Reaction Steps
A mixture of 213 (1.00 g, 1.53 mmol), Bu3SnH (550 mg, 1.83 mmol), and AIBN (50 mg, 0.31 mmol) in benzene (25 mL) was heated at reflux for 15 min, then concentrated under reduced pressure. The residue was partitioned between EtOAc and H2O and the EtOAc layer was washed with H2O, brine and dried and evaporated. The residue was purified by chromatography on silica gel, eluting with petroleum ether/EtOAc (9:1) to give tert-butyl 1-(chloromethyl)-8-[(dibenzylamino)sulfonyl]-1,2-dihydro-3H-benzo[e]indole-3-carboxylate (214) (850 mg, 97%). A sample was recrystallised from Et2O/petroleum ether as colorless needles: mp 131-133° C.; 1H NMR (CDCl3) δ 8.30 (br s, 1H), 8.29 (d, J=1.5 Hz, 1H), 7.93 (d, J=8.7 Hz, 1H), 7.84 (d, J=9.0 Hz, 1H), 7.66 (dd, J=8.6, 1.8 Hz, 1H), 7.23-7.15 (m, 6H), 7.09-7.03 (m, 4H), 4.41 (s, 4H), 4.28 (d, J=11.5 Hz, 1H), 4.15 (dd, J=11.6, 9.0 Hz, 1H), 4.02 (tt, J=9.0, 2.9 Hz, 1 H), 3.75 (dd, J=11.3, 3.5 Hz, 1H), 3.48 (dd, J=11.2, 9.3 Hz, 1H), 1.61 (s, 9H); 13C NMR δ 152.4, 142.7, 138.9, 135.5, 131.3, 130.5, 129.8, 128.9, 128.50, 128.46, 127.7, 124.3, 122.4, 120.3, 118.4, 81.8, 52.7, 50.5, 46.4, 41.4, 28.4. Anal. (C32H33ClN2O4S) C, H, N.
