A-Methyl phenylacetic acid

FIGURE 3. The NMR spectra of the two racemic diastereomers of lV-(4-methyl-2-pentyl)-a-methoxy-a-trifluoromethylphenylacetamide prepared from racemic a-methoxy-a-(trifluoromethyl)phenylacetic acid [MTPA, ( )-83] and racemic 4-methyl-2-pentylamine [( )-84] (A) 60-MHz proton spectrum in chloroform-4 with tetramethylsilane (TMS) as the internal standard (B) 94.1-MHz fluorine-19 spectrum in chloroform-4 with trifluoroacetic acid as the internal standard. Reprinted with permission from Reference 76. Copyright (1969) American Chemical Society... 

The Curtius rearrangement of the acyl azide derived from optically pure a-methoxy-a-(trifluoro-methyl)phenylacetic acid (MTPA 48) also proceeds with retention of configuration, giving a-methoxy-a-(trifluoromethyl)benzyl isocyanate (49 equation 26). The isocyanate (49) is useful for the determination of the enantiomeric composition of optically active primary and secondary amines. 

In order to obtain cyclization of an N-a-carboxy dithiocarbamic acid (CLXXXI) to the thiazolidin-5-one-2-thione (CLXIII), dehydrating agents are necessary. These same products may, however, be obtained by simply warming the a-amino carboxylic acid esters with carbon disulfide, especially when there is an aromatic ring attached to the -carbon atom (method D). In this way a-(methylamino) phenylacetic acid and carbon disulfide yield 3-methyl-4-phenylthiazolidin-5-one-2-thione [121) (Table 24). 

More recently (I )-0-acetylmandelic acid [(/ )-99], (S)-a -methoxy-a -(trifluoro-methyl)phenylacetic acid (MTPA) [(5 )-83] and other chiral acids have been used as CSAs. These acids form diastereomeric salts soluble in benzene- /6 or chloroform-d with a wide range of amines and amino alcohols, permitting a direct measure of their enantiomeric composition. EnantiomCTs of l,l -binaphth-2,2 -diol (100) and 1,1 -binaphth-2,2 -diylphosphoric acid (101) and other derivatives of 100 and 101 have also been successfully used as CSAs in chloroform- / and benzene- /6 for the estimation of enantiomeric excesses of a number of -amino alcohols , and enantiomers of 101 have been used for cyclic secondary and tertiary amines . ... 

To a stirred solution of 0.1 mmol (4R,VS)- and (45,l 5 )-4-(l -f rf-butoxycarbonyl-amino-2 -hydroxyethyl)-6-methyl-2-oxo-l,2,3,4-tetrahydropyrimidine-5-carboxylic acid ethyl ester in 1 mL anhydrous CH2CI2 were added 29 mg (R)-Qf-methoxy-a -(trifluoro-methyl)phenylacetic acid (0.12 mmol), 25 mg 1,3-dicyclohexylcarbodiimide (0.12 mmol), and a catalytic amount of 4-A, A-(dimethylamino)pyridine. The mixture was stirred for an additional 12 h at room temperature, then concentrated. The residue was taken into EtOAc, washed with saturated aqueous NaHCOs and brine, dried over Na2S04, and concentrated. The residue was purified by preparative TLC, affording the corresponding Mosher ester in almost quantitative yield. 

Cresylol. See Cresylic acid m-Cresyl phenylacetate CAS 122-27-0 EINECS/ELINCS 204-531-0 Synonyms Acetic acid, phenyl-, m-tolyl ester Benzeneacetic acid, 3-methyl phenyl ester m-Cresyl a-toluate Phenylacetic acid, m-tolyl ester m-Tolyl phenylacetate Empirical C15H14O2 Toxicology TSCA listed Uses Fragrance in cosmetics Manuf/Distrib. Advanced Synthesis Tech. http //www.advancedsynthesis.com, Aldrich http //www.sigma-aldrich. com... 

Synonyms Benzeneacetic acid, methyl ester Methyl benzeneacetate Methyl a-toluate Phenylacetic acid, methyl ester... 

