摘要:
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.
摘要:
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.
摘要:
A new process is disclosed for preparing N-acylcarnosine which comprises reacting histidine with 3-acylaminopropionic acid reactive derivatives under basic conditions, and 3-acylaminopropionic acid reactive derivative being acid chloride, mixed acid anhydride salt with sulfuric acid, mixed acid anhydride with mono alkyl carbonate or mixed acid anhydride with phosphoric acid derivatives.