Acetonitrile → (R)-6-methoxy-5-methyl-2H-spiro[benzofuran-3,3'-indolin]-2'-one

Participants

Reaction Steps

6-Methoxy-5-methylspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (2.16 g, 0.10 g per run) was resolved on a semi-prep chiral IA column with 10% acetonitrile in tert-butyl methylether. (R)-6-methoxy-5-methyl-2H-spiro[benzofuran-3,3′-indolin]-2′-one was isolated as a crystalline colorless solid (0.81 g, 75% recovery): ee>99% (analytical chiralpak IA, 1:1 acetonitrile/tert-butyl methylether); mp>250° C.; 1H NMR (300 MHz, DMSO-d6) δ10.57 (s, 1H), 7.23 (ddd, J=7.6, 7.6, 1.3 Hz, 1H), 7.07 (d, J=6.8 Hz, 1H), 6.99-6.89 (m, 1H), 6.61 (s, 1H), 6.45 (s, 1H), 4.81-4.74 (m, 1H), 4.64 (d, J=9.2 Hz, 1H), 3.77 (s, 1H), 1.95 (s, 1H); 13C NMR (75 MHz, DMSO-d6) δ179.2, 160.4, 158.9, 142.2, 133.4, 129.1, 124.4, 124.2, 122.7, 120.3, 118.4, 110.2, 94.3, 80.1, 58.0, 56.0, 16.0; MS (ES+) m/z 282.1 (M+1).

Provenance & Evidence