1-benzyl-3-(3-chloropropyl)-5-methyl-2,4(1H,3H)-pyrimidinedione → 3-(3-chloropropyl)-5-methyl-2,4(1H,3H)-pyrimidinedione

A mixture of 1-benzyl-3-(3-chloropropyl)-5-methyl-2,4(1H,3H)-pyrimidinedione (1 g, 3.41 mmol), prepared as in Example 19, 10% palladium on carbon (1 g) and 0.1M ammonium formate/methanol (340 mL) was heated 3 hours at reflux under argon. The reaction mixture was allowed to cool to 25° C., then filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with hexane-ethyl acetate (1:1) to give 3-(3-chloropropyl)-5-methyl-2,4(1H,3H)-pyrimidinedione (0.52 g, 2.57 mmol), m.p. 117°-121° C.