A simple approach for the synthesis of new pyrimidinyl α-amino acids

A simple synthetic method for the preparation of optically active pyrimidinyl α-amino acids is presented. A nucleophilic ipso-substitution reaction between 2-(benzylsulfonyl)-4-isopropoxypyrimidines and a nucleophilic side chain of several protected natural α-amino acids is investigated to obtain new pyrimidin-2-yl α-amino acids. A detailed optimisation study of this reaction is discussed. Moreover, the selective O-alkylation of 2-(benzylsulfanyl)-4(3H)pyrimidinones with a hydroxylic side chain of some natural α-amino acids under Mitsunobu conditions is studied as a method to prepare new pyrimidin-4-yl α-aminoesters.