Halogenated simple phenols

Halogenated phenols are more powerful disinfectants than simple phenols, as they are more lipophilic. They are also more toxic to the central nervous system. The chlorinated phenols are the most active. Toxicity is specific to each compound. 

Colourless solids. Carbohydrates simple phenols high rnoLwt. carboxylic adds, their salts and amides sulphonic adds, their salts and amides simple imides polyhydric alcohols Mgher mol.wt. esters polyhalogeno-aromatic hydrocarbons halogen substituted aromatic acids, their salts and amides bisulphite compounds of aldehydes and ketones aldehyde-anunonias condensation products of aldehydo- and keto-compounds. 

As recently as 1970, only about 30 naturally occurring organohalogen compounds were known. It was simply assumed that chloroform, halogenated phenols, chlorinated aromatic compounds called PCBs, and other such substances found in the environment were industrial pollutants. Now, only a third of a century later, the situation js quite different. More than 5000 organohalogen compounds have been found to occur naturally, and tens of thousands more surely exist. From a simple compound like chloromethane to an extremely complex one like vancomycin, a remarkably diverse range of organohalogen compounds exists in plants, bacteria, and animals. Many even have valuable physiological activity. Vancomycin, for instance, is a powerful antibiotic produced by the bacterium Amycolatopsis orientalis and used clinically to treat methicillin-resistant Staphylococcus aureus (MRSA). 

The extension of the Srn 1 reaction to polycyclic aromatic substrates has been limited almost entirely to the simple halogenated derivatives (see tables and references in Section 2.2.3). The substrates used include 4-halobiphenyls, 1- and 2-halonaphthalenes, 9-bromoanthracene and 9-bromophenanthrene. There appears to be only one report on the effect of additional substituents on these ring systems the ionized phenolic group in l-bromo-2-naphthoxide causes substitution of the bromine by CH2CN to be completely supplanted by a reductive process.39... 

With the simple aryl halides such as the mono-chlor derivatives of benzene or its homologues this reaction does not take place. Tf, however, a benzene halide has also substituted in the ring two nitro, sul-phonic acid or carboxyl groups, in the ortho and para positions to the halogen, then treatment of the halide with potassium hydroxide results in replacing the halogen with hydroxyl and the corresponding substituted phenol will be obtained. 

The analogs were prepared from readily available anilines. Halogen substitution as well as substitution with other electron withdrawing groups did not substantially improve potency in the PCA assay. Simple alkyls also had only minor impact on potency. More significant improvements were made with hydroxyl functions and their derivatives, as shown in Table II. The phenol esters were prepared by conventional methods from the phenoxide and a suitable acid halide or anhydride. The PCA activity of the various esters reached a maximum with the valerate (19) but even this was not significantly more potent than the parent 4-hydroxy derivative, 15, which was our early lead candidate. 

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