Pentachlorophenol, synthesis

The synthesis of chlorarul [118-75-2] (20) has been improved. The old processes starting from phenol or 2,4,6-trichlorophenol have been replaced by new ones involving hydroquinone chlorination. These processes allow the preparation of chlorarul of higher purity, avoiding traces of pentachlorophenol. Different types of chlorination conditions have been disclosed. The reaction can be performed according to the following stoichiometry, operating with chlorine in aqueous acetic acid (86,87), biphasic medium (88), or in the presence of surfactants (89). 

The tolerance of the strains to high concentrations of pentachlorophenol—S. chlorophenolica appears to be less sensitive than M. chlorophenolicus (Miethling and Karlson 1996). This may be attribnted to the ability of the cells to adapt their metabolism to avoid synthesis of toxic concentrations of chlorinated hydroquinones, and is consistent with the low levels of these metabolites measnred in the cytoplasm of cells metabolizing pentachlorophenol (McCarthy et al. 1997). Inocnla have also been immobilized on polyurethane that, in addition, ameliorates the toxicity of chlorophenols (Valo et al. 1990). 

Ehrlich, W., M Mangir, and E.R. Lochmann. 1987. The effect of pentachlorophenol and its metabolite tetrachlorohydroquinone on RNA, protein, and ribosome synthesis in Saccharomyces cells. Ecotoxicol. Environ. Safety 13 7-12. 

Wood preservation Intermediates in industrial synthesis of Pentachlorophenol 2.3.4.6- Tetrachlorophenol 2.4.6- Trichlorophenol... 

In addition to its use in resins and adhesives, phenol is also the starting material lor the synthesis of chlorinated phenols and the food presen -atives BHT (butylated hydrox5rtoluene) and BHA (butylated hydroi -anisole). Pentachlorophenol, a widely used wood preservative, is prepared by reaction of phenol with excass C12- The herbicide 2,4-D (2,4-dich)oro-phenoxyacetic acid) is prepared from 2,4-dichlorophenol, and the hospital antiseptic agent hexachlorophene is prepared from 2,4,5-trichlorophenol. 

Peptide synthesis /-Amyl chloroformate. Bis-(2,4-dinitrophenyl)carbonate. Bis-o-phenylene pyrophosphite. i-Butyl chloroformate. sec-Butyl chloroformate. /-Butyl chloroformate. /-Butyl 2,4,5-trichlorophenyl carbonate. CopoIy(ethylene-N-hydroxymaleimide). N,N-Diethyl-I-propynylamine. Di-(p-nitrophenyl)sulfate. Ethoxyacetylene. N-Ethoxycarbonyl-2-ethoxy-l,2-dihydroquinoline. N-Ethylbenzisoxazolium fluoroborate. Ethyl chloroformate. N-Ethyl-5-phenylisoxazolium-3 -sulfonate. N-Hydroxysuccinimide trifluoroacetate. Methyl-morpholine. 4-Methylthiophenol. p-Nitrophenol. Oxalylchloride. Pentachlorophenol. Pentamethylbenzyl chloride. /-Pentyl chloroformate. Phenacyl bromide. Polyhexamethylene carbodiimide. Tetraethyl pyrophosphite. 1,2,4-Triazole. 

Dioxins are chemical contaminants produced during the synthesis of chlorophenols and certain other halogenated aromatic hydrocarbons. There are 75 dioxin isomers of which 2,3,7,8 tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is the most toxic in animal studies (1 ). Table I illustrates some major substances contaminated with isomers of dioxin. These manufactured products include 2,4,5-trichloro-phenol (TCP) and its derivatives, such as 2,4,5-trichlorophenoxy-acetic acid (2,4,5-T), which are contaminated with 2,3,7,8-TCDD, as well as pentachlorophenol, which is contaminated with hexa-, hepta-, and octachlorinated isomers of dioxin. 

The herbicides of this group are mostly superseded and replaced by less toxic chemicals. Pentachlorophenol (PCP, 1) was introduced in 1936 as a timber preservative in the United States. It is produced by catalytic chlorination of phenol (Stoesser, 1937). Other procedure for the synthesis of pentachlorophenol uses the inactive hexachlorocyclohexane isomers as starting material. The isomer mixture is partially hydrolised, then from the polychlorophenol mixture formed pentachlorophenol is obtained by chlorination ... 

Hedayatullah and Hugueny358 developed a useful synthesis for the preparation of N,N -disubstituted sulphamides (354) using chlorosulphonylisocyanate. The reaction involves heating pentachlorophenol at 130 °C with chlorosulphonylisocyanate to yield the N-... 

Storage Store in cool, dry place keep tightly closed keep away from oxidizing materials Uses Starting material in mfg. of trichlorophenols, tetrachlorophenols, and pentachlorophenols Regulatory SARA 313 reportable Manuf./Distrib. Aarti Ind. Ltd http //WWW. aarti group, com, AccuStandard http //www.accustandard.com, Acros Org. http //www.acros.be, Advanced Synthesis Tech. http //WWW.advancedsynthesis. com,... 

Uses Organic synthesis fungicide for seeds wood preservative mfg. of pentachlorophenol prod, of aromatic fluorocarbons in... 

Dextrin Lactose penicillin precursors Benzyl chloride penicillin purification reagent Potassium acetate penicillin synthesis 3-Trimethylsilyl-2-oxazolidinone pennyroyal, perfumes Piperitenone pens/pencils Acetal copolymer pentachlorophenol mfg. 

Hirota, in the total synthesis of quassinoid amaroUde 257 [56], used a nonacidic catalysis with pentachlorophenol. Under these conditions and in the presence of 4 A molecular sieves, the expected ester 259 was obtained in moderate yield. However, large amounts of starting material were recovered. The diastereo-... 

Phenol is the starting material for the synthesis of 2,3,4,5,6-pentachlorophenol, known alternatively as pentachlorophenol, or more simply as penta. At one time, penta was widely used as a wood preservative for decks, siding, and outdoor wood furniture. Draw the structural formula for pentachlorophenol and describe its synthesis from phenol. 

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