Novel, water-soluble phosphate derivatives of 2′-ethoxy carbonylpaclitaxel as potential prodrugs of paclitaxel: Synthesis and antitumor evaluation

Three new phosphate derivatives of paclitaxel-2′-ethylcarbonate 4a, 4b, and 4c, have been synthesized and evaluated for in vivo antitumor activity. All were soluble in water and two derivatives 4a and 4b were found to exhibit in vivo antitumor activity, comparable to paclitaxel in the M109 murine tumor model.