Phenolics from 4-Alkylphenol compounds

Azo dyes derived from alkylphenols have been utilised in silver halide colour photographic compositions for obtaining improved sharpness (ref. 91). In the compound illustrated, R = a phenolic or alkylphenolic group having an hydroxyl substituent o- or p- to the azo group, R = OH or NHj and R = an organic group or atom. 

Long-chain alkylphenols have been investigated extensively (33) by both adsorption and reversed-phase partition methods (34). The cashew phenols (from Anacardium occidentale) comprise cardanol (1), cardol (2), 2-methylcardol (3), and anacardic acid (4), each existing as a mixture of the saturated, 8 -monoene, 8 ,11 -diene, and 8 ,1 l ,14 -trieneconstituents. In ammoniated solvent [light petroleum-diethyl ether-ammonia (60 40 2)] the acidic compound anacardic acid remained practically on the baseline, whereas in an acidic solvent [light petroleum-diethyl ether-formic acid (70 30 1)] it migrated toward the solvent front as an intramolecularly bonded substance. In natural cashew nut shell liquid the phenols and their unsaturated constituents have the values 0.20 (cardol). 

Contamination of water by phenol or substituted phenols is very often due to industrial activity, because these are commercially very important chemicals. Phenol, cresylic acids, and cresols are used for making phenol-formaldehyde resins and tricesyl phosphates. Phenol, alkylphenol, and polyphenols are important raw materials for a wide variety of organic compounds, dyes, pharmaceuticals, plastizers, antioxidants, etc. Phenols are also present in effluents from coke ovens, blast furnaces, and shale oil processing [1]. 

Because of the formation of emulsions at phase boundaries for APE surfactants, EEE is limited to the degradation products APs, alkylphenol monoethoxylate to triethoxylate (APE(l-3)) and alkylphenol ethoxy carboxylate (APEC). Dichloromethane and hexane are the solvents commonly used in the extraction of APs and APE(l-3) from liquid samples.For phenolic compounds including BPA, OP, and NP, water samples are often acidified to pH < 4 with hydrochloric acid. Acidification of water samples suppresses the dissociation of phenols and prevents the ionization of the analytes, which increased the efficiency of the extraction. Del Olmo et al. " studied the effect of pH on extraction of BPA using sodium hydroxide and hydrochloric acid for adjustment. The result obtained showed that the extraction efficiency remains constant for pH values lower than 6.5, decreasing sharply for higher values. This behavior agrees with the weak acid nature of BPA. 

Some of the preparative methods for alkyl phenols and their reactions are unique to this class and both therefore warrant separate treatment from the parent compound. These features are even more prevalent in the hindered phenols a group of substances first synthesised less than half a century ago. In this account the synthesis of alkylphenols bearing purely methylenic side-chains in the benzenoid, naphthalenic and polycyclic series are considered first. Alkylphenols with side-chains containing oxy or alkoxycarbonyl groups are then reviewed, followed by mention of those containing Si, N or S in the side-chain and finally polycyclic types with saturated and unsaturated rings bearing hetero atoms. As before emphasis has been placed on developments in the last decade. 

With the exception of 4-(1,1,3,3-tetramethylbutyl)phenol prepared from diisobutylene, all the mutti-branched alkylphenols discussed consist of isomeric mixtures. In the pursuance of structure/property interests several studies have aimed to synthesise pure compounds. Thus by Wurtz-type methodology the reaction of the isomeric chloroanisoles with (i) alkyl iodides in ethereal solution in the presene of sodium and (ii) demethylation of the resultant alkylanisoles with aluminium bromide, a range of C5, Cg and Cg alkylanisoles has been synthesised (ref. 14). Numerous other methods are available for the synthesis of the isomeric n-, iso-, sec- and tert-alkylphenols some of which are referred to in Chapter 13. Reaction of a mixture of the appropriate alkyl chloride and 2-,... 

The determination of phenols was preferentially performed using GC-MS with analytes in underivatized or derivatized form, but LC-MS methods were also developed. API methods for the analysis of phenols in aqueous matrices were applied [315, 316, 317]. APCI-LC-MS was found to be more sensitive than ESI application despite the possibility of improving ESI-sensitivity by a post-column addition of diethyla-mine [317]. Detection limits were observed with 0.02-20 ng injected onto the column. The determination of alkylphenols and bisphenol A as compounds with endocrine disrupter potential was also performed by ESI-LC-MS from aqueous [318, 319] and sediment samples with detection limits in the low pg L range [346]. 

E. Blanco, M.C. Casais, M.C. Mejuto and R. Cela, Approaches for the simultaneous extraction of tetrabromobisphenol A, tetrachlorobisphenol A and related phenolic compounds from sewage sludge and sediment samples based on matrix sohd-phase dispersion, J. Chromatogr. A, 78, 2772-2778, 2006. S. Takeda, A. Omura, K. Chayama, H. Tsuji, K. Fukushi, M. Yamane, S.-I. Wakida, S. Tsubota and S. Terabe, Separation and on-line concentration of bisphenol A and alkylphenols by micellar electrokinetic chromatography with cationic surfactant, J. Chromatogr. A, 979, 425-429, 2002. 

As an improvement in product economics, a distillate of an alkylphenol mixture was used for phenolic resin production to reduce the production costs. The constituents ofthe distilled alkylphenol are 4-ethylphenol, 3,4-dimethylphenol, 3-methyl-4-ethylphenol, 2-hydroxyphenol, and alkylated products of 2-hydroxyphenol [161]. The distilled alkylphenol contains approximately 40% benzenediol compounds that faster react than phenolic compounds. Therefore, gum rosin was added to slow down the reaction rate. Gum rosin or colophon is a thermoplastic acidic product isolated from living pine trees that consists of a complex mixture of monocarboxylic acids of alkylated hydrophenanthrene nuclei (Scheme 23). 

Formulators can choose from a variety of commercially available phenolic compounds, including, in addition to phenol itself, the isomers of cresol, the isomers of xylenol, resorcinol, catechol, hydroquinone, bisphenol A, and various alkylphenols. Formaldehyde is usually used as the second major component, but acetaldehyde, furfuraldehyde, and paraformaldehyde (the polymer of... 

Rate of depuration from fish tissues is extremely variable. Phenol has a particularly short half-life (<1 hour), as does 3-nitrophenol (- 1 hour). Several other compounds, such as 3,5-diethylphenol and 4-aminophenol, also have a short half-life (5-7 hours), but a number of the alkylphenols persist in tissues for extended periods of time. For example, McLeese etal. 

Right from the start Zinke planned a comprehensive study of chemical processes involved in the curing (= hardening) of phenol-formaldehyde resins. Thus, the series he published received the title Zur Kenntnis des Hartungsprozesses von Phenol-Formaldehyd-Harzen . The first paper [19] appeared in 1939 [20], the last contribution [21], number XXVHI in this series, in 1958 [22]. In the industrial production of phenolic resins not only phenol itself but also alkylphenolss, and mixtures thereof, are valuable parts of the recipes, Zinke used ortho and/or para substituted alkylphenols as model compounds. Also, 2- and 4-chlorophenol and 2,4-dichlorophenol were employed to block reactive sites in order to simplify the first reaction steps. The work performed in Graz has certainly added much to our... 

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