Phenolic acetates

Guanidine, EtOH, CH2CI2, rt, 85-100% yield.Acetamides, benzoates, and pivaloates are stable under these conditions. Phenolic acetates can be removed in the presence of primary and secondary acetates with excellent selectivity. 

The following set of conditions will selectively remove a phenolic acetate in the presence of an alcoholic acetate. 

Bi(III)-mandelate, DMSO, 80-125°, 44-96% yield. Phenolic acetates with strong electron-withdrawing groups are hydrolyzed the fastest. ... 

It is obtained by allowing a solution of one molecule of phenol-acetic -ester in three to four times its weight of absolute alcohol, to fall in drops on a quantity of sodium calculated for six atoms. It is then heated for several hours on an oil-bath, until the sodium has disappeared, if necessary adding more alcohol. After cooling, water is added, and the ester which is not attacked is saponified. The alcohol and phenyl-ethyl alcohol are then distilled off with steam, when the latter is at once obtained in the pure state. 

Reductive alkylations have been carried out successfully with compounds that are not carbonyls or amines, but which are transformed during the hydrogenation to suitable functions. Azides, azo, hydrazo, nitro and nitroso compounds, oximes, pyridines, and hydroxylamines serve as amines phenols, acetals, ketals, or hydrazones serve as carbonyls 6,7,8,9,12,17,24,41,42,58). Alkylations using masked functions have been successful at times when use of unmasked functions have failed (2). In a synthesis leading to methoxatin, a key... 

Chamical Nama 4-[ [4-(acetyloxy)phenyl] cyclohexylidenemethyl] phenol acetate Common Name p,p -diacetoxybanzhydrilidenecyclohexane Structural Formula ... 

Chamical Name 4-[2-(Dimethvlamino)ethoxy] 2-methyl-5-(1-methylethyD-phenol acetate (ester)... 

CN 4-[2-(dimethylamino)ethoxy]-2-raethyl-5-(l-methylethyl)phenol acetate (ester) hydrochloride... 

The quinone methide can also be generated in situ, at least in aqueous NaOH, directly from the peracetate, as hydrolysis of the phenolic acetate is faster than the benzylic acetate (see an example in Section 12.5.3). This method was used to demonstrate the addition of anthrahydroquinone (AHQ) and anthranol to (actual polymeric) lignin quinone methides in studies elucidating the anthraquinone (AQ)-catalyzed 8-0-4-aryl ether cleavage mechanisms in alkaline pulping.64-66... 

Oxidation of the benzylic methylene group in cyclazocine to a ketone is also consistent with analgesic activity. Acetylation of benzomorphan 62 affords the diacetate 63. Selective hydrolysis of the phenolic acetate (64) followed by methylation of the thus uncovered phenol affords intermediate 65. 

Phenol—formaldehyde resins, 10 408—409 Phenol—formaldehyde reactions, 18 760 Phenolic acetates, 20 45 Phenolic adhesives, 1 543—544 Phenolic antioxidants, 10 806... 

In the 19th century, various carbons were studied for their ability to decolorize solutions and adsorb compounds from gases and vapors. Commercial applications of activated carbon began early in the 20th century. Solutions containing phenols, acetic acid, herbicides, dyes, chlorophenols, cyanide and chromium have been successfully treated by carbon adsorption ( ). 

It is evident that some leeway is available in the substituents tolerable in the m-position. The bronchodilator sulfonterol (28) is descended from this observation. Chloromethylanisole (29) is reacted with methylmereaptan to give 30, and the newly introduced group is oxidized to the methyl-sulfonyl moiety of 31 with hydrogen peroxide. Ether cleavage, acetylation and Fries rearrangement of the phenolic acetate produces 32, which is next brominated with pyrrolidinone hydrobromide tribromide and then oxidized to the glyoxal (33) with dimethyl sulfoxide. 

Bipyridine and 4,4 -bipyridine form molecular complexes with halo-genated nitrophenols." " The former also complexes with urea, thiourea and related compounds," benzyl alcohol, phenol," acetic... 

