Synthesis and in vitro evaluation of sugar-modified carboranyluridines

Sugar-part modified carboranyluridines 5 and 6 were synthesized. Although cytotoxicities of 5 and 6 were similar to those of 1 and 2 having ordinary sugar parts, selective uptake of 6 into TIG-1–20 cells was accomplished by changing the sugar part to a sulfur containing one.