Synthesis and hydrolytic properties of thymidine boranomonophosphate

Detailed synthetic procedures of thymidine 5′-O-(P-borano)monophosphate (TMPB) via an H-phosphonate approach are reported. The hydrolytic properties of TMPB in pH 1.8 and 6.76 buffers at 22 or 37 °C were studied using LC–MS. One nucleoside product, thymidine, was observed, supporting cleavage at the P–O ester bond to release nucleoside and boranophosphate (O3P-BH3−3). Higher temperatures and acidic conditions increase the hydrolysis rates.