Phenolic compounds, supported liquid

Jung V, Chimuka L, Jdnsson JA, Niedack N, Bowens P, and Alsanius B. Supported liquid membrane extraction for identihcation of phenolic compounds in the nutrient solution of closed hydroponic growing systems for tomato. Anal. Chim. Acta 2002 474 49-57. 

Several coumarins starting from appropriate phenolic compounds have been synthesized in a microwave-assisted reaction using trifluoroacetic acid, which acts as an acidic reagent and a reaction medium. Alternatively, polymer-supported sulfonic acid Amberlyst-15 could also be utilized to assist the formation of coumarins. The usage of a particularly built microwave synthesizer with liquid handling tools rendered the automated synthesis of a coumarin library achievable (07CHE151). 

The allcylation of a number of aromatic compounds through the use of a chloroa-luminate(III) ionic liquid on a solid support has been investigated by Holderich and co-workers [87, 88]. Here the allcylation of aromatic compounds such as benzene, toluene, naphthalene, and phenol with dodecene was performed using the ionic liquid [BMIM]C1/A1C13 supported on silica, alumina, and zirconia. With benzene, monoalkylated dodecylbenzenes were obtained (Scheme 5.1-56). 

Detailed discussion of these findings will be presented elsewhere. Here we only wish to point out that responses to a hydrogen donor tend to be critically affected by minor structural differences between the compounds. Thus, while diphenyl ether remains substantially unaffected by the donor, its hydroxy-derivatives (phenoxy phenols) often display fairly high reactivity. Taken in conjunction with the failure of low-rank coals (7) and phenoxy phenols (10) to suffer reductive cleavage when treated with sodium in liquid ammonia, this lends some support for the existence of phenoxy phenol entities in low rank coals. 

Alkylation. Friedel-Crafts alkylation (qv) of benzene with ethylene or propylene to produce ethylbenzene [100-41 -4], CgH10, or isopropylbenzene [98-82-8], C9H12 (cumene) is readily accomplished in the liquid or vapor phase with various catalysts such as BF3 (22), aluminum chloride, or supported polyphosphoric acid. The oldest method of alkylation employs the liquid-phase reaction of benzene with anhydrous aluminum chloride and ethylene (23). Ethylbenzene is produced commercially almost entirely for styrene manufacture. Cumene [98-82-8] is catalytically oxidized to cumene hydroperoxide, which is used to manufacture phenol and acetone. Benzene is also alkylated with C1Q—C20 linear alkenes to produce linear alkyl aromatics. Sulfonation of these compounds produces linear alkane sulfonates (LAS) which are used as biodegradable deteigents. 

The first series of compounds assayed directly by CD detection were the morphine alkaloids. They were supported in aqueous solutions, in a chiral cholesteric liquid crystal solvent, and mixed in pellet form with solid KBr. ° Contrary to expectations, the homogeneous aqueous solution medium gave the best selectivity among 10 related opiates and the most quantitative results. The pH-dependence of phenol substituted analogs, which in some instances caused the sign of the CD signal to invert, enhanced the selectivity. Heroin was assayed both directly and as the morphine hydroly-sate.f Direct multicomponent analyses were made for prepared mixtures of morphine, codeine, thebaine, noscapine, and opium extracts. ... 

Tapia et al. [23] described the use of nitric acid supported on silica gel for the mono-nitration of activated aromatic compounds such as phenols and aryl methyl ethers. Riego et al. [24] used sulfuric acid supported on silica gel for the mononitration of a variety of aromatic compounds. The reaction was performed at ambient temperature with 70 % nitric acid or isopropyl nitrate as reagents and yielded mono-nitrated products within short reaction periods. Toluene was quantitatively converted to NT in 0.1 h, without a solvent, by use of a catalyst containing 10 mmol g as supported 70% H2SO4. A comparative study of the reaction kinetics of the nitration using supported and unsupported liquid acids revealed that the performance of supported sulfuric acid is comparable with that of 90 % sulfuric acid in the classical liquid phase reaction where complete protonation of nitric acid occurs [25]. 

Phenolic resins are supplied as liquids and powders and quite often they are compounded into adhesives by the addition of extenders, solvents, and catalysts just prior to use. Compounded phenolic adhesives are also supplied, as supported or unsupported films, one-part catalyzed pastes, or two-part room temperature curing pastes. 

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