Synthesis of 2-alkylcysteine

摘要

Non-natural amino acids such as 2-alkylated amino acids allow for the synthesis of a wider variety of peptidal and non-peptidal pharmaceutically active agents. A method of preparing a 2-alkylcysteine involves condensing cysteine with an aryl nitrile to form a 2-arylthiazoline-4-carboxylic acid, followed by alkylating the 2-arylthiazoline-4-carboxylic acid at the 4-position. The present invention also discloses a method of preparing a class of iron chelating agents related to desferrithiocin, all of which contain a thiazoline ring. In this method, an aryl nitrile or imidate is condensed with cysteine or a 2-alkyl cysteine.