Biphenyl-2-acetic acid

Rearrangement to acids is accomplished by adding a dioxane solution of diazoketone to a suspension of silver oxide in warm aqueous sodium thiosulfate solution. Examples include biphenyl-2-acetic acid (86%), ° 1-ace-naphthylacetic acid (64%), decane-1,10-dicarboxylic acid (72%), and o-bromophenylacetic acid (63%). ... 

Acid chlorides are reacted with diazomethane to yield the diazoketone which upon reaction with silver oxide rearranges to the next higher homolog of the acid. Biphenyl-2-acetic acid is produced in 86% by the method described below [18]. 

To 0.6 mole of silver oxide in 0.84 mole of sodium thiosulfate in 1 liter of warm water is added a 1 M dioxane solution of oi-diazo-o-phenylacetophenone. The mixture is stirred for 3 hr at room temperature while an additional quantity of freshly precipitated silver oxide (equal in amount to that used initially) is added in portions at intervals and the temperature is kept at 50°C for 1 hr. The solution is cooled and filtered and the residue washed with a 1 % sodium hydroxide solution. This slowly deposits a flocculent precipitate upon acidifying. The residue is again treated with about one-half the amount of silver oxide used above and worked up as before to yield a further quantity of product. The total yield of biphenyl-2-acetic acid is 86% mp 116°C (from benzene). 

More than 90 years ago Bamberger (1897) discovered that iV-nitrosoacetanilide decomposes easily in benzene to give biphenyl, acetic acid, and molecular nitrogen (Scheme 2-24). 

Recent developments involve utilization of cyclodextrins that are absorbed only in minor quantities in the small intestine but are fermented by the colonic bacteria. In a recent study [56,57], the use of biphenyl acetic acid conjugates of P-cylcodextrins was described. The ester conjugate released the drug preferentially when incubated with rat cecal contents, and almost no release was observed on incubation with the contents of the stomach or the small intestine. 

Uekama, K., et al. 1986. Possible utility of (3-cyclodextrin complexation in the preparation of biphenyl acetic acid suppositories. Yakugaku Zasshi 106 1126. 

Arima, H., T. Rondo, and T. Irie. 1992. Use of water-soluble (3-cyclodextrin derivatives as carriers of anti-inflammatory drug biphenyl-acetic acid in rectal delivery. Yakugaku Zasshi 112 65. 

Since no intermediates could be detected in the in vitro studies of the oxidation of acetylenic derivatives, it was assumed that very short-lived intermediates were probably formed. In order to further characterize this pathyway, studies with deuterium and labeled biphenylacetylene (acetylenic hydrogen and internal acetylenic carbon, respectively) were initiated. The mass and nuclear magnetic resonance spectra of the resulting biphenyl acetic acid derivative showed that ... 

In the classical methods of diazotization an equimolar amount of water is formed as by-product. In certain cases this is not desirable. One method for obtaining diazonium salts without formation of water is the rearrangement of N-nitroso-N-arylacetamides. Bamberger discovered in 1897 that A -nitrosoacetanilide decomposes easily in benzene to give biphenyl, acetic acid and dinitrogen (equation 10). Huisgen and Horeld showed that the key step of Bamberger s reaction is the isomerization of N-nitrosoacetanilide to the diazo acetate (27) and Suschitzky found that 27 dissociates into the diazonium-acetate ion pair 28 (equation 11). 

W emulsion 1-Biphenyl acetic acid In viiro/in vivo (rabbits) 13... 

Acetic acid Acrylic acid Adipic acid Benzene Biphenyl Bisphenol-A Caprolactam Chloroacetic acid p-Chloro toluene p-Cresol... 

Biphenyl [92-52-4] M 154.2, m 70-71 , b 255 , d 0.992. Crystd from EtOH, MeOH, aq MeOH, pet ether (b 40-60 ) or glacial acetic acid. Freed from polar impurities by passage through an alumina column in benzene, followed by evapn. A in CCI4 has been purified by vac distn and by zone refining. Treatment with maleic anhydride removed anthracene-like impurities. Recrystd from EtOH followed by repeated vacuum sublimation and passage through a zone refiner. [Taliani and Breed Phys Chem 88 2351 1984.]... 

Substances Biphenyl-2-ylamine Sulfuric acid (25%) Ethanol Glacial acetic acid Orthophosphoric acid (85%)... 

De la Mare and Maxwell199 measured the rate of bromination of biphenyl by hypobromous acid in 75 % aqueous acetic acid, in some cases catalysed by perchloric acid, at temperatures between —3.78 and +20.1 °C. They showed that whereas when mineral acid is present the brominating species is Br+ (or a solvate), in the absence of mineral acid it is BrOAc which is a highly reactive brominating species giving Ea = 7.9 (this value is only approximate since it also includes a contribution from bromination by HOBr), and the appropriate kinetic equation is then... 

