Halogenation phenols and

Under aerobic conditions, S -adenosyhnethionine is the methyl donor for methylation of meth-anethiol and methaneselenol (Drotar et al. 1987), and probably for the bacterial methylation of halogenated phenols and thiophenols (Neilson et al. 1988). It is also the probable methyl donor for fungal methylation of the oxyanions of As and Sb (Bentley and Chasteen 2002). 

Neilson AH, C Lindgren, P-A Hynning, M Remberger (1988) Methylation of halogenated phenols and thiophenols by cell extracts of Gram-positive and Gram-negative bacteria. Appl Environ Microbiol 54 524-530. 

Bollag J-M, S-Y Liu (1985) Copolymerization of halogenated phenols and syringic acid. Pest Biochem Physiol 23 261-272. 

The persistence of halogenated phenols and anilines in anaerobic environments is determined by the activity of anaerobic dehalogenating bacteria. Extensive effort has therefore been devoted to isolating the relevant organisms and an increasing number of strains have been obtained in pure culture. They display different specificities for the position of the halogen several bring about dechlorination specifically at positions ortho to the chlorine, while some of them can use the aromatic substrate as... 

E. Klarmann, V.A. Shtemov and L.W. Gates, The alkyl derivatives of halogen phenols and their bactericidal action. I. Chlorophenols. J. Am. Chem. Soc., 55 (1933) 2576-2589. 

Higa, T., Fujiyama, T., and Scheuer, P. J., Halogenated phenol and indole constituents of acorn worms, Comp. Biochem. Physiol., 65B, 525, 1980. 

The primary chemicals associated with taints are solvents or inks, aliphatic aldehydes and ketones, phenols or halogenated phenols, and anisoles (Lord, 2003). 

The photochemistry of the halogenated anilines had received little attention until about 10 years ago, when the elucidation of the mechanisms of the photolysis of the halophenols, as described above, raised the question of the more general applicability of the obtained results. As will be detailed below, there are indeed close similarities between the halogenated phenols and anilines, but characteristic differences also exist. 

A few other biocides related to the halogenated phenols and anilines have been studied during the last years this work is summarized in the following section. The compound structures are shown in Table 3. 

The photoreactions characteristic for the halogenated phenols and anilines have shown to occur in most members of the series of chlorophenoxy and halophenylurea derivative pesticides, and in some other related biocides as well. Photohydrolysis is a frequently encountered process, but carbene formation has been demonstrated in several cases too. The phototransformation mechanisms of these molecules, however, are frequently complex, owing to the greater complexity of the molecules in question, and homolytic cleavage steps have been found to contribute in several cases. 

Indications. An immediate brown colour, or a green colour changing to brown, indicates the presence of an aminophenol or of a phenol having two or more hydroxy groups in adjacent positions on the ring. Monophenols, halogenated phenols, and phenols with hydroxyl groups meta to each other react more slowly or not at all. 

Higa T, Fujiyama T, Scheuer PJ. Halogenated phenol and indole constitute of acorn worm. Comp Biochem Physiol 1980 65B 525-30. 

The CZE separation of halogenated phenolic and bisphenolic compounds from 25 potentially interfering phenolic derivatives for inspection in water, sludge, and sediments has been attempted " using aqueous (borate buffer at pH 9.4) and nonaqueous (borate buffer in MeOH) systems (details in Table 31.9). 

E. Blanco, M.C. Casais, M.C. Mejuto and R. Cela, Comparative study of aqueous and non-aqueous capillary electrophoresis in the separation of halogenated phenolic and bisphenohc compounds in water samples, J. Chromatogr. A, 1068, 189-199, 2005. 

Han, Tao, and their co-workers [233,234] studied the pK s of several sets of halogenated phenols and found correlations between the 0-H anc C-0 bond lengths in the phenols, as determined by B3LYP/6-311-I-I-G or MP2/6-311-h-G calculations, and the halophenol pK s. In later studies they examined complexes of water and ammonia with both halophenols... 

A wide study of the chromatographic behavior of alkyl, halogenated phenols, and phenols containing alkyl and halogen groups by reversed-phase TLC has been performed by Bark and Graham on cellulose impregnated with ethyl oleate eluted with aqueous ethanol (Table 1). 

Maarse, H., Nijsen, L.M., Angelino, S.A.G.F. (1988) Halogenated phenols and chloroanisoles occurrence, formation and prevention. In Proceedings of the Second Wartburg Aroma Symposium, Warfhwrg, November 16-19, 1987, edited by Rothe, M. Berlin Akademie Verlag Berlin, pp. 43-61. 

Phenol and its derivatives are known to form phthaleins with phthalic anhydrides and the products are very well known acid-base indicators. With maleic anhydride, a variety of phenols have been examined by Webster and Kamstra, including halogenated phenols and aminophenols while using anhydrous stannic chloride and sulfuric acid as catalysts. Although indicator properties of some were shown, no rigorous structure proof or yield data were given. Maleins 146 were reported to have formed. 

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