3-Phenylbutyric acid ethyl ester

In a related investigation, the same authors used the identical system but a different substrate, namely, 3-phenylbutyric acid ethyl ester 141). In this case, en-antioselectivity of the WT E — 3.5) was increased slightly, to " = 5.8 and 6.6, by the formation of two mutants, one having mutation D158N and the other L181Q. Again, as a consequence of the paucity of data, it difficult to draw any sound conclusions. 

In a more detailed study, the same esterase P. fluorescens) was again subjected to mutagenesis using the same mutator strain, but also by saturation mutagenesis at selected positions 133a). In addition to 3-phenylbutyric acid ethyl ester (27), 3-bromo-2-methyl-propionic acid methyl ester rac-31) was chosen for the hydrolytic kinetic resolution, with the WT PFE showing an E factor of 12 in favor of the (5)-32. 

Cyano-3-phenylbutyric acid ethyl ester, A 39.18 1 -Benzyl-3-methylpiperidine-2,6-dione, A"24.10... 

The transformation of racemic 4-oxo-3-phenylbutyric acid ethyl ester to the desired (R)-enantiomer was catalyzed by an (R)- -transaminase [76]. For a complete theoretical conversion, the coproduct pyruvate was converted to lactate by a lactate dehydrogenase. Under the tested reaction conditions (with 100 mg racemic substrate, 30 mg of the enzyme at 30 °C, and pH values between 6.5 and 9.0), spontaneous... 

Dioxo-4-phenylbutyric acid ethyl ester (0.14 mL, 1.0 mmol) in 10 mL ethanol was treated drop wise with 0.12 mL phenyl hydrazine (1.2 mmol), and the resulting solution was refluxed over a period of 3 h. After the mixture was cooled to room temperature, the solvent was distilled off in vacuo. The residue was purified by means of silica gel column chromatography (petroleum ether/EtOAc, 4 1) to give 140 mg 5-methyl- 1-pheny 1-pyrazole-3-carboxylic acid ethyl ester as a pale brownish solid (0.61 mmol), in a yield of 60.8%, m.p. 

DioxaphetyL Butyrate, a-Diphenyl-d-morpho-iinebutanoic acid ethyl ester ethyl 4-morph<.ilino-2,2-di -phenylbutyrate 4-mOrpholino-2T2-diphenylbuiync acid ethyl ester Amidalgon Spasmoxal(e). C H NO mol wt 353,44, C 74.75%, H 7-70%, N 3.96%, O 13.58%. Prepn Specter et al, J, Am, Chem, Soc, 71, 57 (1949) Dupre et al,... 

Ethyl Y-phenylbutyrate is prepared in 85-88 per cent yields by refluxing for three hours a mixture of 50 g. of 7-phenylbutyric acid (Org. Syn. 15, 64), 150 cc. of alcohol dried over lime, and 5 g. of concentrated sulfuric acid. The ester is isolated by distilling 100 cc. of the alcohol under reduced pressure from a steam bath, diluting with 200 cc. of water, separating, and extracting the aqueous layer twice with 50-cc. portions of ether. The combined ester and ether layers are dried with sodium sulfate, the ether removed, and the residue distilled under diminished pressure the portion boiling at 144-147° at 19 mm. is collected. 

Fig. 5.10. Gas chromatogram of ethyl esters of phenylcarboxylic adds (2.5 —7.5 Mg). Peaks 1 = benzoic 2 = phenylacetic 3 = 2-phenylpropionic 4 = 2-phenylbutyric 5 = 3-phenylpropionic 6 = 3-phenylbutyric 7 = 4-phenylbutyric 8 = 4-phenylvaleric 9 = 5-phenylvaleric acid S = n-tridecane (internal standard) X = blanks of reagent and products from side-reactions. Conditions column,...

Direct esterification, however, has the advantage of being a single-step synthesis it can often be made useful by application of our knowledge of equilibria. If either the acid or the alcohol is cheap and readily available, it can be used in large excess to shift the equilibrium toward the products and thus to increase the yield of ester. For example, it is worthwhile to use eight moles of cheap ethyl alcohol to convert one mole of valuable y-phenylbutyric acid more completely into the ester ... 

Oxeladlll. a,a -Diethylbemeneacetic acid 2-[2-(di-ethylamino ethoxy]ethyl ester 2-ethyl-2-phenylbutyric acid 2-(2-diethylaminoetho.xy)ethyl ester 2-(2-diethylaminoeth-oxy)ethyl a,o-diethy]phenylacetate a.a -dieth y 1 phenyl acetic acid 2-(2-diethylaminoethoxy)ethyl ester. C H NO, mol wt 335.47. C 71.60%. H 9.92%, N 4.18%, O 14.31%. Prepn V. Petrow et al, J. Pharm. Pharmacol. 10, 40 (1958) eidem. U.S. pat. 2,885,404 (1959 to Brit. Drug Houses). 

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