Diisopropylethylamine → (S)-tert-butyl 3-(2-chloro-5-fluoropyrimidin-4-ylamino)pyrrolidine-1-carboxylate

To a mixture of 2,4-dichloro-5-fluoro-pyrimidine (1.75 g, 10.48 mmol) and iPr2NEt (3.27 mL, 18.78 mmol) in THF (50 mL) was added tert-butyl (3S)-3-aminopyrrolidine-1-carboxylate (1.83 mL, 10.48 mmol) in THF (2 mL). The resulting solution was allowed to stir at room temperature for 2 hours. The mixture was concentrated to dryness, diluted with dichloromethane and washed with water. The organic layer was dried over Na2SO4 and concentrated in vacuo to afford 3.41 g of 7a, as a white foamy solid.