To a solution of 6-fluoro-N-methylpyridin-3-amine (272 mg, 2.16 mmol) in THF (70 mL) was added isopropyl magnesium chloride solution 2M in THF (1.08 mL, 2.16 mmol) dropwise at 0° C. The mixture was allowed to stir at 0° C. for 20 min. Then, a solution of (R)-methyl 1-(4-(5-isopropyl-1H-pyrazol-3-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-2-yl)pyrrolidine-2-carboxylate (200 mg, 0.54 mmol) in THF (3 mL) was added and the reaction mixture was allowed to stir at RT for 2 h. The reaction was quenched with saturated ammonium chloride solution (50 mL) and the mixture was extracted with EtOAc (3×50 mL). The combined organic layer was washed with brine and dried over anhydrous sodium sulfate. Removal of EtOAc under reduced pressure gave an oily residue that was purified by reverse phase HPLC to afford 17 mg of (R)—N-(6-fluoropyridin-3-yl)-1-(4-(5-isopropyl-1H-pyrazol-3-ylamino)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-2-yl)-N-methylpyrrolidine-2-carboxamide. 1HNMR (400 MHz, CDCl3) δ (ppm): 1.20-1.35 (m, 6H), 1.79-2.25 (m, 6H), 2.57-2.68 (m, 2H), 2.79-2.82 (m, 2H), 2.91-3.01 (m, 1H), 3.30 (s, 3H), 3.59-3.80 (m, 2H), 4.35-4.45 (m, 1H), 6.16 (s, 1H), 6.90-7.05 (m, 2H), 8.01 (brs, 1H), 8.40 (brs, 1H). The other enantiomer is prepared using the (S) chiral starting material.
