Ethyl-phenol structure

The hydroxyphenylbenzotriazole structure was constructed by a coupling of the diazonium salt of o-nitroaniline with 4-ethyl-phenol, followed by reduction of the nitro-azobenzene to the benzotriazole with zinc powder and NaOH. After blocking of the phenol by acetylation, bromination and dehydrobromination were performed as described earlier, and treatment with aqueous NaOH... 

The stable tannin-ethyl-anthocyanin structures are apparently transformed at varying rates into orange compounds, via the fixation of the polarized double bond of the vinyl-procyanidins on the anthocyanins, to form procyanidin-pyranoantho-cyanin complexes (Francia-Aricha et al., 1997). The rate of conversion depends on the wine s phenol content, the origin of the tannins (skins or seeds), and the phenolic structures (tannin-anthocyanin combinations) present at the end of the aging period. 

A tetradentate ligand 2- bis[2-(2-pyridyl)ethyl]aminomethyl phenolate complexes zinc with an N30 donor set including pyridyl and phenolic groups. The X-ray structure reveals that a dimeric... 

A bismuth-catalyzed alkylation of warfarins has not been described, although a bismuth-mediated synthesis of the coumarin core structure 21 starting from phenols 19 and ethyl acetoacetate 20 is known (Scheme 17) [51]. The synthesis of coumarins proceeds in the same way as the above-described indene synthesis. The initial reaction of phenol 19 and ethyl acetoacetate 20 leads to the ester. 

M. Shi and Y.-L. Shi reported the synthesis and application of new bifunctional axially chiral (thio) urea-phosphine organocatalysts in the asymmetric aza-Morita-Baylis-Hillman (MBH) reaction [176, 177] of N-sulfonated imines with methyl vinyl ketone (MVK), phenyl vinyl ketone (PVK), ethyl vinyl ketone (EVK) or acrolein [316]. The design of the catalyst structure is based on axially chiral BINOL-derived phosphines [317, 318] that have already been successfully utilized as bifunctional catalysts in asymmetric aza-MBH reactions. The formal replacement of the hydrogen-bonding phenol group with a (thio)urea functionality led to catalysts 166-168 (Figure 6.51). 

Phenols are a major chemical lump present in coal liquids. Phenols have basically one or more aromatic ring structures with alkyl substituents. Methyl, ethyl and propyl are the most common alkyl substituents. The smallest specie is the one with a hydroxyl group attached to a benzene ring. Addition of a methyl group produces three isomers - o-, m-, and p-cresols. It appears that all three are present in more or less same proportion. The number of possible isomers increases as the possible number and size of alkyl substituents increases. It is expected that higher... 

A similar reaction of 1,3-dimethyl ether p-t-Bu-calix[4]arene, abbreviated as (H2L), with Et2Zn affords a monomeric compound (EtZn)2(L) (169) with a less complex structure (Figure 84) °. The zinc atoms in this compound form a flat Zn—O—Zn—O arrangement together with the phenolate oxygen atoms. To each zinc atom one ethyl group is bonded, and tetrahedral coordination is reached by the additional coordination of one methoxy group. 

Mesitylene. One of the principal derivatives of mesitylene is the sterically hindered phenol of the structure shown in Figure 4. Its trade name is Ethanox 330 and it is produced by Albemade Corporation (formedy Ethyl Corporation) (31). Ethanox 330 is an important noncoloring antioxidant and thermal stabilizer for plastics, adhesives, rubber, and waxes (qv) (32,33) (see Antioxidants). The oral toxicity of Antioxidant 330 is extremely low (oral 1D. in rats > 15 g/kg) since its large size, Cc4H7 0, effectively eliminates absorption from the gastrointestinal tract. 

Inclusion complexes were prepared by crystallization of Cl-MIT and host compounds from methanol. When alkyl phenol compounds (2-10) were used as hosts, a 2 1 complex (17) of 2,4-di-ferf-butylphenol (8) and Cl-MIT (1) was obtained (Table 2). However, other similarly structured phenol compounds (2-7,9,10) failed to yield inclusion complexes. For example, when a tert -butyl group from 8 was exchanged for a methyl group (6) or an ethyl group (7), no inclusion complex was obtained, so it is obvious that even a slight difference in structure influences whether or not an inclusion complex is formed. 

Another phenoxide activating approach published by Buchwald et al. [18] is based on the reaction of cesium phenoxides with aryl bromides or iodides in the presence of catalytic amounts of copper(I) triflate and ethyl acetate in refluxing toluene (Scheme 3b). In certain cases equimolar amounts of 1-naphthoic acid have been added in order to increase the reactivity of the phenoxide. The authors assume the formation of a cuprate-like intermediate of the structure [(ArO)2Cu] Cs+ as the reactive species. In addition, diaryl ether formation between phenols and aryl halides has been achieved using a phosphazene base forming naked phenoxide in the presence of copper bromide in refluxing toluene or 1,4-dioxane [19]. 

Dry clean tanshen rhizomes were powdered and extracted with hexane for three days at room temperature. The hexane solution was kept overnight and then filtered. After removal of the solvent a residue was obtained which was separated into seven colored fractions by column chromatography with silica gel. Miltirone was isolated by preparative tic from fraction 1 (light red) using hexane ethyl acetate (4 1) followed by benzene-acetone (20 1). The product obtained was recrystallized from ethylacetate, m.p. 100-101°C. Its structure was confirmed by mass spectrum, NMR, IR and UV spectra which agree quite closely with those of Ho et al [76], Miltirone showed antioxidant behavior comparable to that of the commonly used phenolics BHT and BEA [77], The antioxidant activity of miltirone in lard at 100°C was determined with a Rancimat. Miltirone and other related compounds may have the potential of being used as natural antioxidants in food and cosmetics. 

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