Potassium Carbonate → 3-(3-But-2-enyl-5-isopropyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidine-4-carbonyl)-5-methyl-benzonitrile

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Reaction Steps

To a stirred solution of 3-(5-isopropyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidine-4-carbonyl)-5-methyl-benzonitrile (Compound 1) (297 mg, 1 mmol), anhydrous powdered potassium carbonate (165 mg, 1.2 mmol), and lithium iodide (134 mg, 1 mmol) in DMF (5 mL) at room temperature, was added crotyl chloride (97 μL, 1 mmol). After stirring for overnight, the mixture was evaporated in vacuo and the residue was purified by silica gel column chromatography (eluent, ethyl acetate:hexane (1:2)) to give 300 mg (85%) of 3-(3-but-2-enyl-5-isopropyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidine-4-carbonyl)-5-methyl-benzonitrile (80) as a white solid. The product was recrystallized from chloroform-ether-hexane to afford a white solid. m.p. 177-178° C.; 1H-NMR (300 MHz, CDCl3) δ 1.12 (3H, d, J=6.6 Hz), 1.21 (3H, d, J=6.6 Hz), 1.44 (3H, d, J=5.1 Hz), 2.22 (1H, m), 2.53 (3H, s), 4.02-4.20 (2H, m), 5.19-5.43 (2H, m), 7.78 (1H, s), 7.93 (1H, s), 8.03 (1H, s), 8.95 (1H, s). m/z (EI) 351 (M+).

Provenance & Evidence