Phosphoric Acid → HCID 57474458, compound

Participants

Reaction Steps

A solution of 5-nitroindole (38) (0.5 g, 3.083 mmol) in glacial acetic acid (10 mL) was treated with tropinone (0.85 g, 6.617 mmol), followed by 2 M H3PO4 in glacial acetic acid (5 mL) at 100° C. and the resulting solution was stirred at same temperature for 24 h. The reaction was brought to room temperature, poured in to ice-cold 10% NH4OH solution (50 mL) and product was extracted into CH2Cl2 (2 25 mL). The combined CH2Cl2 layer was washed with brine (15 mL) and dried (Na2SO4). The solvent was evaporated and crude material was purified by column chromatography on silica gel (2 M NH3 in methanol: CH2Cl2, 1:9) to obtain compound 89 (0.27 g, 31%) as a solid. mp 234-236° C.; 1H NMR (DMSO-d6) δ 1.51-1.60 (m, 1H), 1.79-1.86 (m, 1H), 1.95-2.14 (m, 4H), 2.32 (s, 3H), 2.76-2.83 (m, 1H), 3.43 (t, 1H, J=5.4 Hz), 6.31 (d, 1H, J=5.1 Hz), 7.54 (d, 1H, J=8.7 Hz), 7.61 (s, 1H), 8.01 (dd, 1H, J=2.1, 9.0 Hz), 8.68 (d, 1H, J=2.4 Hz), 11.86 (s, 1H); ESI-MS m/z (%): 284 (MH+, 100).

Provenance & Evidence