- METHOD FOR THE SYNTHESIS OF PEPTIDES WITHOUT SOLVENT
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The disclosure relates to a method for the synthesis of a compound of the formula (I) in which: n is an integer higher than or equal to 1; Rb and each Rn are independently a hydrogen atom, a C1-C6 arylalkyl group or a C1-C6 alkyl group substituted or not by an aryl group, —COOH, C1-C6, —COO-(alkyl), —CONH2, —SH, heteroaryl, —NH2, —NHC(NH)(NH2), C1-C6-s-(alkyl), —OH or phenol; Ra is a N-protective group; Rc is a ORd group in which Rd is a C1-C6 alkyl group or a NReRf group in which Re and Rf Re independently an N-protective group.
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Page/Page column 6
(2010/02/17)
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- Solvent-free synthesis of peptides
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Chamical Equation Presentation A crush on sweetness! The coupling of a urethane-protected N-carboxyanhydride of an amino acid with another amino acid derivative under ball-milling conditions gives a protected dipeptide in very high yield (see scheme; PG: protecting group). The reaction takes place in the solid state. The synthesis was applied to the preparation of a tri peptide and the sweetener aspartame, without any organic solvent or purification.
- Declerck, Valerie,Nun, Pierrick,Martinez, Jean,Lamaty, Frederic
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supporting information; experimental part
p. 9318 - 9321
(2010/03/24)
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- Process for the preparation of alfa-L-aspartyl-L-phenyl-alanine alkyl esters
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A new process for preparing alfa-L-aspartyl-L-phenylalanine alkyl esters of formula I STR1 wherein R represents an alkyl group having from 1 to 5 carbon atoms, starting from the corresponding alfa-haloacyl-alfa-L-aspartyl-L-phenylalanine alkyl esters.
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- Process for the preparation of α-L-aspartyl-L-phenylalanine methyl ester
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A regioselective process for the preparation of α-L-aspartyl-L-phenylalanine methyl ester is disclosed. A controlled aqueous coupling reaction between β-methyl-L-aspartate-N-carboxyanhydride and L-phenylalanine produces the aspartyl methyl ester of α-L-aspartyl-L-phenylalanine which is subsequently hydrolyzed and selectively esterified without isolation. The hydrochloride salt of α-L-aspartyl-L-phenylalanine methyl ester, which is selectively precipitated from the esterification mixture, can be neutralized to α-L-aspartyl-L-phenylalanine methyl ester.
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- Method of removing formyl groups from N-formyl-amino acid and N-formyl-peptide esters having free carboxyl groups
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The masking N-formyl group of an N-formyl-amino acid ester or an N-formyl-peptide ester having a free carboxyl group is removed without major side reactions when the ester is contacted with a strong acid in a mixture of water and a specific organic solvent such as methyl ethyl ketone or acetonitrile. This method is specifically applicable to the production of L-aspartyl amino acid lower alkyl esters which are known as low calorie sweeteners.
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- Method of removing formyl groups from N-formyl-amino acid and N-formyl-peptide esters
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The masking N-formyl group of an N-formyl-amino acid ester or N-formyl-peptide ester is removed without major side reactions when the ester is reacted in an inert liquid medium with hydroxylamine of which at least 70% is present in the form of a salt with a strong acid, the remainder, if any, being present as the free base or the salt of a weak acid.
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