At 0.9 °C the rate of bromination of biphenyl relative to benzene was approximately 1,270, compared to 26.9 in the presence of mineral acid, and this latter value is fairly close to that obtained with 50 % aqueous dioxan. The possibility that the positive brominating species might be protonated bromine acetate, AcOHBr+, was considered a likely one since the reaction rate is faster in aqueous acetic acid than in water, but this latter effect might be an environmental one since bromination by acidified hypobromous acid is slower in 50 % aqueous dioxan than in... 

Mason256 has measured the second-order rate coefficients and Arrhenius parameters for the chlorination of benzene, biphenyl, naphthalene, and phe-nanthrene in acetic acid (containing 0.05 % water) and these are given in Table 62. 

De la Mare et al.260 measured the rates of chlorination of biphenyl, a wide range of its methyl derivatives, and anisole in acetic acid at 25 °C. Second-order rate coefficients (104 2) were biphenyl (6.40), 2-methylbiphenyl (3.20), 3-methyl-biphenyl (820), 4-methylbiphenyl (30.0), 2.2 -dimethylbiphenyl (4.40), 3.3 -dimethylbiphenyl (2,630), 4,4 -dimethylbiphenyl (70.0), 2,6 -dimethylbiphenyl (1,130), 3,4,3, 4 -tetramethylbiphenyl (19,300), anisole (12.5 x 104), and these results showed very clearly the effect of steric inhibition of resonance between the phenyl rings through the presence of ortho methyl groups260. Similar (but rather more emphatic) results were obtained262 in chlorination of the /-butyl derivatives for which the corresponding rate coefficients were 2-/-butylbiphenyl (1.0) 4-/-butylbiphenyl (25.7), 2,2 -di-/-butylbiphenyl (1.8), 4,4 -di-/-butylbiphenyl (70.0). 

The rates of chlorination of benzene, biphenyl, and diphenylmethane by chlorine acetate in 98 % aqueous acetic acid at 25 °C have also been determined and the second-order rate coefficients are 0.00118, 0.0364, and 0.0311, respective-]y209 , 270 jjje varjation in rate with change in water content of the acetic acid was the same as that previously observed209 for toluene, and thus in ca. 75 % aqueous acid the coefficients were 0.00073, 0.027 and 0.0241 however, elsewhere in ref. 209a a 4-fold decrease in rate coefficient for diphenylmethane was claimed to accompany the same increase in water content of the medium. 

An investigation of the relative rates of bromination of benzene, toluene, m-and p-xylene by bromine in acetic acid, catalysed by mercuric acetate, revealed relative rates almost identical with those obtained with molecular bromine322, though as in the bromination of biphenyl by bromine acetate (p. 129) it is quite inconsistent for a much more reactive electrophile to have the same selectivity. Relative rates were (molecular bromination values in parenthesis) benzene 1.0 toluene, 480 (610) p-xylene, 2.1 x 103 (2.2 x 103) m-xylene 2.0 x 10s (2.1 x 10s). 

The relative rates of bromination from the above and additional studies yielded the following relative rates with partial rate factors for the indicated position in parentheses. These rates were mostly obtained by extrapolation of observed rates to those expected in 50% aqueous acetic acid and therefore probably contain small errors benzene, 1.0 (1.0) biphenyl, 1.54 x 103(4-,4.34 x 103) naphthalene, 1.24 x 105(1 -, 1.84 x 10s 2-, 1.86 x 103) phenanthrene, 7.43 x I03(9—, 2.23 x 10s) f uoranthrene, 2.30 x 106(3 —,6.90x 106) chrysene,... 

CN 2-fluoro-a-methyl[l, 1 -biphenyl]-4-acetic acid sodium salt... 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

Reductive cyclization of 2-formyl-2 -nitrobiaryl compounds gives phenanthridine derivatives.136 The Stille coupling of nitroarylstannanes with 2-bromobenzaldehyde are used for the preparation of the requisite 2-formyl-2 -nitrobiaryls. Subsequent treatment of biphenyl derivatives with zinc dust in acetic acid gives the phenanthridine derivatives as shown in Eq. 10.80.137... 

Figure 12.5 Pyrogram of Mowilith 30, a vinyl acetate polymer used in conservation. Peak assignments 1, acetic acid 2, benzene 3, styrene 4, indene 5, 1,2 dihydro naphthalene 6, naphthalene 7, 2 methyl naphthalene 8, 1 methyl naphthalene 9, biphenyl 10, fluorene 11, anthracene...

Japenga et al. [56] determined polychlorinated biphenyls and chlorinated insecticides in River Elbe estuary sediments by a procedure in which the sediments were pretreated with acetic acid, mixed with silica and Soxhlet-extracted with benzene/hexane. Humic material and elemental sulphur were removed by passing the extract through a chromatographic column containing basic alumina, on which sodium sulphite and sodium hydroxide were adsorbed. Silica fractionation was followed by gas chromatography to analyse chlorinated pesticides, polychlorinated biphenyls and polyaromatic hydrocarbons. Recovery experiments with standard solutions gave recoveries of 90-102%. 

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