1-benzyl-5-fluoro-3H-indol-2-one → (1R,2S)-1'-benzyl-2-(1-benzyl-1H-indazol-6-yl)-5'-fluorospiro[cyclopropane-1,3'-indolin]-2'-one

Participants

Reaction Steps

The title compound was prepared in a manner similar to the method of (1R,2S)-1′-benzyl-2-(1-benzyl-1H-indazol-6-yl)spiro[cyclopropane-1,3′-indolin]-2′-one using (S)-1-(1-benzyl-1H-indazol-6-yl)ethane-1,2-diyl dimethanesulfonate (501.4 mg, 1.181 mmol) and 1-benzyl-5-fluoroindolin-2-one (285.0 mg, 1.181 mmol). Purification using Biotage Isolera (SNAP 25 g column, 25-100% EtOAc in hexane) yielded the title compound as a cream solid (352 mg, 63%; 97% ee) with the major (1R,2S) enantiomer eluting at 7.03 min (Phenomenex Lux 5μ Cellulose-1 (150×4.6 mm), 1.0 mL/min isocratic at 80% EtOH in hexane for 1.0 min, then gradient 80-90% EtOH in hexane over 10 min). From the racemic reference standard, the retention time of the (1S,2R) enantiomer was 5.95 min using this method. 1H NMR (400 MHz, CDCl3) δ 8.04 (s, 1H), 7.67 (d, J=8.8 Hz, 1H), 7.40-7.27 (m, 8H), 7.17 (s, 1H), 7.11 (d, J=7.2 Hz, 2H), 6.92 (d, J=8.4 Hz, 1H), 6.67-6.62 (m, 2H), 5.62 (d, J=15.6 Hz, 1H), 5.55 (d, J=15.6 Hz, 1H), 5.51 (t, J=6.0 Hz, 1H), 5.10 (d, J=15.6 Hz, 1H), 4.94 (d, J=16.0 Hz, 1H), 3.53 (t, J=8.4 Hz, 1H), 2.32 (dd, J=9.2, 4.4 Hz, 1H), 2.02 (dd, J=8.0, 3.2 Hz, 1H), MS ESI 474.3 [M+H]+, calcd for [C31H24FN3O+H]+ 474.2.

Provenance & Evidence