Synthesis of carboranyl phenylalanine for potential use in neutron capture therapy of melanoma

Abstract

A phenylalanine derivative incorporating the 1, 2-dicarba-closo-dodecaborane(12) cage has been synthesised by the alkylation of diethylformamidomalonate with benzyl bromide [containing the 1, 2-dicarba-closo-dodecaborane(12) cage at the para-position] in the presence of sodium ethoxide followed by the removal of the protecting groups by hydrolysis and decarboxylation. The closo-carborane species was converted into the anionic nido-form to produce a more water-soluble form of the compound.