- High-efficiency industrial production method of Fmoc-Glu (Otbu)-OH
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The invention relates to the field of organic synthesis, and especially relates to the technical field of a high-efficiency industrial production method of Fmoc-Glu (Otbu)-OH. The method comprises thefollowing steps: synthesizing an intermediate [Glu(OtBu)]2Cu, and then synthesizing the target product Fmoc-Glu (Otbu)-OH. The method has the advantages of great reduction of reaction steps, and goodcontrol of the reaction process. The industrial production method of the Fmoc-Glu (Otbu)-OH can efficiently and stably produce the high-quality Fmoc-Glu (Otbu)-OH, so the purity is greater than 99.5%, and the content of a single impurity is less than 0.1%.
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Paragraph 0026; 0031-0035; 0040-0043
(2020/02/19)
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- Mild oxidative cleavage of 9-BBN-protected amino acid derivatives
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Protection of the amino acid moiety using 9-BBN is an effective method to enable side chain manipulations in synthesis of complex amino acids. We investigated the standard, mild method for deprotection of the 9-BBN group in methanolic chloroform, and found that it relies on a slow oxidation mediated by molecular oxygen. Building on this insight, we have developed a method that allows for a fast and selective deprotection using simple peroxy acid reagents. After Fmoc protection, products were isolated in >90% yield for a series of amino acid derivatives, including a galactosylated derivative of hydroxylysine. A representative set of 9-BBN-protected amino acid derivatives were efficiently deprotected using peracid reagents in excellent yields. Deprotection is orthogonal with several common protecting groups. Its tolerance of highly acid sensitive groups, such as trityl-protected amides and glycosidic linkages, is especially notable.
- Ankner, Tobias,Norberg, Thomas,Kihlberg, Jan
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p. 3767 - 3770
(2015/06/16)
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- Synthesis of l -octaarginine through microencapsulated palladium-catalyzed allyl ester deprotection
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Octaarginine has been described as a molecular transporter. We report a useful synthesis of orthogonally protected l-octaarginine by using a method based on a microencapsulated palladium catalyst. Known palladium-based methods for allyl ester deprotection have been modified to facilitate purification of the unprotected intermediates. This improvement in the purification step has also been tested with a variety of allyl α-amino esters and allyl α,β-unsaturated esters.
- Pérez-López, Ana M.,González-Calderón, Dávir,Occorso, Antonio,Galindo-ángel, Javier,Domínguez-Seglar, José F.,Tamayo, Juan A.,Díaz-Gavilán, Mónica,Gómez-Vidal, José A.
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supporting information
p. 2319 - 2322
(2015/08/06)
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- Derivates of Polyethylene Glycol Modified Thymosin Alpha 1
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Pharmaceutical compositions that include thymosin alpha 1 peptide derivatives modified at the C-terminal of the peptide chain with polyethylene glycol, and their pharmaceutical acceptable salts, are generally disclosed. Also, new methods used to prepare these thymosin alpha 1 peptide derivatives modified at the C-terminal of the peptide chain with polyethylene glycol are generally provided. The presently disclosed compounds and their salts can be prepared administered to humans to treat immune disease and can also be used in adjuvant treatment.
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- Efficient procedure for the preparation of oligomer-free N-fmoc amino acids
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A two-step method is presented for the peptide-free, high-purity, and high-yield synthesis of N-Fmoc amino acids. The first step involves the preparation of stable dicyclohexylammonium-amino acid ionic adduct in acetone. Subsequently, the ionic adducts, on reaction with Fmoc-Nosu under mild alkaline conditions, give dipeptide-free N-Fmoc amino acids. The positive charge of the dicyclohexylammonium counterion in the ionic salt has a longer radius, moderating the nucleophilicity of the carboxylate ion of the amino acid and preventing by-products by arresting the formation of mixed anhydrides, the precursors of oligopeptide impurities.
- Nowshuddin, Shaik,Rao,Reddy, A. Ram
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experimental part
p. 2022 - 2031
(2009/11/30)
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- A convenient, general synthesis of 1,1-dimethylallyl esters as protecting groups for carboxylic acids
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(Chemical Equation Presented) Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl, and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided.
- Sedighi, Minoo,Lipton, Mark A.
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p. 1473 - 1475
(2007/10/03)
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- GLP-2 compounds, formulations, and uses thereof
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The present invention relates to novel human glucagon-like peptide-2 (GLP-2) peptides and human glucagon-like peptide-2 derivatives which have a protracted profile of action as well as polynucleotide constructs encoding such peptides, vectors and host cells comprising and expressing the polynucleotide, pharmaceutical compositions, uses and methods of treatment.
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- Angiopeptin cyclopeptide compounds
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The invention relates to a compound selected from those of formula (I) (SEQ ID NO:1): STR1 in which R1, R2, X1 and X2 are as defined in the description, useful as inhibitor of the proliferation component of vascular smooth muscle cells.
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- Synthesis of ω-tert-butyl esters of aspartic acid and glutamic acid via B,B-difluoroboroxazolidones
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B,B-Difluoroboroxazolidones (DFBONs) were synthesized for the first time from salts of amino acid and BF3·Et2O, and their properties were examined. DFBONs were used in selective preparation of Glu(OBu(t)) and Asp(OBu(t)) in good yields under catalysis with BF3·Et2O and H3PO4. Amberlite XAD-2 resin was successfully employed to purify the above amino acid derivatives.
- Wang, Jidong,Okada, Yoshio,Wang, Zongmu,Wang, Yuhong,Li, Wei
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p. 2189 - 2191
(2007/10/03)
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- A New Synthesis of Thymosin α1
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Thymosin α1, an N-acetylated octacosa thymus peptide, isolated first from thymosin fraction 5, is synthesized by the solid phase method using the p-benzyloxybenzyl alcohol/polystyrene/divinylbenzene resin, Nα-Fmoc-amino acids and those with tert-butyl or Boc side chain protection.All couplings are performed with the Bop reagent.The peptide is purified by a combination of gel chromatography and preparative HPLC, its purity checked by amino acid analysis and analytical HPLC, and the biological activity tested by the E-rosette assay.
- Echner, Hartmut,Voelter, Wolfgang
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p. 1095 - 1098
(2007/10/02)
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- 9-Fluorenylmethyl Pentafluorophenyl Carbonate as a Useful Reagent for the Preparation of N-9-Fluorenylmethyloxycarbonylamino Acids and their Pentafluorophenyl Esters
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9-Fluorenylmethyl pentafluorophenyl carbonate is a useful reagent for the efficient, side reaction-free introduction of N-9-fluorenylmethyloxycarbonyl protecting group into amino acids and for the subsequent preparation of their pentafluorophenyl esters.Some new compounds of both types are described.
- Schoen, Istvan,Kisfaludy, Lajos
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p. 303 - 305
(2007/10/02)
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