Abstract The amino group of doxorubicin 1 is reacted with bis-NHS-ester linkers 6, or anhydrides 13 to offer in high yield modified doxorubicins 7–12 and 14–16, respectively. Compounds 7–12 are mono-NHS-esters, and can be directly coupled with melanotransferrin (p97), a useful vector with the ability to cross the blood-brain barrier, to yield the expected doxorubicin-p97 conjugates. Upon activating the carboxylic group with BTTU, compound ...