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To a suspension of 318 (10 g, 22.05 mmol) in EtOH (216 ml) and water (108 ml) was added iron powder (10.47 g, 187 mmol) and ammonium chloride (1.015 g, 18.97 mmol). The mixture was heated to reflux for 30 min, filtered while hot and the solids were washed with ether (200 mL). The filtrate and washings were combined and concentrated to afford title compound 319 (9.62 g, 99% yield) as a beige solid. This material was used in the next step (Scheme 18) without additional purification. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 8.64 (d, J=2.0 Hz, 1H), 8.51 (dd, J=5.6, 2.0 Hz, 1H), 8.34 (s, 1H), 8.28 (dd, J=8.0, 0.8 Hz, 1H), 7.93 (dd, J=8.4, 2.0 Hz, 1H), 7.13 (t, J=9.0 Hz, 1H), 6.61 (dd, J=5.4, 0.6 Hz, 1H), 6.54 (dd, J=13.2, 2.4 Hz, 1H), 6.46 (ddd, J=8.8, 2.8, 0.6 Hz, 1H), 5.67 (s, 1H), 5.56 (s, 2H), 4.19 (dd, J=10.6, 5.0 Hz, 2H), 3.98 (td, J=12.0, 2.5 Hz, 2H), 2.09-1.99 (m, 1H), 1.49 (dt, J=13.2, 1.3 Hz, 1H). MS (m/z): 424.1 (M+H).

1. temperatureThe mixture was heated
2. temperatureto reflux for 30 min
3. filtrationfiltered while hot and the solids
4. washwere washed with ether (200 mL)
5. concentrationconcentrated