Reaction Steps
In a dried 100 mL round bottom flask under argon, compound 29 (50 mg, 0.19 mmol) was dissolved in anhydrous methanol (3 mL). 4-Acetyl-pyridine (21 μL, 0.19 mmol) and piperidine (19 μL, 0.19 mmol) were added and the reaction was refluxed. After 24 hours, the reaction was cooled, filtered and rinsed with cold hexanes and dried under vacuum, yielding 52 mg (74%) of pure yellow solid. 1H NMR (600 MHz, d6-DMSO): δ 12.350 (s, 1H, N—H), 8.832-8.222 (d, J=6.0, 2H, pyr-2,6H), 8.255-8.241 (d, J=8.4, 1H, indole-4H), 8.125-8.099 (d, J=15.6, 1H, C═CH), 8.008-7.999 (d, J=5.4, 2H, pyr-3,5H), 7.801 (s, 1H, indole-7H), 7.766-7.754 (d, J=7.2, 2 H, phenyl-2,6H), 7.683-7.642 (m, 2H, phenyl-4H, indole-5H), 7.585-7.563 (m, 3H, C═CH, phenyl-3,5H), 2.659 (s, 3H, methyl). 13C NMR (150 MHz, d6-DMSO): δ 195.5, 188.2, 150.6, 148.5, 144.6, 138.7, 138.2, 135.4, 132.0, 130.6, 129.4, 129.2, 128.4, 123.1, 121.5, 119.9, 114.5, 114.1, 109.6, 12.3. Melting point: 267-270° C. TLC (ethyl acetate:hexanes 4:1) Rf=0.29. Elemental analysis calculated for C24H18N2O2 0.05H2O: C, 78.48; H, 4.97; N, 7.63. found: C, 78.08; H, 5.01; N, 7.50.
