A- phenylacetic

Various diastereoselective Michael reactions are based on y-bromo-, y-alkyl-, or y-alkoxy-2(5//)-furanones following the trans-face selectivity shown in Section 1.5.2.3.1.2. Thus the lithium enolates of esters such as ethyl propanoate, ethyl a-methoxyacetate and ethyl a-phenylacetate add to methoxy-2(5/f)-furanone with complete face selectivity269-273 (see Section 1.5.2.4.4.2.). 

Diclofenac is a phenylacetic acid derivative, non-steroidal anti-inflammatory drug. It is available as the potassium and sodium salts. Potassium salts are slightly more soluble than the sodium salts. Diclofenac can be used in breastfeeding mothers since the amount that passes through breast milk is too small to be harmful to the baby. However, diclofenac is contraindicated in pregnancy, especially during the last trimester. 

Cyclopentolate Cyclopentolate, 2-(dimethylamino)ethylic ester of 1-hydroxycyclopentane-a-phenylacetic acid (14.1.39), is synthesized by the esterification of a-(l- droxycylopentyl) phenylacetic acid (14.1.38) using 2-dimethylaminoethylchloride, a-(l- Hydroxycyclopentyl) phenylacetic acid (14.1.38) is synthesized by reacting the sodium salt of phenylacetic acid with cyclopentanone in the presence of isopropylmagnesium bromide [30]. 

Diclofenac Voltaren) is a phenylacetic acid derivative that is a potent inhibitor of COX and that has analgesic, antiinflammatory, and antipyretic effects. Its use is accompanied by side effects similar to those of other NSAIDs. Indications for the drug include rheumatoid arthritis, osteoarthritis, and ophthalmic inflammation (use of an ophthalmic preparation). 

H. Luo, A.L. Beets, M.J. McAllister, M. Greenbaum, D.W. McPherson, F.F. Knapp Jr, Resolution, in vitro and in vivo evaluation of fluorine-18-labeled isomers of 1-azabi-cyclo[2.2.2]oct-3-yl a -(1-fluoropent-5-yl)- a -hydroxy- a -phenylacetate (FQNPe) as new PET candidates for the imaging of muscarinic-cholinergic receptor, J. Label. Compd. Radiopharm. 41 (1998) 681-704. 

H. Luo, A. Hasan, V. Sood, R.C. McRee, B. Zeeberg, R.C. Reba, D.W. McPherson, F.F. Knapp Jr, Evaluation of 1-azabicyclo[2.2.2]oct-3-yl ot-fluoroalkyl-a-hydroxy-a-phenylacetates as potential ligands for the study of muscarinic receptor density by positron emission tomography, Nucl. Med. Biol. 23 (1996) 267-276. 

Problem 16.63 Write formulas for each of the following (a) phenylacetic acid, (b) phenylethanoic acid, (c) 2-methylpropenoic acid, (d) ( )-butenedioic acid, (e) ethanedioic acid, (/) 3-methylbenzenecarboxylic acid. 

Diclofenac is a phenylacetic acid derivative that is relatively nonselective as a COX inhibitor. Pharmacokinetic and dosage characteristics are set forth in Table 36-1. 

Cyclization of the optically active enantiomers of methyl a-(2-carba-moylpiperidinyl)-a-phenylacetate 332 with 1.0 equiv. of NaOH in EtOH provided almost pure optically active l-phenylperhydropyrido[l,2-a]pyr-azine-2,4-diones 333 (09TA1759). 

Diclofenac is a phenylacetic acid derivative used mainly as sodium salt for the treatment of various pain and inflammation. Intramuscular injection occasionally causes tissue damage at the injection site. Suppositories may cause local irritation transient burning and stinging are reported when used for the eye and large doses can cause aplastic anemia.14... 

