Alanine isopropyl esters

Amino acid esters act as chelates to Co111 for example, the /3-alanine isopropyl ester is known as both a chelate and as an /V-bonded monodentate,983 and the mechanism of hydrolysis of the ester, which is activated by coordination, to yield chelated /3-alanine has been closely examined. 

In the Michael addition reaction of (S )-phenylethylamine and L-alanine isopropyl ester to [Pg.444]

Whilst the use of Taddol as an asymmetric phase-transfer catalyst for asymmetric Michael reactions was only moderately successful, it was much more enantioselec-tive in catalyzing alkylation reactions. For this study, Belokon and Kagan employed alanine derivatives lib and 16a-c as substrates, and investigated their alkylation with benzyl bromide under solid-liquid phase-transfer conditions in the presence of 10 mol % of Taddol to form a-methyl phenylalanine, as shown in Scheme 8.8. The best results were obtained using the isopropyl ester of N-benzylidene alanine 16b as substrate and sodium hydroxide as the base. Under these conditions, (R)-a-methyl phenylalanine 17 could be obtained in 81% yield and with 82% ee [19]. Under the same reaction conditions, substrate 16b reacted with allyl bromide to give (R)-Dimethyl allylglycine in 89% yield and with 69% ee, and with (l-naphthyl)methyl chloride to give (R)-a-methyl (l-naphthyl)alanine in 86% yield and with 71% ee [20]. 

The residue, after crystallization from isopropyl alcohol diethyl ether, afforded (2-methylthiazolidine-4-carbonyl)-p-alanine methyl ester hydrochloride (5.4 g). [oc]d20=-85° (c=1, CH3OH) MP = 124°-125°C. 

N-Benzoyl-N-(3-chloro-4-fluorophenyl)-D-aianine iso-propyl ester, Barnon plus BRN 2899801 Commando D-Alanine, N-benzoyl-N-(3-chloro-4-fluorophenyl)-, isopropyl ester Effix Flame Flamprop-m-isopropyl Gunner Power Flame Isopropyl N-ben2oyl-N-(3-chloro-4-fluorophenyl)-D-alaninate Mutaven L Suffix BW Super Barnon Super Suffix Superbarnon WL 43 423 WL 43 425. Herbicide. Used for control of wild oats in cereal crops. Colorless crystals mp = 72 -75" soluble in H2O (0.001 g/100 ml at 20"), MezCO (> 40 g/100 ml), cyclohexanone (68 g/100 ml), EtOH (15 g/100 ml), xylene (=50 g/100 ml), C6Hi4 (sO.6 g/100 ml) LDso (rat, mus orl) > 4000 mg/kg, (rat der) > 1600 mg/kg, (rat ip) > 1200 mg/kg, (fowl orl) > 2000 mg/kg LCso (rainbow trout 96 hr.) = 3,3 mg/l non-toxic to bees, BASF Corp. Shell. 

L-a-Alanine. See L-Alanine P-Alanine, N-acetyl-N-butyl-, ethyl ester. See Ethyl butylacetylaminopropionate P-Alanine, N-(2-aminoethyl)-N-[2-(2-carboxyethoxy) ethyl]-, N-coco acyl derive., 2,2 -iminobisethanol salts. See DEA-cocoamphodipropionate D-Alanine, N-benzoyl-N-(3-chloro-4-fluorophenyl)-, isopropyl ester. See Flamprop-m-isopropyl... 

Synonyms D-Alanine, N-benzoyl-N-(3-chloro-4-fluorophenyl)-, isopropyl ester Isopropyl N-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alaninate... 

An equimolar soln. of glycine isopropyl ester hydrochloride and D-alanine methyl ester in methanoll 3 M tris(hydroxymethyl)aminomethane containing a little 2-mer-captoethanol adjusted to pH 9.5 with 10 MNaOH, 0.5 eqs. of N-benzyloxycarbonyl-phenylalanine methyl ester and a little (crude) papain added successively, the mixture shaken for 1 min, methyl isobutyl ketone added, and stirred vigorously at room temp, for 12 h - Z-Phe-Gly-D-Ala-OMe. Y 57%. A 2-fold increase in yield was observed with methanol as cosolvent compared with dioxane. The method appears to be quite... 

In contrast, when a twofold excess of the dialkoxydihydropyrazine is used, then 2 1 adducts are obtained. This has been demonstrated18 by reacting A,7V-bis(2-iodoethyl)-4-methylben-zenesulfonamide with two equivalents of the lithiated D-valine/alanine-based dialkoxydihydropyrazine 8 to give 7V.fV-bis 2-[(2S,57 )-2,5-dihydro-5-isopropyl-3,6-dimethoxy-2-mcthyl-2-pyrazinyl]ethyl -4-methylbenzenesulfonamide (9) in high yield and >95% de. The adduct can be hydrolyzed in high yield to the corresponding amino acid methyl ester 10. 

Benzoyl chloride, methoxy- Benzoyl chloride, 4-methoxy-. See p-Anisoyl chloride Benzoyl chloride, 3-nitro- Benzoyl chloride, m-nitro-. See m-Nitrobenzoyl chloride N-Benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine 1-methylethyl ester. SeeFlamprop-isopropyl... 

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. 

Di-l-propynyl ketone (MI-90) and primary amines (ethylamine, isopropyl-amine) or amino acids that are unsubstituted in the a-position (glycine, ll-alanine, e-aminocaproic acid, glycylglycine, glycylleucine, alanylglycine) give enamines (W-91), which form V-substituted lutidones when their sodium salts are heated in water or their esters are heated in xylene. When 2-substituents are present, cyclization oocurs when their calcium salts or amides are heated in aqueous alkali. When heated in the presence of Triton B and DMF, a-alanyl-amide and di-I-propynyl ketone give the lutidone. ... 

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