Tosyl-α-amino Acids. I. Degradation of the Acid Chlorides and Azides by Aqueous Alkali

1957 ◽  
Vol 79 (12) ◽  
pp. 3257-3261 ◽  
Author(s):  
A. F. Beecham
Keyword(s):  
Amino Acids ◽  
Aqueous Alkali ◽  
Acid Chlorides

The 2,2,2-Trichloroethyl Group for Carboxyl Protection During Peptide Synthesis

1973 ◽  
Vol 51 (2) ◽  
pp. 208-214 ◽  
Author(s):  
Bernard Marinier ◽  
Yoon C. Kim ◽  
Jean-Marie Navarre
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Peptide Synthesis ◽  
Optical Activity ◽  
Selective Removal ◽  
Acid Chlorides ◽  
Protecting Group

The 2,2,2-trichloroethyl esters of several N-carbobenzoxy-amino acids were prepared by reacting the corresponding acid chlorides with trichloroethanol and the carbobenzoxy groups were selectively removed by HBr–AcOH. The resulting esters were then coupled with various N-carbobenzoxy-amino acids or peptides using dicyclohexylcarbodiimide in acetonitrile to give N-carbobenzoxy-peptide trichloroethyl esters. The selective removal of the trichloroethyl protecting group was effected by reduction using zinc in acetic acid. The optical activity of the N-carbobenzoxy-peptides so obtained agreed well with the values reported in the literature. The overall results suggest that the 2,2,2-trichloroethyl group could be useful for carboxyl protection during peptide synthesis.

scholarly journals The Volume, Adiabatic Compressibility, and Viscosity of Amino Acids in Aqueous Alkali-chloride Solutions

1984 ◽  
Vol 57 (8) ◽  
pp. 2064-2068 ◽  
Author(s):  
Toshio Ogawa ◽  
Kiyoshi Mizutani ◽  
Motoo Yasuda
Keyword(s):  
Amino Acids ◽  
Adiabatic Compressibility ◽  
Aqueous Alkali ◽  
Alkali Chloride ◽  
Chloride Solutions

Amino acids and peptides. VI. Studies on cystine and αα'-dimethylcystine in relation to the alkaline degradation of protein disulphides

1960 ◽  
Vol 13 (3) ◽  
pp. 416 ◽  
Author(s):  
IW Stapleton ◽  
JM Swan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carbon Atom ◽  
Dimethyl Ester ◽  
Aqueous Alkali ◽  
Alkaline Degradation

The synthesis and properties of α-methyl-DL-cysteine and of racemic αα?-dimethyl-cystine and its dimethyl ester are recorded. The new disulphide is very much more stable to aqueous alkali than is cystine, its dimethyl ester is quite stable to methanolic triethylamine whereas cystine dimethyl ester breaks down readily with liberation of sulphur. These results support the β-elimination hypothesis for the alkaline degradation of cystine and its derivatives, namely, that attack occurs at the amino acid α-carbon atom, with synchronous displacement of a sulphenyl thiol anion, RSS-.

Diisopropylethylamine eliminates dipeptide formation during the acylation of amino acids using benzoyl chloride and some alkyl chloroformates

1987 ◽  
Vol 65 (6) ◽  
pp. 1224-1227 ◽  
Author(s):  
Francis M. F. Chen ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Benzoyl Chloride ◽  
Side Reaction ◽  
Aqueous Alkali ◽  
Ethyl Chloroformate ◽  
Alkyl Chloroformates ◽  
Moderate Yield

Acylation of amino acids using benzoyl chloride in aqueous alkali leads to benzoylamino acids containing one percent of benzoyldipeptide. Use of diisopropylethylamine instead of sodium hydroxide as base eliminates the side reaction responsible for the contaminant. Ethoxycarbonylamino acids are advantageously prepared in the same manner using ethyl chloroformate or diethyl dicarbonate. The latter gives rise to some N-substituted dipeptide when used in aqueous alkali. The method is unsatisfactory for the benzyloxycarbonylation of amino acids. Use of 9-fluorenylmethyl chloroformate and diisopropylethylamine gives the pure derivative of leucine in moderate yield.

Amino Acids and Peptides; 67.1Easy Preparation and Use of Benzyloxycarbonyl Derivatives of Amino Acid Chlorides and α-Hydroxycarboxylic Acid Chlorides

Synthesis ◽  
1988 ◽  
Vol 1988 (06) ◽  
pp. 475-477 ◽  
Author(s):  
Ulrich Schmidt ◽  
Matthias Kroner ◽  
Ulrich Beutler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Chlorides ◽  
Hydroxycarboxylic Acid ◽  
Derivatives Of

Metallkomplexe mit biologisch wichtigen Liganden, XXXIII. Reaktionen von α-Aminosäuren und α-Aminosäurederivaten mit Gold(III)-chlorid/ Metal Complexes with Biological Important Ligands, XXXIII. Reactions of α-Amino Acids and Derivatives there of with Gold(III) Chloride

1984 ◽  
Vol 39 (8) ◽  
pp. 1129-1134 ◽  
Author(s):  
Eberhard Ambach ◽  
Mano Mohan Singh ◽  
Ulrich Nagel ◽  
Wolfgang Beck
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Metal Complexes ◽  
Thionyl Chloride ◽  
Ammonium Salts ◽  
Acid Chlorides ◽  
X Ray ◽  
Amino Acids And Derivatives ◽  
Acid Anhydrides

AbstractThe hydrochlorides of a-aminoacid esters react with Au2Cl6 in thionyl chloride to give the ammonium salts [H3NCHRCO2R′]+AuCl4- (R = H , Me, R′ = H , Me, Et). The X-ray structure of [H3NCH(Me)CO2Me]+AuCl4- has been determined. The reactions of a-aminoacids with Au2Cl6 in SOCl2 afford mixtures of ammonium tetrachloroaurate(III) salts with a-amino acids, a-amino acid chlorides or a-amino acid anhydrides as amine components. Cysteine esters reduce gold(III) to give the gold(I) compounds [AuSCH2CH(N H2)CO2R]n (R = Me, Et).

ChemInform Abstract: Transformations of Amino Acids. Part 2. Reaction of 3-Thiazolines with Carboxylic Acid Chlorides.

ChemInform ◽  
1987 ◽  
Vol 18 (44) ◽  
Author(s):  
W. SCHWARZE ◽  
K. DRAUZ ◽  
J. MARTENS
Keyword(s):  
Amino Acids ◽  
Carboxylic Acid ◽  
Acid Chlorides
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