Cyclohexylamine → 2-chloro-N-cyclohexyl-5,6-dimethylpyrimidin-4-amine

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Reaction Steps

To a stirred solution of 2,4-dichloro-5,6-dimethylpyrimidine (9.3 g, 0.05 mol, Step C) in dimethylformamide (100 mL) was added cesium carbonate (37.6 g, 0.12 mol). Cyclohexylamine (5.7 g, 0.058 mol) was then added, keeping the temperature of the reaction mixture at 70° C. After 48 hours, the reaction mixture was concentrated, and the residue was quenched with water (200 mL). The resulting mixture was extracted with dichloromethane (3×120 mL). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered, and concentrated. The solvent was removed by distillation, and the crude product was purified by column chromatography on silica gel eluting with ethyl acetate/methanol (10:1-10:2) to yield 4.9 g (38.9%) of the titled compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.05-1.14 (m, 1H), 1.28-1.33 (m, 4H), 1.61 (d, J=12.36 Hz, 1H), 1.72 (s, 2H), 1.80 (s, 2H), 1.93 (s, 3H), 2.19 (s, 3H), 3.85 (d, J=7.52 Hz, 1H), 6.66 (d, J=7.79 Hz, 1H); MS (ESI) m/z 240.3 (M+1)+.

Provenance & Evidence