cas 5545-52-8, N-Cbz-L-Aspartic acid 4-tert-butyl ester

Articles about 5545-52-8Total 7 be found

A versatile and selective chemo-enzymatic synthesis of β-protected aspartic and γ-protected glutamic acid derivatives
Two versatile, high yielding, and efficient chemo-enzymatic methods for the synthesis of β-protected Asp and γ-protected Glu derivatives using Alcalase are described. The first method is based on the α-selective enzymatic hydrolysis of symmetrical aspartyl and glutamyl diesters. The second method involving mixed diesters comprises a three-step protocol using (i) α-selective enzymatic methyl-esterification, (ii) chemical β-esterification, and finally (iii) α-selective enzymatic methyl ester hydrolysis. The yields of the purified β- and γ-esters range from 77% to 91%.
Nuijens, Timo,Kruijtzer, John A.W.,Cusan, Claudia,Rijkers, Dirk T.S.,Liskamp, Rob M.J.,Quaedflieg, Peter J.L.M.
experimental part
p. 2719 - 2721
(2009/09/06)

Preparation of protected amino acids
The present invention involves a process for preparing protected amino acids. The process produces a di-tert-butyl amino ester or an N-protected di-tert-butyl amino ester by transesterification of an acidic amino acid or an N-protected acidic amino acid. By-products of the transesterification reaction may be recycled for use as part of the starting material. The N-protected di-tert-butyl amino ester may be hydrogenated to form a di-tert-butyl amino ester, which may subsequently form a di-tert-butyl ester hydrocholride salt.
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(2008/06/13)

Facile synthesis of tert-butyl ester of N-protected amino acids with tert-butyl bromide
A facile synthesis of a wide variety of N-benzyloxycarbonyl-amino acid-tert-butyl ester derivatives under mild conditions is described. N-protected amino acids were esterified with tert-butyl bromide in dimethylacetamide as solvent, in the presence of benzyltriethylammonium chloride (BTEAC)and a large excess of potassium carbonate. Many amino Z-acid-Tert-butyl esters that might be difficult to prepare by other methods have been synthesized in high yields by this procedure. The reaction is simple, unexpansive, easily scaled up, and proceeds without observable racemization.
Chevallet, Pierre,Garrouste, Patrick,Malawska, Barbara,Martinez, Jean
p. 7409 - 7412
(2007/10/02)

Synthesis of (3R)- and (3S)-3,4-diamino-butyric acid from L-aspartic acid
A short and convenient synthesis for both enantiomers of GABOB amino-analogue 1a,b is reported, starting from L-aspartic acid. The protected diester 3 is the common intermediate for the synthetic pathway.
Misiti,Santaniello,Zappia
p. 883 - 891
(2007/10/02)

MONO-ESTERIFICATION OF N-PROTECTED DI-ACIDS ASPARTIC AND GLUTAMIC BY CHLOROFORMATE ACTIVATION
Mono-esters of N-protected di-acids aspartic and glutamic are prepared by a one-pot activation with alkyl chloroformates or isopropenyl chloroformate and an additionnal alcohol.This process involves the intermediate internal anhydride formation.
Jouin, P.,Castro, B.,Zeggaf, C.,Pantaloni, A.,Senet, J.P,et al
p. 1665 - 1668
(2007/10/02)

The synthesis of peptides related to the N-terminal sequence of bovine trypsinogen. I. The synthesis of protected peptides
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Savrda,Bricas
p. 2423 - 2429
(2007/10/05)