Esters alanine ethyl

C(,H,2CaN204 J6i27-40-Q see Calcium pantothenate DL-alanine ethyl ester hydrochloride (C5H12CINO2 677-27-6) see Pyridoxine (5)-alaninol... 

N-(3-ethoxy-3-oxopropy])-A -(phenylmethyl)-P-alanine ethyl ester... 

The presence of small amounts of water was found to be essential even for hydrophobic ionic liquids (284). When a-chymotrypsin (in the form of salt-free lyophilized powder) was applied for the transesterification of Ai-acetyl-L-phenyl-alanine ethyl ester with 1-propanol in the dry ionic liquids [BMIM]PFg and [OMIMJPFg, little enzymatic activity was observed. The maximum activity was observed when 0.5 vol% water was added to the ionic liquids. Supercritical CO2 was also sufficient to activate the enzyme in dry ionic liquids. The addition of water to the supercritical C02-ionic liquid system further enhanced the enzymatic activity. 

The quaternization method is also highlighted by the short asymmetric synthesis of cell adhesion molecule BIRT-377 (Scheme 5.24), which is a potent inhibitor of the interaction between intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) [16]. Thus, asymmetricp-bromobenzylation of the alanine derivative 42 (R1 = Me) with (S)-18 under similar phase-transfer conditions as described above gave rise to p-bromobenzylalanine ester 10 in 97% ee (83% yield). A similar asymmetric p-bromobenzylation of alanine ethyl ester 42 (R1 = Me, R= Et) gave the amino ester 47 (R= Et) in 90% ee (86% yield). The amino ester 47 (R = t-Bu or Et) was treated with 3,5-dichlorophenyl isocyanate in the presence of sodium carbonate in dimethylsulfoxide (DMSO) to furnish the hydantoin 48 in 86%... 

A 5 L, 3-neck round bottom flask equipped with a mechanical stirrer was charged with the N-acetyl-3-(4-thiazolyl)-DL-alanine ethyl ester (210.0 g, 0.87 mol), distilled water (1.6 L), and 1 M aqueous KCI (0.8 L). The homogeneous solution was adjusted to pH 7.0 with 0.1 M NaOH and then was treated with Subtilisin Carlsberg (1.8 g) dissolved in 0.1 M aqueous KCI (25 ml). The reaction mixture was stirred at room temperature with 1.0 M NaOH added as required to maintain the pH at 6.25-7.25. After 4 h, 430 ml of base had been consumed and the reaction was judged to be complete. The reaction mixture was then extracted with chloroform (4x1.5 L), the aqueous phase was carefully acidified to pH 4 with 2 M HCI and then was concentrated under reduced pressure. Residual water was removed by consecutive evaporation... 

II4-chloro-2-(2-lluorobenzoyl)phenyl]amino]-3-oxo-alanine ethyl ester monohydrobromide (C 8H 7Br(TFN204 77822-80-1) see Ethyl loflazepatc Ar-[4-chloro-2-(2-fluorobenzoyl)phenyl]-2-(dicthylami-nolacctamidc... 

The nonenzymatic 1,2-migration of an amino group in Scheme 1 is an efficient way to transform 2-methyl-3-bromoalanine ethyl ester into 2-methyl- alanine ethyl ester. It is possible that this nonenzymatic counterpart to the enzymatic rearrangement may serve as the foundation for an efficient synthetic transformation of a-amino acid derivatives into P-amino acid derivatives, which may in turn be of some use in the drug industry. Under conditions of low concentrations of tributyltin hydride in the process of Scheme 1, the ratio of P-amino acid ester to a-amino acid ester is 13/1, presumably because the radical 5 is more stable than 4 owing to the delocalization of the unpaired electron into the adjoining carboethoxy group. 

C6H13N02 N-methyl-beta-alanine, ethyl ester 2213-08-3 446.58 38.776 2 8970 C6H140 1-hexanol 111-27-3 430.15 45.925 1,2... 

The amination of the a-carbon atom of carboxylic acid derivatives has been extensively studied by Ef-fenberger and coworkers. Ethyl (S)-a-bromopropionate reacted with (/ )- -phenylethylamine to give (2R,l R)- and (25,r/ )-iV-(r-phenylethyl)alanine ethyl ester, e.g. (2/ ,l f )-(4) and (2S,r/ )-(4). Prolonged reaction time afforded the products in higher yields with decreasing stereospecificity (Scheme 5). 

The amino alcohol, i -2-amino-l,l-di-(2-octyoxy-5-ferf-butyl-phenyl)-propa-nol, was prepared by the reaction of a Grignard reagent from 2-bromo-4-ferf-butylphenyl octyl ether [35] with D-alanine ethyl ester. The copper complex was prepared in the similar manner as above. In this case, neither the amino alcohol, the Schiff base, nor the copper complex was crystalline. 

The Schiff base was purified by column chromatography on silica gel (65% yield based on alanine ethyl ester). An equimolar mixture of the Schiff base and cupric acetate monohydrate in ethanol was heated under reflux for 1 h. After evaporation of the ethanol in vacuo, the dark green residue was dissolved in toluene and treated with aqueous sodium hydroxide. Removal of the toluene and drying in vacuo gave the copper complex as a dark green viscous oil, [a]546 -1-730 ° (c 0.076,benzene), which is used in the subsequent reaction. 

Alanine 60 Ethyl cyanoacetate (30 g) is converted into / -alanine ethyl ester by catalytic hydrogenation on Pt02 in glacial acetic acid/sulfuric acid. After removal of the catalyst the solution is concentrated in a vacuum so far as possible, and the residue is poured into water (300 ml), treated with finely powdered barium hydroxide (100 g), and boiled for 3 h. Then, after cooling, the barium is precipitated with dilute sulfuric acid and separated by centrifugation. The solution is concentrated greatly in a vacuum, whereupon the -alanine rapidly crystallizes (17 g, 72%) recrystallized from aqueous alcohol-ether, it has m.p. 195°. 

In another study (82JOC5258), air oxidation of a-methyl-3,4-dihydroxyphenyl-alanine ethyl ester was shown to lead to ethyl 5,6-dihydroxy-2-methylindole-3-carboxylate 31 via a remarkable 1,2-migration of the ethoxycarbonyl group of the aminochrome intermediate (Eq. (4)). The structure of the product was confirmed by an independent synthesis ... 

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