Synthesis of allyloxycarbonyloxymethyl-5-fluorouracil and copolymerizations with N-vinylpyrrolidinone

Poly(N-vinylpyrrolidinone) (PNVP) bearing 5-fluorouracil (5-FU) moieties wa s synthesised via a three-step method. Firstly, 5-FU reacted with formaldeh yde to form a mixture of mono- and disubstituted hydroxymethyl-5-FUs. The m ixture was then treated with allyl chloroformate to afford allyloxycarbonyl oxymethyl-5-FUs. This reaction showed site-specificity: the hydroxymethyl g oup at the N-1 position readily reacted with chloroformate whereas the N-3 hydroxymethyl group partially decomposed into formaldehyde and the amide gr oup. 1-Allyloxycarbonyloxymethyl-5-FU (4) and NVP were copolymerized in dio xane using azobisisobutyronitrile as an initiator. The monomer reactivity r atios, r(4) = 0.32 and r(NVP) = 0.97, were evaluated by both linear and non -linear methods.