Figure S.21 Resulting chromatogram at the optimum conditions predicted by figure S.20. pH = S.8 concentration of n-octylamine = 3.2 mM. ODS column mobile phase methanol-water (20/80) with 0.010 M acetate buffer. Solutes E = phenylethylamine, P = phenylalanine, V = vanillic acid, C = trans caffeic acid, M = trans p-coumaric acid, F = trans ferulic acid, A = phenylacetic acid, H = hydrocinnamic acid and N = trans cinnamic acid. Figure taken from ref. [559]. Reprinted with permission. 

Difenpiramide, a phenylacetic acid derivative, is less efficacious but has fewer adverse effects than indometacin or phenylbutazone. The most frequent reactions are in the gastrointestinal tract and skin (1). However, gastrointestinal tolerance is, as one would expect, better (2). 

Amino-2,4-disulphonamido-phenylhydrazinc Benzylhydrazinc Triphenylmethylhydrazine Ethyl a-hydrazino-a-phenylacetate Ethyl a-hydrazino-j3-phenyl-propionate... 

Carbohydrate crown ethers were obtained with ethylene spacers from a crown ether point of view, the carbohydrate vicinal diols are replacing one ethylene glycol unit [181,182], Cyclic compounds synthesized include bis-gluco-15-crown-5 82, bis-gluco-21-crown-7, and tetra-gluco-24-crown-8 (O Scheme 14). These chiral macrocycles could serve as catalysts in the asymmetric Michael addition of methyl a-phenylacetate to methyl acrylate. With the goal to study molecular interactions, P,P, and Q, Q -bis-maltosides with aliphatic two-, three-, or four-earbon spacers were synthesized [183]. Spaced cyclodextrins were prepared to study their supramolecular properties [184,185]. 

Downard el al. [9] have reported the application of a phenylacetate layer to glassy carbon macroelectrodes. Their study determined dopamine levels in the presence of ascorbic acid. Differential pulse voltammetry of dopamine and ascorbic acid at both modified and unmodified electrodes showed almost a six-fold enhancement of dopamine anodic peaks at the modified electrodes. For ascorbic acid, while the magnitude of its anodic current remained similar at modified electrodes, the peaks were no longer as well-resolved as for unmodified electrodes. 

The passing of the years has not diminished the interest in photolabile protecting groups. Many such systems are available and have been described in the literature. A new method has been proposed for the protection of amino acids. This involves the conversion of the amino acid into the phenacyl derivatives 120. Irradiation of these derivatives in a buffered aqueous solution results in the release of the amino acid and the transformation of the phenacyl group into a phenylacetic acid. This occurs via the triplet state within which there is intramolecular displacement of the amino acid moiety as represented in 121. The resultant intermediate 122 undergoes ring opening by attack by water to afford the... 

For the irradiation of methyl a-diazo-a-phenylacetate in styrene, the transjcis ratio of the resulting methyl 1,2-diphenylcyclopropane-l-carboxylate (6) was markedly diminished if the reaction was carried out in a frozen matrix rather than in liquid solution.This effect, which... 

Penicillin G Acylase. This method was used to cleave a phenylacetate in the presence of an acetate. ... 

The carbonylation of a benzyl halide in the presence of iron pentacarbonyl to give a phenylacetic acid may serve to exemplify the interaction of a metal carbonyl, carbon monoxide, PT catalyst, aqueous sodium hydroxide, and the substrate [79]. Fe(CO)5 is attacked by QOH at the interphase, and the species formed is extracted into the depths of the oganic phase, where it reacts with CO and benzyl halide (Eqs. 13 and 14). This new anion 3 is the actual catalyst. It reacts with a second benzyl halide to give a non-ionic intermediate 4 (Eq. 15). By insertion of CO and attack of QOH, 4 is decomposed to the reaction product under regeneration of 3 (Eq. 16). Thus, the action of the PT catalyst is twofold. Firstly it transports the metal carbonyl anion. More important seems to be its involvement in the (rate-determining) decomposition step. A basically similar mechanism was proposed for cobalt carbonyl reactions [80], which have been modified somewhat quite recently (see below). 

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