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