To a stirred solution of 2-{1-[6-(3-cyano-5-methyl-benzoyl)-5-isopropyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl]-cyclopropyl}-N-(4-methoxy-benzyl)-acetamide (97 mg, 0.18 mmol) in acetonitrile (4 mL) and glacial acetic acid (1 mL) at room temperature, were added ceric ammonium nitrate (201 mg, 0.36 mmol) and water (2 mL) in this order. After stirring for 20 min., the mixture was diluted with ethyl acetate, washed with water twice, dried with MgSO4, filtered, and evaporated in vacuo. The residue was purified by silica gel column chromatography (eluent, from ethyl acetate to 10% methanol in ethyl acetate) to give 59 mg (78%) of 2-{1-[6-(3-cyano-5-methyl-benzoyl)-5-isopropyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-ylmethyl]-cyclopropyl}-acetamide (85) as a white solid. m.p. 283-285° C.; 1H-NMR (500 MHz, DMSO-d6) δ 0.20-0.27 (2H, m), 0.31-0.36 (1H, m), 0.43-0.47 (1H, m), 0.99 (3H, d, J=6.8 Hz), 1.08 (3H, d, J=6.8 Hz), 2.02-2.13 (2H, m), 2.17 (1H, d, J=16.5 Hz), 2.44 (3H, s), 3.32 (1H, d, J=15.1 Hz), 3.39-3.41 (1H, m), 3.46-3.51 (1H, m), 3.79 (1H, d, J=15.1 Hz), 8.08 (1H, s), 8.19 (1H, s), 8.42 (1H, s), 11.45 (1H, s); m/z (EI) 408 (M+).
