 grams of oleum 20% was added dropwise and the addition was So regulated that the temperature increased, without the application of external heat, until it reached 135°C at the end of the acid addition, which took 10 to 15 minutes. The contents of the reaction vessel were stirred for 2 minutes more and then allowed to run into a solution of 100 grams of sodium hydroxide in 1,000 cc of water. 

It would be diflBcult to estimate the quantity of TGDD which enters the environment each year. In addition to the common pesticides listed in Table I, other chlorophenols nd their derivatives are used widely. For example, large amounts of the disinfectant, hexachlorophene (2,2 -methylenebis(3,4,6-trichlorophenol)), are used in homes, hospitals, and industry, and the Dowcides 2 and B (2,4,5-trichlorophenol and its sodium salt) are industrial microbiocides. More than 50,000,000 lbs of trichloro-phenol are made in the United States each year (24), and much of it eventually must be dispersed in the environment. The dioxin content seems to be variable but is generally below 0.5 ppm (25). 

Octachlorodibenzo- -dioxin. Pentachlorophenol was purified by sublimation and recrystallization to yield a product with the following composition trichlorophenol, 0.04% tetrachlorophenol, 0.07% and pentachlorophenol, 100.4 1%. Pentachlorophenol (300 grams, 1.13 mole) was dissolved in 900 ml of trichlorobenzene and chlorinated anhydrously for 18 hours at reflux. Ghlorine addition was stopped and the mixture was heated for 28 more hours at reflux. The crystalline product was washed with 2-liter portions of chloroform, IN NaOH, methanol, and water. Analysis by GLG suggested the presence of 5-15% heptachloro-dibenzo-p-dioxin. The mixture was carefully added to a cleaning solution of 200 ml water, 3.5 liters sulfuric acid, and 125 grams sodium dichromate. The mixture was heated at 150 °G for six hours. The product was recrystallized from hot o-dichlorobenzene and then from anisole. The purified product (160 grams, mp 329.8° 0.5°G) contained <0.1% heptachlorodibenzo-p-dioxin, determined by GLG. 

Note The sulfanilic acid can also ers in this case the chromatogram in 10 mol hydrochloric acid) [5]. I diazotized sulfanilic acid [3]. In tl alcoholic iodine solution to cleave sodium carbonate solution and f 2,4,6-Trichlorophenol and 2,3,4 The detection limits for phenol are 0.1-1 pg substance per chron The reagent can be used, for c lulose layers. 

Haloprogin Haloprogin, 3-iodo-2-propinyl-2,4,5-trichlorophenyl ether (35.4.11), is synthesized by an iodide substitution using a mixture of iodine and potassium iodide and a cupric derivative of 2,4,5-trichlorophenylpropargyl ether (35.4.10), which is synthesized by a standard method from propargyl bromide and 2,4,5-trichlorophenol in the presence of sodium hydroxide [65-67]. 

However, a substantial proportion of the processed wood does not require long term perservation. Fresh-cut lumber is protected against attack by fungi and molds by passing the lumber through a spray tunnel, or by dipping. The chemicals used for this purpose are the sodium salts of PCP (US, Canada) or 2,3,, 6--tetra- and 2,U,6-trichlorophenol (Scandinavia). 

Trichlorophenol (see also Chlorophenols Chlorophenols occupational exposures to Polychlorophenols and their sodium salts)... 

Solutions of 1.0 M hydrogen peroxide in acetonitrile and 4.45 mM trichlorophenol (TCP) in ethyl acetate were used as postcolumn reagents, with the flow rates optimized at 1.0 ml/min each. The chromatographic eluent ranged from 70 to 80% acetonitrile-4 mM sodium phosphate buffer at apparent pH 7.5. The absorbance and fluorescence wavelengths for coumarin tags were as follows ... 

Another herbicide, 2,4,5-trichlorophenoxyacetic acid, is synthesized by starting with the chlorination of benzene to give 1,2,4,5-tetrachloroben-zene, which reacts with caustic to give 2,4,5-trichlorophenol. Conversion to the sodium salt followed by reaction with sodium chloroacetate and acidification gives 2,4,5-trichlorophenoxyacetic acid. Agent Orange is a 1-to-l mixture of the butyl esters of 2,4,5-trichlorophenoxyacetic acid and 2,4,-dichlorophenoxyacetic acid. 

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