N-bromobutanimide → Tert-butyl 5-chloro-2-oxospiro[indoline-3,3'-pyrrolidine]-1'-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 6-chloro-3,4-dihydro-1H-pyrido[3,4-b]indole-2(9H)-carboxylate (0.500 g, 1.63 mmol) in 1:1:1 THF/AcOH/H2O (45 mL) at about 0° C. was treated with N-Bromosuccinimide (0.319 g, 1.79 mmol) portionwise over about 20 minutes. The resulting mixture was stirred for about 90 minutes at about 0° C. The mixture was then quenched by the addition of saturated Na2CO3 (100 mL) and extracted with DCM. The combined organics were washed with saturated NaHCO3 (2×) and brine, dried over MgSO4, filtered and concentrated. The crude residue was purified by column chromatography (20% EtOAc/Hexane) to yield tert-butyl 5-chloro-2-oxospiro[indoline-3,3′-pyrrolidine]-1′-carboxylate (0.530 g, 100%). LCMS (APCI+) m/z 223, 225 [M+H−Boc]+; Rt=3.26 min.

Provenance & Evidence