Water → (R)-tert-butyl 3-(4-chloro-3-fluorobenzoyl)pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

(R)-tert-Butyl 3-(methoxy(methyl)carbamoyl)pyrrolidine-1-carboxylate (1.107 g, 4.285 mmol) was dissolved in THF (21.4 mL, 0.2M), cooled to 0° C., and degassed with N2. 4-Chloro-3-fluorophenylmagnesium bromide (0.5M in THF; 17.14 mL, 8.571 mmol) was added drop wise by syringe, and the reaction was then stirred at 0° C. for 1.5 hours. Water (10 mL) was then added to quench the reaction. The mixture was concentrated by rotovap to remove the bulk of the THF. The remaining mixture was diluted to 50 mL with water and extracted with 4/1 dichloromethane/isopropyl alcohol (2×50 mL). The combined organics were washed with water (100 mL), were isolated, dried over sodium sulfate, filtered and concentrated. The crude product was loaded onto an SP1 samplet and purified by silica gel chromatography using a gradient from 2% to 50% ethyl acetate in hexanes. Product containing fractions were pooled and concentrated to afford (R)-tert-butyl 3-(4-chloro-3-fluorobenzoyl)pyrrolidine-1-carboxylate as an oil (920 mg, 65% yield).

Provenance & Evidence