Methyl iodide → 2-(Methylthio)-4-(2-pyridinyl)pyrimidine

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Reaction Steps

To a stirred solution of sodium ethoxide (freshly prepared from sodium metal (5.11 g, 222 mmol) and ethanol (350 mL)) was added 3-dimethylamino-1-pyridin-2-yl-propenone (28.0 g, 159 mmol) and thiourea (12.9 g, 170 mmol). The solution was heated to reflux and stirred for 3 hours. The solution was allowed to cool to room temperature, and then iodomethane (13.8 mL, 222 mmol) was added dropwise over 10 minutes. The solution was stirred at room temperature for 2 hours, and then diluted with saturated ammonium chloride solution (250 mL) and water (250 mL). The suspension was extracted with ethyl ether (200 mL×3), and the combined organic extracts washed with saturated sodium thiosulfate solution (150 mL) and brine (150 mL). The organic phase was dried (magnesium sulfate), filtered, and concentrated to provide 30.1 g (96%) of the product as a brown oil: 1H NMR (CDCl3) δ 8.70-8.69 (m, 1H), 8.64 (d, J=5.2 Hz, 1H), 8.48 (d,J=7.9 Hz, 1H), 8.01 (d, J=5.2 Hz, 1H), 7.87-7.82 (m, 1H), 7.41-7.38 (m, 1H), 2.65 (s, 3H) ppm. 13C NMR (CDCl3) δ 172.6, 163.1, 158.5, 153.9, 149.7, 137.3, 125.7, 122.0, 112.6, 14.5 ppm.

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