A diiral GC column has the potential to separate enantiomers of epoxy pheromoies in the Type II class, but die applications are vay limited because no good column with a universal ability fw the resolution has been commercialized. On the odia hand, the resolution abilities of chiral HPLC columns have been examined in detail (77). The Chiralpak AD column qierated under a nmnal-phase oonditiiMi suffidaitly separates the two enantiomers of 9,10-epoxydienes, 6,7-epoxymonoenes and 9,10-epoxy-monoenes. Another normal-phase column, the Chiralpak AS column, is suitable fiir the resolution of the 3,4-epoxydienes. The Chiralcel OJ-R colunm operated unda a reversed-phase condition sufficiently accomplishes the enantiomeric separation of 6,7-epoxydienes and 6,7-epoxymonoenes 18). The stereochemistry of each enantiomer separated by chird HPLC has been studied after methanolysis of the epoity ring. Examining the H NMR data of esters of the produced methoxyalcohols with (S)- and (Ry)-a-methoxy-a-(trifluoro-methyl)phenylacetic acid Ity a modified Mosher s method (79), die parent epoxides widi shorter Rts have been indicated to be (3.9,47 )-, (69,77 )-, and (97 105)-isomers (77). 

The dibenzyl ketone has a very high b.p. (ca. 200°/21 mm.) and this remains in the flask when the unsymmetrical ketone has been removed by distillation. The dialkyl ketone has a comparatively low b.p. and is therefore easily removed by fractionation under normal pressure acetone is most simply separated by washing with water. In this way methyl benzyl ketone (R = CHj), ethyl benzyl ketone (R = CHgCH,) and n-propyl benzyl ketone (R = CHjCHjCH,) are prepared. By using hydrocinnamic acid in place of phenylacetic acid ... 

This procedure is called chloromethylation and will not only turn 1,3-benzodioxole into a methyl chloride but will work equally well in converting plain old benzene into benzyl chloride. Both are important stepping stones towards the production of X and meth. For example, benzyl chloride is a schedule I controlled substance because it will beget benzaldehyde and phenylacetonitrile (a precursor for phenylacetic acid). 

In this process, penicillin G is first hydrolysed to 6-APA with the acylase derived from Kluyvera citwphila at a slightly alkaline pH (pH 75). Subsequently the 6-APA is incubated with an acylase derived from Pseudomonas mdanogenum and with DL-phenylglydne methyl ester at pH 55. This produces ampiciilin in reasonable yields only because of the specificity of the P. melanogenum enzyme. This enzyme does not react with penicillin G nor phenylacetic acid. 

Substituted phenylacetic acids form Kolbe dimers when the phenyl substituents are hydrogen or are electron attracting (Table 2, Nos. 20-23) they yield methyl ethers (non-Kolbe products), when the substituents are electron donating (see also chap. 8). Benzoic acid does not decarboxylate to diphenyl. Here the aromatic nucleus is rather oxidized to a radical cation, that undergoes aromatic substitution with the solvent [145]. 

Lithium enolates of carboxylic acids such as phenylacetic acid or of amides such as N-methyl-N-phenylvaleric acid amide 1974 are oxidized by BTSP 1949 to a-hydroxy acids, which are isolated after esterification, e.g., to 1973, or to a-hydroxyamides such as 1975 [155] (Scheme 12.43) (cf. also the formation of 3-hydroxybutyrolactam 1962). 

Synthesis of pyrazole 3 by the Medicinal Chemistry route was straightforward from N-Boc isonipecotic acid (45), so we utilized the route after some optimizations, as summarized in Table 2.4. The key 1,3-diketone intermediate 48 was prepared from 45 without issues. A minor problem in the original route was the exothermic nature of the Claisen condensation between methyl ketone 47 and methyl phenylacetate. Slow addition of l.lequiv of methyl phenylacetate to a mixture of 47, 0.2equiv of MeOH, and 2.5equiv of NaH in THF at room temperature solved this exothermic issue and reduced the amount of self-condensation of... 

Structure-activity studies in the phenylacetic acid antiinflammatory series have shown that inclusion of a methyl group on the benzylic carbon usually leads to maximal activity. It is of note that this... 

Dibenzyl ether reacted with Mg after five days of reflux in THF to give phenylacetic acid in 42% yield after carbonation. Maercker(99) was able to obtain a 15% yield of 3-butenoic acid from allyl methyl ether after 56 h of reflux. 

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