Chlorosulfonic acid → 4-[(3R,3'S)-3-(3,5-dichlorophenyl)-2'-oxo-1,3'-bipyrrolidin-1'-yl]benzene-1-sulfonyl chloride

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Reaction Conditions

Reaction Steps

Synthesized according to General Procedure 11. To a solution of (3R,3′S)-3-(3,5-dichlorophenyl)-1′-phenyl-1,3′-bipyrrolidin-2′-one (900 mg, 2.40 mmol) in DCE (10 mL) at 0° C. was added chlorosulfonic acid (1.40 g, 800 μL, 12.0 mmol) slowly. The reaction mixture was then stirred at 0° C. for 30 min, at RT for 1 hour and at 50° C. for 1 hour. At this time more chlorosulfonic acid (279 mg, 160 μL, 2.40 mmol) was added and the reaction mixture was stirred at 50° C. for 1 hour, the reaction mixture was then heated to 70° C. for 10 min, cooled to RT and slowly poured onto ice water. The pH was brought to ˜7 with saturated aqueous NaHCO3 and the reaction mixture was extracted with EtOAc (3×). The combined organic phases were washed with water, brine, dried over MgSO4 and evaporated to dryness to afford 4-[(3R,3′S)-3-(3,5-dichlorophenyl)-2′-oxo-1,3′-bipyrrolidin-1′-yl]benzene-1-sulfonyl chloride as a tan solid (1.00 g, 88%). LC/MS (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA)), m/z: M+1 obs=473.3; tR=1.58 min.

Provenance & Evidence