Synthesis of a (B12H11S)2− containing glucuronoside as potential prodrug for BNCT

A B12H11SH2− containing glycoside of glucuronic acid has been prepared, for possible use as prodrug in BNCT. The synthesis was carried out by the Koenigs–Knorr reaction of the acetylated glucopyranosyluronate bromide with the nucleophile cyanoethylthioundecahydro-closo-dodecaborate(2−). After removal of the cyanoethyl-group, deacetylation and saponification of the reaction product tris(tetramethylammonium)-[S-(β-d-glucuronate)-thio] undecahydro-closo-dodecaborate(3−) could be prepared.