Brass, bronze, steel, phenolic, acetal, and nylon (natural) had been used with various degrees of success. A specially formulated cast polyamide was recommended, tested, and designed into the function. The part is currently offering a longer wear life, with less moisture pick-up and greater ease of installation. 

A freshly prepared solution of nitroguanidine in concentrated sulfuric acid contains no nitric acid, for none can be distilled out of it, but it is ready to produce nitric acid (by the hydration of the nitroamide) if some material is present which will react with it. Thus, it gives up its nitro group quantitatively in the nitrometer, and it is a reagent for the nitration of such substances as aniline, phenol, acet-p-toluide, and cinnamic acid which are conveniently nitrated in sulfuric acid solution. 

Scheme 5 The polymers were imprinted with the TSA (25) to mimic the tetrahedral transition state (24) generated during the hydrolysis of the 4-nitro-phenol-acetate (23)...

Meng and Sode [35, 36] also reported the preparation of imprinted polymers to be used as reaction vessels for the transesterification of p-nitro-phenol acetate (23) and hexanol. The MIP showed eightfold increased activity when compared to the NIP. 

As already shown by Moore and co-workers9 and Tour and coworkers,10 addition of methyl iodide to a triazene resin at elevated temperature (110°) gives rise to aryliodides 17-1 (Nu = I) in excellent yields. We have shown that aryl halides 17-X (X = Cl, Br, I) are readily available by the action of lithium halides in the presence of an acidic ion-exchange resin or with the corresponding trimethylsilyl halide at room temperature.26 A mixture of acetic anhydride and acetic acid produces phenol acetates 17-OAc.26... 

Chemical Name 4-[[4-(Acetyloxy)phenyl]cyclohexylidenemethyl]phenol acetate... 

Several histidine-containing cyclic dipeptides catalyse phenolic acetates (65). Cyelo(Gly-L-His), cydo(L-Leu-L-His) and cyclo(D-Leu-L-His) have almost the same pK value of their imidazole moieties as that of imidazole. Nevertheless, catalytic activities of the former two cyclic dipeptides are less than that of imidazole and the latter has an activity of 20-times that of imidazole. This was also explained by showing that there are considerable steric hindrances influencing the catalysis and that the latter has a remarkably effective hydrophobic interaction which exceeds the hindrance. 

Acetates of fatty [1] and polyhydric [2] alcohols, phenols [3] and chlorophenols [4] have been studied. Fell and Lee [3] described a GC method for the determination of polyhydric phenols in urine, which, having been extracted, were acetylated with acetic anhydride in the presence of 4-dimethylaminopyridine. According to these authors this substance shows much stronger catalytic effects than does the usually used pyridine. The derivatives are formed rapidly and quantitatively even in very dilute solutions. In the absence of the catalyst, bifunctional phenols provide more than one GC peak. Slightly polar OV-210 is recommended for the separation of phenol acetates, but analysis on nonpolar OV-101 leads to tailing, probably as a consequence of insufficient deactivation of the column. 

Fig. 5.1. Separation of chlorophenol acetates (2-0.02 ng). Peaks 1 = 2-chloro 2 = 3-chloro 3 = 4-chloro 4 = 2,6-dichloro 5 = 2,5-dichloro 6 = 2,4-dichloio 7 = 3,4-dichloro 8 = 2,3-dichIoro 9 = 3,5-dichloro 10 = 2,4,6-trichloro 11 = 2,4,5-trichloro 12 = 2,3,4,6-tetrachloro 13 = pentachloro-phenol acetates. Conditions Pyrex glass column (25 m X 0.35 mm I.D.), dynamically coated with SE-30 temperature programme, 3°C/min (95-180°C) helium flow-rate, 2-3 ml/min splitting flow-rate, 0-60 ml/min. (Reproduced from J. Chromatogr. 131 (1977) 412.)...

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