Trifluoroacetic acid → HCID 59352434, compound

Participants

Reaction Steps

A solution of tert-butyl (2S)-2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]pyrrolidine-1-carboxylate (0.74 g, 1.60 mmol) and trifluoroacetic acid (1.6 mL) in dichloromethane (8 mL) was stirred at ambient temperature for 80 h. The reaction was made basic with 1 M sodium hydroxide (30 mL) and was extracted with dichloromethane (3×25 mL). The combined organic solution was dried over sodium sulfate, filtered and concentrated under reduced pressure to afford 1′-[(2S)-pyrrolidin-2-ylmethyl]-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one (0.51 g, 89%) as a pale yellow solid: mp 83-86° C. (hexanes); 1H NMR (300 MHz, CDCl3) (diastereomers) δ 7.29 (dd, J=7.8, 7.5 Hz, 1H), 7.16 (d, J=7.5 Hz, 1H), 7.07-6.99 (m, 2H), 6.52, 6.46 (s, 1H), 6.40 (s, 1H), 4.95, 4.91 (d, J=9.0 Hz, 1H), 4.66 (d, J=9.0 Hz, 1H), 4.53 (t, J=8.7 Hz, 2H), 3.91-3.71 (m, 2H), 3.69-3.60 (m, 1H), 3.14-2.90 (m, 5H), 1.98-1.70 (m, 3H), 1.66-1.51 (m, 1H); MS (ES+) m/z 363.1 (M+1).

Provenance & Evidence