1-(3-hydroxymethylpyrrolidin-1-yl)-5-chlorouracil

Acetic acid 1-(4-amino-2-oxo-2H-pyrimidin-1-yl)-pyrrolidin-3-ylmethyl ester

Acetic acid 1-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-pyrrolidin-3-ylmethyl ester