Alanine, phenyl-, 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. 

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... 

Inhib. abbrev. DTT = dithioghreitol E64D = epoxysuccinyl-L-leucyl-amido-3-methyl-butane ethyl ester EDTA = ethylene-diamine-tetra-acetic acid EGTA = ethylen-glycol-tetra-acetic acid LHVS = morpholinurea-leucine-homophenyl-alanine-vinylsulfone-phenyl NEM = N-ethyl-maleimide PAI = plasminogen activator inhib. PMSF = phenil-methyl-sulfonil fluoride SBTl = soybean trypsin inhib. TIMP = tissue inhib. of metalloproteinases TPCK = tosyl-L-phenyl-alanyl-chloro-methane Al.so termed stephins. 

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. 

Acetylbenzene. See Acetophenone Acetyl benzoyl. See 1-Phenyl-1,2-propanedione N-Acetyl-N-butyl-P-alanine, ethyl ester. See Ethyl butylacetylaminopropionate Acetyl butyl citrate. See Acetyl tributyl citrate 2-Acetyl-5-t-butyl-4,6-dinitroxylene. See Musk ketone... 

Catalyst (140) promotes the reaction between various N-benzyl amines and ethyldiazoacetate (142) at room temperature to give aziridination products (143) in good yields and excellent enantioselectivity (Equation 85) [87]. The corresponding aziridines could be transformed into valuable D-phenyl alanine ethyl ester by treatment with palladium black in acidic conditions [87]. 

The SAR study on phosphoramidate prodrugs of PSI-6206 was focused on the aryloxy-phosphoramidate side chain. Compared to the common aryloxy-phosphoramidate prodrugs, modifications at amino acid ester, aryl phosphate ester, and amino acid side chain were conducted on PSI-6206 phosphoramidate. An examination of these modifications for 29 compounds found that a small simple alkyl and branched alkyl at the amino acid ester, phenyl and halogenated aryl at the phosphate ester, and a-methyl at the amino acid side chain produced better antiviral activity and the least cytotoxicity. The groups for the amino acid ester part (R ) were chosen from methyl, ethyl, isopropyl, and cyclohexyl the groups for the aryl phosphate ester (R ) were selected from phenyl and para-halogenated phenyl and the substituent for the amino acid side chain was fixed with a-methyl (r-alanine). These combinations of modifications resulted in 16 compounds (12-27, Table 1) for further evaluation. 

Triethylamine and N-chloromethylphthalimide added to a soln. of carbo-benzoxy-L-phenylalanine in dry ethyl acetate, allowed to stand overnight at 37°, then refluxed 15-30 min. phthalimidomethyl carbobenzoxy-L-phenyl-alaninate. Y 70-80%.—No racemization takes place and the esters can be cleaved under mild conditions. F. e. s. G. H. L. Nefkens, Nature 193, 974 (1962). 

Benzylidene derivatives are easily formed from esters of a-amino acids, but those of the free acids are unstable. When an ortho hydroxyl group is present in the aldehyde the derivative is stabilized by hydrogen bond formation as in (33) and Sheehan and Grenda have reported that the Schiff bases of L -valine with 5-chlorosalicylaldehyde (33) and 2-hydroxy-l-naphthaldehyde may be coupled with ethyl glycinate and methyl L-phenyl-alaninate using dicyclohexylcarbodi-imide [207]. The arylidene... 

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